xref: /linux/drivers/net/wireless/ralink/rt2x00/rt2x00mac.c (revision 24ebfcbdd1ba623daa1ba140067d7b6102bcfe0d)
1 /*
2 	Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
3 	<http://rt2x00.serialmonkey.com>
4 
5 	This program is free software; you can redistribute it and/or modify
6 	it under the terms of the GNU General Public License as published by
7 	the Free Software Foundation; either version 2 of the License, or
8 	(at your option) any later version.
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 
19 /*
20 	Module: rt2x00mac
21 	Abstract: rt2x00 generic mac80211 routines.
22  */
23 
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 
27 #include "rt2x00.h"
28 #include "rt2x00lib.h"
29 
30 static int rt2x00mac_tx_rts_cts(struct rt2x00_dev *rt2x00dev,
31 				struct data_queue *queue,
32 				struct sk_buff *frag_skb)
33 {
34 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(frag_skb);
35 	struct ieee80211_tx_info *rts_info;
36 	struct sk_buff *skb;
37 	unsigned int data_length;
38 	int retval = 0;
39 
40 	if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
41 		data_length = sizeof(struct ieee80211_cts);
42 	else
43 		data_length = sizeof(struct ieee80211_rts);
44 
45 	skb = dev_alloc_skb(data_length + rt2x00dev->hw->extra_tx_headroom);
46 	if (unlikely(!skb)) {
47 		rt2x00_warn(rt2x00dev, "Failed to create RTS/CTS frame\n");
48 		return -ENOMEM;
49 	}
50 
51 	skb_reserve(skb, rt2x00dev->hw->extra_tx_headroom);
52 	skb_put(skb, data_length);
53 
54 	/*
55 	 * Copy TX information over from original frame to
56 	 * RTS/CTS frame. Note that we set the no encryption flag
57 	 * since we don't want this frame to be encrypted.
58 	 * RTS frames should be acked, while CTS-to-self frames
59 	 * should not. The ready for TX flag is cleared to prevent
60 	 * it being automatically send when the descriptor is
61 	 * written to the hardware.
62 	 */
63 	memcpy(skb->cb, frag_skb->cb, sizeof(skb->cb));
64 	rts_info = IEEE80211_SKB_CB(skb);
65 	rts_info->control.rates[0].flags &= ~IEEE80211_TX_RC_USE_RTS_CTS;
66 	rts_info->control.rates[0].flags &= ~IEEE80211_TX_RC_USE_CTS_PROTECT;
67 
68 	if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
69 		rts_info->flags |= IEEE80211_TX_CTL_NO_ACK;
70 	else
71 		rts_info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
72 
73 	/* Disable hardware encryption */
74 	rts_info->control.hw_key = NULL;
75 
76 	/*
77 	 * RTS/CTS frame should use the length of the frame plus any
78 	 * encryption overhead that will be added by the hardware.
79 	 */
80 	data_length += rt2x00crypto_tx_overhead(rt2x00dev, skb);
81 
82 	if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
83 		ieee80211_ctstoself_get(rt2x00dev->hw, tx_info->control.vif,
84 					frag_skb->data, data_length, tx_info,
85 					(struct ieee80211_cts *)(skb->data));
86 	else
87 		ieee80211_rts_get(rt2x00dev->hw, tx_info->control.vif,
88 				  frag_skb->data, data_length, tx_info,
89 				  (struct ieee80211_rts *)(skb->data));
90 
91 	retval = rt2x00queue_write_tx_frame(queue, skb, NULL, true);
92 	if (retval) {
93 		dev_kfree_skb_any(skb);
94 		rt2x00_warn(rt2x00dev, "Failed to send RTS/CTS frame\n");
95 	}
96 
97 	return retval;
98 }
99 
100 void rt2x00mac_tx(struct ieee80211_hw *hw,
101 		  struct ieee80211_tx_control *control,
102 		  struct sk_buff *skb)
103 {
104 	struct rt2x00_dev *rt2x00dev = hw->priv;
105 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
106 	enum data_queue_qid qid = skb_get_queue_mapping(skb);
107 	struct data_queue *queue = NULL;
108 
109 	/*
110 	 * Mac80211 might be calling this function while we are trying
111 	 * to remove the device or perhaps suspending it.
