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regulator: lp3971: Do not hardcode return value
[linux-2.6/btrfs-unstable.git] / net / wireless / chan.c
blob78559b5bbd1fe1d98c533f18dd1cc4fce4087baa
1 /*
2 * This file contains helper code to handle channel
3 * settings and keeping track of what is possible at
4 * any point in time.
5 *
6 * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
7 */
8
9 #include <linux/export.h>
10 #include <net/cfg80211.h>
11 #include "core.h"
12 #include "rdev-ops.h"
13
14 void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
15 struct ieee80211_channel *chan,
16 enum nl80211_channel_type chan_type)
17 {
18 if (WARN_ON(!chan))
19 return;
20
21 chandef->chan = chan;
22 chandef->center_freq2 = 0;
23
24 switch (chan_type) {
25 case NL80211_CHAN_NO_HT:
26 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
27 chandef->center_freq1 = chan->center_freq;
28 break;
29 case NL80211_CHAN_HT20:
30 chandef->width = NL80211_CHAN_WIDTH_20;
31 chandef->center_freq1 = chan->center_freq;
32 break;
33 case NL80211_CHAN_HT40PLUS:
34 chandef->width = NL80211_CHAN_WIDTH_40;
35 chandef->center_freq1 = chan->center_freq + 10;
36 break;
37 case NL80211_CHAN_HT40MINUS:
38 chandef->width = NL80211_CHAN_WIDTH_40;
39 chandef->center_freq1 = chan->center_freq - 10;
40 break;
41 default:
42 WARN_ON(1);
43 }
44 }
45 EXPORT_SYMBOL(cfg80211_chandef_create);
46
47 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
48 {
49 u32 control_freq;
50
51 if (!chandef->chan)
52 return false;
53
54 control_freq = chandef->chan->center_freq;
55
56 switch (chandef->width) {
57 case NL80211_CHAN_WIDTH_5:
58 case NL80211_CHAN_WIDTH_10:
59 case NL80211_CHAN_WIDTH_20:
60 case NL80211_CHAN_WIDTH_20_NOHT:
61 if (chandef->center_freq1 != control_freq)
62 return false;
63 if (chandef->center_freq2)
64 return false;
65 break;
66 case NL80211_CHAN_WIDTH_40:
67 if (chandef->center_freq1 != control_freq + 10 &&
68 chandef->center_freq1 != control_freq - 10)
69 return false;
70 if (chandef->center_freq2)
71 return false;
72 break;
73 case NL80211_CHAN_WIDTH_80P80:
74 if (chandef->center_freq1 != control_freq + 30 &&
75 chandef->center_freq1 != control_freq + 10 &&
76 chandef->center_freq1 != control_freq - 10 &&
77 chandef->center_freq1 != control_freq - 30)
78 return false;
79 if (!chandef->center_freq2)
80 return false;
81 /* adjacent is not allowed -- that's a 160 MHz channel */
82 if (chandef->center_freq1 - chandef->center_freq2 == 80 ||
83 chandef->center_freq2 - chandef->center_freq1 == 80)
84 return false;
85 break;
86 case NL80211_CHAN_WIDTH_80:
87 if (chandef->center_freq1 != control_freq + 30 &&
88 chandef->center_freq1 != control_freq + 10 &&
89 chandef->center_freq1 != control_freq - 10 &&
90 chandef->center_freq1 != control_freq - 30)
91 return false;
92 if (chandef->center_freq2)
93 return false;
94 break;
95 case NL80211_CHAN_WIDTH_160:
96 if (chandef->center_freq1 != control_freq + 70 &&
97 chandef->center_freq1 != control_freq + 50 &&
98 chandef->center_freq1 != control_freq + 30 &&
99 chandef->center_freq1 != control_freq + 10 &&
100 chandef->center_freq1 != control_freq - 10 &&
101 chandef->center_freq1 != control_freq - 30 &&
102 chandef->center_freq1 != control_freq - 50 &&
103 chandef->center_freq1 != control_freq - 70)
104 return false;
105 if (chandef->center_freq2)
106 return false;
107 break;
108 default:
109 return false;
110 }
111
112 return true;
113 }
114 EXPORT_SYMBOL(cfg80211_chandef_valid);
115
116 static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
117 int *pri40, int *pri80)
118 {
119 int tmp;
120
121 switch (c->width) {
122 case NL80211_CHAN_WIDTH_40:
123 *pri40 = c->center_freq1;
124 *pri80 = 0;
125 break;
126 case NL80211_CHAN_WIDTH_80:
127 case NL80211_CHAN_WIDTH_80P80:
