1 /*
2 * UWB reservation management.
3 *
4 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18 #include <linux/kernel.h>
19 #include <linux/uwb.h>
20 #include <linux/slab.h>
21 #include <linux/random.h>
22 #include <linux/export.h>
23
24 #include "uwb-internal.h"
25
26 static void uwb_rsv_timer(struct timer_list *t);
27
28 static const char *rsv_states[] = {
29 [UWB_RSV_STATE_NONE] = "none ",
30 [UWB_RSV_STATE_O_INITIATED] = "o initiated ",
31 [UWB_RSV_STATE_O_PENDING] = "o pending ",
32 [UWB_RSV_STATE_O_MODIFIED] = "o modified ",
33 [UWB_RSV_STATE_O_ESTABLISHED] = "o established ",
34 [UWB_RSV_STATE_O_TO_BE_MOVED] = "o to be moved ",
35 [UWB_RSV_STATE_O_MOVE_EXPANDING] = "o move expanding",
36 [UWB_RSV_STATE_O_MOVE_COMBINING] = "o move combining",
37 [UWB_RSV_STATE_O_MOVE_REDUCING] = "o move reducing ",
38 [UWB_RSV_STATE_T_ACCEPTED] = "t accepted ",
39 [UWB_RSV_STATE_T_CONFLICT] = "t conflict ",
40 [UWB_RSV_STATE_T_PENDING] = "t pending ",
41 [UWB_RSV_STATE_T_DENIED] = "t denied ",
42 [UWB_RSV_STATE_T_RESIZED] = "t resized ",
43 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = "t expanding acc ",
44 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = "t expanding conf",
45 [UWB_RSV_STATE_T_EXPANDING_PENDING] = "t expanding pend",
46 [UWB_RSV_STATE_T_EXPANDING_DENIED] = "t expanding den ",
47 };
48
49 static const char *rsv_types[] = {
50 [UWB_DRP_TYPE_ALIEN_BP] = "alien-bp",
51 [UWB_DRP_TYPE_HARD] = "hard",
52 [UWB_DRP_TYPE_SOFT] = "soft",
53 [UWB_DRP_TYPE_PRIVATE] = "private",
54 [UWB_DRP_TYPE_PCA] = "pca",
55 };
56
uwb_rsv_has_two_drp_ies(struct uwb_rsv * rsv)57 bool uwb_rsv_has_two_drp_ies(struct uwb_rsv *rsv)
58 {
59 static const bool has_two_drp_ies[] = {
60 [UWB_RSV_STATE_O_INITIATED] = false,
61 [UWB_RSV_STATE_O_PENDING] = false,
62 [UWB_RSV_STATE_O_MODIFIED] = false,
63 [UWB_RSV_STATE_O_ESTABLISHED] = false,
64 [UWB_RSV_STATE_O_TO_BE_MOVED] = false,
65 [UWB_RSV_STATE_O_MOVE_COMBINING] = false,
66 [UWB_RSV_STATE_O_MOVE_REDUCING] = false,
67 [UWB_RSV_STATE_O_MOVE_EXPANDING] = true,
68 [UWB_RSV_STATE_T_ACCEPTED] = false,
69 [UWB_RSV_STATE_T_CONFLICT] = false,
70 [UWB_RSV_STATE_T_PENDING] = false,
71 [UWB_RSV_STATE_T_DENIED] = false,
72 [UWB_RSV_STATE_T_RESIZED] = false,
73 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = true,
74 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = true,
75 [UWB_RSV_STATE_T_EXPANDING_PENDING] = true,
76 [UWB_RSV_STATE_T_EXPANDING_DENIED] = true,
77 };
78
79 return has_two_drp_ies[rsv->state];
80 }
81
82 /**
83 * uwb_rsv_state_str - return a string for a reservation state
84 * @state: the reservation state.
85 */
uwb_rsv_state_str(enum uwb_rsv_state state)86 const char *uwb_rsv_state_str(enum uwb_rsv_state state)
87 {
88 if (state < UWB_RSV_STATE_NONE || state >= UWB_RSV_STATE_LAST)
89 return "unknown";
90 return rsv_states[state];
91 }
92 EXPORT_SYMBOL_GPL(uwb_rsv_state_str);
93
94 /**
95 * uwb_rsv_type_str - return a string for a reservation type
96 * @type: the reservation type
97 */
uwb_rsv_type_str(enum uwb_drp_type type)98 const char *uwb_rsv_type_str(enum uwb_drp_type type)
99 {
100 if (type < UWB_DRP_TYPE_ALIEN_BP || type > UWB_DRP_TYPE_PCA)
101 return "invalid";
102 return rsv_types[type];
103 }
104 EXPORT_SYMBOL_GPL(uwb_rsv_type_str);
105
uwb_rsv_dump(char * text,struct uwb_rsv * rsv)106 void uwb_rsv_dump(char *text, struct uwb_rsv *rsv)
107 {
108 struct device *dev = &rsv->rc->uwb_dev.dev;
109 struct uwb_dev_addr devaddr;
110 char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE];
111
112 uwb_dev_addr_print(owner, sizeof(owner), &rsv->owner->dev_addr);
113 if (rsv->target.type == UWB_RSV_TARGET_DEV)
114 devaddr = rsv->target.dev->dev_addr;
115 else
116 devaddr = rsv->target.devaddr;
117 uwb_dev_addr_print(target, sizeof(target), &devaddr);
118
119 dev_dbg(dev, "rsv %s %s -> %s: %s\n",
120 text, owner, target, uwb_rsv_state_str(rsv->state));
121 }
122
uwb_rsv_release(struct kref * kref)123 static void uwb_rsv_release(struct kref *kref)
124 {
125 struct uwb_rsv *rsv = container_of(kref, struct uwb_rsv, kref);
126
127 kfree(rsv);
128 }
129
uwb_rsv_get(struct uwb_rsv * rsv)130 void uwb_rsv_get(struct uwb_rsv *rsv)
131 {
132 kref_get(&rsv->kref);
133 }
134
uwb_rsv_put(struct uwb_rsv * rsv)135 void uwb_rsv_put(struct uwb_rsv *rsv)
136 {
137 kref_put(&rsv->kref, uwb_rsv_release);
138 }
139
140 /*
141 * Get a free stream index for a reservation.
