xref: /linux/drivers/net/wireless/ath/carl9170/tx.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
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.ack_signal) != 20);
281 
282 	memset(&txinfo->status.ack_signal, 0,
283 	       sizeof(struct ieee80211_tx_info) -
284 	       offsetof(struct ieee80211_tx_info, status.ack_signal));
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 			   !(txinfo->flags & IEEE80211_TX_CTL_REQ_TX_STATUS)) {
301 			/*
302 			 * drop redundant tx_status reports:
303 			 *
304 			 * 1. ampdu_ack_len of the final tx_status does
305 			 *    include the feedback of this particular frame.
306 			 *
307 			 * 2. tx_status_irqsafe only queues up to 128
308 			 *    tx feedback reports and discards the rest.
309 			 *
310 			 * 3. minstrel_ht is picky, it only accepts
311 			 *    reports of frames with the TX_STATUS_AMPDU flag.
312 			 *
313 			 * 4. mac80211 is not particularly interested in
314 			 *    feedback either [CTL_REQ_TX_STATUS not set]
315 			 */
316 
317 			ieee80211_free_txskb(ar->hw, skb);
318 			return;
319 		} else {
320 			/*
321 			 * Either the frame transmission has failed or
322 			 * mac80211 requested tx status.
323 			 */
324 		}
325 	}
326 
327 	skb_pull(skb, sizeof(struct _carl9170_tx_superframe));
328 	ieee80211_tx_status_irqsafe(ar->hw, skb);
329 }
330 
331 void carl9170_tx_get_skb(struct sk_buff *skb)
332 {
333 	struct carl9170_tx_info *arinfo = (void *)
334 		(IEEE80211_SKB_CB(skb))->rate_driver_data;
335 	kref_get(&arinfo->ref);
336 }
337 
338 int carl9170_tx_put_skb(struct sk_buff *skb)
339 {
340 	struct carl9170_tx_info *arinfo = (void *)
341 		(IEEE80211_SKB_CB(skb))->rate_driver_data;
342 
343 	return kref_put(&arinfo->ref, carl9170_tx_release);
344 }
345 
346 /* Caller must hold the tid_info->lock & rcu_read_lock */
347 static void carl9170_tx_shift_bm(struct ar9170 *ar,
348 	struct carl9170_sta_tid *tid_info, u16 seq)
349 {
350 	u16 off;
351 
352 	off = SEQ_DIFF(seq, tid_info->bsn);
353 
354 	if (WARN_ON_ONCE(off >= CARL9170_BAW_BITS))
355 		return;
356 
357 	/*
358 	 * Sanity check. For each MPDU we set the bit in bitmap and
359 	 * clear it once we received the tx_status.
360 	 * But if the bit is already cleared then we've been bitten
361 	 * by a bug.
362 	 */
363 	WARN_ON_ONCE(!test_and_clear_bit(off, tid_info->bitmap));
364 
365 	off = SEQ_DIFF(tid_info->snx, tid_info->bsn);
366 	if (WARN_ON_ONCE(off >= CARL9170_BAW_BITS))
367 		return;
368 
369 	if (!bitmap_empty(tid_info->bitmap, off))
370 		off = find_first_bit(tid_info->bitmap, off);
371 
372 	tid_info->bsn += off;
373 	tid_info->bsn &= 0x0fff;
374 
375 	bitmap_shift_right(tid_info->bitmap, tid_info->bitmap,
376 			   off, CARL9170_BAW_BITS);
377 }
378 
379 static void carl9170_tx_status_process_ampdu(struct ar9170 *ar,
380 	struct sk_buff *skb, struct ieee80211_tx_info *txinfo)
381 {
382 	struct _carl9170_tx_superframe *super = (void *) skb->data;
383 	struct ieee80211_hdr *hdr = (void *) super->frame_data;
384 	struct ieee80211_sta *sta;
385 	struct carl9170_sta_info *sta_info;
386 	struct carl9170_sta_tid *tid_info;
387 	u8 tid;
