1 /*
2  * Atheros CARL9170 driver
3  *
4  * 802.11 xmit & status routines
5  *
6  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
7  * Copyright 2009, 2010, Christian Lamparter <chunkeey@googlemail.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; see the file COPYING.  If not, see
21  * http://www.gnu.org/licenses/.
22  *
23  * This file incorporates work covered by the following copyright and
24  * permission notice:
25  *    Copyright (c) 2007-2008 Atheros Communications, Inc.
26  *
27  *    Permission to use, copy, modify, and/or distribute this software for any
28  *    purpose with or without fee is hereby granted, provided that the above
29  *    copyright notice and this permission notice appear in all copies.
30  *
31  *    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
32  *    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
33  *    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
34  *    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
35  *    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
36  *    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
37  *    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
38  */
39 
40 #include <linux/init.h>
41 #include <linux/slab.h>
42 #include <linux/module.h>
43 #include <linux/etherdevice.h>
44 #include <net/mac80211.h>
45 #include "carl9170.h"
46 #include "hw.h"
47 #include "cmd.h"
48 
49 static inline unsigned int __carl9170_get_queue(struct ar9170 *ar,
50 						unsigned int queue)
51 {
52 	if (unlikely(modparam_noht)) {
53 		return queue;
54 	} else {
55 		/*
56 		 * This is just another workaround, until
57 		 * someone figures out how to get QoS and
58 		 * AMPDU to play nicely together.
59 		 */
60 
61 		return 2;		/* AC_BE */
62 	}
63 }
64 
65 static inline unsigned int carl9170_get_queue(struct ar9170 *ar,
66 					      struct sk_buff *skb)
67 {
68 	return __carl9170_get_queue(ar, skb_get_queue_mapping(skb));
69 }
70 
71 static bool is_mem_full(struct ar9170 *ar)
72 {
73 	return (DIV_ROUND_UP(IEEE80211_MAX_FRAME_LEN, ar->fw.mem_block_size) >
74 		atomic_read(&ar->mem_free_blocks));
75 }
76 
77 static void carl9170_tx_accounting(struct ar9170 *ar, struct sk_buff *skb)
78 {
79 	int queue, i;
80 	bool mem_full;
81 
82 	atomic_inc(&ar->tx_total_queued);
83 
84 	queue = skb_get_queue_mapping(skb);
85 	spin_lock_bh(&ar->tx_stats_lock);
86 
87 	/*
88 	 * The driver has to accept the frame, regardless if the queue is
89 	 * full to the brim, or not. We have to do the queuing internally,
90 	 * since mac80211 assumes that a driver which can operate with
91 	 * aggregated frames does not reject frames for this reason.
92 	 */
93 	ar->tx_stats[queue].len++;
94 	ar->tx_stats[queue].count++;
95 
96 	mem_full = is_mem_full(ar);
97 	for (i = 0; i < ar->hw->queues; i++) {
98 		if (mem_full || ar->tx_stats[i].len >= ar->tx_stats[i].limit) {
99 			ieee80211_stop_queue(ar->hw, i);
100 			ar->queue_stop_timeout[i] = jiffies;
101 		}
102 	}
103 
104 	spin_unlock_bh(&ar->tx_stats_lock);
105 }
106 
107 /* needs rcu_read_lock */
108 static struct ieee80211_sta *__carl9170_get_tx_sta(struct ar9170 *ar,
109 						   struct sk_buff *skb)
110 {
111 	struct _carl9170_tx_superframe *super = (void *) skb->data;
112 	struct ieee80211_hdr *hdr = (void *) super->frame_data;
113 	struct ieee80211_vif *vif;
114 	unsigned int vif_id;
115 
116 	vif_id = (super->s.misc & CARL9170_TX_SUPER_MISC_VIF_ID) >>
117 		 CARL9170_TX_SUPER_MISC_VIF_ID_S;
118 
119 	if (WARN_ON_ONCE(vif_id >= AR9170_MAX_VIRTUAL_MAC))
120 		return NULL;
121 
122 	vif = rcu_dereference(ar->vif_priv[vif_id].vif);
123 	if (unlikely(!vif))
124 		return NULL;
125 
126 	/*
127 	 * Normally we should use wrappers like ieee80211_get_DA to get
128 	 * the correct peer ieee80211_sta.
129 	 *
130 	 * But there is a problem with indirect traffic (broadcasts, or
131 	 * data which is designated for other stations) in station mode.
132 	 * The frame will be directed to the AP for distribution and not
133 	 * to the actual destination.
134 	 */
135 
136 	return ieee80211_find_sta(vif, hdr->addr1);
137 }
138 
139 static void carl9170_tx_ps_unblock(struct ar9170 *ar, struct sk_buff *skb)
140 {
141 	struct ieee80211_sta *sta;
142 	struct carl9170_sta_info *sta_info;
143 
144 	rcu_read_lock();
145 	sta = __carl9170_get_tx_sta(ar, skb);
146 	if (unlikely(!sta))
147 		goto out_rcu;
148 
149 	sta_info = (struct carl9170_sta_info *) sta->drv_priv;
150 	if (atomic_dec_return(&sta_info->pending_frames) == 0)
151 		ieee80211_sta_block_awake(ar->hw, sta, false);
152 
153 out_rcu:
154 	rcu_read_unlock();
155 }
156 
157 static void carl9170_tx_accounting_free(struct ar9170 *ar, struct sk_buff *skb)
158 {
159 	int queue;
160 
161 	queue = skb_get_queue_mapping(skb);
162 
163 	spin_lock_bh(&ar->tx_stats_lock);
164 
165 	ar->tx_stats[queue].len--;
166 
167 	if (!is_mem_full(ar)) {
168 		unsigned int i;
169 		for (i = 0; i < ar->hw->queues; i++) {
170 			if (ar->tx_stats[i].len >= CARL9170_NUM_TX_LIMIT_SOFT)
171 				continue;
172 
173 			if (ieee80211_queue_stopped(ar->hw, i)) {
174 				unsigned long tmp;
175 
176 				tmp = jiffies - ar->queue_stop_timeout[i];
177 				if (tmp > ar->max_queue_stop_timeout[i])
178 					ar->max_queue_stop_timeout[i] = tmp;
179 			}
180 
181 			ieee80211_wake_queue(ar->hw, i);
182 		}
183 	}
184 
185 	spin_unlock_bh(&ar->tx_stats_lock);
186 
187 	if (atomic_dec_and_test(&ar->tx_total_queued))
188 		complete(&ar->tx_flush);
189 }
190 
191 static int carl9170_alloc_dev_space(struct ar9170 *ar, struct sk_buff *skb)
192 {
193 	struct _carl9170_tx_superframe *super = (void *) skb->data;
194 	unsigned int chunks;
195 	int cookie = -1;
196 
197 	atomic_inc(&ar->mem_allocs);
198 
199 	chunks = DIV_ROUND_UP(skb->len, ar->fw.mem_block_size);
200 	if (unlikely(atomic_sub_return(chunks, &ar->mem_free_blocks) < 0)) {
201 		atomic_add(chunks, &ar->mem_free_blocks);
202 		return -ENOSPC;
203 	}
204 
205 	spin_lock_bh(&ar->mem_lock);
206 	cookie = bitmap_find_free_region(ar->mem_bitmap, ar->fw.mem_blocks, 0);
207 	spin_unlock_bh(&ar->mem_lock);
208 
209 	if (unlikely(cookie < 0)) {
210 		atomic_add(chunks, &ar->mem_free_blocks);
211 		return -ENOSPC;
212 	}
213 
214 	super = (void *) skb->data;
215 
216 	/*
217 	 * Cookie #0 serves two special purposes:
218 	 *  1. The firmware might use it generate BlockACK frames
219 	 *     in responds of an incoming BlockAckReqs.