128 *pri80 = c->center_freq1;
129 /* n_P20 */
130 tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
131 /* n_P40 */
132 tmp /= 2;
133 /* freq_P40 */
134 *pri40 = c->center_freq1 - 20 + 40 * tmp;
135 break;
136 case NL80211_CHAN_WIDTH_160:
137 /* n_P20 */
138 tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
139 /* n_P40 */
140 tmp /= 2;
141 /* freq_P40 */
142 *pri40 = c->center_freq1 - 60 + 40 * tmp;
143 /* n_P80 */
144 tmp /= 2;
145 *pri80 = c->center_freq1 - 40 + 80 * tmp;
146 break;
147 default:
148 WARN_ON_ONCE(1);
149 }
150 }
151
152 static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
153 {
154 int width;
155
156 switch (c->width) {
157 case NL80211_CHAN_WIDTH_5:
158 width = 5;
159 break;
160 case NL80211_CHAN_WIDTH_10:
161 width = 10;
162 break;
163 case NL80211_CHAN_WIDTH_20:
164 case NL80211_CHAN_WIDTH_20_NOHT:
165 width = 20;
166 break;
167 case NL80211_CHAN_WIDTH_40:
168 width = 40;
169 break;
170 case NL80211_CHAN_WIDTH_80P80:
171 case NL80211_CHAN_WIDTH_80:
172 width = 80;
173 break;
174 case NL80211_CHAN_WIDTH_160:
175 width = 160;
176 break;
177 default:
178 WARN_ON_ONCE(1);
179 return -1;
180 }
181 return width;
182 }
183
184 const struct cfg80211_chan_def *
185 cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
186 const struct cfg80211_chan_def *c2)
187 {
188 u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80;
189
190 /* If they are identical, return */
191 if (cfg80211_chandef_identical(c1, c2))
192 return c1;
193
194 /* otherwise, must have same control channel */
195 if (c1->chan != c2->chan)
196 return NULL;
197
198 /*
199 * If they have the same width, but aren't identical,
200 * then they can't be compatible.
201 */
202 if (c1->width == c2->width)
203 return NULL;
204
205 /*
206 * can't be compatible if one of them is 5 or 10 MHz,
207 * but they don't have the same width.
208 */
209 if (c1->width == NL80211_CHAN_WIDTH_5 ||
210 c1->width == NL80211_CHAN_WIDTH_10 ||
211 c2->width == NL80211_CHAN_WIDTH_5 ||
212 c2->width == NL80211_CHAN_WIDTH_10)
213 return NULL;
214
215 if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
216 c1->width == NL80211_CHAN_WIDTH_20)
217 return c2;
218
219 if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
220 c2->width == NL80211_CHAN_WIDTH_20)
221 return c1;
222
223 chandef_primary_freqs(c1, &c1_pri40, &c1_pri80);
224 chandef_primary_freqs(c2, &c2_pri40, &c2_pri80);
225
226 if (c1_pri40 != c2_pri40)
227 return NULL;
228
229 WARN_ON(!c1_pri80 && !c2_pri80);
230 if (c1_pri80 && c2_pri80 && c1_pri80 != c2_pri80)
231 return NULL;
232
233 if (c1->width > c2->width)
234 return c1;
235 return c2;
236 }
237 EXPORT_SYMBOL(cfg80211_chandef_compatible);
238
239 static void cfg80211_set_chans_dfs_state(struct wiphy *wiphy, u32 center_freq,
240 u32 bandwidth,
241 enum nl80211_dfs_state dfs_state)
242 {
243 struct ieee80211_channel *c;
244 u32 freq;
245
246 for (freq = center_freq - bandwidth/2 + 10;
247 freq <= center_freq + bandwidth/2 - 10;
248 freq += 20) {
249 c = ieee80211_get_channel(wiphy, freq);
250 if (!c || !(c->flags & IEEE80211_CHAN_RADAR))
251 continue;
252
253 c->dfs_state = dfs_state;
254 c->dfs_state_entered = jiffies;
255 }
256 }
257
258 void cfg80211_set_dfs_state(struct wiphy *wiphy,
259 const struct cfg80211_chan_def *chandef,
260 enum nl80211_dfs_state dfs_state)
261 {
262 int width;
263
264 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
265 return;
266
267 width = cfg80211_chandef_get_width(chandef);
268 if (width < 0)
269 return;
270
271 cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq1,
272 width, dfs_state);
273
274 if (!chandef->center_freq2)
275 return;
276 cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq2,
277 width, dfs_state);
278 }
279
