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
23 #include "uwb-internal.h"
24
25 static void uwb_rsv_timer(unsigned long arg);
26
27 static const char *rsv_states[] = {
28 [UWB_RSV_STATE_NONE] = "none ",
29 [UWB_RSV_STATE_O_INITIATED] = "o initiated ",
30 [UWB_RSV_STATE_O_PENDING] = "o pending ",
31 [UWB_RSV_STATE_O_MODIFIED] = "o modified ",
32 [UWB_RSV_STATE_O_ESTABLISHED] = "o established ",
33 [UWB_RSV_STATE_O_TO_BE_MOVED] = "o to be moved ",
34 [UWB_RSV_STATE_O_MOVE_EXPANDING] = "o move expanding",
35 [UWB_RSV_STATE_O_MOVE_COMBINING] = "o move combining",
36 [UWB_RSV_STATE_O_MOVE_REDUCING] = "o move reducing ",
37 [UWB_RSV_STATE_T_ACCEPTED] = "t accepted ",
38 [UWB_RSV_STATE_T_CONFLICT] = "t conflict ",
39 [UWB_RSV_STATE_T_PENDING] = "t pending ",
40 [UWB_RSV_STATE_T_DENIED] = "t denied ",
41 [UWB_RSV_STATE_T_RESIZED] = "t resized ",
42 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = "t expanding acc ",
43 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = "t expanding conf",
44 [UWB_RSV_STATE_T_EXPANDING_PENDING] = "t expanding pend",
45 [UWB_RSV_STATE_T_EXPANDING_DENIED] = "t expanding den ",
46 };
47
48 static const char *rsv_types[] = {
49 [UWB_DRP_TYPE_ALIEN_BP] = "alien-bp",
50 [UWB_DRP_TYPE_HARD] = "hard",
51 [UWB_DRP_TYPE_SOFT] = "soft",
52 [UWB_DRP_TYPE_PRIVATE] = "private",
53 [UWB_DRP_TYPE_PCA] = "pca",
54 };
55
uwb_rsv_has_two_drp_ies(struct uwb_rsv * rsv)56 bool uwb_rsv_has_two_drp_ies(struct uwb_rsv *rsv)
57 {
58 static const bool has_two_drp_ies[] = {
59 [UWB_RSV_STATE_O_INITIATED] = false,
60 [UWB_RSV_STATE_O_PENDING] = false,
61 [UWB_RSV_STATE_O_MODIFIED] = false,
62 [UWB_RSV_STATE_O_ESTABLISHED] = false,
63 [UWB_RSV_STATE_O_TO_BE_MOVED] = false,
64 [UWB_RSV_STATE_O_MOVE_COMBINING] = false,
65 [UWB_RSV_STATE_O_MOVE_REDUCING] = false,
66 [UWB_RSV_STATE_O_MOVE_EXPANDING] = true,
67 [UWB_RSV_STATE_T_ACCEPTED] = false,
68 [UWB_RSV_STATE_T_CONFLICT] = false,
69 [UWB_RSV_STATE_T_PENDING] = false,
70 [UWB_RSV_STATE_T_DENIED] = false,
71 [UWB_RSV_STATE_T_RESIZED] = false,
72 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = true,
73 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = true,
74 [UWB_RSV_STATE_T_EXPANDING_PENDING] = true,
75 [UWB_RSV_STATE_T_EXPANDING_DENIED] = true,
76 };
77
78 return has_two_drp_ies[rsv->state];
79 }
80
81 /**
82 * uwb_rsv_state_str - return a string for a reservation state
83 * @state: the reservation state.
84 */
uwb_rsv_state_str(enum uwb_rsv_state state)85 const char *uwb_rsv_state_str(enum uwb_rsv_state state)
86 {
87 if (state < UWB_RSV_STATE_NONE || state >= UWB_RSV_STATE_LAST)
88 return "unknown";
89 return rsv_states[state];
90 }
91 EXPORT_SYMBOL_GPL(uwb_rsv_state_str);
92
93 /**
94 * uwb_rsv_type_str - return a string for a reservation type
95 * @type: the reservation type
96 */
uwb_rsv_type_str(enum uwb_drp_type type)97 const char *uwb_rsv_type_str(enum uwb_drp_type type)
98 {
99 if (type < UWB_DRP_TYPE_ALIEN_BP || type > UWB_DRP_TYPE_PCA)
100 return "invalid";
101 return rsv_types[type];
102 }
103 EXPORT_SYMBOL_GPL(uwb_rsv_type_str);
104
uwb_rsv_dump(char * text,struct uwb_rsv * rsv)105 void uwb_rsv_dump(char *text, struct uwb_rsv *rsv)
106 {
107 struct device *dev = &rsv->rc->uwb_dev.dev;
108 struct uwb_dev_addr devaddr;
109 char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE];
110
111 uwb_dev_addr_print(owner, sizeof(owner), &rsv->owner->dev_addr);
112 if (rsv->target.type == UWB_RSV_TARGET_DEV)
113 devaddr = rsv->target.dev->dev_addr;
114 else
115 devaddr = rsv->target.devaddr;
116 uwb_dev_addr_print(target, sizeof(target), &devaddr);
117
118 dev_dbg(dev, "rsv %s %s -> %s: %s\n",
119 text, owner, target, uwb_rsv_state_str(rsv->state));
120 }
121
uwb_rsv_release(struct kref * kref)122 static void uwb_rsv_release(struct kref *kref)
123 {
124 struct uwb_rsv *rsv = container_of(kref, struct uwb_rsv, kref);
125
126 kfree(rsv);
127 }
128
uwb_rsv_get(struct uwb_rsv * rsv)129 void uwb_rsv_get(struct uwb_rsv *rsv)
130 {
131 kref_get(&rsv->kref);
132 }
133
uwb_rsv_put(struct uwb_rsv * rsv)134 void uwb_rsv_put(struct uwb_rsv *rsv)
135 {
136 kref_put(&rsv->kref, uwb_rsv_release);
137 }
138
139 /*
140 * Get a free stream index for a reservation.