388 
389 	if (!(txinfo->flags & IEEE80211_TX_CTL_AMPDU) ||
390 	    txinfo->flags & IEEE80211_TX_CTL_INJECTED ||
391 	   (!(super->f.mac_control & cpu_to_le16(AR9170_TX_MAC_AGGR))))
392 		return;
393 
394 	rcu_read_lock();
395 	sta = __carl9170_get_tx_sta(ar, skb);
396 	if (unlikely(!sta))
397 		goto out_rcu;
398 
399 	tid = get_tid_h(hdr);
400 
401 	sta_info = (void *) sta->drv_priv;
402 	tid_info = rcu_dereference(sta_info->agg[tid]);
403 	if (!tid_info)
404 		goto out_rcu;
405 
406 	spin_lock_bh(&tid_info->lock);
407 	if (likely(tid_info->state >= CARL9170_TID_STATE_IDLE))
408 		carl9170_tx_shift_bm(ar, tid_info, get_seq_h(hdr));
409 
410 	if (sta_info->stats[tid].clear) {
411 		sta_info->stats[tid].clear = false;
412 		sta_info->stats[tid].req = false;
413 		sta_info->stats[tid].ampdu_len = 0;
414 		sta_info->stats[tid].ampdu_ack_len = 0;
415 	}
416 
417 	sta_info->stats[tid].ampdu_len++;
418 	if (txinfo->status.rates[0].count == 1)
419 		sta_info->stats[tid].ampdu_ack_len++;
420 
421 	if (!(txinfo->flags & IEEE80211_TX_STAT_ACK))
422 		sta_info->stats[tid].req = true;
423 
424 	if (super->f.mac_control & cpu_to_le16(AR9170_TX_MAC_IMM_BA)) {
425 		super->s.rix = sta_info->stats[tid].ampdu_len;
426 		super->s.cnt = sta_info->stats[tid].ampdu_ack_len;
427 		txinfo->flags |= IEEE80211_TX_STAT_AMPDU;
428 		if (sta_info->stats[tid].req)
429 			txinfo->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
430 
431 		sta_info->stats[tid].clear = true;
432 	}
433 	spin_unlock_bh(&tid_info->lock);
434 
435 out_rcu:
436 	rcu_read_unlock();
437 }
438 
439 static void carl9170_tx_bar_status(struct ar9170 *ar, struct sk_buff *skb,
440 	struct ieee80211_tx_info *tx_info)
441 {
442 	struct _carl9170_tx_superframe *super = (void *) skb->data;
443 	struct ieee80211_bar *bar = (void *) super->frame_data;
444 
445 	/*
446 	 * Unlike all other frames, the status report for BARs does
447 	 * not directly come from the hardware as it is incapable of
448 	 * matching a BA to a previously send BAR.
449 	 * Instead the RX-path will scan for incoming BAs and set the
450 	 * IEEE80211_TX_STAT_ACK if it sees one that was likely
451 	 * caused by a BAR from us.
452 	 */
453 
454 	if (unlikely(ieee80211_is_back_req(bar->frame_control)) &&
455 	   !(tx_info->flags & IEEE80211_TX_STAT_ACK)) {
456 		struct carl9170_bar_list_entry *entry;
457 		int queue = skb_get_queue_mapping(skb);
458 
459 		rcu_read_lock();
460 		list_for_each_entry_rcu(entry, &ar->bar_list[queue], list) {
461 			if (entry->skb == skb) {
462 				spin_lock_bh(&ar->bar_list_lock[queue]);
463 				list_del_rcu(&entry->list);
464 				spin_unlock_bh(&ar->bar_list_lock[queue]);
465 				kfree_rcu(entry, head);
466 				goto out;
467 			}
468 		}
469 
470 		WARN(1, "bar not found in %d - ra:%pM ta:%pM c:%x ssn:%x\n",
471 		       queue, bar->ra, bar->ta, bar->control,
472 			bar->start_seq_num);
473 out:
474 		rcu_read_unlock();
475 	}
476 }
477 
478 void carl9170_tx_status(struct ar9170 *ar, struct sk_buff *skb,
479 			const bool success)
480 {
481 	struct ieee80211_tx_info *txinfo;
482 
483 	carl9170_tx_accounting_free(ar, skb);