112 	 * Note that we can only stop the TX queues inside the TX path
113 	 * due to possible race conditions in mac80211.
114 	 */
115 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
116 		goto exit_free_skb;
117 
118 	/*
119 	 * Use the ATIM queue if appropriate and present.
120 	 */
121 	if (tx_info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM &&
122 	    rt2x00_has_cap_flag(rt2x00dev, REQUIRE_ATIM_QUEUE))
123 		qid = QID_ATIM;
124 
125 	queue = rt2x00queue_get_tx_queue(rt2x00dev, qid);
126 	if (unlikely(!queue)) {
127 		rt2x00_err(rt2x00dev,
128 			   "Attempt to send packet over invalid queue %d\n"
129 			   "Please file bug report to %s\n", qid, DRV_PROJECT);
130 		goto exit_free_skb;
131 	}
132 
133 	/*
134 	 * If CTS/RTS is required. create and queue that frame first.
135 	 * Make sure we have at least enough entries available to send
136 	 * this CTS/RTS frame as well as the data frame.
137 	 * Note that when the driver has set the set_rts_threshold()
138 	 * callback function it doesn't need software generation of
139 	 * either RTS or CTS-to-self frame and handles everything
140 	 * inside the hardware.
141 	 */
142 	if (!rt2x00dev->ops->hw->set_rts_threshold &&
143 	    (tx_info->control.rates[0].flags & (IEEE80211_TX_RC_USE_RTS_CTS |
144 						IEEE80211_TX_RC_USE_CTS_PROTECT))) {
145 		if (rt2x00queue_available(queue) <= 1) {
146 			/*
147 			 * Recheck for full queue under lock to avoid race
148 			 * conditions with rt2x00lib_txdone().
149 			 */
150 			spin_lock(&queue->tx_lock);
151 			if (rt2x00queue_threshold(queue))
152 				rt2x00queue_pause_queue(queue);
153 			spin_unlock(&queue->tx_lock);
154 
155 			goto exit_free_skb;
156 		}
157 
158 		if (rt2x00mac_tx_rts_cts(rt2x00dev, queue, skb))
159 			goto exit_free_skb;
160 	}
161 
162 	if (unlikely(rt2x00queue_write_tx_frame(queue, skb, control->sta, false)))
163 		goto exit_free_skb;
164 
165 	return;
166 
167  exit_free_skb:
168 	ieee80211_free_txskb(hw, skb);
169 }
170 EXPORT_SYMBOL_GPL(rt2x00mac_tx);
171 
172 int rt2x00mac_start(struct ieee80211_hw *hw)
173 {
174 	struct rt2x00_dev *rt2x00dev = hw->priv;
175 
176 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
177 		return 0;
178 
179 	return rt2x00lib_start(rt2x00dev);
180 }
181 EXPORT_SYMBOL_GPL(rt2x00mac_start);
182 
183 void rt2x00mac_stop(struct ieee80211_hw *hw)
184 {
185 	struct rt2x00_dev *rt2x00dev = hw->priv;
186 
187 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
188 		return;
189 
190 	rt2x00lib_stop(rt2x00dev);
191 }
192 EXPORT_SYMBOL_GPL(rt2x00mac_stop);
193 
194 int rt2x00mac_add_interface(struct ieee80211_hw *hw,
195 			    struct ieee80211_vif *vif)
196 {
197 	struct rt2x00_dev *rt2x00dev = hw->priv;
198 	struct rt2x00_intf *intf = vif_to_intf(vif);
199 	struct data_queue *queue = rt2x00dev->bcn;
200 	struct queue_entry *entry = NULL;
201 	unsigned int i;
202 
203 	/*
204 	 * Don't allow interfaces to be added
205 	 * the device has disappeared.
206 	 */
207 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
208 	    !test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
209 		return -ENODEV;
210 
211 	/*
212 	 * Loop through all beacon queues to find a free
213 	 * entry. Since there are as much beacon entries
214 	 * as the maximum interfaces, this search shouldn't
215 	 * fail.