141 *
142 * If the target is a DevAddr (e.g., a WUSB cluster reservation) then
143 * the stream is allocated from a pool of per-RC stream indexes,
144 * otherwise a unique stream index for the target is selected.
145 */
uwb_rsv_get_stream(struct uwb_rsv * rsv)146 static int uwb_rsv_get_stream(struct uwb_rsv *rsv)
147 {
148 struct uwb_rc *rc = rsv->rc;
149 struct device *dev = &rc->uwb_dev.dev;
150 unsigned long *streams_bm;
151 int stream;
152
153 switch (rsv->target.type) {
154 case UWB_RSV_TARGET_DEV:
155 streams_bm = rsv->target.dev->streams;
156 break;
157 case UWB_RSV_TARGET_DEVADDR:
158 streams_bm = rc->uwb_dev.streams;
159 break;
160 default:
161 return -EINVAL;
162 }
163
164 stream = find_first_zero_bit(streams_bm, UWB_NUM_STREAMS);
165 if (stream >= UWB_NUM_STREAMS)
166 return -EBUSY;
167
168 rsv->stream = stream;
169 set_bit(stream, streams_bm);
170
171 dev_dbg(dev, "get stream %d\n", rsv->stream);
172
173 return 0;
174 }
175
uwb_rsv_put_stream(struct uwb_rsv * rsv)176 static void uwb_rsv_put_stream(struct uwb_rsv *rsv)
177 {
178 struct uwb_rc *rc = rsv->rc;
179 struct device *dev = &rc->uwb_dev.dev;
180 unsigned long *streams_bm;
181
182 switch (rsv->target.type) {
183 case UWB_RSV_TARGET_DEV:
184 streams_bm = rsv->target.dev->streams;
185 break;
186 case UWB_RSV_TARGET_DEVADDR:
187 streams_bm = rc->uwb_dev.streams;
188 break;
189 default:
190 return;
191 }
192
193 clear_bit(rsv->stream, streams_bm);
194
195 dev_dbg(dev, "put stream %d\n", rsv->stream);
196 }
197
uwb_rsv_backoff_win_timer(unsigned long arg)198 void uwb_rsv_backoff_win_timer(unsigned long arg)
199 {
200 struct uwb_drp_backoff_win *bow = (struct uwb_drp_backoff_win *)arg;
201 struct uwb_rc *rc = container_of(bow, struct uwb_rc, bow);
202 struct device *dev = &rc->uwb_dev.dev;
203
204 bow->can_reserve_extra_mases = true;
205 if (bow->total_expired <= 4) {
206 bow->total_expired++;
207 } else {
208 /* after 4 backoff window has expired we can exit from
209 * the backoff procedure */
210 bow->total_expired = 0;
211 bow->window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
212 }
213 dev_dbg(dev, "backoff_win_timer total_expired=%d, n=%d\n: ", bow->total_expired, bow->n);
214
215 /* try to relocate all the "to be moved" relocations */
216 uwb_rsv_handle_drp_avail_change(rc);
217 }
218
uwb_rsv_backoff_win_increment(struct uwb_rc * rc)219 void uwb_rsv_backoff_win_increment(struct uwb_rc *rc)
220 {
221 struct uwb_drp_backoff_win *bow = &rc->bow;
222 struct device *dev = &rc->uwb_dev.dev;
223 unsigned timeout_us;
224
225 dev_dbg(dev, "backoff_win_increment: window=%d\n", bow->window);
226
227 bow->can_reserve_extra_mases = false;
228
229 if((bow->window << 1) == UWB_DRP_BACKOFF_WIN_MAX)
230 return;
231
232 bow->window <<= 1;
233 bow->n = random32() & (bow->window - 1);
234 dev_dbg(dev, "new_window=%d, n=%d\n: ", bow->window, bow->n);
235
236 /* reset the timer associated variables */
237 timeout_us = bow->n * UWB_SUPERFRAME_LENGTH_US;
238 bow->total_expired = 0;
239 mod_timer(&bow->timer, jiffies + usecs_to_jiffies(timeout_us));
240 }
241
uwb_rsv_stroke_timer(struct uwb_rsv * rsv)242 static void uwb_rsv_stroke_timer(struct uwb_rsv *rsv)
243 {
244 int sframes = UWB_MAX_LOST_BEACONS;
245
246 /*
247 * Multicast reservations can become established within 1
248 * super frame and should not be terminated if no response is
249 * received.