220 	 *
221 	 *  2. Prevent double-free bugs.
222 	 */
223 	super->s.cookie = (u8) cookie + 1;
224 	return 0;
225 }
226 
227 static void carl9170_release_dev_space(struct ar9170 *ar, struct sk_buff *skb)
228 {
229 	struct _carl9170_tx_superframe *super = (void *) skb->data;
230 	int cookie;
231 
232 	/* make a local copy of the cookie */
233 	cookie = super->s.cookie;
234 	/* invalidate cookie */
235 	super->s.cookie = 0;
236 
237 	/*
238 	 * Do a out-of-bounds check on the cookie:
239 	 *
240 	 *  * cookie "0" is reserved and won't be assigned to any
241 	 *    out-going frame. Internally however, it is used to
242 	 *    mark no longer/un-accounted frames and serves as a
243 	 *    cheap way of preventing frames from being freed
244 	 *    twice by _accident_. NB: There is a tiny race...
245 	 *
246 	 *  * obviously, cookie number is limited by the amount
247 	 *    of available memory blocks, so the number can
248 	 *    never execeed the mem_blocks count.
249 	 */
250 	if (unlikely(WARN_ON_ONCE(cookie == 0) ||
251 	    WARN_ON_ONCE(cookie > ar->fw.mem_blocks)))
252 		return;
253 
254 	atomic_add(DIV_ROUND_UP(skb->len, ar->fw.mem_block_size),
255 		   &ar->mem_free_blocks);
256 
257 	spin_lock_bh(&ar->mem_lock);
258 	bitmap_release_region(ar->mem_bitmap, cookie - 1, 0);
259 	spin_unlock_bh(&ar->mem_lock);
260 }
261 
262 /* Called from any context */
263 static void carl9170_tx_release(struct kref *ref)
264 {
265 	struct ar9170 *ar;
266 	struct carl9170_tx_info *arinfo;
267 	struct ieee80211_tx_info *txinfo;
268 	struct sk_buff *skb;
269 
270 	arinfo = container_of(ref, struct carl9170_tx_info, ref);
271 	txinfo = container_of((void *) arinfo, struct ieee80211_tx_info,
272 			      rate_driver_data);
273 	skb = container_of((void *) txinfo, struct sk_buff, cb);
274 
275 	ar = arinfo->ar;
276 	if (WARN_ON_ONCE(!ar))
277 		return;
278 
279 	BUILD_BUG_ON(
280 	    offsetof(struct ieee80211_tx_info, status.ampdu_ack_len) != 23);
281 
282 	memset(&txinfo->status.ampdu_ack_len, 0,
283 	       sizeof(struct ieee80211_tx_info) -
284 	       offsetof(struct ieee80211_tx_info, status.ampdu_ack_len));
285 
286 	if (atomic_read(&ar->tx_total_queued))
287 		ar->tx_schedule = true;
288 
289 	if (txinfo->flags & IEEE80211_TX_CTL_AMPDU) {
290 		if (!atomic_read(&ar->tx_ampdu_upload))
291 			ar->tx_ampdu_schedule = true;
292 
293 		if (txinfo->flags & IEEE80211_TX_STAT_AMPDU) {
294 			struct _carl9170_tx_superframe *super;
295 
296 			super = (void *)skb->data;
297 			txinfo->status.ampdu_len = super->s.rix;
298 			txinfo->status.ampdu_ack_len = super->s.cnt;
299 		} else if (txinfo->flags & IEEE80211_TX_STAT_ACK) {
300 			/*
301 			 * drop redundant tx_status reports:
302 			 *
303 			 * 1. ampdu_ack_len of the final tx_status does
304 			 *    include the feedback of this particular frame.
305 			 *
306 			 * 2. tx_status_irqsafe only queues up to 128
307 			 *    tx feedback reports and discards the rest.
308 			 *
309 			 * 3. minstrel_ht is picky, it only accepts
310 			 *    reports of frames with the TX_STATUS_AMPDU flag.
311 			 */
312 
313 			dev_kfree_skb_any(skb);
314 			return;
315 		} else {
316 			/*
317 			 * Frame has failed, but we want to keep it in
318 			 * case it was lost due to a power-state
319 			 * transition.
320 			 */
321 		}
322 	}
323 
324 	skb_pull(skb, sizeof(struct _carl9170_tx_superframe));
325 	ieee80211_tx_status_irqsafe(ar->hw, skb);
326 }
327 
328 void carl9170_tx_get_skb(struct sk_buff *skb)
329 {
330 	struct carl9170_tx_info *arinfo = (void *)
331 		(IEEE80211_SKB_CB(skb))->rate_driver_data;
332 	kref_get(&arinfo->ref);
333 }
334 
335 int carl9170_tx_put_skb(struct sk_buff *skb)
336 {
337 	struct carl9170_tx_info *arinfo = (void *)
338 		(IEEE80211_SKB_CB(skb))->rate_driver_data;
339 
340 	return kref_put(&arinfo->ref, carl9170_tx_release);
341 }
342 
343 /* Caller must hold the tid_info->lock & rcu_read_lock */
344 static void carl9170_tx_shift_bm(struct ar9170 *ar,
345 	struct carl9170_sta_tid *tid_info, u16 seq)
346 {
347 	u16 off;
348 
349 	off = SEQ_DIFF(seq, tid_info->bsn);
350 
351 	if (WARN_ON_ONCE(off >= CARL9170_BAW_BITS))
352 		return;
353 
354 	/*
355 	 * Sanity check. For each MPDU we set the bit in bitmap and
356 	 * clear it once we received the tx_status.
357 	 * But if the bit is already cleared then we've been bitten
358 	 * by a bug.
