xref: /openbmc/linux/drivers/net/wireless/ath/regd.c (revision 81d67439)
1 /*
2  * Copyright (c) 2008-2009 Atheros Communications Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/kernel.h>
18 #include <net/cfg80211.h>
19 #include <net/mac80211.h>
20 #include "regd.h"
21 #include "regd_common.h"
22 
23 /*
24  * This is a set of common rules used by our world regulatory domains.
25  * We have 12 world regulatory domains. To save space we consolidate
26  * the regulatory domains in 5 structures by frequency and change
27  * the flags on our reg_notifier() on a case by case basis.
28  */
29 
30 /* Only these channels all allow active scan on all world regulatory domains */
31 #define ATH9K_2GHZ_CH01_11	REG_RULE(2412-10, 2462+10, 40, 0, 20, 0)
32 
33 /* We enable active scan on these a case by case basis by regulatory domain */
34 #define ATH9K_2GHZ_CH12_13	REG_RULE(2467-10, 2472+10, 40, 0, 20,\
35 					NL80211_RRF_PASSIVE_SCAN)
36 #define ATH9K_2GHZ_CH14		REG_RULE(2484-10, 2484+10, 40, 0, 20,\
37 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_OFDM)
38 
39 /* We allow IBSS on these on a case by case basis by regulatory domain */
40 #define ATH9K_5GHZ_5150_5350	REG_RULE(5150-10, 5350+10, 40, 0, 30,\
41 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
42 #define ATH9K_5GHZ_5470_5850	REG_RULE(5470-10, 5850+10, 40, 0, 30,\
43 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
44 #define ATH9K_5GHZ_5725_5850	REG_RULE(5725-10, 5850+10, 40, 0, 30,\
45 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
46 
47 #define ATH9K_2GHZ_ALL		ATH9K_2GHZ_CH01_11, \
48 				ATH9K_2GHZ_CH12_13, \
49 				ATH9K_2GHZ_CH14
50 
51 #define ATH9K_5GHZ_ALL		ATH9K_5GHZ_5150_5350, \
52 				ATH9K_5GHZ_5470_5850
53 
54 /* This one skips what we call "mid band" */
55 #define ATH9K_5GHZ_NO_MIDBAND	ATH9K_5GHZ_5150_5350, \
56 				ATH9K_5GHZ_5725_5850
57 
58 /* Can be used for:
59  * 0x60, 0x61, 0x62 */
60 static const struct ieee80211_regdomain ath_world_regdom_60_61_62 = {
61 	.n_reg_rules = 5,
62 	.alpha2 =  "99",
63 	.reg_rules = {
64 		ATH9K_2GHZ_ALL,
65 		ATH9K_5GHZ_ALL,
66 	}
67 };
68 
69 /* Can be used by 0x63 and 0x65 */
70 static const struct ieee80211_regdomain ath_world_regdom_63_65 = {
71 	.n_reg_rules = 4,
72 	.alpha2 =  "99",
73 	.reg_rules = {
74 		ATH9K_2GHZ_CH01_11,
75 		ATH9K_2GHZ_CH12_13,
76 		ATH9K_5GHZ_NO_MIDBAND,
77 	}
78 };
79 
80 /* Can be used by 0x64 only */
81 static const struct ieee80211_regdomain ath_world_regdom_64 = {
82 	.n_reg_rules = 3,
83 	.alpha2 =  "99",
84 	.reg_rules = {
85 		ATH9K_2GHZ_CH01_11,
86 		ATH9K_5GHZ_NO_MIDBAND,
87 	}
88 };
89 
90 /* Can be used by 0x66 and 0x69 */
91 static const struct ieee80211_regdomain ath_world_regdom_66_69 = {
92 	.n_reg_rules = 3,
93 	.alpha2 =  "99",
94 	.reg_rules = {
95 		ATH9K_2GHZ_CH01_11,
96 		ATH9K_5GHZ_ALL,
97 	}
98 };
99 
100 /* Can be used by 0x67, 0x68, 0x6A and 0x6C */
101 static const struct ieee80211_regdomain ath_world_regdom_67_68_6A_6C = {
102 	.n_reg_rules = 4,
103 	.alpha2 =  "99",
104 	.reg_rules = {
105 		ATH9K_2GHZ_CH01_11,
106 		ATH9K_2GHZ_CH12_13,
107 		ATH9K_5GHZ_ALL,
108 	}
109 };
110 
111 static inline bool is_wwr_sku(u16 regd)
112 {