280 static u32 cfg80211_get_start_freq(u32 center_freq,
281 u32 bandwidth)
282 {
283 u32 start_freq;
284
285 if (bandwidth <= 20)
286 start_freq = center_freq;
287 else
288 start_freq = center_freq - bandwidth/2 + 10;
289
290 return start_freq;
291 }
292
293 static u32 cfg80211_get_end_freq(u32 center_freq,
294 u32 bandwidth)
295 {
296 u32 end_freq;
297
298 if (bandwidth <= 20)
299 end_freq = center_freq;
300 else
301 end_freq = center_freq + bandwidth/2 - 10;
302
303 return end_freq;
304 }
305
306 static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
307 u32 center_freq,
308 u32 bandwidth)
309 {
310 struct ieee80211_channel *c;
311 u32 freq, start_freq, end_freq;
312
313 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
314 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
315
316 for (freq = start_freq; freq <= end_freq; freq += 20) {
317 c = ieee80211_get_channel(wiphy, freq);
318 if (!c)
319 return -EINVAL;
320
321 if (c->flags & IEEE80211_CHAN_RADAR)
322 return 1;
323 }
324 return 0;
325 }
326
327
328 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
329 const struct cfg80211_chan_def *chandef)
330 {
331 int width;
332 int r;
333
334 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
335 return -EINVAL;
336
337 width = cfg80211_chandef_get_width(chandef);
338 if (width < 0)
339 return -EINVAL;
340
341 r = cfg80211_get_chans_dfs_required(wiphy, chandef->center_freq1,
342 width);
343 if (r)
344 return r;
345
346 if (!chandef->center_freq2)
347 return 0;
348
349 return cfg80211_get_chans_dfs_required(wiphy, chandef->center_freq2,
350 width);
351 }
352 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
353
354 static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
355 u32 center_freq,
356 u32 bandwidth)
357 {
358 struct ieee80211_channel *c;
359 u32 freq, start_freq, end_freq;
360 int count = 0;
361
362 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
363 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
364
365 /*
366 * Check entire range of channels for the bandwidth.
367 * Check all channels are DFS channels (DFS_USABLE or
368 * DFS_AVAILABLE). Return number of usable channels
369 * (require CAC). Allow DFS and non-DFS channel mix.
370 */
371 for (freq = start_freq; freq <= end_freq; freq += 20) {
372 c = ieee80211_get_channel(wiphy, freq);
373 if (!c)
374 return -EINVAL;
375
376 if (c->flags & IEEE80211_CHAN_DISABLED)
377 return -EINVAL;
378
379 if (c->flags & IEEE80211_CHAN_RADAR) {
380 if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
381 return -EINVAL;
382
383 if (c->dfs_state == NL80211_DFS_USABLE)
384 count++;
385 }
386 }
387
388 return count;
389 }
390
391 bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
392 const struct cfg80211_chan_def *chandef)
393 {
394 int width;
395 int r1, r2 = 0;
396
397 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
398 return false;
399
400 width = cfg80211_chandef_get_width(chandef);
401 if (width < 0)
402 return false;
403
404 r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
405 width);
406
407 if (r1 < 0)
408 return false;
409
410 switch (chandef->width) {
411 case NL80211_CHAN_WIDTH_80P80:
412 WARN_ON(!chandef->center_freq2);
413 r2 = cfg80211_get_chans_dfs_usable(wiphy,
414 chandef->center_freq2,
415 width);
416 if (r2 < 0)
417 return false;
418 break;
419 default:
420 WARN_ON(chandef->center_freq2);
421 break;
422 }
423
424 return (r1 + r2 > 0);
425 }
426
427
428 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
429 u32 center_freq,
430 u32 bandwidth)
431 {
432 struct ieee80211_channel *c;
433 u32 freq, start_freq, end_freq;
434
435 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
436 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
437
438 /*
439 * Check entire range of channels for the bandwidth.
