source: mainline/kernel/generic/src/ipc/ipc.c@ cb4afd8b

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since cb4afd8b was 5c8ba05, checked in by Jakub Jermar <jakub@…>, 19 years ago

Cleanup the waitq_wakeup() interface.
Replace numeric constants (i.e. 0)
and boolean constants (i.e. false) with
more readable WAKEUP_FIRST. Also change the
type of the second argument of waitq_wakeup()
to a newly introduced type wakeup_mode_t.

Fix behaviour of waitq_wakeup() in case
that WAKEUP_ALL semantics is required
but no threads are sleeping in the wait
queue. This is a similar fix to that of
Jan Hudecek committed in the RCU branch,
but, IMHO, is more straightforward and
also doesn't eat up previous missed
wakeups.
  • Property mode set to 100644
File size: 14.6 KB
Line 
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 <proc/thread.h>
53#include <arch/interrupt.h>
54#include <ipc/irq.h>
55
56/* Open channel that is assigned automatically to new tasks */
57answerbox_t *ipc_phone_0 = NULL;
58
59static slab_cache_t *ipc_call_slab;
60
61/* Initialize new call */
62static void _ipc_call_init(call_t *call)
63{
64 memsetb((uintptr_t)call, sizeof(*call), 0);
65 call->callerbox = &TASK->answerbox;
66 call->sender = TASK;
67}
68
69/** Allocate & initialize call structure
70 *
71 * The call is initialized, so that the reply will be directed
72 * to TASK->answerbox
73 *
74 * @param flags Parameters for slab_alloc (ATOMIC, etc.)
75 */
76call_t * ipc_call_alloc(int flags)
77{
78 call_t *call;
79
80 call = slab_alloc(ipc_call_slab, flags);
81 _ipc_call_init(call);
82
83 return call;
84}
85
86/** Initialize allocated call */
87void ipc_call_static_init(call_t *call)
88{
89 _ipc_call_init(call);
90 call->flags |= IPC_CALL_STATIC_ALLOC;
91}
92
93/** Deallocate call stracuture */
94void ipc_call_free(call_t *call)
95{
96 slab_free(ipc_call_slab, call);
97}
98
99/** Initialize answerbox structure
100 */
101void ipc_answerbox_init(answerbox_t *box)
102{
103 spinlock_initialize(&box->lock, "ipc_box_lock");
104 spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
105 waitq_initialize(&box->wq);
106 list_initialize(&box->connected_phones);
107 list_initialize(&box->calls);
108 list_initialize(&box->dispatched_calls);
109 list_initialize(&box->answers);
110 list_initialize(&box->irq_notifs);
111 list_initialize(&box->irq_head);
112 box->task = TASK;
113}
114
115/** Connect phone to answerbox */
116void ipc_phone_connect(phone_t *phone, answerbox_t *box)
117{
118 spinlock_lock(&phone->lock);
119
120 phone->state = IPC_PHONE_CONNECTED;
121 phone->callee = box;
122
123 spinlock_lock(&box->lock);
124 list_append(&phone->link, &box->connected_phones);
125 spinlock_unlock(&box->lock);
126
127 spinlock_unlock(&phone->lock);
128}
129
130/** Initialize phone structure and connect phone to answerbox
131 */
132void ipc_phone_init(phone_t *phone)
133{
134 spinlock_initialize(&phone->lock, "phone_lock");
135 phone->callee = NULL;
136 phone->state = IPC_PHONE_FREE;
137 atomic_set(&phone->active_calls, 0);
138}
139
140/** Helper function to facilitate synchronous calls */
141void ipc_call_sync(phone_t *phone, call_t *request)
142{
143 answerbox_t sync_box;
144
145 ipc_answerbox_init(&sync_box);
146
147 /* We will receive data on special box */
148 request->callerbox = &sync_box;
149
150 ipc_call(phone, request);
151 ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
152}
153
154/** Answer message that was not dispatched and is not entered in
155 * any queue
156 */
157static void _ipc_answer_free_call(call_t *call)
158{
159 answerbox_t *callerbox = call->callerbox;
160
161 call->flags |= IPC_CALL_ANSWERED;
162
163 spinlock_lock(&callerbox->lock);
164 list_append(&call->link, &callerbox->answers);
165 spinlock_unlock(&callerbox->lock);
166 waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);
167}
168
169/** Answer message, that is in callee queue
170 *
171 * @param box Answerbox that is answering the message
172 * @param call Modified request that is being sent back
173 */
174void ipc_answer(answerbox_t *box, call_t *call)
175{
176 /* Remove from active box */
177 spinlock_lock(&box->lock);
178 list_remove(&call->link);
179 spinlock_unlock(&box->lock);
180 /* Send back answer */
181 _ipc_answer_free_call(call);
182}
183
184/** Simulate sending back a message
185 *
186 * Most errors are better handled by forming a normal backward
187 * message and sending it as a normal answer.