359 	 */
360 	WARN_ON_ONCE(!test_and_clear_bit(off, tid_info->bitmap));
361 
362 	off = SEQ_DIFF(tid_info->snx, tid_info->bsn);
363 	if (WARN_ON_ONCE(off >= CARL9170_BAW_BITS))
364 		return;
365 
366 	if (!bitmap_empty(tid_info->bitmap, off))
367 		off = find_first_bit(tid_info->bitmap, off);
368 
369 	tid_info->bsn += off;
370 	tid_info->bsn &= 0x0fff;
371 
372 	bitmap_shift_right(tid_info->bitmap, tid_info->bitmap,
373 			   off, CARL9170_BAW_BITS);
374 }
375 
376 static void carl9170_tx_status_process_ampdu(struct ar9170 *ar,
377 	struct sk_buff *skb, struct ieee80211_tx_info *txinfo)
378 {
379 	struct _carl9170_tx_superframe *super = (void *) skb->data;
380 	struct ieee80211_hdr *hdr = (void *) super->frame_data;
381 	struct ieee80211_sta *sta;
382 	struct carl9170_sta_info *sta_info;
383 	struct carl9170_sta_tid *tid_info;
384 	u8 tid;
385 
386 	if (!(txinfo->flags & IEEE80211_TX_CTL_AMPDU) ||
387 	    txinfo->flags & IEEE80211_TX_CTL_INJECTED ||
388 	   (!(super->f.mac_control & cpu_to_le16(AR9170_TX_MAC_AGGR))))
389 		return;
390 
391 	rcu_read_lock();
392 	sta = __carl9170_get_tx_sta(ar, skb);
393 	if (unlikely(!sta))
394 		goto out_rcu;
395 
396 	tid = get_tid_h(hdr);
397 
398 	sta_info = (void *) sta->drv_priv;
399 	tid_info = rcu_dereference(sta_info->agg[tid]);
400 	if (!tid_info)
401 		goto out_rcu;
402 
403 	spin_lock_bh(&tid_info->lock);
404 	if (likely(tid_info->state >= CARL9170_TID_STATE_IDLE))
405 		carl9170_tx_shift_bm(ar, tid_info, get_seq_h(hdr));
406 
407 	if (sta_info->stats[tid].clear) {
408 		sta_info->stats[tid].clear = false;
409 		sta_info->stats[tid].req = false;
410 		sta_info->stats[tid].ampdu_len = 0;
411 		sta_info->stats[tid].ampdu_ack_len = 0;
412 	}
413 
414 	sta_info->stats[tid].ampdu_len++;
415 	if (txinfo->status.rates[0].count == 1)
416 		sta_info->stats[tid].ampdu_ack_len++;
417 
418 	if (!(txinfo->flags & IEEE80211_TX_STAT_ACK))
419 		sta_info->stats[tid].req = true;
420 
421 	if (super->f.mac_control & cpu_to_le16(AR9170_TX_MAC_IMM_BA)) {
422 		super->s.rix = sta_info->stats[tid].ampdu_len;
423 		super->s.cnt = sta_info->stats[tid].ampdu_ack_len;
424 		txinfo->flags |= IEEE80211_TX_STAT_AMPDU;
425 		if (sta_info->stats[tid].req)
426 			txinfo->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
427 
428 		sta_info->stats[tid].clear = true;
429 	}
430 	spin_unlock_bh(&tid_info->lock);
431 
432 out_rcu:
433 	rcu_read_unlock();
434 }
435 
436 void carl9170_tx_status(struct ar9170 *ar, struct sk_buff *skb,
437 			const bool success)
438 {
439 	struct ieee80211_tx_info *txinfo;
440 
441 	carl9170_tx_accounting_free(ar, skb);
442 
443 	txinfo = IEEE80211_SKB_CB(skb);
444 
445 	if (success)
446 		txinfo->flags |= IEEE80211_TX_STAT_ACK;
447 	else
448 		ar->tx_ack_failures++;
449 
450 	if (txinfo->flags & IEEE80211_TX_CTL_AMPDU)
451 		carl9170_tx_status_process_ampdu(ar, skb, txinfo);
452 
453 	carl9170_tx_ps_unblock(ar, skb);
454 	carl9170_tx_put_skb(skb);
455 }
456 
457 /* This function may be called form any context */
458 void carl9170_tx_callback(struct ar9170 *ar, struct sk_buff *skb)
459 {
460 	struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
461 
462 	atomic_dec(&ar->tx_total_pending);
463 
464 	if (txinfo->flags & IEEE80211_TX_CTL_AMPDU)
465 		atomic_dec(&ar->tx_ampdu_upload);
466 
467 	if (carl9170_tx_put_skb(skb))
468 		tasklet_hi_schedule(&ar->usb_tasklet);
469 }
470 
471 static struct sk_buff *carl9170_get_queued_skb(struct ar9170 *ar, u8 cookie,
472 					       struct sk_buff_head *queue)
473 {
474 	struct sk_buff *skb;
475 
476 	spin_lock_bh(&queue->lock);
477 	skb_queue_walk(queue, skb) {
478 		struct _carl9170_tx_superframe *txc = (void *) skb->data;
479 
480 		if (txc->s.cookie != cookie)
481 			continue;
482 
483 		__skb_unlink(skb, queue);
484 		spin_unlock_bh(&queue->lock);
485 
486 		carl9170_release_dev_space(ar, skb);
487 		return skb;
488 	}
489 	spin_unlock_bh(&queue->lock);
490 
491 	return NULL;
492 }
493 
494 static void carl9170_tx_fill_rateinfo(struct ar9170 *ar, unsigned int rix,
495 	unsigned int tries, struct ieee80211_tx_info *txinfo)
496 {
497 	unsigned int i;
498 
499 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
500 		if (txinfo->status.rates[i].idx < 0)
501 			break;
502 
503 		if (i == rix) {
504 			txinfo->status.rates[i].count = tries;
505 			i++;
506 			break;
507 		}
508 	}
509 
510 	for (; i < IEEE80211_TX_MAX_RATES; i++) {
511 		txinfo->status.rates[i].idx = -1;
512 		txinfo->status.rates[i].count = 0;
513 	}
514 }
515 
516 static void carl9170_check_queue_stop_timeout(struct ar9170 *ar)
517 {
518 	int i;
519 	struct sk_buff *skb;
520 	struct ieee80211_tx_info *txinfo;
521 	struct carl9170_tx_info *arinfo;
522 	bool restart = false;
523 
524 	for (i = 0; i < ar->hw->queues; i++) {
525 		spin_lock_bh(&ar->tx_status[i].lock);
526 
527 		skb = skb_peek(&ar->tx_status[i]);
528 
529 		if (!skb)
530 			goto next;
531 
532 		txinfo = IEEE80211_SKB_CB(skb);
533 		arinfo = (void *) txinfo->rate_driver_data;
534 
535 		if (time_is_before_jiffies(arinfo->timeout +
536 		    msecs_to_jiffies(CARL9170_QUEUE_STUCK_TIMEOUT)) == true)
537 			restart = true;
538 
539 next:
540 		spin_unlock_bh(&ar->tx_status[i].lock);
541 	}
542 
543 	if (restart) {
544 		/*
545 		 * At least one queue has been stuck for long enough.
546 		 * Give the device a kick and hope it gets back to
547 		 * work.
548 		 *
549 		 * possible reasons may include:
550 		 *  - frames got lost/corrupted (bad connection to the device)
551 		 *  - stalled rx processing/usb controller hiccups
552 		 *  - firmware errors/bugs
553 		 *  - every bug you can think of.
554 		 *  - all bugs you can't...
555 		 *  - ...
556 		 */
557 		carl9170_restart(ar, CARL9170_RR_STUCK_TX);
558 	}
559 }
560 
561 static void carl9170_tx_ampdu_timeout(struct ar9170 *ar)
562 {
563 	struct carl9170_sta_tid *iter;
564 	struct sk_buff *skb;
565 	struct ieee80211_tx_info *txinfo;
566 	struct carl9170_tx_info *arinfo;
567 	struct ieee80211_sta *sta;
568 
569 	rcu_read_lock();
570 	list_for_each_entry_rcu(iter, &ar->tx_ampdu_list, list) {
571 		if (iter->state < CARL9170_TID_STATE_IDLE)
572 			continue;
573 
574 		spin_lock_bh(&iter->lock);
575 		skb = skb_peek(&iter->queue);
576 		if (!skb)
577 			goto unlock;
578 
579 		txinfo = IEEE80211_SKB_CB(skb);
580 		arinfo = (void *)txinfo->rate_driver_data;
581 		if (time_is_after_jiffies(arinfo->timeout +
582 		    msecs_to_jiffies(CARL9170_QUEUE_TIMEOUT)))
583 			goto unlock;
584 
585 		sta = __carl9170_get_tx_sta(ar, skb);
586 		if (WARN_ON(!sta))
587 			goto unlock;
588 
589 		ieee80211_stop_tx_ba_session(sta, iter->tid);
590 unlock:
591 		spin_unlock_bh(&iter->lock);
592 
593 	}
594 	rcu_read_unlock();
595 }
596 
597 void carl9170_tx_janitor(struct work_struct *work)
598 {
599 	struct ar9170 *ar = container_of(work, struct ar9170,
600 					 tx_janitor.work);
601 	if (!IS_STARTED(ar))
602 		return;
603 
604 	ar->tx_janitor_last_run = jiffies;
605 
606 	carl9170_check_queue_stop_timeout(ar);
607 	carl9170_tx_ampdu_timeout(ar);
608 
609 	if (!atomic_read(&ar->tx_total_queued))
610 		return;
611 
612 	ieee80211_queue_delayed_work(ar->hw, &ar->tx_janitor,
613 		msecs_to_jiffies(CARL9170_TX_TIMEOUT));
614 }
615 
616 static void __carl9170_tx_process_status(struct ar9170 *ar,
617 	const uint8_t cookie, const uint8_t info)
618 {
619 	struct sk_buff *skb;
620 	struct ieee80211_tx_info *txinfo;
621 	unsigned int r, t, q;
622 	bool success = true;
623 
624 	q = ar9170_qmap[info & CARL9170_TX_STATUS_QUEUE];
625 
626 	skb = carl9170_get_queued_skb(ar, cookie, &ar->tx_status[q]);
627 	if (!skb) {
628 		/*
629 		 * We have lost the race to another thread.
