1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * UWB reservation management.
4 *
5 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
6 */
7 #include <linux/kernel.h>
8 #include <linux/slab.h>
9 #include <linux/random.h>
10 #include <linux/export.h>
11
12 #include "uwb.h"
13 #include "uwb-internal.h"
14
15 static void uwb_rsv_timer(struct timer_list *t);
16
17 static const char *rsv_states[] = {
18 [UWB_RSV_STATE_NONE] = "none ",
19 [UWB_RSV_STATE_O_INITIATED] = "o initiated ",
20 [UWB_RSV_STATE_O_PENDING] = "o pending ",
21 [UWB_RSV_STATE_O_MODIFIED] = "o modified ",
22 [UWB_RSV_STATE_O_ESTABLISHED] = "o established ",
23 [UWB_RSV_STATE_O_TO_BE_MOVED] = "o to be moved ",
24 [UWB_RSV_STATE_O_MOVE_EXPANDING] = "o move expanding",
25 [UWB_RSV_STATE_O_MOVE_COMBINING] = "o move combining",
26 [UWB_RSV_STATE_O_MOVE_REDUCING] = "o move reducing ",
27 [UWB_RSV_STATE_T_ACCEPTED] = "t accepted ",
28 [UWB_RSV_STATE_T_CONFLICT] = "t conflict ",
29 [UWB_RSV_STATE_T_PENDING] = "t pending ",
30 [UWB_RSV_STATE_T_DENIED] = "t denied ",
31 [UWB_RSV_STATE_T_RESIZED] = "t resized ",
32 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = "t expanding acc ",
33 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = "t expanding conf",
34 [UWB_RSV_STATE_T_EXPANDING_PENDING] = "t expanding pend",
35 [UWB_RSV_STATE_T_EXPANDING_DENIED] = "t expanding den ",
36 };
37
38 static const char *rsv_types[] = {
39 [UWB_DRP_TYPE_ALIEN_BP] = "alien-bp",
40 [UWB_DRP_TYPE_HARD] = "hard",
41 [UWB_DRP_TYPE_SOFT] = "soft",
42 [UWB_DRP_TYPE_PRIVATE] = "private",
43 [UWB_DRP_TYPE_PCA] = "pca",
44 };
45
uwb_rsv_has_two_drp_ies(struct uwb_rsv * rsv)46 bool uwb_rsv_has_two_drp_ies(struct uwb_rsv *rsv)
47 {
48 static const bool has_two_drp_ies[] = {
49 [UWB_RSV_STATE_O_INITIATED] = false,
50 [UWB_RSV_STATE_O_PENDING] = false,
51 [UWB_RSV_STATE_O_MODIFIED] = false,
52 [UWB_RSV_STATE_O_ESTABLISHED] = false,
53 [UWB_RSV_STATE_O_TO_BE_MOVED] = false,
54 [UWB_RSV_STATE_O_MOVE_COMBINING] = false,
55 [UWB_RSV_STATE_O_MOVE_REDUCING] = false,
56 [UWB_RSV_STATE_O_MOVE_EXPANDING] = true,
57 [UWB_RSV_STATE_T_ACCEPTED] = false,
58 [UWB_RSV_STATE_T_CONFLICT] = false,
59 [UWB_RSV_STATE_T_PENDING] = false,
60 [UWB_RSV_STATE_T_DENIED] = false,
61 [UWB_RSV_STATE_T_RESIZED] = false,
62 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = true,
63 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = true,
64 [UWB_RSV_STATE_T_EXPANDING_PENDING] = true,
65 [UWB_RSV_STATE_T_EXPANDING_DENIED] = true,
66 };
67
68 return has_two_drp_ies[rsv->state];
69 }
70
71 /**
72 * uwb_rsv_state_str - return a string for a reservation state
73 * @state: the reservation state.
74 */
uwb_rsv_state_str(enum uwb_rsv_state state)75 const char *uwb_rsv_state_str(enum uwb_rsv_state state)
76 {
77 if (state < UWB_RSV_STATE_NONE || state >= UWB_RSV_STATE_LAST)
78 return "unknown";
79 return rsv_states[state];
80 }
81 EXPORT_SYMBOL_GPL(uwb_rsv_state_str);
82
83 /**
84 * uwb_rsv_type_str - return a string for a reservation type
85 * @type: the reservation type
86 */
uwb_rsv_type_str(enum uwb_drp_type type)87 const char *uwb_rsv_type_str(enum uwb_drp_type type)
88 {
89 if (type < UWB_DRP_TYPE_ALIEN_BP || type > UWB_DRP_TYPE_PCA)
90 return "invalid";
91 return rsv_types[type];
92 }
93 EXPORT_SYMBOL_GPL(uwb_rsv_type_str);
94
uwb_rsv_dump(char * text,struct uwb_rsv * rsv)95 void uwb_rsv_dump(char *text, struct uwb_rsv *rsv)
96 {
97 struct device *dev = &rsv->rc->uwb_dev.dev;
98 struct uwb_dev_addr devaddr;
99 char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE];
100
101 uwb_dev_addr_print(owner, sizeof(owner), &rsv->owner->dev_addr);
102 if (rsv->target.type == UWB_RSV_TARGET_DEV)
103 devaddr = rsv->target.dev->dev_addr;
104 else
105 devaddr = rsv->target.devaddr;
106 uwb_dev_addr_print(target, sizeof(target), &devaddr);
107
108 dev_dbg(dev, "rsv %s %s -> %s: %s\n",
109 text, owner, target, uwb_rsv_state_str(rsv->state));
110 }
111
uwb_rsv_release(struct kref * kref)112 static void uwb_rsv_release(struct kref *kref)
113 {
114 struct uwb_rsv *rsv = container_of(kref, struct uwb_rsv, kref);
115
116 kfree(rsv);
117 }
118
uwb_rsv_get(struct uwb_rsv * rsv)119 void uwb_rsv_get(struct uwb_rsv *rsv)
120 {
121 kref_get(&rsv->kref);
122 }
123
uwb_rsv_put(struct uwb_rsv * rsv)124 void uwb_rsv_put(struct uwb_rsv *rsv)
125 {
126 kref_put(&rsv->kref, uwb_rsv_release);
127 }
128
129 /*
130 * Get a free stream index for a reservation.