142 *
143 * If the target is a DevAddr (e.g., a WUSB cluster reservation) then
144 * the stream is allocated from a pool of per-RC stream indexes,
145 * otherwise a unique stream index for the target is selected.
146 */
uwb_rsv_get_stream(struct uwb_rsv * rsv)147 static int uwb_rsv_get_stream(struct uwb_rsv *rsv)
148 {
149 struct uwb_rc *rc = rsv->rc;
150 struct device *dev = &rc->uwb_dev.dev;
151 unsigned long *streams_bm;
152 int stream;
153
154 switch (rsv->target.type) {
155 case UWB_RSV_TARGET_DEV:
156 streams_bm = rsv->target.dev->streams;
157 break;
158 case UWB_RSV_TARGET_DEVADDR:
159 streams_bm = rc->uwb_dev.streams;
160 break;
161 default:
162 return -EINVAL;
163 }
164
165 stream = find_first_zero_bit(streams_bm, UWB_NUM_STREAMS);
166 if (stream >= UWB_NUM_STREAMS) {
167 dev_err(dev, "%s: no available stream found\n", __func__);
168 return -EBUSY;
169 }
170
171 rsv->stream = stream;
172 set_bit(stream, streams_bm);
173
174 dev_dbg(dev, "get stream %d\n", rsv->stream);
175
176 return 0;
177 }
178
uwb_rsv_put_stream(struct uwb_rsv * rsv)179 static void uwb_rsv_put_stream(struct uwb_rsv *rsv)
180 {
181 struct uwb_rc *rc = rsv->rc;
182 struct device *dev = &rc->uwb_dev.dev;
183 unsigned long *streams_bm;
184
185 switch (rsv->target.type) {
186 case UWB_RSV_TARGET_DEV:
187 streams_bm = rsv->target.dev->streams;
188 break;
189 case UWB_RSV_TARGET_DEVADDR:
190 streams_bm = rc->uwb_dev.streams;
191 break;
192 default:
193 return;
194 }
195
196 clear_bit(rsv->stream, streams_bm);
197
198 dev_dbg(dev, "put stream %d\n", rsv->stream);
199 }
200
uwb_rsv_backoff_win_timer(struct timer_list * t)201 void uwb_rsv_backoff_win_timer(struct timer_list *t)
202 {
203 struct uwb_drp_backoff_win *bow = from_timer(bow, t, timer);
204 struct uwb_rc *rc = container_of(bow, struct uwb_rc, bow);
205 struct device *dev = &rc->uwb_dev.dev;
206
207 bow->can_reserve_extra_mases = true;
208 if (bow->total_expired <= 4) {
209 bow->total_expired++;
210 } else {
211 /* after 4 backoff window has expired we can exit from
212 * the backoff procedure */
213 bow->total_expired = 0;
214 bow->window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
215 }
216 dev_dbg(dev, "backoff_win_timer total_expired=%d, n=%d\n", bow->total_expired, bow->n);
217
218 /* try to relocate all the "to be moved" relocations */
219 uwb_rsv_handle_drp_avail_change(rc);
220 }
221
uwb_rsv_backoff_win_increment(struct uwb_rc * rc)222 void uwb_rsv_backoff_win_increment(struct uwb_rc *rc)
223 {
224 struct uwb_drp_backoff_win *bow = &rc->bow;
225 struct device *dev = &rc->uwb_dev.dev;
226 unsigned timeout_us;
227
228 dev_dbg(dev, "backoff_win_increment: window=%d\n", bow->window);
229
230 bow->can_reserve_extra_mases = false;
231
232 if((bow->window << 1) == UWB_DRP_BACKOFF_WIN_MAX)
233 return;
234
235 bow->window <<= 1;
236 bow->n = prandom_u32() & (bow->window - 1);
237 dev_dbg(dev, "new_window=%d, n=%d\n", bow->window, bow->n);
238
239 /* reset the timer associated variables */
240 timeout_us = bow->n * UWB_SUPERFRAME_LENGTH_US;
241 bow->total_expired = 0;
242 mod_timer(&bow->timer, jiffies + usecs_to_jiffies(timeout_us));
243 }
244
uwb_rsv_stroke_timer(struct uwb_rsv * rsv)245 static void uwb_rsv_stroke_timer(struct uwb_rsv *rsv)
246 {
247 int sframes = UWB_MAX_LOST_BEACONS;
248
249 /*
250 * Multicast reservations can become established within 1
251 * super frame and should not be terminated if no response is
252 * received.