630 		 */
631 
632 		return ;
633 	}
634 
635 	txinfo = IEEE80211_SKB_CB(skb);
636 
637 	if (!(info & CARL9170_TX_STATUS_SUCCESS))
638 		success = false;
639 
640 	r = (info & CARL9170_TX_STATUS_RIX) >> CARL9170_TX_STATUS_RIX_S;
641 	t = (info & CARL9170_TX_STATUS_TRIES) >> CARL9170_TX_STATUS_TRIES_S;
642 
643 	carl9170_tx_fill_rateinfo(ar, r, t, txinfo);
644 	carl9170_tx_status(ar, skb, success);
645 }
646 
647 void carl9170_tx_process_status(struct ar9170 *ar,
648 				const struct carl9170_rsp *cmd)
649 {
650 	unsigned int i;
651 
652 	for (i = 0;  i < cmd->hdr.ext; i++) {
653 		if (WARN_ON(i > ((cmd->hdr.len / 2) + 1))) {
654 			print_hex_dump_bytes("UU:", DUMP_PREFIX_NONE,
655 					     (void *) cmd, cmd->hdr.len + 4);
656 			break;
657 		}
658 
659 		__carl9170_tx_process_status(ar, cmd->_tx_status[i].cookie,
660 					     cmd->_tx_status[i].info);
661 	}
662 }
663 
664 static void carl9170_tx_rate_tpc_chains(struct ar9170 *ar,
665 	struct ieee80211_tx_info *info,	struct ieee80211_tx_rate *txrate,
666 	unsigned int *phyrate, unsigned int *tpc, unsigned int *chains)
667 {
668 	struct ieee80211_rate *rate = NULL;
669 	u8 *txpower;
670 	unsigned int idx;
671 
672 	idx = txrate->idx;
673 	*tpc = 0;
674 	*phyrate = 0;
675 
676 	if (txrate->flags & IEEE80211_TX_RC_MCS) {
677 		if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
678 			/* +1 dBm for HT40 */
679 			*tpc += 2;
680 
681 			if (info->band == IEEE80211_BAND_2GHZ)
682 				txpower = ar->power_2G_ht40;
683 			else
684 				txpower = ar->power_5G_ht40;
685 		} else {
686 			if (info->band == IEEE80211_BAND_2GHZ)
687 				txpower = ar->power_2G_ht20;
688 			else
689 				txpower = ar->power_5G_ht20;
690 		}
691 
692 		*phyrate = txrate->idx;
693 		*tpc += txpower[idx & 7];
694 	} else {
695 		if (info->band == IEEE80211_BAND_2GHZ) {
696 			if (idx < 4)
697 				txpower = ar->power_2G_cck;
698 			else
699 				txpower = ar->power_2G_ofdm;
700 		} else {
701 			txpower = ar->power_5G_leg;
702 			idx += 4;
703 		}
704 
705 		rate = &__carl9170_ratetable[idx];
706 		*tpc += txpower[(rate->hw_value & 0x30) >> 4];
707 		*phyrate = rate->hw_value & 0xf;
708 	}
709 
710 	if (ar->eeprom.tx_mask == 1) {
711 		*chains = AR9170_TX_PHY_TXCHAIN_1;
712 	} else {
713 		if (!(txrate->flags & IEEE80211_TX_RC_MCS) &&
714 		    rate && rate->bitrate >= 360)
715 			*chains = AR9170_TX_PHY_TXCHAIN_1;
716 		else
717 			*chains = AR9170_TX_PHY_TXCHAIN_2;
718 	}
719 }
720 
721 static __le32 carl9170_tx_physet(struct ar9170 *ar,
722 	struct ieee80211_tx_info *info, struct ieee80211_tx_rate *txrate)
723 {
724 	unsigned int power = 0, chains = 0, phyrate = 0;
725 	__le32 tmp;
726 
727 	tmp = cpu_to_le32(0);
728 
729 	if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
730 		tmp |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ <<
731 			AR9170_TX_PHY_BW_S);
732 	/* this works because 40 MHz is 2 and dup is 3 */
733 	if (txrate->flags & IEEE80211_TX_RC_DUP_DATA)
734 		tmp |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ_DUP <<
735 			AR9170_TX_PHY_BW_S);
736 
737 	if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
738 		tmp |= cpu_to_le32(AR9170_TX_PHY_SHORT_GI);
739 
740 	if (txrate->flags & IEEE80211_TX_RC_MCS) {
741 		SET_VAL(AR9170_TX_PHY_MCS, phyrate, txrate->idx);
742 
743 		/* heavy clip control */
744 		tmp |= cpu_to_le32((txrate->idx & 0x7) <<
745 			AR9170_TX_PHY_TX_HEAVY_CLIP_S);
746 
747 		tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_HT);
748 
749 		/*
750 		 * green field preamble does not work.
751 		 *
752 		 * if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
753 		 * tmp |= cpu_to_le32(AR9170_TX_PHY_GREENFIELD);
754 		 */
755 	} else {
756 		if (info->band == IEEE80211_BAND_2GHZ) {
757 			if (txrate->idx <= AR9170_TX_PHY_RATE_CCK_11M)
758 				tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_CCK);
759 			else
760 				tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_OFDM);
761 		} else {
762 			tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_OFDM);
763 		}
764 
765 		/*
766 		 * short preamble seems to be broken too.
767 		 *
768 		 * if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
769 		 *	tmp |= cpu_to_le32(AR9170_TX_PHY_SHORT_PREAMBLE);
770 		 */
771 	}
772 	carl9170_tx_rate_tpc_chains(ar, info, txrate,
773 				    &phyrate, &power, &chains);
774 
775 	tmp |= cpu_to_le32(SET_CONSTVAL(AR9170_TX_PHY_MCS, phyrate));
776 	tmp |= cpu_to_le32(SET_CONSTVAL(AR9170_TX_PHY_TX_PWR, power));
777 	tmp |= cpu_to_le32(SET_CONSTVAL(AR9170_TX_PHY_TXCHAIN, chains));
778 	return tmp;
779 }
780 
781 static bool carl9170_tx_rts_check(struct ar9170 *ar,
782 				  struct ieee80211_tx_rate *rate,
783 				  bool ampdu, bool multi)
784 {
785 	switch (ar->erp_mode) {
786 	case CARL9170_ERP_AUTO:
787 		if (ampdu)
788 			break;
789 
790 	case CARL9170_ERP_MAC80211:
791 		if (!(rate->flags & IEEE80211_TX_RC_USE_RTS_CTS))
792 			break;
793 
794 	case CARL9170_ERP_RTS:
795 		if (likely(!multi))
796 			return true;
797 
798 	default:
799 		break;
800 	}
801 
802 	return false;
803 }
804 
805 static bool carl9170_tx_cts_check(struct ar9170 *ar,
806 				  struct ieee80211_tx_rate *rate)
807 {
808 	switch (ar->erp_mode) {
809 	case CARL9170_ERP_AUTO:
810 	case CARL9170_ERP_MAC80211:
811 		if (!(rate->flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
812 			break;
813 
814 	case CARL9170_ERP_CTS:
815 		return true;
816 
817 	default:
818 		break;
819 	}
820 
821 	return false;
822 }
823 
824 static int carl9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
825 {
826 	struct ieee80211_hdr *hdr;
827 	struct _carl9170_tx_superframe *txc;
828 	struct carl9170_vif_info *cvif;
829 	struct ieee80211_tx_info *info;
830 	struct ieee80211_tx_rate *txrate;
831 	struct ieee80211_sta *sta;
832 	struct carl9170_tx_info *arinfo;
833 	unsigned int hw_queue;
834 	int i;
835 	__le16 mac_tmp;
836 	u16 len;
837 	bool ampdu, no_ack;
838 
839 	BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
840 	BUILD_BUG_ON(sizeof(struct _carl9170_tx_superdesc) !=
841 		     CARL9170_TX_SUPERDESC_LEN);
842 
843 	BUILD_BUG_ON(sizeof(struct _ar9170_tx_hwdesc) !=
844 		     AR9170_TX_HWDESC_LEN);
845 
846 	BUILD_BUG_ON(IEEE80211_TX_MAX_RATES < CARL9170_TX_MAX_RATES);
847 
848 	BUILD_BUG_ON(AR9170_MAX_VIRTUAL_MAC >
849 		((CARL9170_TX_SUPER_MISC_VIF_ID >>
850 		 CARL9170_TX_SUPER_MISC_VIF_ID_S) + 1));
851 
852 	hw_queue = ar9170_qmap[carl9170_get_queue(ar, skb)];
853 
854 	hdr = (void *)skb->data;
855 	info = IEEE80211_SKB_CB(skb);
856 	len = skb->len;
857 
858 	/*
859 	 * Note: If the frame was sent through a monitor interface,
860 	 * the ieee80211_vif pointer can be NULL.