216 	 */
217 	for (i = 0; i < queue->limit; i++) {
218 		entry = &queue->entries[i];
219 		if (!test_and_set_bit(ENTRY_BCN_ASSIGNED, &entry->flags))
220 			break;
221 	}
222 
223 	if (unlikely(i == queue->limit))
224 		return -ENOBUFS;
225 
226 	/*
227 	 * We are now absolutely sure the interface can be created,
228 	 * increase interface count and start initialization.
229 	 */
230 
231 	if (vif->type == NL80211_IFTYPE_AP)
232 		rt2x00dev->intf_ap_count++;
233 	else
234 		rt2x00dev->intf_sta_count++;
235 
236 	mutex_init(&intf->beacon_skb_mutex);
237 	intf->beacon = entry;
238 
239 	/*
240 	 * The MAC address must be configured after the device
241 	 * has been initialized. Otherwise the device can reset
242 	 * the MAC registers.
243 	 * The BSSID address must only be configured in AP mode,
244 	 * however we should not send an empty BSSID address for
245 	 * STA interfaces at this time, since this can cause
246 	 * invalid behavior in the device.
247 	 */
248 	rt2x00lib_config_intf(rt2x00dev, intf, vif->type,
249 			      vif->addr, NULL);
250 
251 	/*
252 	 * Some filters depend on the current working mode. We can force
253 	 * an update during the next configure_filter() run by mac80211 by
254 	 * resetting the current packet_filter state.
255 	 */
256 	rt2x00dev->packet_filter = 0;
257 
258 	return 0;
259 }
260 EXPORT_SYMBOL_GPL(rt2x00mac_add_interface);
261 
262 void rt2x00mac_remove_interface(struct ieee80211_hw *hw,
263 				struct ieee80211_vif *vif)
264 {
265 	struct rt2x00_dev *rt2x00dev = hw->priv;
266 	struct rt2x00_intf *intf = vif_to_intf(vif);
267 
268 	/*
269 	 * Don't allow interfaces to be remove while
270 	 * either the device has disappeared or when
271 	 * no interface is present.
272 	 */
273 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
274 	    (vif->type == NL80211_IFTYPE_AP && !rt2x00dev->intf_ap_count) ||
275 	    (vif->type != NL80211_IFTYPE_AP && !rt2x00dev->intf_sta_count))
276 		return;
277 
278 	if (vif->type == NL80211_IFTYPE_AP)
279 		rt2x00dev->intf_ap_count--;
280 	else
281 		rt2x00dev->intf_sta_count--;
282 
283 	/*
284 	 * Release beacon entry so it is available for
285 	 * new interfaces again.
286 	 */
287 	clear_bit(ENTRY_BCN_ASSIGNED, &intf->beacon->flags);
288 
289 	/*
290 	 * Make sure the bssid and mac address registers
291 	 * are cleared to prevent false ACKing of frames.
292 	 */
293 	rt2x00lib_config_intf(rt2x00dev, intf,
294 			      NL80211_IFTYPE_UNSPECIFIED, NULL, NULL);
295 }
296 EXPORT_SYMBOL_GPL(rt2x00mac_remove_interface);
297 
298 int rt2x00mac_config(struct ieee80211_hw *hw, u32 changed)
299 {
300 	struct rt2x00_dev *rt2x00dev = hw->priv;
301 	struct ieee80211_conf *conf = &hw->conf;
302 
303 	/*
304 	 * mac80211 might be calling this function while we are trying
305 	 * to remove the device or perhaps suspending it.
306 	 */
307 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
308 		return 0;
309 
310 	/*
311 	 * Some configuration parameters (e.g. channel and antenna values) can
312 	 * only be set when the radio is enabled, but do require the RX to
313 	 * be off. During this period we should keep link tuning enabled,
314 	 * if for any reason the link tuner must be reset, this will be
315 	 * handled by rt2x00lib_config().
316 	 */
317 	rt2x00queue_stop_queue(rt2x00dev->rx);
318 
319 	/* Do not race with with link tuner. */
320 	mutex_lock(&rt2x00dev->conf_mutex);
321 
322 	/*
323 	 * When we've just turned on the radio, we want to reprogram
324 	 * everything to ensure a consistent state
325 	 */
326 	rt2x00lib_config(rt2x00dev, conf, changed);
327 
328 	/*
329 	 * After the radio has been enabled we need to configure
330 	 * the antenna to the default settings. rt2x00lib_config_antenna()
331 	 * should determine if any action should be taken based on
332 	 * checking if diversity has been enabled or no antenna changes
333 	 * have been made since the last configuration change.