131 *
132 * If the target is a DevAddr (e.g., a WUSB cluster reservation) then
133 * the stream is allocated from a pool of per-RC stream indexes,
134 * otherwise a unique stream index for the target is selected.
135 */
uwb_rsv_get_stream(struct uwb_rsv * rsv)136 static int uwb_rsv_get_stream(struct uwb_rsv *rsv)
137 {
138 struct uwb_rc *rc = rsv->rc;
139 struct device *dev = &rc->uwb_dev.dev;
140 unsigned long *streams_bm;
141 int stream;
142
143 switch (rsv->target.type) {
144 case UWB_RSV_TARGET_DEV:
145 streams_bm = rsv->target.dev->streams;
146 break;
147 case UWB_RSV_TARGET_DEVADDR:
148 streams_bm = rc->uwb_dev.streams;
149 break;
150 default:
151 return -EINVAL;
152 }
153
154 stream = find_first_zero_bit(streams_bm, UWB_NUM_STREAMS);
155 if (stream >= UWB_NUM_STREAMS) {
156 dev_err(dev, "%s: no available stream found\n", __func__);
157 return -EBUSY;
158 }
159
160 rsv->stream = stream;
161 set_bit(stream, streams_bm);
162
163 dev_dbg(dev, "get stream %d\n", rsv->stream);
164
165 return 0;
166 }
167
uwb_rsv_put_stream(struct uwb_rsv * rsv)168 static void uwb_rsv_put_stream(struct uwb_rsv *rsv)
169 {
170 struct uwb_rc *rc = rsv->rc;
171 struct device *dev = &rc->uwb_dev.dev;
172 unsigned long *streams_bm;
173
174 switch (rsv->target.type) {
175 case UWB_RSV_TARGET_DEV:
176 streams_bm = rsv->target.dev->streams;
177 break;
178 case UWB_RSV_TARGET_DEVADDR:
179 streams_bm = rc->uwb_dev.streams;
180 break;
181 default:
182 return;
183 }
184
185 clear_bit(rsv->stream, streams_bm);
186
187 dev_dbg(dev, "put stream %d\n", rsv->stream);
188 }
189
uwb_rsv_backoff_win_timer(struct timer_list * t)190 void uwb_rsv_backoff_win_timer(struct timer_list *t)
191 {
192 struct uwb_drp_backoff_win *bow = from_timer(bow, t, timer);
193 struct uwb_rc *rc = container_of(bow, struct uwb_rc, bow);
194 struct device *dev = &rc->uwb_dev.dev;
195
196 bow->can_reserve_extra_mases = true;
197 if (bow->total_expired <= 4) {
198 bow->total_expired++;
199 } else {
200 /* after 4 backoff window has expired we can exit from
201 * the backoff procedure */
202 bow->total_expired = 0;
203 bow->window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
204 }
205 dev_dbg(dev, "backoff_win_timer total_expired=%d, n=%d\n", bow->total_expired, bow->n);
206
207 /* try to relocate all the "to be moved" relocations */
208 uwb_rsv_handle_drp_avail_change(rc);
209 }
210
uwb_rsv_backoff_win_increment(struct uwb_rc * rc)211 void uwb_rsv_backoff_win_increment(struct uwb_rc *rc)
212 {
213 struct uwb_drp_backoff_win *bow = &rc->bow;
214 struct device *dev = &rc->uwb_dev.dev;
215 unsigned timeout_us;
216
217 dev_dbg(dev, "backoff_win_increment: window=%d\n", bow->window);
218
219 bow->can_reserve_extra_mases = false;
220
221 if((bow->window << 1) == UWB_DRP_BACKOFF_WIN_MAX)
222 return;
223
224 bow->window <<= 1;
225 bow->n = prandom_u32() & (bow->window - 1);
226 dev_dbg(dev, "new_window=%d, n=%d\n", bow->window, bow->n);
227
228 /* reset the timer associated variables */
229 timeout_us = bow->n * UWB_SUPERFRAME_LENGTH_US;
230 bow->total_expired = 0;
231 mod_timer(&bow->timer, jiffies + usecs_to_jiffies(timeout_us));
232 }
233
uwb_rsv_stroke_timer(struct uwb_rsv * rsv)234 static void uwb_rsv_stroke_timer(struct uwb_rsv *rsv)
235 {
236 int sframes = UWB_MAX_LOST_BEACONS;
237
238 /*
239 * Multicast reservations can become established within 1
240 * super frame and should not be terminated if no response is
241 * received.