253 */
254 if (rsv->state == UWB_RSV_STATE_NONE) {
255 sframes = 0;
256 } else if (rsv->is_multicast) {
257 if (rsv->state == UWB_RSV_STATE_O_INITIATED
258 || rsv->state == UWB_RSV_STATE_O_MOVE_EXPANDING
259 || rsv->state == UWB_RSV_STATE_O_MOVE_COMBINING
260 || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING)
261 sframes = 1;
262 if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED)
263 sframes = 0;
264
265 }
266
267 if (sframes > 0) {
268 /*
269 * Add an additional 2 superframes to account for the
270 * time to send the SET DRP IE command.
271 */
272 unsigned timeout_us = (sframes + 2) * UWB_SUPERFRAME_LENGTH_US;
273 mod_timer(&rsv->timer, jiffies + usecs_to_jiffies(timeout_us));
274 } else
275 del_timer(&rsv->timer);
276 }
277
278 /*
279 * Update a reservations state, and schedule an update of the
280 * transmitted DRP IEs.
281 */
uwb_rsv_state_update(struct uwb_rsv * rsv,enum uwb_rsv_state new_state)282 static void uwb_rsv_state_update(struct uwb_rsv *rsv,
283 enum uwb_rsv_state new_state)
284 {
285 rsv->state = new_state;
286 rsv->ie_valid = false;
287
288 uwb_rsv_dump("SU", rsv);
289
290 uwb_rsv_stroke_timer(rsv);
291 uwb_rsv_sched_update(rsv->rc);
292 }
293
uwb_rsv_callback(struct uwb_rsv * rsv)294 static void uwb_rsv_callback(struct uwb_rsv *rsv)
295 {
296 if (rsv->callback)
297 rsv->callback(rsv);
298 }
299
uwb_rsv_set_state(struct uwb_rsv * rsv,enum uwb_rsv_state new_state)300 void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state)
301 {
302 struct uwb_rsv_move *mv = &rsv->mv;
303
304 if (rsv->state == new_state) {
305 switch (rsv->state) {
306 case UWB_RSV_STATE_O_ESTABLISHED:
307 case UWB_RSV_STATE_O_MOVE_EXPANDING:
308 case UWB_RSV_STATE_O_MOVE_COMBINING:
309 case UWB_RSV_STATE_O_MOVE_REDUCING:
310 case UWB_RSV_STATE_T_ACCEPTED:
311 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
312 case UWB_RSV_STATE_T_RESIZED:
313 case UWB_RSV_STATE_NONE:
314 uwb_rsv_stroke_timer(rsv);
315 break;
316 default:
317 /* Expecting a state transition so leave timer
318 as-is. */
319 break;
320 }
321 return;
322 }
323
324 uwb_rsv_dump("SC", rsv);
325
326 switch (new_state) {
327 case UWB_RSV_STATE_NONE:
328 uwb_rsv_state_update(rsv, UWB_RSV_STATE_NONE);
329 uwb_rsv_remove(rsv);
330 uwb_rsv_callback(rsv);
331 break;
332 case UWB_RSV_STATE_O_INITIATED:
333 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_INITIATED);
334 break;
335 case UWB_RSV_STATE_O_PENDING:
336 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_PENDING);
337 break;
338 case UWB_RSV_STATE_O_MODIFIED:
339 /* in the companion there are the MASes to drop */
340 bitmap_andnot(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
341 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MODIFIED);
342 break;
343 case UWB_RSV_STATE_O_ESTABLISHED:
344 if (rsv->state == UWB_RSV_STATE_O_MODIFIED
345 || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING) {
346 uwb_drp_avail_release(rsv->rc, &mv->companion_mas);
347 rsv->needs_release_companion_mas = false;
348 }
349 uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
350 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_ESTABLISHED);
351 uwb_rsv_callback(rsv);
352 break;
353 case UWB_RSV_STATE_O_MOVE_EXPANDING:
354 rsv->needs_release_companion_mas = true;
355 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
356 break;
357 case UWB_RSV_STATE_O_MOVE_COMBINING:
358 rsv->needs_release_companion_mas = false;
359 uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
360 bitmap_or(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
361 rsv->mas.safe += mv->companion_mas.safe;
362 rsv->mas.unsafe += mv->companion_mas.unsafe;
363 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
364 break;
365 case UWB_RSV_STATE_O_MOVE_REDUCING:
366 bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
367 rsv->needs_release_companion_mas = true;
368 rsv->mas.safe = mv->final_mas.safe;
369 rsv->mas.unsafe = mv->final_mas.unsafe;
370 bitmap_copy(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
371 bitmap_copy(rsv->mas.unsafe_bm, mv->final_mas.unsafe_bm, UWB_NUM_MAS);
372 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
373 break;
374 case UWB_RSV_STATE_T_ACCEPTED:
375 case UWB_RSV_STATE_T_RESIZED:
376 rsv->needs_release_companion_mas = false;
377 uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
378 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_ACCEPTED);
379 uwb_rsv_callback(rsv);
380 break;