113 	return ((regd & COUNTRY_ERD_FLAG) != COUNTRY_ERD_FLAG) &&
114 		(((regd & WORLD_SKU_MASK) == WORLD_SKU_PREFIX) ||
115 		(regd == WORLD));
116 }
117 
118 static u16 ath_regd_get_eepromRD(struct ath_regulatory *reg)
119 {
120 	return reg->current_rd & ~WORLDWIDE_ROAMING_FLAG;
121 }
122 
123 bool ath_is_world_regd(struct ath_regulatory *reg)
124 {
125 	return is_wwr_sku(ath_regd_get_eepromRD(reg));
126 }
127 EXPORT_SYMBOL(ath_is_world_regd);
128 
129 static const struct ieee80211_regdomain *ath_default_world_regdomain(void)
130 {
131 	/* this is the most restrictive */
132 	return &ath_world_regdom_64;
133 }
134 
135 static const struct
136 ieee80211_regdomain *ath_world_regdomain(struct ath_regulatory *reg)
137 {
138 	switch (reg->regpair->regDmnEnum) {
139 	case 0x60:
140 	case 0x61:
141 	case 0x62:
142 		return &ath_world_regdom_60_61_62;
143 	case 0x63:
144 	case 0x65:
145 		return &ath_world_regdom_63_65;
146 	case 0x64:
147 		return &ath_world_regdom_64;
148 	case 0x66:
149 	case 0x69:
150 		return &ath_world_regdom_66_69;
151 	case 0x67:
152 	case 0x68:
153 	case 0x6A:
154 	case 0x6C:
155 		return &ath_world_regdom_67_68_6A_6C;
156 	default:
157 		WARN_ON(1);
158 		return ath_default_world_regdomain();
159 	}
160 }
161 
162 bool ath_is_49ghz_allowed(u16 regdomain)
163 {
164 	/* possibly more */
165 	return regdomain == MKK9_MKKC;
166 }
167 EXPORT_SYMBOL(ath_is_49ghz_allowed);
168 
169 /* Frequency is one where radar detection is required */
170 static bool ath_is_radar_freq(u16 center_freq)
171 {
172 	return (center_freq >= 5260 && center_freq <= 5700);
173 }
174 
175 /*
176  * N.B: These exception rules do not apply radar freqs.
177  *
178  * - We enable adhoc (or beaconing) if allowed by 11d
179  * - We enable active scan if the channel is allowed by 11d
180  * - If no country IE has been processed and a we determine we have
181  *   received a beacon on a channel we can enable active scan and
182  *   adhoc (or beaconing).
183  */
184 static void
185 ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
186 			      enum nl80211_reg_initiator initiator)
187 {
188 	enum ieee80211_band band;
189 	struct ieee80211_supported_band *sband;
190 	const struct ieee80211_reg_rule *reg_rule;
191 	struct ieee80211_channel *ch;
192 	unsigned int i;
193 	u32 bandwidth = 0;
194 	int r;
195 
196 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
197 
198 		if (!wiphy->bands[band])
199 			continue;
200 
201 		sband = wiphy->bands[band];
202 
203 		for (i = 0; i < sband->n_channels; i++) {
204 
205 			ch = &sband->channels[i];
206 
207 			if (ath_is_radar_freq(ch->center_freq) ||
208 			    (ch->flags & IEEE80211_CHAN_RADAR))
209 				continue;
210 
211 			if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
212 				r = freq_reg_info(wiphy,
213 						  ch->center_freq,
214 						  bandwidth,
215 						  &reg_rule);
216 				if (r)
217 					continue;
218 				/*
219 				 * If 11d had a rule for this channel ensure
220 				 * we enable adhoc/beaconing if it allows us to
221 				 * use it. Note that we would have disabled it
222 				 * by applying our static world regdomain by
223 				 * default during init, prior to calling our
224 				 * regulatory_hint().