484 
485 	txinfo = IEEE80211_SKB_CB(skb);
486 
487 	carl9170_tx_bar_status(ar, skb, txinfo);
488 
489 	if (success)
490 		txinfo->flags |= IEEE80211_TX_STAT_ACK;
491 	else
492 		ar->tx_ack_failures++;
493 
494 	if (txinfo->flags & IEEE80211_TX_CTL_AMPDU)
495 		carl9170_tx_status_process_ampdu(ar, skb, txinfo);
496 
497 	carl9170_tx_ps_unblock(ar, skb);
498 	carl9170_tx_put_skb(skb);
499 }
500 
501 /* This function may be called form any context */
502 void carl9170_tx_callback(struct ar9170 *ar, struct sk_buff *skb)
503 {
504 	struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
505 
506 	atomic_dec(&ar->tx_total_pending);
507 
508 	if (txinfo->flags & IEEE80211_TX_CTL_AMPDU)
509 		atomic_dec(&ar->tx_ampdu_upload);
510 
511 	if (carl9170_tx_put_skb(skb))
512 		tasklet_hi_schedule(&ar->usb_tasklet);
513 }
514 
515 static struct sk_buff *carl9170_get_queued_skb(struct ar9170 *ar, u8 cookie,
516 					       struct sk_buff_head *queue)
517 {
518 	struct sk_buff *skb;
519 
520 	spin_lock_bh(&queue->lock);
521 	skb_queue_walk(queue, skb) {
522 		struct _carl9170_tx_superframe *txc = (void *) skb->data;
523 
524 		if (txc->s.cookie != cookie)
525 			continue;
526 
527 		__skb_unlink(skb, queue);
528 		spin_unlock_bh(&queue->lock);
529 
530 		carl9170_release_dev_space(ar, skb);
531 		return skb;
532 	}
533 	spin_unlock_bh(&queue->lock);
534 
535 	return NULL;
536 }
537 
538 static void carl9170_tx_fill_rateinfo(struct ar9170 *ar, unsigned int rix,
539 	unsigned int tries, struct ieee80211_tx_info *txinfo)
540 {
541 	unsigned int i;
542 
543 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
544 		if (txinfo->status.rates[i].idx < 0)
545 			break;
546 
547 		if (i == rix) {
548 			txinfo->status.rates[i].count = tries;
549 			i++;
550 			break;
551 		}
552 	}
553 
554 	for (; i < IEEE80211_TX_MAX_RATES; i++) {
555 		txinfo->status.rates[i].idx = -1;
556 		txinfo->status.rates[i].count = 0;
557 	}
558 }
559 
560 static void carl9170_check_queue_stop_timeout(struct ar9170 *ar)
561 {
562 	int i;
563 	struct sk_buff *skb;
564 	struct ieee80211_tx_info *txinfo;
565 	struct carl9170_tx_info *arinfo;
566 	bool restart = false;
567 
568 	for (i = 0; i < ar->hw->queues; i++) {
569 		spin_lock_bh(&ar->tx_status[i].lock);
570 
571 		skb = skb_peek(&ar->tx_status[i]);
572 
573 		if (!skb)
574 			goto next;
575 
576 		txinfo = IEEE80211_SKB_CB(skb);
577 		arinfo = (void *) txinfo->rate_driver_data;
578 
579 		if (time_is_before_jiffies(arinfo->timeout +
580 		    msecs_to_jiffies(CARL9170_QUEUE_STUCK_TIMEOUT)) == true)
581 			restart = true;
582 
583 next:
584 		spin_unlock_bh(&ar->tx_status[i].lock);
585 	}
586 
587 	if (restart) {
588 		/*
589 		 * At least one queue has been stuck for long enough.
590 		 * Give the device a kick and hope it gets back to
591 		 * work.
592 		 *
593 		 * possible reasons may include:
594 		 *  - frames got lost/corrupted (bad connection to the device)
595 		 *  - stalled rx processing/usb controller hiccups
596 		 *  - firmware errors/bugs
597 		 *  - every bug you can think of.
598 		 *  - all bugs you can't...
599 		 *  - ...