250 */
251 if (rsv->is_multicast) {
252 if (rsv->state == UWB_RSV_STATE_O_INITIATED
253 || rsv->state == UWB_RSV_STATE_O_MOVE_EXPANDING
254 || rsv->state == UWB_RSV_STATE_O_MOVE_COMBINING
255 || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING)
256 sframes = 1;
257 if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED)
258 sframes = 0;
259
260 }
261
262 if (sframes > 0) {
263 /*
264 * Add an additional 2 superframes to account for the
265 * time to send the SET DRP IE command.
266 */
267 unsigned timeout_us = (sframes + 2) * UWB_SUPERFRAME_LENGTH_US;
268 mod_timer(&rsv->timer, jiffies + usecs_to_jiffies(timeout_us));
269 } else
270 del_timer(&rsv->timer);
271 }
272
273 /*
274 * Update a reservations state, and schedule an update of the
275 * transmitted DRP IEs.
276 */
uwb_rsv_state_update(struct uwb_rsv * rsv,enum uwb_rsv_state new_state)277 static void uwb_rsv_state_update(struct uwb_rsv *rsv,
278 enum uwb_rsv_state new_state)
279 {
280 rsv->state = new_state;
281 rsv->ie_valid = false;
282
283 uwb_rsv_dump("SU", rsv);
284
285 uwb_rsv_stroke_timer(rsv);
286 uwb_rsv_sched_update(rsv->rc);
287 }
288
uwb_rsv_callback(struct uwb_rsv * rsv)289 static void uwb_rsv_callback(struct uwb_rsv *rsv)
290 {
291 if (rsv->callback)
292 rsv->callback(rsv);
293 }
294
uwb_rsv_set_state(struct uwb_rsv * rsv,enum uwb_rsv_state new_state)295 void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state)
296 {
297 struct uwb_rsv_move *mv = &rsv->mv;
298
299 if (rsv->state == new_state) {
300 switch (rsv->state) {
301 case UWB_RSV_STATE_O_ESTABLISHED:
302 case UWB_RSV_STATE_O_MOVE_EXPANDING:
303 case UWB_RSV_STATE_O_MOVE_COMBINING:
304 case UWB_RSV_STATE_O_MOVE_REDUCING:
305 case UWB_RSV_STATE_T_ACCEPTED:
306 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
307 case UWB_RSV_STATE_T_RESIZED:
308 case UWB_RSV_STATE_NONE:
309 uwb_rsv_stroke_timer(rsv);
310 break;
311 default:
312 /* Expecting a state transition so leave timer
313 as-is. */
314 break;
315 }
316 return;
317 }
318
319 uwb_rsv_dump("SC", rsv);
320
321 switch (new_state) {
322 case UWB_RSV_STATE_NONE:
323 uwb_rsv_state_update(rsv, UWB_RSV_STATE_NONE);
324 uwb_rsv_callback(rsv);
325 break;
326 case UWB_RSV_STATE_O_INITIATED:
327 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_INITIATED);
328 break;
329 case UWB_RSV_STATE_O_PENDING:
330 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_PENDING);
331 break;
332 case UWB_RSV_STATE_O_MODIFIED:
333 /* in the companion there are the MASes to drop */
334 bitmap_andnot(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
335 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MODIFIED);
336 break;
337 case UWB_RSV_STATE_O_ESTABLISHED:
338 if (rsv->state == UWB_RSV_STATE_O_MODIFIED
339 || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING) {
340 uwb_drp_avail_release(rsv->rc, &mv->companion_mas);
341 rsv->needs_release_companion_mas = false;
342 }
343 uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
344 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_ESTABLISHED);
345 uwb_rsv_callback(rsv);
346 break;
347 case UWB_RSV_STATE_O_MOVE_EXPANDING:
348 rsv->needs_release_companion_mas = true;
349 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
350 break;
351 case UWB_RSV_STATE_O_MOVE_COMBINING:
352 rsv->needs_release_companion_mas = false;
353 uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
354 bitmap_or(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
355 rsv->mas.safe += mv->companion_mas.safe;
356 rsv->mas.unsafe += mv->companion_mas.unsafe;
357 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
358 break;
359 case UWB_RSV_STATE_O_MOVE_REDUCING:
360 bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
361 rsv->needs_release_companion_mas = true;
362 rsv->mas.safe = mv->final_mas.safe;
363 rsv->mas.unsafe = mv->final_mas.unsafe;
364 bitmap_copy(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
365 bitmap_copy(rsv->mas.unsafe_bm, mv->final_mas.unsafe_bm, UWB_NUM_MAS);
366 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
367 break;
368 case UWB_RSV_STATE_T_ACCEPTED:
369 case UWB_RSV_STATE_T_RESIZED:
370 rsv->needs_release_companion_mas = false;
371 uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
372 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_ACCEPTED);
373 uwb_rsv_callback(rsv);
374 break;
375 case UWB_RSV_STATE_T_DENIED:
376 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_DENIED);