242 */
243 if (rsv->state == UWB_RSV_STATE_NONE) {
244 sframes = 0;
245 } else if (rsv->is_multicast) {
246 if (rsv->state == UWB_RSV_STATE_O_INITIATED
247 || rsv->state == UWB_RSV_STATE_O_MOVE_EXPANDING
248 || rsv->state == UWB_RSV_STATE_O_MOVE_COMBINING
249 || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING)
250 sframes = 1;
251 if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED)
252 sframes = 0;
253
254 }
255
256 if (sframes > 0) {
257 /*
258 * Add an additional 2 superframes to account for the
259 * time to send the SET DRP IE command.
260 */
261 unsigned timeout_us = (sframes + 2) * UWB_SUPERFRAME_LENGTH_US;
262 mod_timer(&rsv->timer, jiffies + usecs_to_jiffies(timeout_us));
263 } else
264 del_timer(&rsv->timer);
265 }
266
267 /*
268 * Update a reservations state, and schedule an update of the
269 * transmitted DRP IEs.
270 */
uwb_rsv_state_update(struct uwb_rsv * rsv,enum uwb_rsv_state new_state)271 static void uwb_rsv_state_update(struct uwb_rsv *rsv,
272 enum uwb_rsv_state new_state)
273 {
274 rsv->state = new_state;
275 rsv->ie_valid = false;
276
277 uwb_rsv_dump("SU", rsv);
278
279 uwb_rsv_stroke_timer(rsv);
280 uwb_rsv_sched_update(rsv->rc);
281 }
282
uwb_rsv_callback(struct uwb_rsv * rsv)283 static void uwb_rsv_callback(struct uwb_rsv *rsv)
284 {
285 if (rsv->callback)
286 rsv->callback(rsv);
287 }
288
uwb_rsv_set_state(struct uwb_rsv * rsv,enum uwb_rsv_state new_state)289 void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state)
290 {
291 struct uwb_rsv_move *mv = &rsv->mv;
292
293 if (rsv->state == new_state) {
294 switch (rsv->state) {
295 case UWB_RSV_STATE_O_ESTABLISHED:
296 case UWB_RSV_STATE_O_MOVE_EXPANDING:
297 case UWB_RSV_STATE_O_MOVE_COMBINING:
298 case UWB_RSV_STATE_O_MOVE_REDUCING:
299 case UWB_RSV_STATE_T_ACCEPTED:
300 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
301 case UWB_RSV_STATE_T_RESIZED:
302 case UWB_RSV_STATE_NONE:
303 uwb_rsv_stroke_timer(rsv);
304 break;
305 default:
306 /* Expecting a state transition so leave timer
307 as-is. */
308 break;
309 }
310 return;
311 }
312
313 uwb_rsv_dump("SC", rsv);
314
315 switch (new_state) {
316 case UWB_RSV_STATE_NONE:
317 uwb_rsv_state_update(rsv, UWB_RSV_STATE_NONE);
318 uwb_rsv_remove(rsv);
319 uwb_rsv_callback(rsv);
320 break;
321 case UWB_RSV_STATE_O_INITIATED:
322 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_INITIATED);
323 break;
324 case UWB_RSV_STATE_O_PENDING:
325 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_PENDING);
326 break;
327 case UWB_RSV_STATE_O_MODIFIED:
328 /* in the companion there are the MASes to drop */
329 bitmap_andnot(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
330 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MODIFIED);
331 break;
332 case UWB_RSV_STATE_O_ESTABLISHED:
333 if (rsv->state == UWB_RSV_STATE_O_MODIFIED
334 || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING) {
335 uwb_drp_avail_release(rsv->rc, &mv->companion_mas);
336 rsv->needs_release_companion_mas = false;
337 }
338 uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
339 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_ESTABLISHED);
340 uwb_rsv_callback(rsv);
341 break;
342 case UWB_RSV_STATE_O_MOVE_EXPANDING:
343 rsv->needs_release_companion_mas = true;
344 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
345 break;
346 case UWB_RSV_STATE_O_MOVE_COMBINING:
347 rsv->needs_release_companion_mas = false;
348 uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
349 bitmap_or(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
350 rsv->mas.safe += mv->companion_mas.safe;
351 rsv->mas.unsafe += mv->companion_mas.unsafe;
352 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
353 break;
354 case UWB_RSV_STATE_O_MOVE_REDUCING:
355 bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
356 rsv->needs_release_companion_mas = true;
357 rsv->mas.safe = mv->final_mas.safe;
358 rsv->mas.unsafe = mv->final_mas.unsafe;
359 bitmap_copy(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
360 bitmap_copy(rsv->mas.unsafe_bm, mv->final_mas.unsafe_bm, UWB_NUM_MAS);
361 uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
362 break;
363 case UWB_RSV_STATE_T_ACCEPTED:
364 case UWB_RSV_STATE_T_RESIZED:
365 rsv->needs_release_companion_mas = false;
366 uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
367 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_ACCEPTED);
368 uwb_rsv_callback(rsv);
369 break;
370 case UWB_RSV_STATE_T_DENIED:
371 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_DENIED);
372 break;
373 case UWB_RSV_STATE_T_CONFLICT:
374 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_CONFLICT);
375 break;
376 case UWB_RSV_STATE_T_PENDING:
377 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_PENDING);
378 break;
379 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
380 rsv->needs_release_companion_mas = true;
381 uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
382 uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
383 break;
384 default:
385 dev_err(&rsv->rc->uwb_dev.dev, "unhandled state: %s (%d)\n",
386 uwb_rsv_state_str(new_state), new_state);
387 }
388 }
389
uwb_rsv_handle_timeout_work(struct work_struct * work)390 static void uwb_rsv_handle_timeout_work(struct work_struct *work)
391 {
392 struct uwb_rsv *rsv = container_of(work, struct uwb_rsv,
393 handle_timeout_work);
394 struct uwb_rc *rc = rsv->rc;
395
396 mutex_lock(&rc->rsvs_mutex);
397
398 uwb_rsv_dump("TO", rsv);
399
400 switch (rsv->state) {
401 case UWB_RSV_STATE_O_INITIATED:
402 if (rsv->is_multicast) {
403 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
404 goto unlock;
405 }
406 break;
407 case UWB_RSV_STATE_O_MOVE_EXPANDING:
408 if (rsv->is_multicast) {
409 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
410 goto unlock;
411 }
412 break;
413 case UWB_RSV_STATE_O_MOVE_COMBINING:
414 if (rsv->is_multicast) {
415 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
416 goto unlock;
417 }
418 break;
419 case UWB_RSV_STATE_O_MOVE_REDUCING:
420 if (rsv->is_multicast) {
421 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
422 goto unlock;
423 }
424 break;
425 case UWB_RSV_STATE_O_ESTABLISHED:
426 if (rsv->is_multicast)
427 goto unlock;
428 break;
429 case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
430 /*
431 * The time out could be for the main or of the
432 * companion DRP, assume it's for the companion and
433 * drop that first. A further time out is required to
434 * drop the main.
435 */
436 uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
437 uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
438 goto unlock;
439 case UWB_RSV_STATE_NONE:
440 goto unlock;
441 default:
442 break;
443 }
444
445 uwb_rsv_remove(rsv);
446
447 unlock:
448 mutex_unlock(&rc->rsvs_mutex);
449 }
450
uwb_rsv_alloc(struct uwb_rc * rc)451 static struct uwb_rsv *uwb_rsv_alloc(struct uwb_rc *rc)
452 {
453 struct uwb_rsv *rsv;
454
455 rsv = kzalloc(sizeof(struct uwb_rsv), GFP_KERNEL);
456 if (!rsv)
457 return NULL;
458
459 INIT_LIST_HEAD(&rsv->rc_node);
460 INIT_LIST_HEAD(&rsv->pal_node);
461 kref_init(&rsv->kref);
462 timer_setup(&rsv->timer, uwb_rsv_timer, 0);
463
464 rsv->rc = rc;
465 INIT_WORK(&rsv->handle_timeout_work, uwb_rsv_handle_timeout_work);
466
467 return rsv;
468 }
469
470 /**
471 * uwb_rsv_create - allocate and initialize a UWB reservation structure
472 * @rc: the radio controller
473 * @cb: callback to use when the reservation completes or terminates
474 * @pal_priv: data private to the PAL to be passed in the callback
475 *
476 * The callback is called when the state of the reservation changes from:
477 *
478 * - pending to accepted
479 * - pending to denined
480 * - accepted to terminated
481 * - pending to terminated
482 */
uwb_rsv_create(struct uwb_rc * rc,uwb_rsv_cb_f cb,void * pal_priv)483 struct uwb_rsv *uwb_rsv_create(struct uwb_rc *rc, uwb_rsv_cb_f cb, void *pal_priv)
484 {
485 struct uwb_rsv *rsv;
486
487 rsv = uwb_rsv_alloc(rc);
488 if (!rsv)
489 return NULL;
490
491 rsv->callback = cb;
492 rsv->pal_priv = pal_priv;
493
494 return rsv;
495 }
496 EXPORT_SYMBOL_GPL(uwb_rsv_create);
497
uwb_rsv_remove(struct uwb_rsv * rsv)498 void uwb_rsv_remove(struct uwb_rsv *rsv)
499 {
500 uwb_rsv_dump("RM", rsv);
501
502 if (rsv->state != UWB_RSV_STATE_NONE)
503 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
504
505 if (rsv->needs_release_companion_mas)
506 uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
507 uwb_drp_avail_release(rsv->rc, &rsv->mas);
508
509 if (uwb_rsv_is_owner(rsv))
510 uwb_rsv_put_stream(rsv);
511
512 uwb_dev_put(rsv->owner);
513 if (rsv->target.type == UWB_RSV_TARGET_DEV)
514 uwb_dev_put(rsv->target.dev);
515
516 list_del_init(&rsv->rc_node);
517 uwb_rsv_put(rsv);
518 }
519
520 /**
521 * uwb_rsv_destroy - free a UWB reservation structure
522 * @rsv: the reservation to free
523 *
524 * The reservation must already be terminated.