861 	 */
862 	if (likely(info->control.vif))
863 		cvif = (void *) info->control.vif->drv_priv;
864 	else
865 		cvif = NULL;
866 
867 	sta = info->control.sta;
868 
869 	txc = (void *)skb_push(skb, sizeof(*txc));
870 	memset(txc, 0, sizeof(*txc));
871 
872 	SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, txc->s.misc, hw_queue);
873 
874 	if (likely(cvif))
875 		SET_VAL(CARL9170_TX_SUPER_MISC_VIF_ID, txc->s.misc, cvif->id);
876 
877 	if (unlikely(info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM))
878 		txc->s.misc |= CARL9170_TX_SUPER_MISC_CAB;
879 
880 	if (unlikely(info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ))
881 		txc->s.misc |= CARL9170_TX_SUPER_MISC_ASSIGN_SEQ;
882 
883 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control)))
884 		txc->s.misc |= CARL9170_TX_SUPER_MISC_FILL_IN_TSF;
885 
886 	mac_tmp = cpu_to_le16(AR9170_TX_MAC_HW_DURATION |
887 			      AR9170_TX_MAC_BACKOFF);
888 	mac_tmp |= cpu_to_le16((hw_queue << AR9170_TX_MAC_QOS_S) &
889 			       AR9170_TX_MAC_QOS);
890 
891 	no_ack = !!(info->flags & IEEE80211_TX_CTL_NO_ACK);
892 	if (unlikely(no_ack))
893 		mac_tmp |= cpu_to_le16(AR9170_TX_MAC_NO_ACK);
894 
895 	if (info->control.hw_key) {
896 		len += info->control.hw_key->icv_len;
897 
898 		switch (info->control.hw_key->cipher) {
899 		case WLAN_CIPHER_SUITE_WEP40:
900 		case WLAN_CIPHER_SUITE_WEP104:
901 		case WLAN_CIPHER_SUITE_TKIP:
902 			mac_tmp |= cpu_to_le16(AR9170_TX_MAC_ENCR_RC4);
903 			break;
904 		case WLAN_CIPHER_SUITE_CCMP:
905 			mac_tmp |= cpu_to_le16(AR9170_TX_MAC_ENCR_AES);
906 			break;
907 		default:
908 			WARN_ON(1);
909 			goto err_out;
910 		}
911 	}
912 
913 	ampdu = !!(info->flags & IEEE80211_TX_CTL_AMPDU);
914 	if (ampdu) {
915 		unsigned int density, factor;
916 
917 		if (unlikely(!sta || !cvif))
918 			goto err_out;
919 
920 		factor = min_t(unsigned int, 1u, sta->ht_cap.ampdu_factor);
921 		density = sta->ht_cap.ampdu_density;
922 
923 		if (density) {
924 			/*
925 			 * Watch out!
926 			 *
927 			 * Otus uses slightly different density values than
928 			 * those from the 802.11n spec.
929 			 */
930 
931 			density = max_t(unsigned int, density + 1, 7u);
932 		}
933 
934 		SET_VAL(CARL9170_TX_SUPER_AMPDU_DENSITY,
935 			txc->s.ampdu_settings, density);
936 
937 		SET_VAL(CARL9170_TX_SUPER_AMPDU_FACTOR,
938 			txc->s.ampdu_settings, factor);
939 
940 		for (i = 0; i < CARL9170_TX_MAX_RATES; i++) {
941 			txrate = &info->control.rates[i];
942 			if (txrate->idx >= 0) {
943 				txc->s.ri[i] =
944 					CARL9170_TX_SUPER_RI_AMPDU;
945 
946 				if (WARN_ON(!(txrate->flags &
947 					      IEEE80211_TX_RC_MCS))) {
948 					/*
949 					 * Not sure if it's even possible
950 					 * to aggregate non-ht rates with
951 					 * this HW.
952 					 */
953 					goto err_out;
954 				}
955 				continue;
956 			}
957 
958 			txrate->idx = 0;
959 			txrate->count = ar->hw->max_rate_tries;
960 		}
961 
962 		mac_tmp |= cpu_to_le16(AR9170_TX_MAC_AGGR);
963 	}
964 
965 	/*
966 	 * NOTE: For the first rate, the ERP & AMPDU flags are directly
967 	 * taken from mac_control. For all fallback rate, the firmware
968 	 * updates the mac_control flags from the rate info field.
969 	 */
970 	for (i = 1; i < CARL9170_TX_MAX_RATES; i++) {
971 		txrate = &info->control.rates[i];
972 		if (txrate->idx < 0)
973 			break;
974 
975 		SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[i],
976 			txrate->count);
977 
978 		if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
979 			txc->s.ri[i] |= (AR9170_TX_MAC_PROT_RTS <<
980 				CARL9170_TX_SUPER_RI_ERP_PROT_S);
981 		else if (carl9170_tx_cts_check(ar, txrate))
982 			txc->s.ri[i] |= (AR9170_TX_MAC_PROT_CTS <<
983 				CARL9170_TX_SUPER_RI_ERP_PROT_S);
984 
985 		txc->s.rr[i - 1] = carl9170_tx_physet(ar, info, txrate);
986 	}
987 
988 	txrate = &info->control.rates[0];
989 	SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[0], txrate->count);
990 
991 	if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
992 		mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_RTS);
993 	else if (carl9170_tx_cts_check(ar, txrate))
994 		mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_CTS);
995 
996 	txc->s.len = cpu_to_le16(skb->len);
997 	txc->f.length = cpu_to_le16(len + FCS_LEN);
998 	txc->f.mac_control = mac_tmp;
999 	txc->f.phy_control = carl9170_tx_physet(ar, info, txrate);
1000 
1001 	arinfo = (void *)info->rate_driver_data;
1002 	arinfo->timeout = jiffies;
1003 	arinfo->ar = ar;
1004 	kref_init(&arinfo->ref);
1005 	return 0;
1006 
1007 err_out:
1008 	skb_pull(skb, sizeof(*txc));
1009 	return -EINVAL;
1010 }
1011 
1012 static void carl9170_set_immba(struct ar9170 *ar, struct sk_buff *skb)
1013 {
1014 	struct _carl9170_tx_superframe *super;
1015 
1016 	super = (void *) skb->data;
1017 	super->f.mac_control |= cpu_to_le16(AR9170_TX_MAC_IMM_BA);
1018 }
1019 
1020 static void carl9170_set_ampdu_params(struct ar9170 *ar, struct sk_buff *skb)
1021 {
1022 	struct _carl9170_tx_superframe *super;
1023 	int tmp;
1024 
1025 	super = (void *) skb->data;
1026 
1027 	tmp = (super->s.ampdu_settings & CARL9170_TX_SUPER_AMPDU_DENSITY) <<
1028 		CARL9170_TX_SUPER_AMPDU_DENSITY_S;
1029 
1030 	/*
1031 	 * If you haven't noticed carl9170_tx_prepare has already filled
1032 	 * in all ampdu spacing & factor parameters.