600 		 */
601 		carl9170_restart(ar, CARL9170_RR_STUCK_TX);
602 	}
603 }
604 
605 static void carl9170_tx_ampdu_timeout(struct ar9170 *ar)
606 {
607 	struct carl9170_sta_tid *iter;
608 	struct sk_buff *skb;
609 	struct ieee80211_tx_info *txinfo;
610 	struct carl9170_tx_info *arinfo;
611 	struct ieee80211_sta *sta;
612 
613 	rcu_read_lock();
614 	list_for_each_entry_rcu(iter, &ar->tx_ampdu_list, list) {
615 		if (iter->state < CARL9170_TID_STATE_IDLE)
616 			continue;
617 
618 		spin_lock_bh(&iter->lock);
619 		skb = skb_peek(&iter->queue);
620 		if (!skb)
621 			goto unlock;
622 
623 		txinfo = IEEE80211_SKB_CB(skb);
624 		arinfo = (void *)txinfo->rate_driver_data;
625 		if (time_is_after_jiffies(arinfo->timeout +
626 		    msecs_to_jiffies(CARL9170_QUEUE_TIMEOUT)))
627 			goto unlock;
628 
629 		sta = __carl9170_get_tx_sta(ar, skb);
630 		if (WARN_ON(!sta))
631 			goto unlock;
632 
633 		ieee80211_stop_tx_ba_session(sta, iter->tid);
634 unlock:
635 		spin_unlock_bh(&iter->lock);
636 
637 	}
638 	rcu_read_unlock();
639 }
640 
641 void carl9170_tx_janitor(struct work_struct *work)
642 {
643 	struct ar9170 *ar = container_of(work, struct ar9170,
644 					 tx_janitor.work);
645 	if (!IS_STARTED(ar))
646 		return;
647 
648 	ar->tx_janitor_last_run = jiffies;
649 
650 	carl9170_check_queue_stop_timeout(ar);
651 	carl9170_tx_ampdu_timeout(ar);
652 
653 	if (!atomic_read(&ar->tx_total_queued))
654 		return;
655 
656 	ieee80211_queue_delayed_work(ar->hw, &ar->tx_janitor,
657 		msecs_to_jiffies(CARL9170_TX_TIMEOUT));
658 }
659 
660 static void __carl9170_tx_process_status(struct ar9170 *ar,
661 	const uint8_t cookie, const uint8_t info)
662 {
663 	struct sk_buff *skb;
664 	struct ieee80211_tx_info *txinfo;
665 	unsigned int r, t, q;
666 	bool success = true;
667 
668 	q = ar9170_qmap[info & CARL9170_TX_STATUS_QUEUE];
669 
670 	skb = carl9170_get_queued_skb(ar, cookie, &ar->tx_status[q]);
671 	if (!skb) {
672 		/*
673 		 * We have lost the race to another thread.
674 		 */
675 
676 		return ;
677 	}
678 
679 	txinfo = IEEE80211_SKB_CB(skb);
680 
681 	if (!(info & CARL9170_TX_STATUS_SUCCESS))
682 		success = false;
683 
684 	r = (info & CARL9170_TX_STATUS_RIX) >> CARL9170_TX_STATUS_RIX_S;
685 	t = (info & CARL9170_TX_STATUS_TRIES) >> CARL9170_TX_STATUS_TRIES_S;
686 
687 	carl9170_tx_fill_rateinfo(ar, r, t, txinfo);
688 	carl9170_tx_status(ar, skb, success);
689 }
690 
691 void carl9170_tx_process_status(struct ar9170 *ar,
692 				const struct carl9170_rsp *cmd)
693 {
694 	unsigned int i;
695 
696 	for (i = 0;  i < cmd->hdr.ext; i++) {
697 		if (WARN_ON(i > ((cmd->hdr.len / 2) + 1))) {
698 			print_hex_dump_bytes("UU:", DUMP_PREFIX_NONE,
699 					     (void *) cmd, cmd->hdr.len + 4);
700 			break;
701 		}
702 
703 		__carl9170_tx_process_status(ar, cmd->_tx_status[i].cookie,
704 					     cmd->_tx_status[i].info);
705 	}
706 }
707 
708 static void carl9170_tx_rate_tpc_chains(struct ar9170 *ar,
709 	struct ieee80211_tx_info *info,	struct ieee80211_tx_rate *txrate,
710 	unsigned int *phyrate, unsigned int *tpc, unsigned int *chains)
711 {
712 	struct ieee80211_rate *rate = NULL;
713 	u8 *txpower;
714 	unsigned int idx;
715 
716 	idx = txrate->idx;
717 	*tpc = 0;
718 	*phyrate = 0;
719 
720 	if (txrate->flags & IEEE80211_TX_RC_MCS) {
721 		if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
722 			/* +1 dBm for HT40 */
723 			*tpc += 2;
724 
725 			if (info->band == IEEE80211_BAND_2GHZ)
726 				txpower = ar->power_2G_ht40;
727 			else
728 				txpower = ar->power_5G_ht40;
729 		} else {
730 			if (info->band == IEEE80211_BAND_2GHZ)