381 case UWB_RSV_STATE_T_DENIED:
382 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_DENIED);
383 break;
384 case UWB_RSV_STATE_T_CONFLICT:
385 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_CONFLICT);
386 break;
387 case UWB_RSV_STATE_T_PENDING:
388 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_PENDING);
389 break;
390 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
391 rsv->needs_release_companion_mas = true;
392 uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
393 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
394 break;
395 default:
396 dev_err(&rsv->rc->uwb_dev.dev, "unhandled state: %s (%d)\n",
397 uwb_rsv_state_str(new_state), new_state);
398 }
399 }
400
uwb_rsv_handle_timeout_work(struct work_struct * work)401 static void uwb_rsv_handle_timeout_work(struct work_struct *work)
402 {
403 struct uwb_rsv *rsv = container_of(work, struct uwb_rsv,
404 handle_timeout_work);
405 struct uwb_rc *rc = rsv->rc;
406
407 mutex_lock(&rc->rsvs_mutex);
408
409 uwb_rsv_dump("TO", rsv);
410
411 switch (rsv->state) {
412 case UWB_RSV_STATE_O_INITIATED:
413 if (rsv->is_multicast) {
414 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
415 goto unlock;
416 }
417 break;
418 case UWB_RSV_STATE_O_MOVE_EXPANDING:
419 if (rsv->is_multicast) {
420 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
421 goto unlock;
422 }
423 break;
424 case UWB_RSV_STATE_O_MOVE_COMBINING:
425 if (rsv->is_multicast) {
426 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
427 goto unlock;
428 }
429 break;
430 case UWB_RSV_STATE_O_MOVE_REDUCING:
431 if (rsv->is_multicast) {
432 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
433 goto unlock;
434 }
435 break;
436 case UWB_RSV_STATE_O_ESTABLISHED:
437 if (rsv->is_multicast)
438 goto unlock;
439 break;
440 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
441 /*
442 * The time out could be for the main or of the
443 * companion DRP, assume it's for the companion and
444 * drop that first. A further time out is required to
445 * drop the main.
446 */
447 uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
448 uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
449 goto unlock;
450 case UWB_RSV_STATE_NONE:
451 goto unlock;
452 default:
453 break;
454 }
455
456 uwb_rsv_remove(rsv);
457
458 unlock:
459 mutex_unlock(&rc->rsvs_mutex);
460 }
461
uwb_rsv_alloc(struct uwb_rc * rc)462 static struct uwb_rsv *uwb_rsv_alloc(struct uwb_rc *rc)
463 {
464 struct uwb_rsv *rsv;
465
466 rsv = kzalloc(sizeof(struct uwb_rsv), GFP_KERNEL);
467 if (!rsv)
468 return NULL;
469
470 INIT_LIST_HEAD(&rsv->rc_node);
471 INIT_LIST_HEAD(&rsv->pal_node);
472 kref_init(&rsv->kref);
473 timer_setup(&rsv->timer, uwb_rsv_timer, 0);
474
475 rsv->rc = rc;
476 INIT_WORK(&rsv->handle_timeout_work, uwb_rsv_handle_timeout_work);
477
478 return rsv;
479 }
480
481 /**
482 * uwb_rsv_create - allocate and initialize a UWB reservation structure
483 * @rc: the radio controller
484 * @cb: callback to use when the reservation completes or terminates
485 * @pal_priv: data private to the PAL to be passed in the callback
486 *
487 * The callback is called when the state of the reservation changes from:
488 *
489 * - pending to accepted
490 * - pending to denined
491 * - accepted to terminated
492 * - pending to terminated
493 */
uwb_rsv_create(struct uwb_rc * rc,uwb_rsv_cb_f cb,void * pal_priv)494 struct uwb_rsv *uwb_rsv_create(struct uwb_rc *rc, uwb_rsv_cb_f cb, void *pal_priv)
495 {
496 struct uwb_rsv *rsv;
497
498 rsv = uwb_rsv_alloc(rc);
499 if (!rsv)
500 return NULL;
501
502 rsv->callback = cb;
503 rsv->pal_priv = pal_priv;
504
505 return rsv;
506 }
507 EXPORT_SYMBOL_GPL(uwb_rsv_create);
508
uwb_rsv_remove(struct uwb_rsv * rsv)509 void uwb_rsv_remove(struct uwb_rsv *rsv)
510 {
511 uwb_rsv_dump("RM", rsv);
512
513 if (rsv->state != UWB_RSV_STATE_NONE)
514 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
515
516 if (rsv->needs_release_companion_mas)
517 uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
518 uwb_drp_avail_release(rsv->rc, &rsv->mas);
519
520 if (uwb_rsv_is_owner(rsv))
521 uwb_rsv_put_stream(rsv);
522
523 uwb_dev_put(rsv->owner);
524 if (rsv->target.type == UWB_RSV_TARGET_DEV)
525 uwb_dev_put(rsv->target.dev);
526
527 list_del_init(&rsv->rc_node);
528 uwb_rsv_put(rsv);
529 }
530
531 /**
532 * uwb_rsv_destroy - free a UWB reservation structure
533 * @rsv: the reservation to free
534 *
535 * The reservation must already be terminated.