334 	 */
335 	rt2x00lib_config_antenna(rt2x00dev, rt2x00dev->default_ant);
336 
337 	mutex_unlock(&rt2x00dev->conf_mutex);
338 
339 	/* Turn RX back on */
340 	rt2x00queue_start_queue(rt2x00dev->rx);
341 
342 	return 0;
343 }
344 EXPORT_SYMBOL_GPL(rt2x00mac_config);
345 
346 void rt2x00mac_configure_filter(struct ieee80211_hw *hw,
347 				unsigned int changed_flags,
348 				unsigned int *total_flags,
349 				u64 multicast)
350 {
351 	struct rt2x00_dev *rt2x00dev = hw->priv;
352 
353 	/*
354 	 * Mask off any flags we are going to ignore
355 	 * from the total_flags field.
356 	 */
357 	*total_flags &=
358 	    FIF_ALLMULTI |
359 	    FIF_FCSFAIL |
360 	    FIF_PLCPFAIL |
361 	    FIF_CONTROL |
362 	    FIF_PSPOLL |
363 	    FIF_OTHER_BSS;
364 
365 	/*
366 	 * Apply some rules to the filters:
367 	 * - Some filters imply different filters to be set.
368 	 * - Some things we can't filter out at all.
369 	 * - Multicast filter seems to kill broadcast traffic so never use it.
370 	 */
371 	*total_flags |= FIF_ALLMULTI;
372 
373 	/*
374 	 * If the device has a single filter for all control frames,
375 	 * FIF_CONTROL and FIF_PSPOLL flags imply each other.
376 	 * And if the device has more than one filter for control frames
377 	 * of different types, but has no a separate filter for PS Poll frames,
378 	 * FIF_CONTROL flag implies FIF_PSPOLL.
379 	 */
380 	if (!rt2x00_has_cap_control_filters(rt2x00dev)) {
381 		if (*total_flags & FIF_CONTROL || *total_flags & FIF_PSPOLL)
382 			*total_flags |= FIF_CONTROL | FIF_PSPOLL;
383 	}
384 	if (!rt2x00_has_cap_control_filter_pspoll(rt2x00dev)) {
385 		if (*total_flags & FIF_CONTROL)
386 			*total_flags |= FIF_PSPOLL;
387 	}
388 
389 	rt2x00dev->packet_filter = *total_flags;
390 
391 	rt2x00dev->ops->lib->config_filter(rt2x00dev, *total_flags);
392 }
393 EXPORT_SYMBOL_GPL(rt2x00mac_configure_filter);
394 
395 static void rt2x00mac_set_tim_iter(void *data, u8 *mac,
396 				   struct ieee80211_vif *vif)
397 {
398 	struct rt2x00_intf *intf = vif_to_intf(vif);
399 
400 	if (vif->type != NL80211_IFTYPE_AP &&
401 	    vif->type != NL80211_IFTYPE_ADHOC &&
402 	    vif->type != NL80211_IFTYPE_MESH_POINT &&
403 	    vif->type != NL80211_IFTYPE_WDS)
404 		return;
405 
406 	set_bit(DELAYED_UPDATE_BEACON, &intf->delayed_flags);
407 }
408 
409 int rt2x00mac_set_tim(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
410 		      bool set)
411 {
412 	struct rt2x00_dev *rt2x00dev = hw->priv;
413 
414 	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
415 		return 0;
416 
417 	ieee80211_iterate_active_interfaces_atomic(
418 		rt2x00dev->hw, IEEE80211_IFACE_ITER_RESUME_ALL,
419 		rt2x00mac_set_tim_iter, rt2x00dev);
420 
421 	/* queue work to upodate the beacon template */
422 	ieee80211_queue_work(rt2x00dev->hw, &rt2x00dev->intf_work);
423 	return 0;
424 }
425 EXPORT_SYMBOL_GPL(rt2x00mac_set_tim);
426 
427 #ifdef CONFIG_RT2X00_LIB_CRYPTO