377 break;
378 case UWB_RSV_STATE_T_CONFLICT:
379 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_CONFLICT);
380 break;
381 case UWB_RSV_STATE_T_PENDING:
382 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_PENDING);
383 break;
384 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
385 rsv->needs_release_companion_mas = true;
386 uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
387 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
388 break;
389 default:
390 dev_err(&rsv->rc->uwb_dev.dev, "unhandled state: %s (%d)\n",
391 uwb_rsv_state_str(new_state), new_state);
392 }
393 }
394
uwb_rsv_handle_timeout_work(struct work_struct * work)395 static void uwb_rsv_handle_timeout_work(struct work_struct *work)
396 {
397 struct uwb_rsv *rsv = container_of(work, struct uwb_rsv,
398 handle_timeout_work);
399 struct uwb_rc *rc = rsv->rc;
400
401 mutex_lock(&rc->rsvs_mutex);
402
403 uwb_rsv_dump("TO", rsv);
404
405 switch (rsv->state) {
406 case UWB_RSV_STATE_O_INITIATED:
407 if (rsv->is_multicast) {
408 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
409 goto unlock;
410 }
411 break;
412 case UWB_RSV_STATE_O_MOVE_EXPANDING:
413 if (rsv->is_multicast) {
414 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
415 goto unlock;
416 }
417 break;
418 case UWB_RSV_STATE_O_MOVE_COMBINING:
419 if (rsv->is_multicast) {
420 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
421 goto unlock;
422 }
423 break;
424 case UWB_RSV_STATE_O_MOVE_REDUCING:
425 if (rsv->is_multicast) {
426 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
427 goto unlock;
428 }
429 break;
430 case UWB_RSV_STATE_O_ESTABLISHED:
431 if (rsv->is_multicast)
432 goto unlock;
433 break;
434 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
435 /*
436 * The time out could be for the main or of the
437 * companion DRP, assume it's for the companion and
438 * drop that first. A further time out is required to
439 * drop the main.
440 */
441 uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
442 uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
443 goto unlock;
444 default:
445 break;
446 }
447
448 uwb_rsv_remove(rsv);
449
450 unlock:
451 mutex_unlock(&rc->rsvs_mutex);
452 }
453
uwb_rsv_alloc(struct uwb_rc * rc)454 static struct uwb_rsv *uwb_rsv_alloc(struct uwb_rc *rc)
455 {
456 struct uwb_rsv *rsv;
457
458 rsv = kzalloc(sizeof(struct uwb_rsv), GFP_KERNEL);
459 if (!rsv)
460 return NULL;
461
462 INIT_LIST_HEAD(&rsv->rc_node);
463 INIT_LIST_HEAD(&rsv->pal_node);
464 kref_init(&rsv->kref);
465 init_timer(&rsv->timer);
466 rsv->timer.function = uwb_rsv_timer;
467 rsv->timer.data = (unsigned long)rsv;
468
469 rsv->rc = rc;
470 INIT_WORK(&rsv->handle_timeout_work, uwb_rsv_handle_timeout_work);
471
472 return rsv;
473 }
474
475 /**
476 * uwb_rsv_create - allocate and initialize a UWB reservation structure
477 * @rc: the radio controller
478 * @cb: callback to use when the reservation completes or terminates
479 * @pal_priv: data private to the PAL to be passed in the callback
480 *
481 * The callback is called when the state of the reservation changes from:
482 *
483 * - pending to accepted
484 * - pending to denined
485 * - accepted to terminated
486 * - pending to terminated
487 */
uwb_rsv_create(struct uwb_rc * rc,uwb_rsv_cb_f cb,void * pal_priv)488 struct uwb_rsv *uwb_rsv_create(struct uwb_rc *rc, uwb_rsv_cb_f cb, void *pal_priv)
489 {
490 struct uwb_rsv *rsv;
491
492 rsv = uwb_rsv_alloc(rc);
493 if (!rsv)
494 return NULL;
495
496 rsv->callback = cb;
497 rsv->pal_priv = pal_priv;
498
499 return rsv;
500 }
501 EXPORT_SYMBOL_GPL(uwb_rsv_create);
502
uwb_rsv_remove(struct uwb_rsv * rsv)503 void uwb_rsv_remove(struct uwb_rsv *rsv)
504 {
505 uwb_rsv_dump("RM", rsv);
506
507 if (rsv->state != UWB_RSV_STATE_NONE)
508 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
509
510 if (rsv->needs_release_companion_mas)
511 uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
512 uwb_drp_avail_release(rsv->rc, &rsv->mas);
513
514 if (uwb_rsv_is_owner(rsv))
515 uwb_rsv_put_stream(rsv);
516
517 uwb_dev_put(rsv->owner);
518 if (rsv->target.type == UWB_RSV_TARGET_DEV)
519 uwb_dev_put(rsv->target.dev);
520
521 list_del_init(&rsv->rc_node);
522 uwb_rsv_put(rsv);
523 }
524
525 /**
526 * uwb_rsv_destroy - free a UWB reservation structure
527 * @rsv: the reservation to free
528 *
529 * The reservation must already be terminated.