525 */
uwb_rsv_destroy(struct uwb_rsv * rsv)526 void uwb_rsv_destroy(struct uwb_rsv *rsv)
527 {
528 uwb_rsv_put(rsv);
529 }
530 EXPORT_SYMBOL_GPL(uwb_rsv_destroy);
531
532 /**
533 * usb_rsv_establish - start a reservation establishment
534 * @rsv: the reservation
535 *
536 * The PAL should fill in @rsv's owner, target, type, max_mas,
537 * min_mas, max_interval and is_multicast fields. If the target is a
538 * uwb_dev it must be referenced.
539 *
540 * The reservation's callback will be called when the reservation is
541 * accepted, denied or times out.
542 */
uwb_rsv_establish(struct uwb_rsv * rsv)543 int uwb_rsv_establish(struct uwb_rsv *rsv)
544 {
545 struct uwb_rc *rc = rsv->rc;
546 struct uwb_mas_bm available;
547 struct device *dev = &rc->uwb_dev.dev;
548 int ret;
549
550 mutex_lock(&rc->rsvs_mutex);
551 ret = uwb_rsv_get_stream(rsv);
552 if (ret) {
553 dev_err(dev, "%s: uwb_rsv_get_stream failed: %d\n",
554 __func__, ret);
555 goto out;
556 }
557
558 rsv->tiebreaker = prandom_u32() & 1;
559 /* get available mas bitmap */
560 uwb_drp_available(rc, &available);
561
562 ret = uwb_rsv_find_best_allocation(rsv, &available, &rsv->mas);
563 if (ret == UWB_RSV_ALLOC_NOT_FOUND) {
564 ret = -EBUSY;
565 uwb_rsv_put_stream(rsv);
566 dev_err(dev, "%s: uwb_rsv_find_best_allocation failed: %d\n",
567 __func__, ret);
568 goto out;
569 }
570
571 ret = uwb_drp_avail_reserve_pending(rc, &rsv->mas);
572 if (ret != 0) {
573 uwb_rsv_put_stream(rsv);
574 dev_err(dev, "%s: uwb_drp_avail_reserve_pending failed: %d\n",
575 __func__, ret);
576 goto out;
577 }
578
579 uwb_rsv_get(rsv);
580 list_add_tail(&rsv->rc_node, &rc->reservations);
581 rsv->owner = &rc->uwb_dev;
582 uwb_dev_get(rsv->owner);
583 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_INITIATED);
584 out:
585 mutex_unlock(&rc->rsvs_mutex);
586 return ret;
587 }
588 EXPORT_SYMBOL_GPL(uwb_rsv_establish);
589
590 /**
591 * uwb_rsv_modify - modify an already established reservation
592 * @rsv: the reservation to modify
593 * @max_mas: new maximum MAS to reserve
594 * @min_mas: new minimum MAS to reserve
595 * @max_interval: new max_interval to use
596 *
597 * FIXME: implement this once there are PALs that use it.