428 static void memcpy_tkip(struct rt2x00lib_crypto *crypto, u8 *key, u8 key_len)
429 {
430 	if (key_len > NL80211_TKIP_DATA_OFFSET_ENCR_KEY)
431 		memcpy(crypto->key,
432 		       &key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY],
433 		       sizeof(crypto->key));
434 
435 	if (key_len > NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY)
436 		memcpy(crypto->tx_mic,
437 		       &key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY],
438 		       sizeof(crypto->tx_mic));
439 
440 	if (key_len > NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY)
441 		memcpy(crypto->rx_mic,
442 		       &key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY],
443 		       sizeof(crypto->rx_mic));
444 }
445 
446 int rt2x00mac_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
447 		      struct ieee80211_vif *vif, struct ieee80211_sta *sta,
448 		      struct ieee80211_key_conf *key)
449 {
450 	struct rt2x00_dev *rt2x00dev = hw->priv;
451 	int (*set_key) (struct rt2x00_dev *rt2x00dev,
452 			struct rt2x00lib_crypto *crypto,
453 			struct ieee80211_key_conf *key);
454 	struct rt2x00lib_crypto crypto;
455 	static const u8 bcast_addr[ETH_ALEN] =
456 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, };
457 	struct rt2x00_sta *sta_priv = NULL;
458 
459 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
460 		return 0;
461 
462 	if (!rt2x00_has_cap_hw_crypto(rt2x00dev))
463 		return -EOPNOTSUPP;
464 
465 	/*
466 	 * To support IBSS RSN, don't program group keys in IBSS, the
467 	 * hardware will then not attempt to decrypt the frames.
468 	 */
469 	if (vif->type == NL80211_IFTYPE_ADHOC &&
470 	    !(key->flags & IEEE80211_KEY_FLAG_PAIRWISE))
471 		return -EOPNOTSUPP;
472 
473 	if (key->keylen > 32)
474 		return -ENOSPC;
475 
476 	memset(&crypto, 0, sizeof(crypto));
477 
478 	crypto.bssidx = rt2x00lib_get_bssidx(rt2x00dev, vif);
479 	crypto.cipher = rt2x00crypto_key_to_cipher(key);
480 	if (crypto.cipher == CIPHER_NONE)
481 		return -EOPNOTSUPP;
482 	if (crypto.cipher == CIPHER_TKIP && rt2x00_is_usb(rt2x00dev))
483 		return -EOPNOTSUPP;
484 
485 	crypto.cmd = cmd;
486 
487 	if (sta) {
488 		crypto.address = sta->addr;
489 		sta_priv = sta_to_rt2x00_sta(sta);
490 		crypto.wcid = sta_priv->wcid;
491 	} else
492 		crypto.address = bcast_addr;
493 
494 	if (crypto.cipher == CIPHER_TKIP)
495 		memcpy_tkip(&crypto, &key->key[0], key->keylen);
496 	else
497 		memcpy(crypto.key, &key->key[0], key->keylen);
498 	/*
499 	 * Each BSS has a maximum of 4 shared keys.
500 	 * Shared key index values:
501 	 *	0) BSS0 key0
502 	 *	1) BSS0 key1
503 	 *	...
504 	 *	4) BSS1 key0
505 	 *	...
506 	 *	8) BSS2 key0
507 	 *	...
508 	 * Both pairwise as shared key indeces are determined by
509 	 * driver. This is required because the hardware requires
510 	 * keys to be assigned in correct order (When key 1 is
511 	 * provided but key 0 is not, then the key is not found
512 	 * by the hardware during RX).