1033 	 * Now it's the time to check whenever the settings have to be
1034 	 * updated by the firmware, or if everything is still the same.
1035 	 *
1036 	 * There's no sane way to handle different density values with
1037 	 * this hardware, so we may as well just do the compare in the
1038 	 * driver.
1039 	 */
1040 
1041 	if (tmp != ar->current_density) {
1042 		ar->current_density = tmp;
1043 		super->s.ampdu_settings |=
1044 			CARL9170_TX_SUPER_AMPDU_COMMIT_DENSITY;
1045 	}
1046 
1047 	tmp = (super->s.ampdu_settings & CARL9170_TX_SUPER_AMPDU_FACTOR) <<
1048 		CARL9170_TX_SUPER_AMPDU_FACTOR_S;
1049 
1050 	if (tmp != ar->current_factor) {
1051 		ar->current_factor = tmp;
1052 		super->s.ampdu_settings |=
1053 			CARL9170_TX_SUPER_AMPDU_COMMIT_FACTOR;
1054 	}
1055 }
1056 
1057 static bool carl9170_tx_rate_check(struct ar9170 *ar, struct sk_buff *_dest,
1058 				   struct sk_buff *_src)
1059 {
1060 	struct _carl9170_tx_superframe *dest, *src;
1061 
1062 	dest = (void *) _dest->data;
1063 	src = (void *) _src->data;
1064 
1065 	/*
1066 	 * The mac80211 rate control algorithm expects that all MPDUs in
1067 	 * an AMPDU share the same tx vectors.
1068 	 * This is not really obvious right now, because the hardware
1069 	 * does the AMPDU setup according to its own rulebook.
1070 	 * Our nicely assembled, strictly monotonic increasing mpdu
1071 	 * chains will be broken up, mashed back together...
1072 	 */
1073 
1074 	return (dest->f.phy_control == src->f.phy_control);
1075 }
1076 
1077 static void carl9170_tx_ampdu(struct ar9170 *ar)
1078 {
1079 	struct sk_buff_head agg;
1080 	struct carl9170_sta_tid *tid_info;
1081 	struct sk_buff *skb, *first;
1082 	unsigned int i = 0, done_ampdus = 0;
1083 	u16 seq, queue, tmpssn;
1084 
1085 	atomic_inc(&ar->tx_ampdu_scheduler);
1086 	ar->tx_ampdu_schedule = false;
1087 
1088 	if (atomic_read(&ar->tx_ampdu_upload))
1089 		return;
1090 
1091 	if (!ar->tx_ampdu_list_len)
1092 		return;
1093 
1094 	__skb_queue_head_init(&agg);
1095 
1096 	rcu_read_lock();
1097 	tid_info = rcu_dereference(ar->tx_ampdu_iter);
1098 	if (WARN_ON_ONCE(!tid_info)) {
1099 		rcu_read_unlock();
1100 		return;
1101 	}
1102 
1103 retry:
1104 	list_for_each_entry_continue_rcu(tid_info, &ar->tx_ampdu_list, list) {
1105 		i++;
1106 
1107 		if (tid_info->state < CARL9170_TID_STATE_PROGRESS)
1108 			continue;
1109 
1110 		queue = TID_TO_WME_AC(tid_info->tid);
1111 
1112 		spin_lock_bh(&tid_info->lock);
1113 		if (tid_info->state != CARL9170_TID_STATE_XMIT)
1114 			goto processed;
1115 
1116 		tid_info->counter++;
1117 		first = skb_peek(&tid_info->queue);
1118 		tmpssn = carl9170_get_seq(first);
1119 		seq = tid_info->snx;
1120 
1121 		if (unlikely(tmpssn != seq)) {
1122 			tid_info->state = CARL9170_TID_STATE_IDLE;
1123 
1124 			goto processed;
1125 		}
1126 
1127 		while ((skb = skb_peek(&tid_info->queue))) {
1128 			/* strict 0, 1, ..., n - 1, n frame sequence order */
1129 			if (unlikely(carl9170_get_seq(skb) != seq))
1130 				break;
1131 
1132 			/* don't upload more than AMPDU FACTOR allows. */
1133 			if (unlikely(SEQ_DIFF(tid_info->snx, tid_info->bsn) >=
1134 			    (tid_info->max - 1)))
1135 				break;
1136 
1137 			if (!carl9170_tx_rate_check(ar, skb, first))
1138 				break;
1139 
1140 			atomic_inc(&ar->tx_ampdu_upload);
1141 			tid_info->snx = seq = SEQ_NEXT(seq);
1142 			__skb_unlink(skb, &tid_info->queue);
1143 
1144 			__skb_queue_tail(&agg, skb);
1145 
1146 			if (skb_queue_len(&agg) >= CARL9170_NUM_TX_AGG_MAX)
1147 				break;
1148 		}
1149 
1150 		if (skb_queue_empty(&tid_info->queue) ||
1151 		    carl9170_get_seq(skb_peek(&tid_info->queue)) !=
1152 		    tid_info->snx) {
1153 			/*
1154 			 * stop TID, if A-MPDU frames are still missing,
1155 			 * or whenever the queue is empty.