598 */
uwb_rsv_modify(struct uwb_rsv * rsv,int max_mas,int min_mas,int max_interval)599 int uwb_rsv_modify(struct uwb_rsv *rsv, int max_mas, int min_mas, int max_interval)
600 {
601 return -ENOSYS;
602 }
603 EXPORT_SYMBOL_GPL(uwb_rsv_modify);
604
605 /*
606 * move an already established reservation (rc->rsvs_mutex must to be
607 * taken when tis function is called)
608 */
uwb_rsv_try_move(struct uwb_rsv * rsv,struct uwb_mas_bm * available)609 int uwb_rsv_try_move(struct uwb_rsv *rsv, struct uwb_mas_bm *available)
610 {
611 struct uwb_rc *rc = rsv->rc;
612 struct uwb_drp_backoff_win *bow = &rc->bow;
613 struct device *dev = &rc->uwb_dev.dev;
614 struct uwb_rsv_move *mv;
615 int ret = 0;
616
617 if (bow->can_reserve_extra_mases == false)
618 return -EBUSY;
619
620 mv = &rsv->mv;
621
622 if (uwb_rsv_find_best_allocation(rsv, available, &mv->final_mas) == UWB_RSV_ALLOC_FOUND) {
623
624 if (!bitmap_equal(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS)) {
625 /* We want to move the reservation */
626 bitmap_andnot(mv->companion_mas.bm, mv->final_mas.bm, rsv->mas.bm, UWB_NUM_MAS);
627 uwb_drp_avail_reserve_pending(rc, &mv->companion_mas);
628 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
629 }
630 } else {
631 dev_dbg(dev, "new allocation not found\n");
632 }
633
634 return ret;
635 }
636
637 /* It will try to move every reservation in state O_ESTABLISHED giving
638 * to the MAS allocator algorithm an availability that is the real one
639 * plus the allocation already established from the reservation. */
uwb_rsv_handle_drp_avail_change(struct uwb_rc * rc)640 void uwb_rsv_handle_drp_avail_change(struct uwb_rc *rc)
641 {
642 struct uwb_drp_backoff_win *bow = &rc->bow;
643 struct uwb_rsv *rsv;
644 struct uwb_mas_bm mas;
645
646 if (bow->can_reserve_extra_mases == false)
647 return;
648
649 list_for_each_entry(rsv, &rc->reservations, rc_node) {
650 if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED ||
651 rsv->state == UWB_RSV_STATE_O_TO_BE_MOVED) {
652 uwb_drp_available(rc, &mas);
653 bitmap_or(mas.bm, mas.bm, rsv->mas.bm, UWB_NUM_MAS);
654 uwb_rsv_try_move(rsv, &mas);
655 }
656 }
657
658 }
659
660 /**
661 * uwb_rsv_terminate - terminate an established reservation
662 * @rsv: the reservation to terminate
663 *
664 * A reservation is terminated by removing the DRP IE from the beacon,
665 * the other end will consider the reservation to be terminated when
666 * it does not see the DRP IE for at least mMaxLostBeacons.
667 *
668 * If applicable, the reference to the target uwb_dev will be released.
669 */
uwb_rsv_terminate(struct uwb_rsv * rsv)670 void uwb_rsv_terminate(struct uwb_rsv *rsv)
671 {
672 struct uwb_rc *rc = rsv->rc;
673
674 mutex_lock(&rc->rsvs_mutex);
675
676 if (rsv->state != UWB_RSV_STATE_NONE)
677 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
678
679 mutex_unlock(&rc->rsvs_mutex);
680 }
681 EXPORT_SYMBOL_GPL(uwb_rsv_terminate);
682
683 /**
684 * uwb_rsv_accept - accept a new reservation from a peer
685 * @rsv: the reservation
686 * @cb: call back for reservation changes
687 * @pal_priv: data to be passed in the above call back
688 *
689 * Reservation requests from peers are denied unless a PAL accepts it
690 * by calling this function.
691 *
692 * The PAL call uwb_rsv_destroy() for all accepted reservations before
693 * calling uwb_pal_unregister().
694 */
uwb_rsv_accept(struct uwb_rsv * rsv,uwb_rsv_cb_f cb,void * pal_priv)695 void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv)
696 {
697 uwb_rsv_get(rsv);
698
699 rsv->callback = cb;
700 rsv->pal_priv = pal_priv;
701 rsv->state = UWB_RSV_STATE_T_ACCEPTED;
702 }
703 EXPORT_SYMBOL_GPL(uwb_rsv_accept);
704
705 /*
706 * Is a received DRP IE for this reservation?
707 */
uwb_rsv_match(struct uwb_rsv * rsv,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)708 static bool uwb_rsv_match(struct uwb_rsv *rsv, struct uwb_dev *src,
709 struct uwb_ie_drp *drp_ie)
710 {
711 struct uwb_dev_addr *rsv_src;
712 int stream;
713
714 stream = uwb_ie_drp_stream_index(drp_ie);
715
716 if (rsv->stream != stream)
717 return false;
718
719 switch (rsv->target.type) {
720 case UWB_RSV_TARGET_DEVADDR:
721 return rsv->stream == stream;
722 case UWB_RSV_TARGET_DEV:
723 if (uwb_ie_drp_owner(drp_ie))
724 rsv_src = &rsv->owner->dev_addr;
725 else
726 rsv_src = &rsv->target.dev->dev_addr;
727 return uwb_dev_addr_cmp(&src->dev_addr, rsv_src) == 0;
728 }
729 return false;
730 }
731
uwb_rsv_new_target(struct uwb_rc * rc,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)732 static struct uwb_rsv *uwb_rsv_new_target(struct uwb_rc *rc,
733 struct uwb_dev *src,
734 struct uwb_ie_drp *drp_ie)
735 {
736 struct uwb_rsv *rsv;
737 struct uwb_pal *pal;
738 enum uwb_rsv_state state;
739
740 rsv = uwb_rsv_alloc(rc);
741 if (!rsv)
742 return NULL;
743
744 rsv->rc = rc;
745 rsv->owner = src;
746 uwb_dev_get(rsv->owner);
747 rsv->target.type = UWB_RSV_TARGET_DEV;
748 rsv->target.dev = &rc->uwb_dev;
749 uwb_dev_get(&rc->uwb_dev);
750 rsv->type = uwb_ie_drp_type(drp_ie);
751 rsv->stream = uwb_ie_drp_stream_index(drp_ie);
752 uwb_drp_ie_to_bm(&rsv->mas, drp_ie);
753
754 /*
755 * See if any PALs are interested in this reservation. If not,
756 * deny the request.