513 	 */
514 	if (cmd == SET_KEY)
515 		key->hw_key_idx = 0;
516 
517 	if (key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
518 		set_key = rt2x00dev->ops->lib->config_pairwise_key;
519 	else
520 		set_key = rt2x00dev->ops->lib->config_shared_key;
521 
522 	if (!set_key)
523 		return -EOPNOTSUPP;
524 
525 	return set_key(rt2x00dev, &crypto, key);
526 }
527 EXPORT_SYMBOL_GPL(rt2x00mac_set_key);
528 #endif /* CONFIG_RT2X00_LIB_CRYPTO */
529 
530 void rt2x00mac_sw_scan_start(struct ieee80211_hw *hw,
531 			     struct ieee80211_vif *vif,
532 			     const u8 *mac_addr)
533 {
534 	struct rt2x00_dev *rt2x00dev = hw->priv;
535 	set_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags);
536 	rt2x00link_stop_tuner(rt2x00dev);
537 }
538 EXPORT_SYMBOL_GPL(rt2x00mac_sw_scan_start);
539 
540 void rt2x00mac_sw_scan_complete(struct ieee80211_hw *hw,
541 				struct ieee80211_vif *vif)
542 {
543 	struct rt2x00_dev *rt2x00dev = hw->priv;
544 	clear_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags);
545 	rt2x00link_start_tuner(rt2x00dev);
546 }
547 EXPORT_SYMBOL_GPL(rt2x00mac_sw_scan_complete);
548 
549 int rt2x00mac_get_stats(struct ieee80211_hw *hw,
550 			struct ieee80211_low_level_stats *stats)
551 {
552 	struct rt2x00_dev *rt2x00dev = hw->priv;
553 
554 	/*
555 	 * The dot11ACKFailureCount, dot11RTSFailureCount and
556 	 * dot11RTSSuccessCount are updated in interrupt time.
557 	 * dot11FCSErrorCount is updated in the link tuner.
558 	 */
559 	memcpy(stats, &rt2x00dev->low_level_stats, sizeof(*stats));
560 
561 	return 0;
562 }
563 EXPORT_SYMBOL_GPL(rt2x00mac_get_stats);
564 
565 void rt2x00mac_bss_info_changed(struct ieee80211_hw *hw,
566 				struct ieee80211_vif *vif,
567 				struct ieee80211_bss_conf *bss_conf,
568 				u32 changes)
569 {
570 	struct rt2x00_dev *rt2x00dev = hw->priv;
571 	struct rt2x00_intf *intf = vif_to_intf(vif);
572 
573 	/*
574 	 * mac80211 might be calling this function while we are trying
575 	 * to remove the device or perhaps suspending it.
576 	 */
577 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
578 		return;
579 
580 	/*
581 	 * Update the BSSID.
582 	 */
583 	if (changes & BSS_CHANGED_BSSID)
584 		rt2x00lib_config_intf(rt2x00dev, intf, vif->type, NULL,
585 				      bss_conf->bssid);
586 
587 	/*
588 	 * Start/stop beaconing.
589 	 */
590 	if (changes & BSS_CHANGED_BEACON_ENABLED) {
591 		mutex_lock(&intf->beacon_skb_mutex);
592 		if (!bss_conf->enable_beacon && intf->enable_beacon) {
593 			rt2x00dev->intf_beaconing--;
594 			intf->enable_beacon = false;
595 
596 			if (rt2x00dev->intf_beaconing == 0) {
597 				/*
598 				 * Last beaconing interface disabled
599 				 * -> stop beacon queue.
600 				 */
601 				rt2x00queue_stop_queue(rt2x00dev->bcn);
602 			}
603 			/*
604 			 * Clear beacon in the H/W for this vif. This is needed
605 			 * to disable beaconing on this particular interface
606 			 * and keep it running on other interfaces.
607 			 */
608 			rt2x00queue_clear_beacon(rt2x00dev, vif);
609 		} else if (bss_conf->enable_beacon && !intf->enable_beacon) {
610 			rt2x00dev->intf_beaconing++;
611 			intf->enable_beacon = true;
612 			/*
613 			 * Upload beacon to the H/W. This is only required on
614 			 * USB devices. PCI devices fetch beacons periodically.
615 			 */
616 			if (rt2x00_is_usb(rt2x00dev))
617 				rt2x00queue_update_beacon(rt2x00dev, vif);
618 
619 			if (rt2x00dev->intf_beaconing == 1) {
620 				/*
621 				 * First beaconing interface enabled
622 				 * -> start beacon queue.
623 				 */
624 				rt2x00queue_start_queue(rt2x00dev->bcn);
625 			}
626 		}
627 		mutex_unlock(&intf->beacon_skb_mutex);
628 	}
629 
630 	/*
631 	 * When the association status has changed we must reset the link
632 	 * tuner counter. This is because some drivers determine if they
633 	 * should perform link tuning based on the number of seconds
634 	 * while associated or not associated.