530 */
uwb_rsv_destroy(struct uwb_rsv * rsv)531 void uwb_rsv_destroy(struct uwb_rsv *rsv)
532 {
533 uwb_rsv_put(rsv);
534 }
535 EXPORT_SYMBOL_GPL(uwb_rsv_destroy);
536
537 /**
538 * usb_rsv_establish - start a reservation establishment
539 * @rsv: the reservation
540 *
541 * The PAL should fill in @rsv's owner, target, type, max_mas,
542 * min_mas, max_interval and is_multicast fields. If the target is a
543 * uwb_dev it must be referenced.
544 *
545 * The reservation's callback will be called when the reservation is
546 * accepted, denied or times out.
547 */
uwb_rsv_establish(struct uwb_rsv * rsv)548 int uwb_rsv_establish(struct uwb_rsv *rsv)
549 {
550 struct uwb_rc *rc = rsv->rc;
551 struct uwb_mas_bm available;
552 int ret;
553
554 mutex_lock(&rc->rsvs_mutex);
555 ret = uwb_rsv_get_stream(rsv);
556 if (ret)
557 goto out;
558
559 rsv->tiebreaker = random32() & 1;
560 /* get available mas bitmap */
561 uwb_drp_available(rc, &available);
562
563 ret = uwb_rsv_find_best_allocation(rsv, &available, &rsv->mas);
564 if (ret == UWB_RSV_ALLOC_NOT_FOUND) {
565 ret = -EBUSY;
566 uwb_rsv_put_stream(rsv);
567 goto out;
568 }
569
570 ret = uwb_drp_avail_reserve_pending(rc, &rsv->mas);
571 if (ret != 0) {
572 uwb_rsv_put_stream(rsv);
573 goto out;
574 }
575
576 uwb_rsv_get(rsv);
577 list_add_tail(&rsv->rc_node, &rc->reservations);
578 rsv->owner = &rc->uwb_dev;
579 uwb_dev_get(rsv->owner);
580 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_INITIATED);
581 out:
582 mutex_unlock(&rc->rsvs_mutex);
583 return ret;
584 }
585 EXPORT_SYMBOL_GPL(uwb_rsv_establish);
586
587 /**
588 * uwb_rsv_modify - modify an already established reservation
589 * @rsv: the reservation to modify
590 * @max_mas: new maximum MAS to reserve
591 * @min_mas: new minimum MAS to reserve
592 * @max_interval: new max_interval to use
593 *
594 * FIXME: implement this once there are PALs that use it.
595 */
uwb_rsv_modify(struct uwb_rsv * rsv,int max_mas,int min_mas,int max_interval)596 int uwb_rsv_modify(struct uwb_rsv *rsv, int max_mas, int min_mas, int max_interval)
597 {
598 return -ENOSYS;
599 }
600 EXPORT_SYMBOL_GPL(uwb_rsv_modify);
601
602 /*
603 * move an already established reservation (rc->rsvs_mutex must to be
604 * taken when tis function is called)
605 */
uwb_rsv_try_move(struct uwb_rsv * rsv,struct uwb_mas_bm * available)606 int uwb_rsv_try_move(struct uwb_rsv *rsv, struct uwb_mas_bm *available)
607 {
608 struct uwb_rc *rc = rsv->rc;
609 struct uwb_drp_backoff_win *bow = &rc->bow;
610 struct device *dev = &rc->uwb_dev.dev;
611 struct uwb_rsv_move *mv;
612 int ret = 0;
613
614 if (bow->can_reserve_extra_mases == false)
615 return -EBUSY;
616
617 mv = &rsv->mv;
618
619 if (uwb_rsv_find_best_allocation(rsv, available, &mv->final_mas) == UWB_RSV_ALLOC_FOUND) {
620
621 if (!bitmap_equal(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS)) {
622 /* We want to move the reservation */
623 bitmap_andnot(mv->companion_mas.bm, mv->final_mas.bm, rsv->mas.bm, UWB_NUM_MAS);
624 uwb_drp_avail_reserve_pending(rc, &mv->companion_mas);
625 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
626 }
627 } else {
628 dev_dbg(dev, "new allocation not found\n");
629 }
630
631 return ret;
632 }
633
634 /* It will try to move every reservation in state O_ESTABLISHED giving
635 * to the MAS allocator algorithm an availability that is the real one
636 * plus the allocation already established from the reservation. */
uwb_rsv_handle_drp_avail_change(struct uwb_rc * rc)637 void uwb_rsv_handle_drp_avail_change(struct uwb_rc *rc)
638 {
639 struct uwb_drp_backoff_win *bow = &rc->bow;
640 struct uwb_rsv *rsv;
641 struct uwb_mas_bm mas;
642
643 if (bow->can_reserve_extra_mases == false)
644 return;
645
646 list_for_each_entry(rsv, &rc->reservations, rc_node) {
647 if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED ||
648 rsv->state == UWB_RSV_STATE_O_TO_BE_MOVED) {
649 uwb_drp_available(rc, &mas);
650 bitmap_or(mas.bm, mas.bm, rsv->mas.bm, UWB_NUM_MAS);
651 uwb_rsv_try_move(rsv, &mas);
652 }
653 }
654
655 }
656
657 /**
658 * uwb_rsv_terminate - terminate an established reservation
659 * @rsv: the reservation to terminate
660 *
661 * A reservation is terminated by removing the DRP IE from the beacon,
662 * the other end will consider the reservation to be terminated when
663 * it does not see the DRP IE for at least mMaxLostBeacons.