188 */
189void ipc_backsend_err(phone_t *phone, call_t *call, unative_t err)
190{
191 call->data.phone = phone;
192 atomic_inc(&phone->active_calls);
193 IPC_SET_RETVAL(call->data, err);
194 _ipc_answer_free_call(call);
195}
196
197/* Unsafe unchecking ipc_call */
198static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
199{
200 if (! (call->flags & IPC_CALL_FORWARDED)) {
201 atomic_inc(&phone->active_calls);
202 call->data.phone = phone;
203 }
204
205 spinlock_lock(&box->lock);
206 list_append(&call->link, &box->calls);
207 spinlock_unlock(&box->lock);
208 waitq_wakeup(&box->wq, WAKEUP_FIRST);
209}
210
211/** Send a asynchronous request using phone to answerbox
212 *
213 * @param phone Phone connected to answerbox.
214 * @param call Structure representing the call.
215 */
216int ipc_call(phone_t *phone, call_t *call)
217{
218 answerbox_t *box;
219
220 spinlock_lock(&phone->lock);
221 if (phone->state != IPC_PHONE_CONNECTED) {
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 {
227 if (phone->state == IPC_PHONE_HUNGUP)
228 ipc_backsend_err(phone, call, EHANGUP);
229 else
230 ipc_backsend_err(phone, call, ENOENT);
231 }
232 return ENOENT;
233 }
234 box = phone->callee;
235 _ipc_call(phone, box, call);
236
237 spinlock_unlock(&phone->lock);
238 return 0;
239}
240
241/** Disconnect phone from answerbox
242 *
243 * This call leaves the phone in HUNGUP state. The change to 'free' is done
244 * lazily later.
245 *
246 * @param phone Phone to be hung up
247 *
248 * @return 0 - phone disconnected, -1 - the phone was already disconnected
249 */
250int ipc_phone_hangup(phone_t *phone)
251{
252 answerbox_t *box;
253 call_t *call;
254
255 spinlock_lock(&phone->lock);
256 if (phone->state == IPC_PHONE_FREE || phone->state ==IPC_PHONE_HUNGUP \
257 || phone->state == IPC_PHONE_CONNECTING) {
258 spinlock_unlock(&phone->lock);
259 return -1;
260 }
261 box = phone->callee;
262 if (phone->state != IPC_PHONE_SLAMMED) {
263 /* Remove myself from answerbox */
264 spinlock_lock(&box->lock);
265 list_remove(&phone->link);
266 spinlock_unlock(&box->lock);
267
268 if (phone->state != IPC_PHONE_SLAMMED) {
269 call = ipc_call_alloc(0);
270 IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
271 call->flags |= IPC_CALL_DISCARD_ANSWER;
272 _ipc_call(phone, box, call);
273 }
274 }
275
276 phone->state = IPC_PHONE_HUNGUP;
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 */
292int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox)
293{
294 spinlock_lock(&oldbox->lock);
295 list_remove(&call->link);
296 spinlock_unlock(&oldbox->lock);
297
298 return ipc_call(newphone, call);
299}
300
301
302/** Wait for phone call
303 *
304 * @param box Answerbox expecting the call.
305 * @param usec Timeout in microseconds. See documentation for waitq_sleep_timeout() for
306 * decription of its special meaning.
307 * @param flags Select mode of sleep operation. See documentation for waitq_sleep_timeout()i
308 * for description of its special meaning.