225 				 */
226 				if (!(reg_rule->flags &
227 				    NL80211_RRF_NO_IBSS))
228 					ch->flags &=
229 					  ~IEEE80211_CHAN_NO_IBSS;
230 				if (!(reg_rule->flags &
231 				    NL80211_RRF_PASSIVE_SCAN))
232 					ch->flags &=
233 					  ~IEEE80211_CHAN_PASSIVE_SCAN;
234 			} else {
235 				if (ch->beacon_found)
236 					ch->flags &= ~(IEEE80211_CHAN_NO_IBSS |
237 					  IEEE80211_CHAN_PASSIVE_SCAN);
238 			}
239 		}
240 	}
241 
242 }
243 
244 /* Allows active scan scan on Ch 12 and 13 */
245 static void
246 ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
247 				enum nl80211_reg_initiator initiator)
248 {
249 	struct ieee80211_supported_band *sband;
250 	struct ieee80211_channel *ch;
251 	const struct ieee80211_reg_rule *reg_rule;
252 	u32 bandwidth = 0;
253 	int r;
254 
255 	sband = wiphy->bands[IEEE80211_BAND_2GHZ];
256 
257 	/*
258 	 * If no country IE has been received always enable active scan
259 	 * on these channels. This is only done for specific regulatory SKUs
260 	 */
261 	if (initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
262 		ch = &sband->channels[11]; /* CH 12 */
263 		if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
264 			ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
265 		ch = &sband->channels[12]; /* CH 13 */
266 		if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
267 			ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
268 		return;
269 	}
270 
271 	/*
272 	 * If a country IE has been received check its rule for this
273 	 * channel first before enabling active scan. The passive scan
274 	 * would have been enforced by the initial processing of our
275 	 * custom regulatory domain.
276 	 */
277 
278 	ch = &sband->channels[11]; /* CH 12 */
279 	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
280 	if (!r) {
281 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
282 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
283 				ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
284 	}
285 
286 	ch = &sband->channels[12]; /* CH 13 */
287 	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
288 	if (!r) {
289 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
290 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
291 				ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
292 	}
293 }
294 
295 /* Always apply Radar/DFS rules on freq range 5260 MHz - 5700 MHz */
296 static void ath_reg_apply_radar_flags(struct wiphy *wiphy)
297 {
298 	struct ieee80211_supported_band *sband;
299 	struct ieee80211_channel *ch;
300 	unsigned int i;
301 
302 	if (!wiphy->bands[IEEE80211_BAND_5GHZ])
303 		return;
304 
305 	sband = wiphy->bands[IEEE80211_BAND_5GHZ];
306 
307 	for (i = 0; i < sband->n_channels; i++) {
308 		ch = &sband->channels[i];
309 		if (!ath_is_radar_freq(ch->center_freq))
310 			continue;
311 		/* We always enable radar detection/DFS on this
312 		 * frequency range. Additionally we also apply on
313 		 * this frequency range:
314 		 * - If STA mode does not yet have DFS supports disable
315 		 *   active scanning
316 		 * - If adhoc mode does not support DFS yet then
317 		 *   disable adhoc in the frequency.
318 		 * - If AP mode does not yet support radar detection/DFS
319 		 *   do not allow AP mode
320 		 */
321 		if (!(ch->flags & IEEE80211_CHAN_DISABLED))
322 			ch->flags |= IEEE80211_CHAN_RADAR |
323 				     IEEE80211_CHAN_NO_IBSS |
324 				     IEEE80211_CHAN_PASSIVE_SCAN;
325 	}
326 }
327 
328 static void ath_reg_apply_world_flags(struct wiphy *wiphy,
329 				      enum nl80211_reg_initiator initiator,
330 				      struct ath_regulatory *reg)
331 {
332 	switch (reg->regpair->regDmnEnum) {
333 	case 0x60:
334 	case 0x63:
335 	case 0x66:
336 	case 0x67:
337 	case 0x6C:
338 		ath_reg_apply_beaconing_flags(wiphy, initiator);
339 		break;
340 	case 0x68:
341 		ath_reg_apply_beaconing_flags(wiphy, initiator);
342 		ath_reg_apply_active_scan_flags(wiphy, initiator);
343 		break;
344 	}
345 }
346 
347 int ath_reg_notifier_apply(struct wiphy *wiphy,
348 			   struct regulatory_request *request,
349 			   struct ath_regulatory *reg)
350 {
351 	/* We always apply this */
352 	ath_reg_apply_radar_flags(wiphy);
353 
354 	/*
355 	 * This would happen when we have sent a custom regulatory request
356 	 * a world regulatory domain and the scheduler hasn't yet processed
357 	 * any pending requests in the queue.