1156 			 */
1157 
1158 			tid_info->state = CARL9170_TID_STATE_IDLE;
1159 		}
1160 		done_ampdus++;
1161 
1162 processed:
1163 		spin_unlock_bh(&tid_info->lock);
1164 
1165 		if (skb_queue_empty(&agg))
1166 			continue;
1167 
1168 		/* apply ampdu spacing & factor settings */
1169 		carl9170_set_ampdu_params(ar, skb_peek(&agg));
1170 
1171 		/* set aggregation push bit */
1172 		carl9170_set_immba(ar, skb_peek_tail(&agg));
1173 
1174 		spin_lock_bh(&ar->tx_pending[queue].lock);
1175 		skb_queue_splice_tail_init(&agg, &ar->tx_pending[queue]);
1176 		spin_unlock_bh(&ar->tx_pending[queue].lock);
1177 		ar->tx_schedule = true;
1178 	}
1179 	if ((done_ampdus++ == 0) && (i++ == 0))
1180 		goto retry;
1181 
1182 	rcu_assign_pointer(ar->tx_ampdu_iter, tid_info);
1183 	rcu_read_unlock();
1184 }
1185 
1186 static struct sk_buff *carl9170_tx_pick_skb(struct ar9170 *ar,
1187 					    struct sk_buff_head *queue)
1188 {
1189 	struct sk_buff *skb;
1190 	struct ieee80211_tx_info *info;
1191 	struct carl9170_tx_info *arinfo;
1192 
1193 	BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
1194 
1195 	spin_lock_bh(&queue->lock);
1196 	skb = skb_peek(queue);
1197 	if (unlikely(!skb))
1198 		goto err_unlock;
1199 
1200 	if (carl9170_alloc_dev_space(ar, skb))
1201 		goto err_unlock;
1202 
1203 	__skb_unlink(skb, queue);
1204 	spin_unlock_bh(&queue->lock);
1205 
1206 	info = IEEE80211_SKB_CB(skb);
1207 	arinfo = (void *) info->rate_driver_data;
1208 
1209 	arinfo->timeout = jiffies;
1210 	return skb;
1211 
1212 err_unlock:
1213 	spin_unlock_bh(&queue->lock);
1214 	return NULL;
1215 }
1216 
1217 void carl9170_tx_drop(struct ar9170 *ar, struct sk_buff *skb)
1218 {
1219 	struct _carl9170_tx_superframe *super;
1220 	uint8_t q = 0;
1221 
1222 	ar->tx_dropped++;
1223 
1224 	super = (void *)skb->data;
1225 	SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, q,
1226 		ar9170_qmap[carl9170_get_queue(ar, skb)]);
1227 	__carl9170_tx_process_status(ar, super->s.cookie, q);
1228 }
1229 
1230 static bool carl9170_tx_ps_drop(struct ar9170 *ar, struct sk_buff *skb)
1231 {
1232 	struct ieee80211_sta *sta;
1233 	struct carl9170_sta_info *sta_info;
1234 
1235 	rcu_read_lock();
1236 	sta = __carl9170_get_tx_sta(ar, skb);
1237 	if (!sta)
1238 		goto out_rcu;
1239 
1240 	sta_info = (void *) sta->drv_priv;
1241 	if (unlikely(sta_info->sleeping)) {
1242 		struct ieee80211_tx_info *tx_info;
1243 
1244 		rcu_read_unlock();
1245 
1246 		tx_info = IEEE80211_SKB_CB(skb);
1247 		if (tx_info->flags & IEEE80211_TX_CTL_AMPDU)
1248 			atomic_dec(&ar->tx_ampdu_upload);
1249 
1250 		tx_info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
1251 		carl9170_tx_status(ar, skb, false);
1252 		return true;
1253 	}
1254 
1255 out_rcu:
1256 	rcu_read_unlock();
1257 	return false;
1258 }
1259 
1260 static void carl9170_tx(struct ar9170 *ar)
1261 {
1262 	struct sk_buff *skb;
1263 	unsigned int i, q;
1264 	bool schedule_garbagecollector = false;
1265 
1266 	ar->tx_schedule = false;
1267 
1268 	if (unlikely(!IS_STARTED(ar)))
1269 		return;
1270 
1271 	carl9170_usb_handle_tx_err(ar);
1272 
1273 	for (i = 0; i < ar->hw->queues; i++) {
1274 		while (!skb_queue_empty(&ar->tx_pending[i])) {
1275 			skb = carl9170_tx_pick_skb(ar, &ar->tx_pending[i]);
1276 			if (unlikely(!skb))
1277 				break;
1278 
1279 			if (unlikely(carl9170_tx_ps_drop(ar, skb)))
1280 				continue;
1281 
1282 			atomic_inc(&ar->tx_total_pending);
1283 
1284 			q = __carl9170_get_queue(ar, i);
1285 			/*
1286 			 * NB: tx_status[i] vs. tx_status[q],
1287 			 * TODO: Move into pick_skb or alloc_dev_space.
1288 			 */
1289 			skb_queue_tail(&ar->tx_status[q], skb);
1290 
1291 			/*
1292 			 * increase ref count to "2".
1293 			 * Ref counting is the easiest way to solve the
1294 			 * race between the urb's completion routine:
1295 			 *	carl9170_tx_callback
1296 			 * and wlan tx status functions:
1297 			 *	carl9170_tx_status/janitor.
1298 			 */
1299 			carl9170_tx_get_skb(skb);
1300 
1301 			carl9170_usb_tx(ar, skb);
1302 			schedule_garbagecollector = true;
1303 		}
1304 	}
1305 
1306 	if (!schedule_garbagecollector)
1307 		return;
1308 
1309 	ieee80211_queue_delayed_work(ar->hw, &ar->tx_janitor,
1310 		msecs_to_jiffies(CARL9170_TX_TIMEOUT));
1311 }
1312 
1313 static bool carl9170_tx_ampdu_queue(struct ar9170 *ar,
1314 	struct ieee80211_sta *sta, struct sk_buff *skb)
1315 {
1316 	struct _carl9170_tx_superframe *super = (void *) skb->data;
1317 	struct carl9170_sta_info *sta_info;
1318 	struct carl9170_sta_tid *agg;
1319 	struct sk_buff *iter;
1320 	u16 tid, seq, qseq, off;
1321 	bool run = false;
1322 
1323 	tid = carl9170_get_tid(skb);
1324 	seq = carl9170_get_seq(skb);
1325 	sta_info = (void *) sta->drv_priv;
1326 
1327 	rcu_read_lock();
1328 	agg = rcu_dereference(sta_info->agg[tid]);
1329 
1330 	if (!agg)
1331 		goto err_unlock_rcu;
1332 
1333 	spin_lock_bh(&agg->lock);
1334 	if (unlikely(agg->state < CARL9170_TID_STATE_IDLE))
1335 		goto err_unlock;
1336 
1337 	/* check if sequence is within the BA window */
1338 	if (unlikely(!BAW_WITHIN(agg->bsn, CARL9170_BAW_BITS, seq)))
1339 		goto err_unlock;
1340 
1341 	if (WARN_ON_ONCE(!BAW_WITHIN(agg->snx, CARL9170_BAW_BITS, seq)))
1342 		goto err_unlock;
1343 
1344 	off = SEQ_DIFF(seq, agg->bsn);
1345 	if (WARN_ON_ONCE(test_and_set_bit(off, agg->bitmap)))
1346 		goto err_unlock;
1347 
1348 	if (likely(BAW_WITHIN(agg->hsn, CARL9170_BAW_BITS, seq))) {
1349 		__skb_queue_tail(&agg->queue, skb);
1350 		agg->hsn = seq;
1351 		goto queued;
1352 	}
1353 
1354 	skb_queue_reverse_walk(&agg->queue, iter) {
1355 		qseq = carl9170_get_seq(iter);
1356 
1357 		if (BAW_WITHIN(qseq, CARL9170_BAW_BITS, seq)) {
1358 			__skb_queue_after(&agg->queue, iter, skb);
1359 			goto queued;
1360 		}
1361 	}
1362 
1363 	__skb_queue_head(&agg->queue, skb);
1364 queued:
1365 
1366 	if (unlikely(agg->state != CARL9170_TID_STATE_XMIT)) {
1367 		if (agg->snx == carl9170_get_seq(skb_peek(&agg->queue))) {
1368 			agg->state = CARL9170_TID_STATE_XMIT;
1369 			run = true;
1370 		}
1371 	}
1372 
1373 	spin_unlock_bh(&agg->lock);
1374 	rcu_read_unlock();
1375 
1376 	return run;
1377 
1378 err_unlock:
1379 	spin_unlock_bh(&agg->lock);
1380 
1381 err_unlock_rcu:
1382 	rcu_read_unlock();
1383 	super->f.mac_control &= ~cpu_to_le16(AR9170_TX_MAC_AGGR);
1384 	carl9170_tx_status(ar, skb, false);
1385 	ar->tx_dropped++;
1386 	return false;
1387 }
1388 
1389 void carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
1390 {
1391 	struct ar9170 *ar = hw->priv;
1392 	struct ieee80211_tx_info *info;
1393 	struct ieee80211_sta *sta;
1394 	bool run;
1395 
1396 	if (unlikely(!IS_STARTED(ar)))
1397 		goto err_free;
1398 
1399 	info = IEEE80211_SKB_CB(skb);
1400 	sta = info->control.sta;
1401 
1402 	if (unlikely(carl9170_tx_prepare(ar, skb)))
1403 		goto err_free;
1404 
1405 	carl9170_tx_accounting(ar, skb);
1406 	/*
1407 	 * from now on, one has to use carl9170_tx_status to free
1408 	 * all ressouces which are associated with the frame.