536 */
uwb_rsv_destroy(struct uwb_rsv * rsv)537 void uwb_rsv_destroy(struct uwb_rsv *rsv)
538 {
539 uwb_rsv_put(rsv);
540 }
541 EXPORT_SYMBOL_GPL(uwb_rsv_destroy);
542
543 /**
544 * usb_rsv_establish - start a reservation establishment
545 * @rsv: the reservation
546 *
547 * The PAL should fill in @rsv's owner, target, type, max_mas,
548 * min_mas, max_interval and is_multicast fields. If the target is a
549 * uwb_dev it must be referenced.
550 *
551 * The reservation's callback will be called when the reservation is
552 * accepted, denied or times out.
553 */
uwb_rsv_establish(struct uwb_rsv * rsv)554 int uwb_rsv_establish(struct uwb_rsv *rsv)
555 {
556 struct uwb_rc *rc = rsv->rc;
557 struct uwb_mas_bm available;
558 struct device *dev = &rc->uwb_dev.dev;
559 int ret;
560
561 mutex_lock(&rc->rsvs_mutex);
562 ret = uwb_rsv_get_stream(rsv);
563 if (ret) {
564 dev_err(dev, "%s: uwb_rsv_get_stream failed: %d\n",
565 __func__, ret);
566 goto out;
567 }
568
569 rsv->tiebreaker = prandom_u32() & 1;
570 /* get available mas bitmap */
571 uwb_drp_available(rc, &available);
572
573 ret = uwb_rsv_find_best_allocation(rsv, &available, &rsv->mas);
574 if (ret == UWB_RSV_ALLOC_NOT_FOUND) {
575 ret = -EBUSY;
576 uwb_rsv_put_stream(rsv);
577 dev_err(dev, "%s: uwb_rsv_find_best_allocation failed: %d\n",
578 __func__, ret);
579 goto out;
580 }
581
582 ret = uwb_drp_avail_reserve_pending(rc, &rsv->mas);
583 if (ret != 0) {
584 uwb_rsv_put_stream(rsv);
585 dev_err(dev, "%s: uwb_drp_avail_reserve_pending failed: %d\n",
586 __func__, ret);
587 goto out;
588 }
589
590 uwb_rsv_get(rsv);
591 list_add_tail(&rsv->rc_node, &rc->reservations);
592 rsv->owner = &rc->uwb_dev;
593 uwb_dev_get(rsv->owner);
594 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_INITIATED);
595 out:
596 mutex_unlock(&rc->rsvs_mutex);
597 return ret;
598 }
599 EXPORT_SYMBOL_GPL(uwb_rsv_establish);
600
601 /**
602 * uwb_rsv_modify - modify an already established reservation
603 * @rsv: the reservation to modify
604 * @max_mas: new maximum MAS to reserve
605 * @min_mas: new minimum MAS to reserve
606 * @max_interval: new max_interval to use
607 *
608 * FIXME: implement this once there are PALs that use it.