358 	 */
359 	if (!request)
360 		return 0;
361 
362 	switch (request->initiator) {
363 	case NL80211_REGDOM_SET_BY_DRIVER:
364 	case NL80211_REGDOM_SET_BY_CORE:
365 	case NL80211_REGDOM_SET_BY_USER:
366 		break;
367 	case NL80211_REGDOM_SET_BY_COUNTRY_IE:
368 		if (ath_is_world_regd(reg))
369 			ath_reg_apply_world_flags(wiphy, request->initiator,
370 						  reg);
371 		break;
372 	}
373 
374 	return 0;
375 }
376 EXPORT_SYMBOL(ath_reg_notifier_apply);
377 
378 static bool ath_regd_is_eeprom_valid(struct ath_regulatory *reg)
379 {
380 	u16 rd = ath_regd_get_eepromRD(reg);
381 	int i;
382 
383 	if (rd & COUNTRY_ERD_FLAG) {
384 		/* EEPROM value is a country code */
385 		u16 cc = rd & ~COUNTRY_ERD_FLAG;
386 		printk(KERN_DEBUG
387 		       "ath: EEPROM indicates we should expect "
388 			"a country code\n");
389 		for (i = 0; i < ARRAY_SIZE(allCountries); i++)
390 			if (allCountries[i].countryCode == cc)
391 				return true;
392 	} else {
393 		/* EEPROM value is a regpair value */
394 		if (rd != CTRY_DEFAULT)
395 			printk(KERN_DEBUG "ath: EEPROM indicates we "
396 			       "should expect a direct regpair map\n");
397 		for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++)
398 			if (regDomainPairs[i].regDmnEnum == rd)
399 				return true;
400 	}
401 	printk(KERN_DEBUG
402 		 "ath: invalid regulatory domain/country code 0x%x\n", rd);
403 	return false;
404 }
405 
406 /* EEPROM country code to regpair mapping */
407 static struct country_code_to_enum_rd*
408 ath_regd_find_country(u16 countryCode)
409 {
410 	int i;
411 
412 	for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
413 		if (allCountries[i].countryCode == countryCode)
414 			return &allCountries[i];
415 	}
416 	return NULL;
417 }
418 
419 /* EEPROM rd code to regpair mapping */
420 static struct country_code_to_enum_rd*
421 ath_regd_find_country_by_rd(int regdmn)
422 {
423 	int i;
424 
425 	for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
426 		if (allCountries[i].regDmnEnum == regdmn)
427 			return &allCountries[i];
428 	}
429 	return NULL;
430 }
431 
432 /* Returns the map of the EEPROM set RD to a country code */
433 static u16 ath_regd_get_default_country(u16 rd)
434 {
435 	if (rd & COUNTRY_ERD_FLAG) {
436 		struct country_code_to_enum_rd *country = NULL;
437 		u16 cc = rd & ~COUNTRY_ERD_FLAG;
438 
439 		country = ath_regd_find_country(cc);
440 		if (country != NULL)
441 			return cc;
442 	}
443 
444 	return CTRY_DEFAULT;
445 }
446 
447 static struct reg_dmn_pair_mapping*
448 ath_get_regpair(int regdmn)
449 {
450 	int i;
451 
452 	if (regdmn == NO_ENUMRD)
453 		return NULL;
454 	for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++) {
455 		if (regDomainPairs[i].regDmnEnum == regdmn)
456 			return &regDomainPairs[i];
457 	}
458 	return NULL;
459 }
460 
461 static int
462 ath_regd_init_wiphy(struct ath_regulatory *reg,
463 		    struct wiphy *wiphy,
464 		    int (*reg_notifier)(struct wiphy *wiphy,
465 					struct regulatory_request *request))
466 {
467 	const struct ieee80211_regdomain *regd;
468 
469 	wiphy->reg_notifier = reg_notifier;
470 	wiphy->flags |= WIPHY_FLAG_STRICT_REGULATORY;
471 
472 	if (ath_is_world_regd(reg)) {
473 		/*
474 		 * Anything applied here (prior to wiphy registration) gets
475 		 * saved on the wiphy orig_* parameters
476 		 */
477 		regd = ath_world_regdomain(reg);
478 		wiphy->flags |= WIPHY_FLAG_CUSTOM_REGULATORY;
479 	} else {
480 		/*
481 		 * This gets applied in the case of the absence of CRDA,
482 		 * it's our own custom world regulatory domain, similar to
483 		 * cfg80211's but we enable passive scanning.
484 		 */
485 		regd = ath_default_world_regdomain();
486 	}
487 	wiphy_apply_custom_regulatory(wiphy, regd);
488 	ath_reg_apply_radar_flags(wiphy);
489 	ath_reg_apply_world_flags(wiphy, NL80211_REGDOM_SET_BY_DRIVER, reg);
490 	return 0;
491 }
492 
493 /*
494  * Some users have reported their EEPROM programmed with
495  * 0x8000 set, this is not a supported regulatory domain
496  * but since we have more than one user with it we need
497  * a solution for them. We default to 0x64, which is the
498  * default Atheros world regulatory domain.