309 * @return Recived message address
310 * - to distinguish between call and answer, look at call->flags
311 */
312call_t * ipc_wait_for_call(answerbox_t *box, uint32_t usec, int flags)
313{
314 call_t *request;
315 ipl_t ipl;
316 int rc;
317
318restart:
319 rc = waitq_sleep_timeout(&box->wq, usec, flags);
320 if (SYNCH_FAILED(rc))
321 return NULL;
322
323 spinlock_lock(&box->lock);
324 if (!list_empty(&box->irq_notifs)) {
325 ipl = interrupts_disable();
326 spinlock_lock(&box->irq_lock);
327
328 request = list_get_instance(box->irq_notifs.next, call_t, link);
329 list_remove(&request->link);
330
331 spinlock_unlock(&box->irq_lock);
332 interrupts_restore(ipl);
333 } else if (!list_empty(&box->answers)) {
334 /* Handle asynchronous answers */
335 request = list_get_instance(box->answers.next, call_t, link);
336 list_remove(&request->link);
337 atomic_dec(&request->data.phone->active_calls);
338 } else if (!list_empty(&box->calls)) {
339 /* Handle requests */
340 request = list_get_instance(box->calls.next, call_t, link);
341 list_remove(&request->link);
342 /* Append request to dispatch queue */
343 list_append(&request->link, &box->dispatched_calls);
344 } else {
345 /* This can happen regularly after ipc_cleanup */
346 spinlock_unlock(&box->lock);
347 goto restart;
348 }
349 spinlock_unlock(&box->lock);
350 return request;
351}
352
353/** Answer all calls from list with EHANGUP msg */
354static void ipc_cleanup_call_list(link_t *lst)
355{
356 call_t *call;
357
358 while (!list_empty(lst)) {
359 call = list_get_instance(lst->next, call_t, link);
360 list_remove(&call->link);
361
362 IPC_SET_RETVAL(call->data, EHANGUP);
363 _ipc_answer_free_call(call);
364 }
365}
366
367/** Cleans up all IPC communication of the current task
368 *
369 * Note: ipc_hangup sets returning answerbox to TASK->answerbox, you
370 * have to change it as well if you want to cleanup other current then current.
371 */
372void ipc_cleanup(void)
373{
374 int i;
375 call_t *call;
376 phone_t *phone;
377 DEADLOCK_PROBE_INIT(p_phonelck);
378
379 /* Disconnect all our phones ('ipc_phone_hangup') */
380 for (i=0;i < IPC_MAX_PHONES; i++)
381 ipc_phone_hangup(&TASK->phones[i]);
382
383 /* Disconnect all connected irqs */
384 ipc_irq_cleanup(&TASK->answerbox);
385
386 /* Disconnect all phones connected to our answerbox */
387restart_phones:
388 spinlock_lock(&TASK->answerbox.lock);
389 while (!list_empty(&TASK->answerbox.connected_phones)) {
390 phone = list_get_instance(TASK->answerbox.connected_phones.next,
391 phone_t, link);
392 if (! spinlock_trylock(&phone->lock)) {
393 spinlock_unlock(&TASK->answerbox.lock);
394 DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);
395 goto restart_phones;
396 }
397
398 /* Disconnect phone */
399 ASSERT(phone->state == IPC_PHONE_CONNECTED);
400 phone->state = IPC_PHONE_SLAMMED;
401 list_remove(&phone->link);
402
403 spinlock_unlock(&phone->lock);
404 }
405
406 /* Answer all messages in 'calls' and 'dispatched_calls' queues */
407 ipc_cleanup_call_list(&TASK->answerbox.dispatched_calls);
408 ipc_cleanup_call_list(&TASK->answerbox.calls);
409 spinlock_unlock(&TASK->answerbox.lock);
410
411 /* Wait for all async answers to arrive */
412 while (1) {
413 /* Go through all phones, until all are FREE... */
414 /* Locking not needed, no one else should modify
415 * it, when we are in cleanup */
416 for (i=0;i < IPC_MAX_PHONES; i++) {
417 if (TASK->phones[i].state == IPC_PHONE_HUNGUP && \
418 atomic_get(&TASK->phones[i].active_calls) == 0)
419 TASK->phones[i].state = IPC_PHONE_FREE;
420