609 */
uwb_rsv_modify(struct uwb_rsv * rsv,int max_mas,int min_mas,int max_interval)610 int uwb_rsv_modify(struct uwb_rsv *rsv, int max_mas, int min_mas, int max_interval)
611 {
612 return -ENOSYS;
613 }
614 EXPORT_SYMBOL_GPL(uwb_rsv_modify);
615
616 /*
617 * move an already established reservation (rc->rsvs_mutex must to be
618 * taken when tis function is called)
619 */
uwb_rsv_try_move(struct uwb_rsv * rsv,struct uwb_mas_bm * available)620 int uwb_rsv_try_move(struct uwb_rsv *rsv, struct uwb_mas_bm *available)
621 {
622 struct uwb_rc *rc = rsv->rc;
623 struct uwb_drp_backoff_win *bow = &rc->bow;
624 struct device *dev = &rc->uwb_dev.dev;
625 struct uwb_rsv_move *mv;
626 int ret = 0;
627
628 if (bow->can_reserve_extra_mases == false)
629 return -EBUSY;
630
631 mv = &rsv->mv;
632
633 if (uwb_rsv_find_best_allocation(rsv, available, &mv->final_mas) == UWB_RSV_ALLOC_FOUND) {
634
635 if (!bitmap_equal(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS)) {
636 /* We want to move the reservation */
637 bitmap_andnot(mv->companion_mas.bm, mv->final_mas.bm, rsv->mas.bm, UWB_NUM_MAS);
638 uwb_drp_avail_reserve_pending(rc, &mv->companion_mas);
639 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
640 }
641 } else {
642 dev_dbg(dev, "new allocation not found\n");
643 }
644
645 return ret;
646 }
647
648 /* It will try to move every reservation in state O_ESTABLISHED giving
649 * to the MAS allocator algorithm an availability that is the real one
650 * plus the allocation already established from the reservation. */
uwb_rsv_handle_drp_avail_change(struct uwb_rc * rc)651 void uwb_rsv_handle_drp_avail_change(struct uwb_rc *rc)
652 {
653 struct uwb_drp_backoff_win *bow = &rc->bow;
654 struct uwb_rsv *rsv;
655 struct uwb_mas_bm mas;
656
657 if (bow->can_reserve_extra_mases == false)
658 return;
659
660 list_for_each_entry(rsv, &rc->reservations, rc_node) {
661 if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED ||
662 rsv->state == UWB_RSV_STATE_O_TO_BE_MOVED) {
663 uwb_drp_available(rc, &mas);
664 bitmap_or(mas.bm, mas.bm, rsv->mas.bm, UWB_NUM_MAS);
665 uwb_rsv_try_move(rsv, &mas);
666 }
667 }
668
669 }
670
671 /**
672 * uwb_rsv_terminate - terminate an established reservation
673 * @rsv: the reservation to terminate
674 *
675 * A reservation is terminated by removing the DRP IE from the beacon,
676 * the other end will consider the reservation to be terminated when
677 * it does not see the DRP IE for at least mMaxLostBeacons.
678 *
679 * If applicable, the reference to the target uwb_dev will be released.
680 */
uwb_rsv_terminate(struct uwb_rsv * rsv)681 void uwb_rsv_terminate(struct uwb_rsv *rsv)
682 {
683 struct uwb_rc *rc = rsv->rc;
684
685 mutex_lock(&rc->rsvs_mutex);
686
687 if (rsv->state != UWB_RSV_STATE_NONE)
688 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
689
690 mutex_unlock(&rc->rsvs_mutex);
691 }
692 EXPORT_SYMBOL_GPL(uwb_rsv_terminate);
693
694 /**
695 * uwb_rsv_accept - accept a new reservation from a peer
696 * @rsv: the reservation
697 * @cb: call back for reservation changes
698 * @pal_priv: data to be passed in the above call back
699 *
700 * Reservation requests from peers are denied unless a PAL accepts it
701 * by calling this function.
702 *
703 * The PAL call uwb_rsv_destroy() for all accepted reservations before
704 * calling uwb_pal_unregister().
705 */
uwb_rsv_accept(struct uwb_rsv * rsv,uwb_rsv_cb_f cb,void * pal_priv)706 void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv)
707 {
708 uwb_rsv_get(rsv);
709
710 rsv->callback = cb;
711 rsv->pal_priv = pal_priv;
712 rsv->state = UWB_RSV_STATE_T_ACCEPTED;
713 }
714 EXPORT_SYMBOL_GPL(uwb_rsv_accept);
715
716 /*
717 * Is a received DRP IE for this reservation?
718 */
uwb_rsv_match(struct uwb_rsv * rsv,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)719 static bool uwb_rsv_match(struct uwb_rsv *rsv, struct uwb_dev *src,
720 struct uwb_ie_drp *drp_ie)
721 {
722 struct uwb_dev_addr *rsv_src;
723 int stream;
724
725 stream = uwb_ie_drp_stream_index(drp_ie);
726
727 if (rsv->stream != stream)
728 return false;
729
730 switch (rsv->target.type) {
731 case UWB_RSV_TARGET_DEVADDR:
732 return rsv->stream == stream;
733 case UWB_RSV_TARGET_DEV:
734 if (uwb_ie_drp_owner(drp_ie))
735 rsv_src = &rsv->owner->dev_addr;
736 else
737 rsv_src = &rsv->target.dev->dev_addr;
738 return uwb_dev_addr_cmp(&src->dev_addr, rsv_src) == 0;
739 }
740 return false;
741 }
742
uwb_rsv_new_target(struct uwb_rc * rc,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)743 static struct uwb_rsv *uwb_rsv_new_target(struct uwb_rc *rc,
744 struct uwb_dev *src,
745 struct uwb_ie_drp *drp_ie)
746 {
747 struct uwb_rsv *rsv;
748 struct uwb_pal *pal;
749 enum uwb_rsv_state state;
750
751 rsv = uwb_rsv_alloc(rc);
752 if (!rsv)
753 return NULL;
754
755 rsv->rc = rc;
756 rsv->owner = src;
757 uwb_dev_get(rsv->owner);
758 rsv->target.type = UWB_RSV_TARGET_DEV;
759 rsv->target.dev = &rc->uwb_dev;
760 uwb_dev_get(&rc->uwb_dev);
761 rsv->type = uwb_ie_drp_type(drp_ie);
762 rsv->stream = uwb_ie_drp_stream_index(drp_ie);
763 uwb_drp_ie_to_bm(&rsv->mas, drp_ie);
764
765 /*
766 * See if any PALs are interested in this reservation. If not,
767 * deny the request.