731 				txpower = ar->power_2G_ht20;
732 			else
733 				txpower = ar->power_5G_ht20;
734 		}
735 
736 		*phyrate = txrate->idx;
737 		*tpc += txpower[idx & 7];
738 	} else {
739 		if (info->band == IEEE80211_BAND_2GHZ) {
740 			if (idx < 4)
741 				txpower = ar->power_2G_cck;
742 			else
743 				txpower = ar->power_2G_ofdm;
744 		} else {
745 			txpower = ar->power_5G_leg;
746 			idx += 4;
747 		}
748 
749 		rate = &__carl9170_ratetable[idx];
750 		*tpc += txpower[(rate->hw_value & 0x30) >> 4];
751 		*phyrate = rate->hw_value & 0xf;
752 	}
753 
754 	if (ar->eeprom.tx_mask == 1) {
755 		*chains = AR9170_TX_PHY_TXCHAIN_1;
756 	} else {
757 		if (!(txrate->flags & IEEE80211_TX_RC_MCS) &&
758 		    rate && rate->bitrate >= 360)
759 			*chains = AR9170_TX_PHY_TXCHAIN_1;
760 		else
761 			*chains = AR9170_TX_PHY_TXCHAIN_2;
762 	}
763 
764 	*tpc = min_t(unsigned int, *tpc, ar->hw->conf.power_level * 2);
765 }
766 
767 static __le32 carl9170_tx_physet(struct ar9170 *ar,
768 	struct ieee80211_tx_info *info, struct ieee80211_tx_rate *txrate)
769 {
770 	unsigned int power = 0, chains = 0, phyrate = 0;
771 	__le32 tmp;
772 
773 	tmp = cpu_to_le32(0);
774 
775 	if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
776 		tmp |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ <<
777 			AR9170_TX_PHY_BW_S);
778 	/* this works because 40 MHz is 2 and dup is 3 */
779 	if (txrate->flags & IEEE80211_TX_RC_DUP_DATA)
780 		tmp |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ_DUP <<
781 			AR9170_TX_PHY_BW_S);
782 
783 	if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
784 		tmp |= cpu_to_le32(AR9170_TX_PHY_SHORT_GI);
785 
786 	if (txrate->flags & IEEE80211_TX_RC_MCS) {
787 		SET_VAL(AR9170_TX_PHY_MCS, phyrate, txrate->idx);
788 
789 		/* heavy clip control */
790 		tmp |= cpu_to_le32((txrate->idx & 0x7) <<
791 			AR9170_TX_PHY_TX_HEAVY_CLIP_S);
792 
793 		tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_HT);
794 
795 		/*
796 		 * green field preamble does not work.
797 		 *
798 		 * if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
799 		 * tmp |= cpu_to_le32(AR9170_TX_PHY_GREENFIELD);
800 		 */
801 	} else {
802 		if (info->band == IEEE80211_BAND_2GHZ) {
803 			if (txrate->idx <= AR9170_TX_PHY_RATE_CCK_11M)
804 				tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_CCK);
805 			else
806 				tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_OFDM);
807 		} else {
808 			tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_OFDM);
809 		}
810 
811 		/*
812 		 * short preamble seems to be broken too.
813 		 *
814 		 * if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
815 		 *	tmp |= cpu_to_le32(AR9170_TX_PHY_SHORT_PREAMBLE);
816 		 */
817 	}
818 	carl9170_tx_rate_tpc_chains(ar, info, txrate,
819 				    &phyrate, &power, &chains);
820 
821 	tmp |= cpu_to_le32(SET_CONSTVAL(AR9170_TX_PHY_MCS, phyrate));
822 	tmp |= cpu_to_le32(SET_CONSTVAL(AR9170_TX_PHY_TX_PWR, power));
823 	tmp |= cpu_to_le32(SET_CONSTVAL(AR9170_TX_PHY_TXCHAIN, chains));
824 	return tmp;
825 }
826 
827 static bool carl9170_tx_rts_check(struct ar9170 *ar,
828 				  struct ieee80211_tx_rate *rate,
829 				  bool ampdu, bool multi)
830 {
831 	switch (ar->erp_mode) {
832 	case CARL9170_ERP_AUTO:
833 		if (ampdu)
834 			break;
835 
836 	case CARL9170_ERP_MAC80211:
837 		if (!(rate->flags & IEEE80211_TX_RC_USE_RTS_CTS))
838 			break;
839 
840 	case CARL9170_ERP_RTS:
841 		if (likely(!multi))
842 			return true;
843 
844 	default:
845 		break;
846 	}
847 
848 	return false;
849 }
850 