440 * If any channel in between is disabled or has not
441 * had gone through CAC return false
442 */
443 for (freq = start_freq; freq <= end_freq; freq += 20) {
444 c = ieee80211_get_channel(wiphy, freq);
445 if (!c)
446 return false;
447
448 if (c->flags & IEEE80211_CHAN_DISABLED)
449 return false;
450
451 if ((c->flags & IEEE80211_CHAN_RADAR) &&
452 (c->dfs_state != NL80211_DFS_AVAILABLE))
453 return false;
454 }
455
456 return true;
457 }
458
459 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
460 const struct cfg80211_chan_def *chandef)
461 {
462 int width;
463 int r;
464
465 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
466 return false;
467
468 width = cfg80211_chandef_get_width(chandef);
469 if (width < 0)
470 return false;
471
472 r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
473 width);
474
475 /* If any of channels unavailable for cf1 just return */
476 if (!r)
477 return r;
478
479 switch (chandef->width) {
480 case NL80211_CHAN_WIDTH_80P80:
481 WARN_ON(!chandef->center_freq2);
482 r = cfg80211_get_chans_dfs_available(wiphy,
483 chandef->center_freq2,
484 width);
485 default:
486 WARN_ON(chandef->center_freq2);
487 break;
488 }
489
490 return r;
491 }
492
493
494 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
495 u32 center_freq, u32 bandwidth,
496 u32 prohibited_flags)
497 {
498 struct ieee80211_channel *c;
499 u32 freq, start_freq, end_freq;
500
501 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
502 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
503
504 for (freq = start_freq; freq <= end_freq; freq += 20) {
505 c = ieee80211_get_channel(wiphy, freq);
506 if (!c || c->flags & prohibited_flags)
507 return false;
508 }
509
510 return true;
511 }
512
513 bool cfg80211_chandef_usable(struct wiphy *wiphy,
514 const struct cfg80211_chan_def *chandef,
515 u32 prohibited_flags)
516 {
517 struct ieee80211_sta_ht_cap *ht_cap;
518 struct ieee80211_sta_vht_cap *vht_cap;
519 u32 width, control_freq;
520
521 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
522 return false;
523
524 ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
525 vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
526
527 control_freq = chandef->chan->center_freq;
528
529 switch (chandef->width) {
530 case NL80211_CHAN_WIDTH_5:
531 width = 5;
532 break;
533 case NL80211_CHAN_WIDTH_10:
534 width = 10;
535 break;
536 case NL80211_CHAN_WIDTH_20:
537 if (!ht_cap->ht_supported)
538 return false;
539 case NL80211_CHAN_WIDTH_20_NOHT:
540 width = 20;
541 break;
542 case NL80211_CHAN_WIDTH_40:
543 width = 40;
544 if (!ht_cap->ht_supported)
545 return false;
546 if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
547 ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
548 return false;
549 if (chandef->center_freq1 < control_freq &&
550 chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
551 return false;
552 if (chandef->center_freq1 > control_freq &&
553 chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
554 return false;
555 break;
556 case NL80211_CHAN_WIDTH_80P80:
557 if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))
558 return false;
559 case NL80211_CHAN_WIDTH_80:
560 if (!vht_cap->vht_supported)
561 return false;
562 prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
563 width = 80;
564 break;
565 case NL80211_CHAN_WIDTH_160:
566 if (!vht_cap->vht_supported)
567 return false;
568 if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ))
569 return false;
570 prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
571 width = 160;
572 break;
573 default:
574 WARN_ON_ONCE(1);
575 return false;
576 }
577
578 /*
579 * TODO: What if there are only certain 80/160/80+80 MHz channels
580 * allowed by the driver, or only certain combinations?