768 */
769 rsv->state = UWB_RSV_STATE_T_DENIED;
770 mutex_lock(&rc->uwb_dev.mutex);
771 list_for_each_entry(pal, &rc->pals, node) {
772 if (pal->new_rsv)
773 pal->new_rsv(pal, rsv);
774 if (rsv->state == UWB_RSV_STATE_T_ACCEPTED)
775 break;
776 }
777 mutex_unlock(&rc->uwb_dev.mutex);
778
779 list_add_tail(&rsv->rc_node, &rc->reservations);
780 state = rsv->state;
781 rsv->state = UWB_RSV_STATE_NONE;
782
783 /* FIXME: do something sensible here */
784 if (state == UWB_RSV_STATE_T_ACCEPTED
785 && uwb_drp_avail_reserve_pending(rc, &rsv->mas) == -EBUSY) {
786 /* FIXME: do something sensible here */
787 } else {
788 uwb_rsv_set_state(rsv, state);
789 }
790
791 return rsv;
792 }
793
794 /**
795 * uwb_rsv_get_usable_mas - get the bitmap of the usable MAS of a reservations
796 * @rsv: the reservation.
797 * @mas: returns the available MAS.
798 *
799 * The usable MAS of a reservation may be less than the negotiated MAS
800 * if alien BPs are present.
801 */
uwb_rsv_get_usable_mas(struct uwb_rsv * rsv,struct uwb_mas_bm * mas)802 void uwb_rsv_get_usable_mas(struct uwb_rsv *rsv, struct uwb_mas_bm *mas)
803 {
804 bitmap_zero(mas->bm, UWB_NUM_MAS);
805 bitmap_andnot(mas->bm, rsv->mas.bm, rsv->rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS);
806 }
807 EXPORT_SYMBOL_GPL(uwb_rsv_get_usable_mas);
808
809 /**
810 * uwb_rsv_find - find a reservation for a received DRP IE.
811 * @rc: the radio controller
812 * @src: source of the DRP IE
813 * @drp_ie: the DRP IE
814 *
815 * If the reservation cannot be found and the DRP IE is from a peer
816 * attempting to establish a new reservation, create a new reservation
817 * and add it to the list.
818 */
uwb_rsv_find(struct uwb_rc * rc,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)819 struct uwb_rsv *uwb_rsv_find(struct uwb_rc *rc, struct uwb_dev *src,
820 struct uwb_ie_drp *drp_ie)
821 {
822 struct uwb_rsv *rsv;
823
824 list_for_each_entry(rsv, &rc->reservations, rc_node) {
825 if (uwb_rsv_match(rsv, src, drp_ie))
826 return rsv;
827 }
828
829 if (uwb_ie_drp_owner(drp_ie))
830 return uwb_rsv_new_target(rc, src, drp_ie);
831
832 return NULL;
833 }
834
835 /*
836 * Go through all the reservations and check for timeouts and (if
837 * necessary) update their DRP IEs.
838 *
839 * FIXME: look at building the SET_DRP_IE command here rather than
840 * having to rescan the list in uwb_rc_send_all_drp_ie().
841 */
uwb_rsv_update_all(struct uwb_rc * rc)842 static bool uwb_rsv_update_all(struct uwb_rc *rc)
843 {
844 struct uwb_rsv *rsv, *t;
845 bool ie_updated = false;
846
847 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
848 if (!rsv->ie_valid) {
849 uwb_drp_ie_update(rsv);
850 ie_updated = true;
851 }
852 }
853
854 return ie_updated;
855 }
856
uwb_rsv_queue_update(struct uwb_rc * rc)857 void uwb_rsv_queue_update(struct uwb_rc *rc)
858 {
859 unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
860
861 queue_delayed_work(rc->rsv_workq, &rc->rsv_update_work, usecs_to_jiffies(delay_us));
862 }
863
864 /**
865 * uwb_rsv_sched_update - schedule an update of the DRP IEs
866 * @rc: the radio controller.
867 *
868 * To improve performance and ensure correctness with [ECMA-368] the
869 * number of SET-DRP-IE commands that are done are limited.
870 *
871 * DRP IEs update come from two sources: DRP events from the hardware
872 * which all occur at the beginning of the superframe ('syncronous'
873 * events) and reservation establishment/termination requests from
874 * PALs or timers ('asynchronous' events).
875 *
876 * A delayed work ensures that all the synchronous events result in
877 * one SET-DRP-IE command.
878 *
879 * Additional logic (the set_drp_ie_pending and rsv_updated_postponed
880 * flags) will prevent an asynchrous event starting a SET-DRP-IE
881 * command if one is currently awaiting a response.
882 *
883 * FIXME: this does leave a window where an asynchrous event can delay
884 * the SET-DRP-IE for a synchronous event by one superframe.