851 static bool carl9170_tx_cts_check(struct ar9170 *ar,
852 				  struct ieee80211_tx_rate *rate)
853 {
854 	switch (ar->erp_mode) {
855 	case CARL9170_ERP_AUTO:
856 	case CARL9170_ERP_MAC80211:
857 		if (!(rate->flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
858 			break;
859 
860 	case CARL9170_ERP_CTS:
861 		return true;
862 
863 	default:
864 		break;
865 	}
866 
867 	return false;
868 }
869 
870 static int carl9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
871 {
872 	struct ieee80211_hdr *hdr;
873 	struct _carl9170_tx_superframe *txc;
874 	struct carl9170_vif_info *cvif;
875 	struct ieee80211_tx_info *info;
876 	struct ieee80211_tx_rate *txrate;
877 	struct ieee80211_sta *sta;
878 	struct carl9170_tx_info *arinfo;
879 	unsigned int hw_queue;
880 	int i;
881 	__le16 mac_tmp;
882 	u16 len;
883 	bool ampdu, no_ack;
884 
885 	BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
886 	BUILD_BUG_ON(sizeof(struct _carl9170_tx_superdesc) !=
887 		     CARL9170_TX_SUPERDESC_LEN);
888 
889 	BUILD_BUG_ON(sizeof(struct _ar9170_tx_hwdesc) !=
890 		     AR9170_TX_HWDESC_LEN);
891 
892 	BUILD_BUG_ON(IEEE80211_TX_MAX_RATES < CARL9170_TX_MAX_RATES);
893 
894 	BUILD_BUG_ON(AR9170_MAX_VIRTUAL_MAC >
895 		((CARL9170_TX_SUPER_MISC_VIF_ID >>
896 		 CARL9170_TX_SUPER_MISC_VIF_ID_S) + 1));
897 
898 	hw_queue = ar9170_qmap[carl9170_get_queue(ar, skb)];
899 
900 	hdr = (void *)skb->data;
901 	info = IEEE80211_SKB_CB(skb);
902 	len = skb->len;
903 
904 	/*
905 	 * Note: If the frame was sent through a monitor interface,
906 	 * the ieee80211_vif pointer can be NULL.
907 	 */
908 	if (likely(info->control.vif))
909 		cvif = (void *) info->control.vif->drv_priv;
910 	else
911 		cvif = NULL;
912 
913 	sta = info->control.sta;
914 
915 	txc = (void *)skb_push(skb, sizeof(*txc));
916 	memset(txc, 0, sizeof(*txc));
917 
918 	SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, txc->s.misc, hw_queue);
919 
920 	if (likely(cvif))
921 		SET_VAL(CARL9170_TX_SUPER_MISC_VIF_ID, txc->s.misc, cvif->id);
922 
923 	if (unlikely(info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM))
924 		txc->s.misc |= CARL9170_TX_SUPER_MISC_CAB;
925 
926 	if (unlikely(info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ))
927 		txc->s.misc |= CARL9170_TX_SUPER_MISC_ASSIGN_SEQ;
928 
929 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control)))
930 		txc->s.misc |= CARL9170_TX_SUPER_MISC_FILL_IN_TSF;
931 
932 	mac_tmp = cpu_to_le16(AR9170_TX_MAC_HW_DURATION |
933 			      AR9170_TX_MAC_BACKOFF);
934 	mac_tmp |= cpu_to_le16((hw_queue << AR9170_TX_MAC_QOS_S) &
935 			       AR9170_TX_MAC_QOS);
936 
937 	no_ack = !!(info->flags & IEEE80211_TX_CTL_NO_ACK);
938 	if (unlikely(no_ack))
939 		mac_tmp |= cpu_to_le16(AR9170_TX_MAC_NO_ACK);
940 
941 	if (info->control.hw_key) {
942 		len += info->control.hw_key->icv_len;
943 
944 		switch (info->control.hw_key->cipher) {
945 		case WLAN_CIPHER_SUITE_WEP40:
946 		case WLAN_CIPHER_SUITE_WEP104:
947 		case WLAN_CIPHER_SUITE_TKIP:
948 			mac_tmp |= cpu_to_le16(AR9170_TX_MAC_ENCR_RC4);
949 			break;
950 		case WLAN_CIPHER_SUITE_CCMP:
951 			mac_tmp |= cpu_to_le16(AR9170_TX_MAC_ENCR_AES);
952 			break;
953 		default:
954 			WARN_ON(1);
955 			goto err_out;
956 		}
957 	}
958 
959 	ampdu = !!(info->flags & IEEE80211_TX_CTL_AMPDU);
960 	if (ampdu) {
961 		unsigned int density, factor;
962 
963 		if (unlikely(!sta || !cvif))
964 			goto err_out;
965 
966 		factor = min_t(unsigned int, 1u, sta->ht_cap.ampdu_factor);
967 		density = sta->ht_cap.ampdu_density;
968 
969 		if (density) {
970 			/*
971 			 * Watch out!