664 *
665 * If applicable, the reference to the target uwb_dev will be released.
666 */
uwb_rsv_terminate(struct uwb_rsv * rsv)667 void uwb_rsv_terminate(struct uwb_rsv *rsv)
668 {
669 struct uwb_rc *rc = rsv->rc;
670
671 mutex_lock(&rc->rsvs_mutex);
672
673 if (rsv->state != UWB_RSV_STATE_NONE)
674 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
675
676 mutex_unlock(&rc->rsvs_mutex);
677 }
678 EXPORT_SYMBOL_GPL(uwb_rsv_terminate);
679
680 /**
681 * uwb_rsv_accept - accept a new reservation from a peer
682 * @rsv: the reservation
683 * @cb: call back for reservation changes
684 * @pal_priv: data to be passed in the above call back
685 *
686 * Reservation requests from peers are denied unless a PAL accepts it
687 * by calling this function.
688 *
689 * The PAL call uwb_rsv_destroy() for all accepted reservations before
690 * calling uwb_pal_unregister().
691 */
uwb_rsv_accept(struct uwb_rsv * rsv,uwb_rsv_cb_f cb,void * pal_priv)692 void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv)
693 {
694 uwb_rsv_get(rsv);
695
696 rsv->callback = cb;
697 rsv->pal_priv = pal_priv;
698 rsv->state = UWB_RSV_STATE_T_ACCEPTED;
699 }
700 EXPORT_SYMBOL_GPL(uwb_rsv_accept);
701
702 /*
703 * Is a received DRP IE for this reservation?
704 */
uwb_rsv_match(struct uwb_rsv * rsv,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)705 static bool uwb_rsv_match(struct uwb_rsv *rsv, struct uwb_dev *src,
706 struct uwb_ie_drp *drp_ie)
707 {
708 struct uwb_dev_addr *rsv_src;
709 int stream;
710
711 stream = uwb_ie_drp_stream_index(drp_ie);
712
713 if (rsv->stream != stream)
714 return false;
715
716 switch (rsv->target.type) {
717 case UWB_RSV_TARGET_DEVADDR:
718 return rsv->stream == stream;
719 case UWB_RSV_TARGET_DEV:
720 if (uwb_ie_drp_owner(drp_ie))
721 rsv_src = &rsv->owner->dev_addr;
722 else
723 rsv_src = &rsv->target.dev->dev_addr;
724 return uwb_dev_addr_cmp(&src->dev_addr, rsv_src) == 0;
725 }
726 return false;
727 }
728
uwb_rsv_new_target(struct uwb_rc * rc,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)729 static struct uwb_rsv *uwb_rsv_new_target(struct uwb_rc *rc,
730 struct uwb_dev *src,
731 struct uwb_ie_drp *drp_ie)
732 {
733 struct uwb_rsv *rsv;
734 struct uwb_pal *pal;
735 enum uwb_rsv_state state;
736
737 rsv = uwb_rsv_alloc(rc);
738 if (!rsv)
739 return NULL;
740
741 rsv->rc = rc;
742 rsv->owner = src;
743 uwb_dev_get(rsv->owner);
744 rsv->target.type = UWB_RSV_TARGET_DEV;
745 rsv->target.dev = &rc->uwb_dev;
746 uwb_dev_get(&rc->uwb_dev);
747 rsv->type = uwb_ie_drp_type(drp_ie);
748 rsv->stream = uwb_ie_drp_stream_index(drp_ie);
749 uwb_drp_ie_to_bm(&rsv->mas, drp_ie);
750
751 /*
752 * See if any PALs are interested in this reservation. If not,
753 * deny the request.