635 	 */
636 	if (changes & BSS_CHANGED_ASSOC) {
637 		rt2x00dev->link.count = 0;
638 
639 		if (bss_conf->assoc)
640 			rt2x00dev->intf_associated++;
641 		else
642 			rt2x00dev->intf_associated--;
643 
644 		rt2x00leds_led_assoc(rt2x00dev, !!rt2x00dev->intf_associated);
645 
646 		clear_bit(CONFIG_QOS_DISABLED, &rt2x00dev->flags);
647 	}
648 
649 	/*
650 	 * Check for access point which do not support 802.11e . We have to
651 	 * generate data frames sequence number in S/W for such AP, because
652 	 * of H/W bug.
653 	 */
654 	if (changes & BSS_CHANGED_QOS && !bss_conf->qos)
655 		set_bit(CONFIG_QOS_DISABLED, &rt2x00dev->flags);
656 
657 	/*
658 	 * When the erp information has changed, we should perform
659 	 * additional configuration steps. For all other changes we are done.
660 	 */
661 	if (changes & (BSS_CHANGED_ERP_CTS_PROT | BSS_CHANGED_ERP_PREAMBLE |
662 		       BSS_CHANGED_ERP_SLOT | BSS_CHANGED_BASIC_RATES |
663 		       BSS_CHANGED_BEACON_INT | BSS_CHANGED_HT))
664 		rt2x00lib_config_erp(rt2x00dev, intf, bss_conf, changes);
665 }
666 EXPORT_SYMBOL_GPL(rt2x00mac_bss_info_changed);
667 
668 int rt2x00mac_conf_tx(struct ieee80211_hw *hw,
669 		      struct ieee80211_vif *vif, u16 queue_idx,
670 		      const struct ieee80211_tx_queue_params *params)
671 {
672 	struct rt2x00_dev *rt2x00dev = hw->priv;
673 	struct data_queue *queue;
674 
675 	queue = rt2x00queue_get_tx_queue(rt2x00dev, queue_idx);
676 	if (unlikely(!queue))
677 		return -EINVAL;
678 
679 	/*
680 	 * The passed variables are stored as real value ((2^n)-1).
681 	 * Ralink registers require to know the bit number 'n'.
682 	 */
683 	if (params->cw_min > 0)
684 		queue->cw_min = fls(params->cw_min);
685 	else
686 		queue->cw_min = 5; /* cw_min: 2^5 = 32. */
687 
688 	if (params->cw_max > 0)
689 		queue->cw_max = fls(params->cw_max);
690 	else
691 		queue->cw_max = 10; /* cw_min: 2^10 = 1024. */
692 
693 	queue->aifs = params->aifs;
694 	queue->txop = params->txop;
695 
696 	rt2x00_dbg(rt2x00dev,
697 		   "Configured TX queue %d - CWmin: %d, CWmax: %d, Aifs: %d, TXop: %d\n",
698 		   queue_idx, queue->cw_min, queue->cw_max, queue->aifs,
699 		   queue->txop);
700 
701 	return 0;
702 }
703 EXPORT_SYMBOL_GPL(rt2x00mac_conf_tx);
704 
705 void rt2x00mac_rfkill_poll(struct ieee80211_hw *hw)
706 {
707 	struct rt2x00_dev *rt2x00dev = hw->priv;
708 	bool active = !!rt2x00dev->ops->lib->rfkill_poll(rt2x00dev);
709 
710 	wiphy_rfkill_set_hw_state(hw->wiphy, !active);
711 }
712 EXPORT_SYMBOL_GPL(rt2x00mac_rfkill_poll);
713 
714 void rt2x00mac_flush(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
715 		     u32 queues, bool drop)
716 {
717 	struct rt2x00_dev *rt2x00dev = hw->priv;
718 	struct data_queue *queue;
719 
720 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
721 		return;
722 
723 	tx_queue_for_each(rt2x00dev, queue)
724 		rt2x00queue_flush_queue(queue, drop);
725 }
726 EXPORT_SYMBOL_GPL(rt2x00mac_flush);
727 
728 int rt2x00mac_set_antenna(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant)
729 {
730 	struct rt2x00_dev *rt2x00dev = hw->priv;
731 	struct link_ant *ant = &rt2x00dev->link.ant;
732 	struct antenna_setup *def = &rt2x00dev->default_ant;
733 	struct antenna_setup setup;
734 
735 	// The antenna value is not supposed to be 0,
736 	// or exceed the maximum number of antenna's.