972 			 *
973 			 * Otus uses slightly different density values than
974 			 * those from the 802.11n spec.
975 			 */
976 
977 			density = max_t(unsigned int, density + 1, 7u);
978 		}
979 
980 		SET_VAL(CARL9170_TX_SUPER_AMPDU_DENSITY,
981 			txc->s.ampdu_settings, density);
982 
983 		SET_VAL(CARL9170_TX_SUPER_AMPDU_FACTOR,
984 			txc->s.ampdu_settings, factor);
985 
986 		for (i = 0; i < CARL9170_TX_MAX_RATES; i++) {
987 			txrate = &info->control.rates[i];
988 			if (txrate->idx >= 0) {
989 				txc->s.ri[i] =
990 					CARL9170_TX_SUPER_RI_AMPDU;
991 
992 				if (WARN_ON(!(txrate->flags &
993 					      IEEE80211_TX_RC_MCS))) {
994 					/*
995 					 * Not sure if it's even possible
996 					 * to aggregate non-ht rates with
997 					 * this HW.
998 					 */
999 					goto err_out;
1000 				}
1001 				continue;
1002 			}
1003 
1004 			txrate->idx = 0;
1005 			txrate->count = ar->hw->max_rate_tries;
1006 		}
1007 
1008 		mac_tmp |= cpu_to_le16(AR9170_TX_MAC_AGGR);
1009 	}
1010 
1011 	/*
1012 	 * NOTE: For the first rate, the ERP & AMPDU flags are directly
1013 	 * taken from mac_control. For all fallback rate, the firmware
1014 	 * updates the mac_control flags from the rate info field.
1015 	 */
1016 	for (i = 1; i < CARL9170_TX_MAX_RATES; i++) {
1017 		txrate = &info->control.rates[i];
1018 		if (txrate->idx < 0)
1019 			break;
1020 
1021 		SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[i],
1022 			txrate->count);
1023 
1024 		if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
1025 			txc->s.ri[i] |= (AR9170_TX_MAC_PROT_RTS <<
1026 				CARL9170_TX_SUPER_RI_ERP_PROT_S);
1027 		else if (carl9170_tx_cts_check(ar, txrate))
1028 			txc->s.ri[i] |= (AR9170_TX_MAC_PROT_CTS <<
1029 				CARL9170_TX_SUPER_RI_ERP_PROT_S);
1030 
1031 		txc->s.rr[i - 1] = carl9170_tx_physet(ar, info, txrate);
1032 	}
1033 
1034 	txrate = &info->control.rates[0];
1035 	SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[0], txrate->count);
1036 
1037 	if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
1038 		mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_RTS);
1039 	else if (carl9170_tx_cts_check(ar, txrate))
1040 		mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_CTS);
1041 
1042 	txc->s.len = cpu_to_le16(skb->len);
1043 	txc->f.length = cpu_to_le16(len + FCS_LEN);
1044 	txc->f.mac_control = mac_tmp;
1045 	txc->f.phy_control = carl9170_tx_physet(ar, info, txrate);
1046 
1047 	arinfo = (void *)info->rate_driver_data;
1048 	arinfo->timeout = jiffies;
1049 	arinfo->ar = ar;
1050 	kref_init(&arinfo->ref);
1051 	return 0;
1052 
1053 err_out:
1054 	skb_pull(skb, sizeof(*txc));
1055 	return -EINVAL;
1056 }
1057 
1058 static void carl9170_set_immba(struct ar9170 *ar, struct sk_buff *skb)
1059 {
1060 	struct _carl9170_tx_superframe *super;
1061 
1062 	super = (void *) skb->data;
1063 	super->f.mac_control |= cpu_to_le16(AR9170_TX_MAC_IMM_BA);
1064 }
1065 
1066 static void carl9170_set_ampdu_params(struct ar9170 *ar, struct sk_buff *skb)
1067 {
1068 	struct _carl9170_tx_superframe *super;
1069 	int tmp;
1070 
1071 	super = (void *) skb->data;
1072 
1073 	tmp = (super->s.ampdu_settings & CARL9170_TX_SUPER_AMPDU_DENSITY) <<
1074 		CARL9170_TX_SUPER_AMPDU_DENSITY_S;
1075 
1076 	/*
1077 	 * If you haven't noticed carl9170_tx_prepare has already filled
1078 	 * in all ampdu spacing & factor parameters.