581 * For 40 MHz the driver can set the NO_HT40 flags, but for
582 * 80/160 MHz and in particular 80+80 MHz this isn't really
583 * feasible and we only have NO_80MHZ/NO_160MHZ so far but
584 * no way to cover 80+80 MHz or more complex restrictions.
585 * Note that such restrictions also need to be advertised to
586 * userspace, for example for P2P channel selection.
587 */
588
589 if (width > 20)
590 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
591
592 /* 5 and 10 MHz are only defined for the OFDM PHY */
593 if (width < 20)
594 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
595
596
597 if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
598 width, prohibited_flags))
599 return false;
600
601 if (!chandef->center_freq2)
602 return true;
603 return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
604 width, prohibited_flags);
605 }
606 EXPORT_SYMBOL(cfg80211_chandef_usable);
607
608 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
609 struct cfg80211_chan_def *chandef)
610 {
611 bool res;
612 u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
613 IEEE80211_CHAN_NO_IR |
614 IEEE80211_CHAN_RADAR;
615
616 trace_cfg80211_reg_can_beacon(wiphy, chandef);
617
618 if (cfg80211_chandef_dfs_required(wiphy, chandef) > 0 &&
619 cfg80211_chandef_dfs_available(wiphy, chandef)) {
620 /* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
621 prohibited_flags = IEEE80211_CHAN_DISABLED;
622 }
623
624 res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
625
626 trace_cfg80211_return_bool(res);
627 return res;
628 }
629 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
630
631 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
632 struct cfg80211_chan_def *chandef)
633 {
634 if (!rdev->ops->set_monitor_channel)
635 return -EOPNOTSUPP;
636 if (!cfg80211_has_monitors_only(rdev))
637 return -EBUSY;
638
639 return rdev_set_monitor_channel(rdev, chandef);
640 }
641
642 void
643 cfg80211_get_chan_state(struct wireless_dev *wdev,
644 struct ieee80211_channel **chan,
645 enum cfg80211_chan_mode *chanmode)
646 {
647 *chan = NULL;
648 *chanmode = CHAN_MODE_UNDEFINED;
649
650 ASSERT_WDEV_LOCK(wdev);
651
652 if (wdev->netdev && !netif_running(wdev->netdev))
653 return;
654
655 switch (wdev->iftype) {
656 case NL80211_IFTYPE_ADHOC:
657 if (wdev->current_bss) {
658 *chan = wdev->current_bss->pub.channel;
659 *chanmode = (wdev->ibss_fixed &&
660 !wdev->ibss_dfs_possible)
661 ? CHAN_MODE_SHARED
662 : CHAN_MODE_EXCLUSIVE;
663 return;
664 }
665 break;
666 case NL80211_IFTYPE_STATION:
667 case NL80211_IFTYPE_P2P_CLIENT:
668 if (wdev->current_bss) {
669 *chan = wdev->current_bss->pub.channel;
670 *chanmode = CHAN_MODE_SHARED;
671 return;
672 }
673 break;
674 case NL80211_IFTYPE_AP:
675 case NL80211_IFTYPE_P2P_GO:
676 if (wdev->cac_started) {
677 *chan = wdev->channel;
678 *chanmode = CHAN_MODE_SHARED;
679 } else if (wdev->beacon_interval) {
680 *chan = wdev->channel;
681 *chanmode = CHAN_MODE_SHARED;
682 }
683 return;
684 case NL80211_IFTYPE_MESH_POINT:
685 if (wdev->mesh_id_len) {
686 *chan = wdev->channel;
687 *chanmode = CHAN_MODE_SHARED;
688 }
689 return;
690 case NL80211_IFTYPE_MONITOR:
691 case NL80211_IFTYPE_AP_VLAN:
692 case NL80211_IFTYPE_WDS:
693 /* these interface types don't really have a channel */
694 return;
695 case NL80211_IFTYPE_P2P_DEVICE:
696 if (wdev->wiphy->features &
697 NL80211_FEATURE_P2P_DEVICE_NEEDS_CHANNEL)
698 *chanmode = CHAN_MODE_EXCLUSIVE;
699 return;
700 case NL80211_IFTYPE_UNSPECIFIED:
701 case NUM_NL80211_IFTYPES:
702 WARN_ON(1);
703 }
704
705 return;
706 }
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