885 */
uwb_rsv_sched_update(struct uwb_rc * rc)886 void uwb_rsv_sched_update(struct uwb_rc *rc)
887 {
888 spin_lock_irq(&rc->rsvs_lock);
889 if (!delayed_work_pending(&rc->rsv_update_work)) {
890 if (rc->set_drp_ie_pending > 0) {
891 rc->set_drp_ie_pending++;
892 goto unlock;
893 }
894 uwb_rsv_queue_update(rc);
895 }
896 unlock:
897 spin_unlock_irq(&rc->rsvs_lock);
898 }
899
900 /*
901 * Update DRP IEs and, if necessary, the DRP Availability IE and send
902 * the updated IEs to the radio controller.
903 */
uwb_rsv_update_work(struct work_struct * work)904 static void uwb_rsv_update_work(struct work_struct *work)
905 {
906 struct uwb_rc *rc = container_of(work, struct uwb_rc,
907 rsv_update_work.work);
908 bool ie_updated;
909
910 mutex_lock(&rc->rsvs_mutex);
911
912 ie_updated = uwb_rsv_update_all(rc);
913
914 if (!rc->drp_avail.ie_valid) {
915 uwb_drp_avail_ie_update(rc);
916 ie_updated = true;
917 }
918
919 if (ie_updated && (rc->set_drp_ie_pending == 0))
920 uwb_rc_send_all_drp_ie(rc);
921
922 mutex_unlock(&rc->rsvs_mutex);
923 }
924
uwb_rsv_alien_bp_work(struct work_struct * work)925 static void uwb_rsv_alien_bp_work(struct work_struct *work)
926 {
927 struct uwb_rc *rc = container_of(work, struct uwb_rc,
928 rsv_alien_bp_work.work);
929 struct uwb_rsv *rsv;
930
931 mutex_lock(&rc->rsvs_mutex);
932
933 list_for_each_entry(rsv, &rc->reservations, rc_node) {
934 if (rsv->type != UWB_DRP_TYPE_ALIEN_BP) {
935 uwb_rsv_callback(rsv);
936 }
937 }
938
939 mutex_unlock(&rc->rsvs_mutex);
940 }
941
uwb_rsv_timer(struct timer_list * t)942 static void uwb_rsv_timer(struct timer_list *t)
943 {
944 struct uwb_rsv *rsv = from_timer(rsv, t, timer);
945
946 queue_work(rsv->rc->rsv_workq, &rsv->handle_timeout_work);
947 }
948
949 /**
950 * uwb_rsv_remove_all - remove all reservations
951 * @rc: the radio controller
952 *
953 * A DRP IE update is not done.
954 */
uwb_rsv_remove_all(struct uwb_rc * rc)955 void uwb_rsv_remove_all(struct uwb_rc *rc)
956 {
957 struct uwb_rsv *rsv, *t;
958
959 mutex_lock(&rc->rsvs_mutex);
960 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
961 if (rsv->state != UWB_RSV_STATE_NONE)
962 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
963 del_timer_sync(&rsv->timer);
964 }
965 /* Cancel any postponed update. */
966 rc->set_drp_ie_pending = 0;
967 mutex_unlock(&rc->rsvs_mutex);
968
969 cancel_delayed_work_sync(&rc->rsv_update_work);
970 flush_workqueue(rc->rsv_workq);
971
972 mutex_lock(&rc->rsvs_mutex);
973 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
974 uwb_rsv_remove(rsv);
975 }
976 mutex_unlock(&rc->rsvs_mutex);
977 }
978
uwb_rsv_init(struct uwb_rc * rc)979 void uwb_rsv_init(struct uwb_rc *rc)
980 {
981 INIT_LIST_HEAD(&rc->reservations);
982 INIT_LIST_HEAD(&rc->cnflt_alien_list);
983 mutex_init(&rc->rsvs_mutex);
984 spin_lock_init(&rc->rsvs_lock);
985 INIT_DELAYED_WORK(&rc->rsv_update_work, uwb_rsv_update_work);
986 INIT_DELAYED_WORK(&rc->rsv_alien_bp_work, uwb_rsv_alien_bp_work);
987 rc->bow.can_reserve_extra_mases = true;
988 rc->bow.total_expired = 0;
989 rc->bow.window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
990 timer_setup(&rc->bow.timer, uwb_rsv_backoff_win_timer, 0);
991
992 bitmap_complement(rc->uwb_dev.streams, rc->uwb_dev.streams, UWB_NUM_STREAMS);
993 }
994
uwb_rsv_setup(struct uwb_rc * rc)995 int uwb_rsv_setup(struct uwb_rc *rc)
996 {
997 char name[16];
998
999 snprintf(name, sizeof(name), "%s_rsvd", dev_name(&rc->uwb_dev.dev));
1000 rc->rsv_workq = create_singlethread_workqueue(name);
1001 if (rc->rsv_workq == NULL)
1002 return -ENOMEM;
1003
1004 return 0;
1005 }
1006
uwb_rsv_cleanup(struct uwb_rc * rc)1007 void uwb_rsv_cleanup(struct uwb_rc *rc)
1008 {
1009 uwb_rsv_remove_all(rc);
1010 destroy_workqueue(rc->rsv_workq);
1011 }
1012