737 	if (!tx_ant || (tx_ant & ~3) || !rx_ant || (rx_ant & ~3))
738 		return -EINVAL;
739 
740 	// When the client tried to configure the antenna to or from
741 	// diversity mode, we must reset the default antenna as well
742 	// as that controls the diversity switch.
743 	if (ant->flags & ANTENNA_TX_DIVERSITY && tx_ant != 3)
744 		ant->flags &= ~ANTENNA_TX_DIVERSITY;
745 	if (ant->flags & ANTENNA_RX_DIVERSITY && rx_ant != 3)
746 		ant->flags &= ~ANTENNA_RX_DIVERSITY;
747 
748 	// If diversity is being enabled, check if we need hardware
749 	// or software diversity. In the latter case, reset the value,
750 	// and make sure we update the antenna flags to have the
751 	// link tuner pick up the diversity tuning.
752 	if (tx_ant == 3 && def->tx == ANTENNA_SW_DIVERSITY) {
753 		tx_ant = ANTENNA_SW_DIVERSITY;
754 		ant->flags |= ANTENNA_TX_DIVERSITY;
755 	}
756 
757 	if (rx_ant == 3 && def->rx == ANTENNA_SW_DIVERSITY) {
758 		rx_ant = ANTENNA_SW_DIVERSITY;
759 		ant->flags |= ANTENNA_RX_DIVERSITY;
760 	}
761 
762 	setup.tx = tx_ant;
763 	setup.rx = rx_ant;
764 	setup.rx_chain_num = 0;
765 	setup.tx_chain_num = 0;
766 
767 	rt2x00lib_config_antenna(rt2x00dev, setup);
768 
769 	return 0;
770 }
771 EXPORT_SYMBOL_GPL(rt2x00mac_set_antenna);
772 
773 int rt2x00mac_get_antenna(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant)
774 {
775 	struct rt2x00_dev *rt2x00dev = hw->priv;
776 	struct link_ant *ant = &rt2x00dev->link.ant;
777 	struct antenna_setup *active = &rt2x00dev->link.ant.active;
778 
779 	// When software diversity is active, we must report this to the
780 	// client and not the current active antenna state.
781 	if (ant->flags & ANTENNA_TX_DIVERSITY)
782 		*tx_ant = ANTENNA_HW_DIVERSITY;
783 	else
784 		*tx_ant = active->tx;
785 
786 	if (ant->flags & ANTENNA_RX_DIVERSITY)
787 		*rx_ant = ANTENNA_HW_DIVERSITY;
788 	else
789 		*rx_ant = active->rx;
790 
791 	return 0;
792 }
793 EXPORT_SYMBOL_GPL(rt2x00mac_get_antenna);
794 
795 void rt2x00mac_get_ringparam(struct ieee80211_hw *hw,
796 			     u32 *tx, u32 *tx_max, u32 *rx, u32 *rx_max)
797 {
798 	struct rt2x00_dev *rt2x00dev = hw->priv;
799 	struct data_queue *queue;
800 
801 	tx_queue_for_each(rt2x00dev, queue) {
802 		*tx += queue->length;
803 		*tx_max += queue->limit;
804 	}
805 
806 	*rx = rt2x00dev->rx->length;
807 	*rx_max = rt2x00dev->rx->limit;
808 }
809 EXPORT_SYMBOL_GPL(rt2x00mac_get_ringparam);
810 
811 bool rt2x00mac_tx_frames_pending(struct ieee80211_hw *hw)
812 {
813 	struct rt2x00_dev *rt2x00dev = hw->priv;
814 	struct data_queue *queue;
815 
816 	tx_queue_for_each(rt2x00dev, queue) {
817 		if (!rt2x00queue_empty(queue))
818 			return true;
819 	}
820 
821 	return false;
822 }
823 EXPORT_SYMBOL_GPL(rt2x00mac_tx_frames_pending);
824