757 */
758 rsv->state = UWB_RSV_STATE_T_DENIED;
759 mutex_lock(&rc->uwb_dev.mutex);
760 list_for_each_entry(pal, &rc->pals, node) {
761 if (pal->new_rsv)
762 pal->new_rsv(pal, rsv);
763 if (rsv->state == UWB_RSV_STATE_T_ACCEPTED)
764 break;
765 }
766 mutex_unlock(&rc->uwb_dev.mutex);
767
768 list_add_tail(&rsv->rc_node, &rc->reservations);
769 state = rsv->state;
770 rsv->state = UWB_RSV_STATE_NONE;
771
772 /* FIXME: do something sensible here */
773 if (state == UWB_RSV_STATE_T_ACCEPTED
774 && uwb_drp_avail_reserve_pending(rc, &rsv->mas) == -EBUSY) {
775 /* FIXME: do something sensible here */
776 } else {
777 uwb_rsv_set_state(rsv, state);
778 }
779
780 return rsv;
781 }
782
783 /**
784 * uwb_rsv_get_usable_mas - get the bitmap of the usable MAS of a reservations
785 * @rsv: the reservation.
786 * @mas: returns the available MAS.
787 *
788 * The usable MAS of a reservation may be less than the negotiated MAS
789 * if alien BPs are present.
790 */
uwb_rsv_get_usable_mas(struct uwb_rsv * rsv,struct uwb_mas_bm * mas)791 void uwb_rsv_get_usable_mas(struct uwb_rsv *rsv, struct uwb_mas_bm *mas)
792 {
793 bitmap_zero(mas->bm, UWB_NUM_MAS);
794 bitmap_andnot(mas->bm, rsv->mas.bm, rsv->rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS);
795 }
796 EXPORT_SYMBOL_GPL(uwb_rsv_get_usable_mas);
797
798 /**
799 * uwb_rsv_find - find a reservation for a received DRP IE.
800 * @rc: the radio controller
801 * @src: source of the DRP IE
802 * @drp_ie: the DRP IE
803 *
804 * If the reservation cannot be found and the DRP IE is from a peer
805 * attempting to establish a new reservation, create a new reservation
806 * and add it to the list.
807 */
uwb_rsv_find(struct uwb_rc * rc,struct uwb_dev * src,struct uwb_ie_drp * drp_ie)808 struct uwb_rsv *uwb_rsv_find(struct uwb_rc *rc, struct uwb_dev *src,
809 struct uwb_ie_drp *drp_ie)
810 {
811 struct uwb_rsv *rsv;
812
813 list_for_each_entry(rsv, &rc->reservations, rc_node) {
814 if (uwb_rsv_match(rsv, src, drp_ie))
815 return rsv;
816 }
817
818 if (uwb_ie_drp_owner(drp_ie))
819 return uwb_rsv_new_target(rc, src, drp_ie);
820
821 return NULL;
822 }
823
824 /*
825 * Go through all the reservations and check for timeouts and (if
826 * necessary) update their DRP IEs.
827 *
828 * FIXME: look at building the SET_DRP_IE command here rather than
829 * having to rescan the list in uwb_rc_send_all_drp_ie().
830 */
uwb_rsv_update_all(struct uwb_rc * rc)831 static bool uwb_rsv_update_all(struct uwb_rc *rc)
832 {
833 struct uwb_rsv *rsv, *t;
834 bool ie_updated = false;
835
836 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
837 if (!rsv->ie_valid) {
838 uwb_drp_ie_update(rsv);
839 ie_updated = true;
840 }
841 }
842
843 return ie_updated;
844 }
845
uwb_rsv_queue_update(struct uwb_rc * rc)846 void uwb_rsv_queue_update(struct uwb_rc *rc)
847 {
848 unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
849
850 queue_delayed_work(rc->rsv_workq, &rc->rsv_update_work, usecs_to_jiffies(delay_us));
851 }
852
853 /**
854 * uwb_rsv_sched_update - schedule an update of the DRP IEs
855 * @rc: the radio controller.
856 *
857 * To improve performance and ensure correctness with [ECMA-368] the
858 * number of SET-DRP-IE commands that are done are limited.
859 *
860 * DRP IEs update come from two sources: DRP events from the hardware
861 * which all occur at the beginning of the superframe ('syncronous'
862 * events) and reservation establishment/termination requests from
863 * PALs or timers ('asynchronous' events).
864 *
865 * A delayed work ensures that all the synchronous events result in
866 * one SET-DRP-IE command.
867 *
868 * Additional logic (the set_drp_ie_pending and rsv_updated_postponed
869 * flags) will prevent an asynchrous event starting a SET-DRP-IE
870 * command if one is currently awaiting a response.
871 *
872 * FIXME: this does leave a window where an asynchrous event can delay
873 * the SET-DRP-IE for a synchronous event by one superframe.