421 /* Just for sure, we might have had some
422 * IPC_PHONE_CONNECTING phones */
423 if (TASK->phones[i].state == IPC_PHONE_CONNECTED)
424 ipc_phone_hangup(&TASK->phones[i]);
425 /* If the hangup succeeded, it has sent a HANGUP
426 * message, the IPC is now in HUNGUP state, we
427 * wait for the reply to come */
428
429 if (TASK->phones[i].state != IPC_PHONE_FREE)
430 break;
431 }
432 /* Voila, got into cleanup */
433 if (i == IPC_MAX_PHONES)
434 break;
435
436 call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
437 ASSERT((call->flags & IPC_CALL_ANSWERED) || (call->flags & IPC_CALL_NOTIF));
438 ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
439
440 atomic_dec(&TASK->active_calls);
441 ipc_call_free(call);
442 }
443}
444
445
446/** Initilize IPC subsystem */
447void ipc_init(void)
448{
449 ipc_call_slab = slab_cache_create("ipc_call", sizeof(call_t), 0, NULL, NULL, 0);
450}
451
452
453/** Kconsole - list answerbox contents */
454void ipc_print_task(task_id_t taskid)
455{
456 task_t *task;
457 int i;
458 call_t *call;
459 link_t *tmp;
460
461 spinlock_lock(&tasks_lock);
462 task = task_find_by_id(taskid);
463 if (task)
464 spinlock_lock(&task->lock);
465 spinlock_unlock(&tasks_lock);
466 if (!task)
467 return;
468
469 /* Print opened phones & details */
470 printf("PHONE:\n");
471 for (i=0; i < IPC_MAX_PHONES;i++) {
472 spinlock_lock(&task->phones[i].lock);
473 if (task->phones[i].state != IPC_PHONE_FREE) {
474 printf("%d: ",i);
475 switch (task->phones[i].state) {
476 case IPC_PHONE_CONNECTING:
477 printf("connecting ");
478 break;
479 case IPC_PHONE_CONNECTED:
480 printf("connected to: %p ",
481 task->phones[i].callee);
482 break;
483 case IPC_PHONE_SLAMMED:
484 printf("slammed by: %p ",
485 task->phones[i].callee);
486 break;
487 case IPC_PHONE_HUNGUP:
488 printf("hung up - was: %p ",
489 task->phones[i].callee);
490 break;
491 default:
492 break;
493 }
494 printf("active: %d\n", atomic_get(&task->phones[i].active_calls));
495 }
496 spinlock_unlock(&task->phones[i].lock);
497 }
498
499
500 /* Print answerbox - calls */
501 spinlock_lock(&task->answerbox.lock);
502 printf("ABOX - CALLS:\n");
503 for (tmp=task->answerbox.calls.next; tmp != &task->answerbox.calls;tmp = tmp->next) {
504 call = list_get_instance(tmp, call_t, link);
505 printf("Callid: %p Srctask:%llu M:%d A1:%d A2:%d A3:%d Flags:%x\n",call,
506 call->sender->taskid, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
507 IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), call->flags);
508 }
509 /* Print answerbox - calls */
510 printf("ABOX - DISPATCHED CALLS:\n");
511 for (tmp=task->answerbox.dispatched_calls.next;
512 tmp != &task->answerbox.dispatched_calls;
513 tmp = tmp->next) {
514 call = list_get_instance(tmp, call_t, link);
515 printf("Callid: %p Srctask:%llu M:%d A1:%d A2:%d A3:%d Flags:%x\n",call,
516 call->sender->taskid, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
517 IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), call->flags);
518 }
519 /* Print answerbox - calls */
520 printf("ABOX - ANSWERS:\n");
521 for (tmp=task->answerbox.answers.next; tmp != &task->answerbox.answers; tmp = tmp->next) {
522 call = list_get_instance(tmp, call_t, link);
523 printf("Callid:%p M:%d A1:%d A2:%d A3:%d Flags:%x\n",call,
524 IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
525 IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), call->flags);
526 }
527
528 spinlock_unlock(&task->answerbox.lock);
529 spinlock_unlock(&task->lock);
530}
531
532/** @}
533 */
Note: See TracBrowser for help on using the repository browser.