1409 	 */
1410 
1411 	if (sta) {
1412 		struct carl9170_sta_info *stai = (void *) sta->drv_priv;
1413 		atomic_inc(&stai->pending_frames);
1414 	}
1415 
1416 	if (info->flags & IEEE80211_TX_CTL_AMPDU) {
1417 		run = carl9170_tx_ampdu_queue(ar, sta, skb);
1418 		if (run)
1419 			carl9170_tx_ampdu(ar);
1420 
1421 	} else {
1422 		unsigned int queue = skb_get_queue_mapping(skb);
1423 
1424 		skb_queue_tail(&ar->tx_pending[queue], skb);
1425 	}
1426 
1427 	carl9170_tx(ar);
1428 	return;
1429 
1430 err_free:
1431 	ar->tx_dropped++;
1432 	dev_kfree_skb_any(skb);
1433 }
1434 
1435 void carl9170_tx_scheduler(struct ar9170 *ar)
1436 {
1437 
1438 	if (ar->tx_ampdu_schedule)
1439 		carl9170_tx_ampdu(ar);
1440 
1441 	if (ar->tx_schedule)
1442 		carl9170_tx(ar);
1443 }
1444 
1445 int carl9170_update_beacon(struct ar9170 *ar, const bool submit)
1446 {
1447 	struct sk_buff *skb = NULL;
1448 	struct carl9170_vif_info *cvif;
1449 	struct ieee80211_tx_info *txinfo;
1450 	struct ieee80211_tx_rate *rate;
1451 	__le32 *data, *old = NULL;
1452 	unsigned int plcp, power, chains;
1453 	u32 word, ht1, off, addr, len;
1454 	int i = 0, err = 0;
1455 
1456 	rcu_read_lock();
1457 	cvif = rcu_dereference(ar->beacon_iter);
1458 retry:
1459 	if (ar->vifs == 0 || !cvif)
1460 		goto out_unlock;
1461 
1462 	list_for_each_entry_continue_rcu(cvif, &ar->vif_list, list) {
1463 		if (cvif->active && cvif->enable_beacon)
1464 			goto found;
1465 	}
1466 
1467 	if (!ar->beacon_enabled || i++)
1468 		goto out_unlock;
1469 
1470 	goto retry;
1471 
1472 found:
1473 	rcu_assign_pointer(ar->beacon_iter, cvif);
1474 
1475 	skb = ieee80211_beacon_get_tim(ar->hw, carl9170_get_vif(cvif),
1476 		NULL, NULL);
1477 
1478 	if (!skb) {
1479 		err = -ENOMEM;
1480 		goto err_free;
1481 	}
1482 
1483 	txinfo = IEEE80211_SKB_CB(skb);
1484 	spin_lock_bh(&ar->beacon_lock);
1485 	data = (__le32 *)skb->data;
1486 	if (cvif->beacon)
1487 		old = (__le32 *)cvif->beacon->data;
1488 
1489 	off = cvif->id * AR9170_MAC_BCN_LENGTH_MAX;
1490 	addr = ar->fw.beacon_addr + off;
1491 	len = roundup(skb->len + FCS_LEN, 4);
1492 
1493 	if ((off + len) > ar->fw.beacon_max_len) {
1494 		if (net_ratelimit()) {
1495 			wiphy_err(ar->hw->wiphy, "beacon does not "
1496 				  "fit into device memory!\n");
1497 		}
1498 		err = -EINVAL;
1499 		goto err_unlock;
1500 	}
1501 
1502 	if (len > AR9170_MAC_BCN_LENGTH_MAX) {
1503 		if (net_ratelimit()) {
1504 			wiphy_err(ar->hw->wiphy, "no support for beacons "
1505 				"bigger than %d (yours:%d).\n",
1506 				 AR9170_MAC_BCN_LENGTH_MAX, len);
1507 		}
1508 
1509 		err = -EMSGSIZE;
1510 		goto err_unlock;
1511 	}
1512 
1513 	ht1 = AR9170_MAC_BCN_HT1_TX_ANT0;
1514 	rate = &txinfo->control.rates[0];
1515 	carl9170_tx_rate_tpc_chains(ar, txinfo, rate, &plcp, &power, &chains);
1516 	if (!(txinfo->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
1517 		if (plcp <= AR9170_TX_PHY_RATE_CCK_11M)
1518 			plcp |= ((skb->len + FCS_LEN) << (3 + 16)) + 0x0400;
1519 		else
1520 			plcp |= ((skb->len + FCS_LEN) << 16) + 0x0010;
1521 	} else {
1522 		ht1 |= AR9170_MAC_BCN_HT1_HT_EN;
1523 		if (rate->flags & IEEE80211_TX_RC_SHORT_GI)
1524 			plcp |= AR9170_MAC_BCN_HT2_SGI;
1525 
1526 		if (rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1527 			ht1 |= AR9170_MAC_BCN_HT1_BWC_40M_SHARED;
1528 			plcp |= AR9170_MAC_BCN_HT2_BW40;
1529 		}
1530 		if (rate->flags & IEEE80211_TX_RC_DUP_DATA) {
1531 			ht1 |= AR9170_MAC_BCN_HT1_BWC_40M_DUP;
1532 			plcp |= AR9170_MAC_BCN_HT2_BW40;
1533 		}
1534 
1535 		SET_VAL(AR9170_MAC_BCN_HT2_LEN, plcp, skb->len + FCS_LEN);
1536 	}
1537 
1538 	SET_VAL(AR9170_MAC_BCN_HT1_PWR_CTRL, ht1, 7);
1539 	SET_VAL(AR9170_MAC_BCN_HT1_TPC, ht1, power);
1540 	SET_VAL(AR9170_MAC_BCN_HT1_CHAIN_MASK, ht1, chains);
1541 	if (chains == AR9170_TX_PHY_TXCHAIN_2)
1542 		ht1 |= AR9170_MAC_BCN_HT1_TX_ANT1;
1543 
1544 	carl9170_async_regwrite_begin(ar);
1545 	carl9170_async_regwrite(AR9170_MAC_REG_BCN_HT1, ht1);
1546 	if (!(txinfo->control.rates[0].flags & IEEE80211_TX_RC_MCS))
1547 		carl9170_async_regwrite(AR9170_MAC_REG_BCN_PLCP, plcp);
1548 	else
1549 		carl9170_async_regwrite(AR9170_MAC_REG_BCN_HT2, plcp);
1550 
1551 	for (i = 0; i < DIV_ROUND_UP(skb->len, 4); i++) {
1552 		/*
1553 		 * XXX: This accesses beyond skb data for up
1554 		 *	to the last 3 bytes!!
1555 		 */
1556 
1557 		if (old && (data[i] == old[i]))
1558 			continue;
1559 
1560 		word = le32_to_cpu(data[i]);
1561 		carl9170_async_regwrite(addr + 4 * i, word);
1562 	}
1563 	carl9170_async_regwrite_finish();
1564 
1565 	dev_kfree_skb_any(cvif->beacon);
1566 	cvif->beacon = NULL;
1567 
1568 	err = carl9170_async_regwrite_result();
1569 	if (!err)
1570 		cvif->beacon = skb;
1571 	spin_unlock_bh(&ar->beacon_lock);
1572 	if (err)
1573 		goto err_free;
1574 
1575 	if (submit) {
1576 		err = carl9170_bcn_ctrl(ar, cvif->id,
1577 					CARL9170_BCN_CTRL_CAB_TRIGGER,
1578 					addr, skb->len + FCS_LEN);
1579 
1580 		if (err)
1581 			goto err_free;
1582 	}
1583 out_unlock:
1584 	rcu_read_unlock();
1585 	return 0;
1586 
1587 err_unlock:
1588 	spin_unlock_bh(&ar->beacon_lock);
1589 
1590 err_free:
1591 	rcu_read_unlock();
1592 	dev_kfree_skb_any(skb);
1593 	return err;
1594 }
1595