874 */
uwb_rsv_sched_update(struct uwb_rc * rc)875 void uwb_rsv_sched_update(struct uwb_rc *rc)
876 {
877 spin_lock_irq(&rc->rsvs_lock);
878 if (!delayed_work_pending(&rc->rsv_update_work)) {
879 if (rc->set_drp_ie_pending > 0) {
880 rc->set_drp_ie_pending++;
881 goto unlock;
882 }
883 uwb_rsv_queue_update(rc);
884 }
885 unlock:
886 spin_unlock_irq(&rc->rsvs_lock);
887 }
888
889 /*
890 * Update DRP IEs and, if necessary, the DRP Availability IE and send
891 * the updated IEs to the radio controller.
892 */
uwb_rsv_update_work(struct work_struct * work)893 static void uwb_rsv_update_work(struct work_struct *work)
894 {
895 struct uwb_rc *rc = container_of(work, struct uwb_rc,
896 rsv_update_work.work);
897 bool ie_updated;
898
899 mutex_lock(&rc->rsvs_mutex);
900
901 ie_updated = uwb_rsv_update_all(rc);
902
903 if (!rc->drp_avail.ie_valid) {
904 uwb_drp_avail_ie_update(rc);
905 ie_updated = true;
906 }
907
908 if (ie_updated && (rc->set_drp_ie_pending == 0))
909 uwb_rc_send_all_drp_ie(rc);
910
911 mutex_unlock(&rc->rsvs_mutex);
912 }
913
uwb_rsv_alien_bp_work(struct work_struct * work)914 static void uwb_rsv_alien_bp_work(struct work_struct *work)
915 {
916 struct uwb_rc *rc = container_of(work, struct uwb_rc,
917 rsv_alien_bp_work.work);
918 struct uwb_rsv *rsv;
919
920 mutex_lock(&rc->rsvs_mutex);
921
922 list_for_each_entry(rsv, &rc->reservations, rc_node) {
923 if (rsv->type != UWB_DRP_TYPE_ALIEN_BP) {
924 uwb_rsv_callback(rsv);
925 }
926 }
927
928 mutex_unlock(&rc->rsvs_mutex);
929 }
930
uwb_rsv_timer(struct timer_list * t)931 static void uwb_rsv_timer(struct timer_list *t)
932 {
933 struct uwb_rsv *rsv = from_timer(rsv, t, timer);
934
935 queue_work(rsv->rc->rsv_workq, &rsv->handle_timeout_work);
936 }
937
938 /**
939 * uwb_rsv_remove_all - remove all reservations
940 * @rc: the radio controller
941 *
942 * A DRP IE update is not done.
943 */
uwb_rsv_remove_all(struct uwb_rc * rc)944 void uwb_rsv_remove_all(struct uwb_rc *rc)
945 {
946 struct uwb_rsv *rsv, *t;
947
948 mutex_lock(&rc->rsvs_mutex);
949 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
950 if (rsv->state != UWB_RSV_STATE_NONE)
951 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
952 del_timer_sync(&rsv->timer);
953 }
954 /* Cancel any postponed update. */
955 rc->set_drp_ie_pending = 0;
956 mutex_unlock(&rc->rsvs_mutex);
957
958 cancel_delayed_work_sync(&rc->rsv_update_work);
959 flush_workqueue(rc->rsv_workq);
960
961 mutex_lock(&rc->rsvs_mutex);
962 list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
963 uwb_rsv_remove(rsv);
964 }
965 mutex_unlock(&rc->rsvs_mutex);
966 }
967
uwb_rsv_init(struct uwb_rc * rc)968 void uwb_rsv_init(struct uwb_rc *rc)
969 {
970 INIT_LIST_HEAD(&rc->reservations);
971 INIT_LIST_HEAD(&rc->cnflt_alien_list);
972 mutex_init(&rc->rsvs_mutex);
973 spin_lock_init(&rc->rsvs_lock);
974 INIT_DELAYED_WORK(&rc->rsv_update_work, uwb_rsv_update_work);
975 INIT_DELAYED_WORK(&rc->rsv_alien_bp_work, uwb_rsv_alien_bp_work);
976 rc->bow.can_reserve_extra_mases = true;
977 rc->bow.total_expired = 0;
978 rc->bow.window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
979 timer_setup(&rc->bow.timer, uwb_rsv_backoff_win_timer, 0);
980
981 bitmap_complement(rc->uwb_dev.streams, rc->uwb_dev.streams, UWB_NUM_STREAMS);
982 }
983
uwb_rsv_setup(struct uwb_rc * rc)984 int uwb_rsv_setup(struct uwb_rc *rc)
985 {
986 char name[16];
987
988 snprintf(name, sizeof(name), "%s_rsvd", dev_name(&rc->uwb_dev.dev));
989 rc->rsv_workq = create_singlethread_workqueue(name);
990 if (rc->rsv_workq == NULL)
991 return -ENOMEM;
992
993 return 0;
994 }
995
uwb_rsv_cleanup(struct uwb_rc * rc)996 void uwb_rsv_cleanup(struct uwb_rc *rc)
997 {
998 uwb_rsv_remove_all(rc);
999 destroy_workqueue(rc->rsv_workq);
1000 }
1001