754 */
755 rsv->state = UWB_RSV_STATE_T_DENIED;
756 mutex_lock(&rc->uwb_dev.mutex);
757 list_for_each_entry(pal, &rc->pals, node) {
758 if (pal->new_rsv)
759 pal->new_rsv(pal, rsv);
760 if (rsv->state == UWB_RSV_STATE_T_ACCEPTED)
761 break;
762 }
763 mutex_unlock(&rc->uwb_dev.mutex);
764
765 list_add_tail(&rsv->rc_node, &rc->reservations);
766 state = rsv->state;
767 rsv->state = UWB_RSV_STATE_NONE;
768
769 /* FIXME: do something sensible here */
770 if (state == UWB_RSV_STATE_T_ACCEPTED
771 && uwb_drp_avail_reserve_pending(rc, &rsv->mas) == -EBUSY) {
772 /* FIXME: do something sensible here */
773 } else {
774 uwb_rsv_set_state(rsv, state);
775 }
776
777 return rsv;
778 }
779
780 /**
781 * uwb_rsv_get_usable_mas - get the bitmap of the usable MAS of a reservations
782 * @rsv: the reservation.
783 * @mas: returns the available MAS.
784 *
785 * The usable MAS of a reservation may be less than the negotiated MAS
786 * if alien BPs are present.
787 */
uwb_rsv_get_usable_mas(struct uwb_rsv * rsv,struct uwb_mas_bm * mas)788 void uwb_rsv_get_usable_mas(struct uwb_rsv *rsv, struct uwb_mas_bm *mas)
789 {
790 bitmap_zero(mas->bm, UWB_NUM_MAS);
791 bitmap_andnot(mas->bm, rsv->mas.bm, rsv->rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS);
792 }
793 EXPORT_SYMBOL_GPL(uwb_rsv_get_usable_mas);
794
795 /**
796 * uwb_rsv_find - find a reservation for a received DRP IE.
797 * @rc: the radio controller
798 * @src: source of the DRP IE
799 * @drp_ie: the DRP IE
800 *
801 * If the reservation cannot be found and the DRP IE is from a peer
802 * attempting to establish a new reservation, create a new reservation
803 * and add it to the list.
804 */
uwb_rsv_find(struct uwb_rc * rc,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)805 struct uwb_rsv *uwb_rsv_find(struct uwb_rc *rc, struct uwb_dev *src,
806 struct uwb_ie_drp *drp_ie)
807 {
808 struct uwb_rsv *rsv;
809
810 list_for_each_entry(rsv, &rc->reservations, rc_node) {
811 if (uwb_rsv_match(rsv, src, drp_ie))
812 return rsv;
813 }
814
815 if (uwb_ie_drp_owner(drp_ie))
816 return uwb_rsv_new_target(rc, src, drp_ie);
817
818 return NULL;
819 }
820
821 /*
822 * Go through all the reservations and check for timeouts and (if
823 * necessary) update their DRP IEs.
824 *
825 * FIXME: look at building the SET_DRP_IE command here rather than
826 * having to rescan the list in uwb_rc_send_all_drp_ie().
827 */
uwb_rsv_update_all(struct uwb_rc * rc)828 static bool uwb_rsv_update_all(struct uwb_rc *rc)
829 {
830 struct uwb_rsv *rsv, *t;
831 bool ie_updated = false;
832
833 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
834 if (!rsv->ie_valid) {
835 uwb_drp_ie_update(rsv);
836 ie_updated = true;
837 }
838 }
839
840 return ie_updated;
841 }
842
uwb_rsv_queue_update(struct uwb_rc * rc)843 void uwb_rsv_queue_update(struct uwb_rc *rc)
844 {
845 unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
846
847 queue_delayed_work(rc->rsv_workq, &rc->rsv_update_work, usecs_to_jiffies(delay_us));
848 }
849
850 /**
851 * uwb_rsv_sched_update - schedule an update of the DRP IEs
852 * @rc: the radio controller.
853 *
854 * To improve performance and ensure correctness with [ECMA-368] the
855 * number of SET-DRP-IE commands that are done are limited.
856 *
857 * DRP IEs update come from two sources: DRP events from the hardware
858 * which all occur at the beginning of the superframe ('syncronous'
859 * events) and reservation establishment/termination requests from
860 * PALs or timers ('asynchronous' events).
861 *
862 * A delayed work ensures that all the synchronous events result in
863 * one SET-DRP-IE command.
864 *
865 * Additional logic (the set_drp_ie_pending and rsv_updated_postponed
866 * flags) will prevent an asynchrous event starting a SET-DRP-IE
867 * command if one is currently awaiting a response.
868 *
869 * FIXME: this does leave a window where an asynchrous event can delay
870 * the SET-DRP-IE for a synchronous event by one superframe.