499  */
500 static void ath_regd_sanitize(struct ath_regulatory *reg)
501 {
502 	if (reg->current_rd != COUNTRY_ERD_FLAG)
503 		return;
504 	printk(KERN_DEBUG "ath: EEPROM regdomain sanitized\n");
505 	reg->current_rd = 0x64;
506 }
507 
508 int
509 ath_regd_init(struct ath_regulatory *reg,
510 	      struct wiphy *wiphy,
511 	      int (*reg_notifier)(struct wiphy *wiphy,
512 				  struct regulatory_request *request))
513 {
514 	struct country_code_to_enum_rd *country = NULL;
515 	u16 regdmn;
516 
517 	if (!reg)
518 		return -EINVAL;
519 
520 	ath_regd_sanitize(reg);
521 
522 	printk(KERN_DEBUG "ath: EEPROM regdomain: 0x%0x\n", reg->current_rd);
523 
524 	if (!ath_regd_is_eeprom_valid(reg)) {
525 		printk(KERN_ERR "ath: Invalid EEPROM contents\n");
526 		return -EINVAL;
527 	}
528 
529 	regdmn = ath_regd_get_eepromRD(reg);
530 	reg->country_code = ath_regd_get_default_country(regdmn);
531 
532 	if (reg->country_code == CTRY_DEFAULT &&
533 	    regdmn == CTRY_DEFAULT) {
534 		printk(KERN_DEBUG "ath: EEPROM indicates default "
535 		       "country code should be used\n");
536 		reg->country_code = CTRY_UNITED_STATES;
537 	}
538 
539 	if (reg->country_code == CTRY_DEFAULT) {
540 		country = NULL;
541 	} else {
542 		printk(KERN_DEBUG "ath: doing EEPROM country->regdmn "
543 		       "map search\n");
544 		country = ath_regd_find_country(reg->country_code);
545 		if (country == NULL) {
546 			printk(KERN_DEBUG
547 				"ath: no valid country maps found for "
548 				"country code: 0x%0x\n",
549 				reg->country_code);
550 			return -EINVAL;
551 		} else {
552 			regdmn = country->regDmnEnum;
553 			printk(KERN_DEBUG "ath: country maps to "
554 			       "regdmn code: 0x%0x\n",
555 			       regdmn);
556 		}
557 	}
558 
559 	reg->regpair = ath_get_regpair(regdmn);
560 
561 	if (!reg->regpair) {
562 		printk(KERN_DEBUG "ath: "
563 			"No regulatory domain pair found, cannot continue\n");
564 		return -EINVAL;
565 	}
566 
567 	if (!country)
568 		country = ath_regd_find_country_by_rd(regdmn);
569 
570 	if (country) {
571 		reg->alpha2[0] = country->isoName[0];
572 		reg->alpha2[1] = country->isoName[1];
573 	} else {
574 		reg->alpha2[0] = '0';
575 		reg->alpha2[1] = '0';
576 	}
577 
578 	printk(KERN_DEBUG "ath: Country alpha2 being used: %c%c\n",
579 		reg->alpha2[0], reg->alpha2[1]);
580 	printk(KERN_DEBUG "ath: Regpair used: 0x%0x\n",
581 		reg->regpair->regDmnEnum);
582 
583 	ath_regd_init_wiphy(reg, wiphy, reg_notifier);
584 	return 0;
585 }
586 EXPORT_SYMBOL(ath_regd_init);
587 
588 u32 ath_regd_get_band_ctl(struct ath_regulatory *reg,
589 			  enum ieee80211_band band)
590 {
591 	if (!reg->regpair ||
592 	    (reg->country_code == CTRY_DEFAULT &&
593 	     is_wwr_sku(ath_regd_get_eepromRD(reg)))) {
594 		return SD_NO_CTL;
595 	}
596 
597 	switch (band) {
598 	case IEEE80211_BAND_2GHZ:
599 		return reg->regpair->reg_2ghz_ctl;
600 	case IEEE80211_BAND_5GHZ:
601 		return reg->regpair->reg_5ghz_ctl;
602 	default:
603 		return NO_CTL;
604 	}
605 }
606 EXPORT_SYMBOL(ath_regd_get_band_ctl);
607