871 */
uwb_rsv_sched_update(struct uwb_rc * rc)872 void uwb_rsv_sched_update(struct uwb_rc *rc)
873 {
874 spin_lock_bh(&rc->rsvs_lock);
875 if (!delayed_work_pending(&rc->rsv_update_work)) {
876 if (rc->set_drp_ie_pending > 0) {
877 rc->set_drp_ie_pending++;
878 goto unlock;
879 }
880 uwb_rsv_queue_update(rc);
881 }
882 unlock:
883 spin_unlock_bh(&rc->rsvs_lock);
884 }
885
886 /*
887 * Update DRP IEs and, if necessary, the DRP Availability IE and send
888 * the updated IEs to the radio controller.
889 */
uwb_rsv_update_work(struct work_struct * work)890 static void uwb_rsv_update_work(struct work_struct *work)
891 {
892 struct uwb_rc *rc = container_of(work, struct uwb_rc,
893 rsv_update_work.work);
894 bool ie_updated;
895
896 mutex_lock(&rc->rsvs_mutex);
897
898 ie_updated = uwb_rsv_update_all(rc);
899
900 if (!rc->drp_avail.ie_valid) {
901 uwb_drp_avail_ie_update(rc);
902 ie_updated = true;
903 }
904
905 if (ie_updated && (rc->set_drp_ie_pending == 0))
906 uwb_rc_send_all_drp_ie(rc);
907
908 mutex_unlock(&rc->rsvs_mutex);
909 }
910
uwb_rsv_alien_bp_work(struct work_struct * work)911 static void uwb_rsv_alien_bp_work(struct work_struct *work)
912 {
913 struct uwb_rc *rc = container_of(work, struct uwb_rc,
914 rsv_alien_bp_work.work);
915 struct uwb_rsv *rsv;
916
917 mutex_lock(&rc->rsvs_mutex);
918
919 list_for_each_entry(rsv, &rc->reservations, rc_node) {
920 if (rsv->type != UWB_DRP_TYPE_ALIEN_BP) {
921 rsv->callback(rsv);
922 }
923 }
924
925 mutex_unlock(&rc->rsvs_mutex);
926 }
927
uwb_rsv_timer(unsigned long arg)928 static void uwb_rsv_timer(unsigned long arg)
929 {
930 struct uwb_rsv *rsv = (struct uwb_rsv *)arg;
931
932 queue_work(rsv->rc->rsv_workq, &rsv->handle_timeout_work);
933 }
934
935 /**
936 * uwb_rsv_remove_all - remove all reservations
937 * @rc: the radio controller
938 *
939 * A DRP IE update is not done.
940 */
uwb_rsv_remove_all(struct uwb_rc * rc)941 void uwb_rsv_remove_all(struct uwb_rc *rc)
942 {
943 struct uwb_rsv *rsv, *t;
944
945 mutex_lock(&rc->rsvs_mutex);
946 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
947 if (rsv->state != UWB_RSV_STATE_NONE)
948 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
949 del_timer_sync(&rsv->timer);
950 }
951 /* Cancel any postponed update. */
952 rc->set_drp_ie_pending = 0;
953 mutex_unlock(&rc->rsvs_mutex);
954
955 cancel_delayed_work_sync(&rc->rsv_update_work);
956 flush_workqueue(rc->rsv_workq);
957
958 mutex_lock(&rc->rsvs_mutex);
959 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
960 uwb_rsv_remove(rsv);
961 }
962 mutex_unlock(&rc->rsvs_mutex);
963 }
964
uwb_rsv_init(struct uwb_rc * rc)965 void uwb_rsv_init(struct uwb_rc *rc)
966 {
967 INIT_LIST_HEAD(&rc->reservations);
968 INIT_LIST_HEAD(&rc->cnflt_alien_list);
969 mutex_init(&rc->rsvs_mutex);
970 spin_lock_init(&rc->rsvs_lock);
971 INIT_DELAYED_WORK(&rc->rsv_update_work, uwb_rsv_update_work);
972 INIT_DELAYED_WORK(&rc->rsv_alien_bp_work, uwb_rsv_alien_bp_work);
973 rc->bow.can_reserve_extra_mases = true;
974 rc->bow.total_expired = 0;
975 rc->bow.window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
976 init_timer(&rc->bow.timer);
977 rc->bow.timer.function = uwb_rsv_backoff_win_timer;
978 rc->bow.timer.data = (unsigned long)&rc->bow;
979
980 bitmap_complement(rc->uwb_dev.streams, rc->uwb_dev.streams, UWB_NUM_STREAMS);
981 }
982
uwb_rsv_setup(struct uwb_rc * rc)983 int uwb_rsv_setup(struct uwb_rc *rc)
984 {
985 char name[16];
986
987 snprintf(name, sizeof(name), "%s_rsvd", dev_name(&rc->uwb_dev.dev));
988 rc->rsv_workq = create_singlethread_workqueue(name);
989 if (rc->rsv_workq == NULL)
990 return -ENOMEM;
991
992 return 0;
993 }
994
uwb_rsv_cleanup(struct uwb_rc * rc)995 void uwb_rsv_cleanup(struct uwb_rc *rc)
996 {
997 uwb_rsv_remove_all(rc);
998 destroy_workqueue(rc->rsv_workq);
999 }
1000