1079 	 * Now it's the time to check whenever the settings have to be
1080 	 * updated by the firmware, or if everything is still the same.
1081 	 *
1082 	 * There's no sane way to handle different density values with
1083 	 * this hardware, so we may as well just do the compare in the
1084 	 * driver.
1085 	 */
1086 
1087 	if (tmp != ar->current_density) {
1088 		ar->current_density = tmp;
1089 		super->s.ampdu_settings |=
1090 			CARL9170_TX_SUPER_AMPDU_COMMIT_DENSITY;
1091 	}
1092 
1093 	tmp = (super->s.ampdu_settings & CARL9170_TX_SUPER_AMPDU_FACTOR) <<
1094 		CARL9170_TX_SUPER_AMPDU_FACTOR_S;
1095 
1096 	if (tmp != ar->current_factor) {
1097 		ar->current_factor = tmp;
1098 		super->s.ampdu_settings |=
1099 			CARL9170_TX_SUPER_AMPDU_COMMIT_FACTOR;
1100 	}
1101 }
1102 
1103 static bool carl9170_tx_rate_check(struct ar9170 *ar, struct sk_buff *_dest,
1104 				   struct sk_buff *_src)
1105 {
1106 	struct _carl9170_tx_superframe *dest, *src;
1107 
1108 	dest = (void *) _dest->data;
1109 	src = (void *) _src->data;
1110 
1111 	/*
1112 	 * The mac80211 rate control algorithm expects that all MPDUs in
1113 	 * an AMPDU share the same tx vectors.
1114 	 * This is not really obvious right now, because the hardware
1115 	 * does the AMPDU setup according to its own rulebook.
1116 	 * Our nicely assembled, strictly monotonic increasing mpdu
1117 	 * chains will be broken up, mashed back together...
1118 	 */
1119 
1120 	return (dest->f.phy_control == src->f.phy_control);
1121 }
1122 
1123 static void carl9170_tx_ampdu(struct ar9170 *ar)
1124 {
1125 	struct sk_buff_head agg;
1126 	struct carl9170_sta_tid *tid_info;
1127 	struct sk_buff *skb, *first;
1128 	unsigned int i = 0, done_ampdus = 0;
1129 	u16 seq, queue, tmpssn;
1130 
1131 	atomic_inc(&ar->tx_ampdu_scheduler);
1132 	ar->tx_ampdu_schedule = false;
1133 
1134 	if (atomic_read(&ar->tx_ampdu_upload))
1135 		return;
1136 
1137 	if (!ar->tx_ampdu_list_len)
1138 		return;
1139 
1140 	__skb_queue_head_init(&agg);
1141 
1142 	rcu_read_lock();
1143 	tid_info = rcu_dereference(ar->tx_ampdu_iter);
1144 	if (WARN_ON_ONCE(!tid_info)) {
1145 		rcu_read_unlock();
1146 		return;
1147 	}
1148 
1149 retry:
1150 	list_for_each_entry_continue_rcu(tid_info, &ar->tx_ampdu_list, list) {
1151 		i++;
1152 
1153 		if (tid_info->state < CARL9170_TID_STATE_PROGRESS)
1154 			continue;
1155 
1156 		queue = TID_TO_WME_AC(tid_info->tid);
1157 
1158 		spin_lock_bh(&tid_info->lock);
1159 		if (tid_info->state != CARL9170_TID_STATE_XMIT)
1160 			goto processed;
1161 
1162 		tid_info->counter++;
1163 		first = skb_peek(&tid_info->queue);
1164 		tmpssn = carl9170_get_seq(first);
1165 		seq = tid_info->snx;
1166 
1167 		if (unlikely(tmpssn != seq)) {
1168 			tid_info->state = CARL9170_TID_STATE_IDLE;
1169 
1170 			goto processed;
1171 		}
1172 
1173 		while ((skb = skb_peek(&tid_info->queue))) {
1174 			/* strict 0, 1, ..., n - 1, n frame sequence order */
1175 			if (unlikely(carl9170_get_seq(skb) != seq))
1176 				break;
1177 
1178 			/* don't upload more than AMPDU FACTOR allows. */
1179 			if (unlikely(SEQ_DIFF(tid_info->snx, tid_info->bsn) >=
1180 			    (tid_info->max - 1)))
1181 				break;
1182 
1183 			if (!carl9170_tx_rate_check(ar, skb, first))
1184 				break;
1185 
1186 			atomic_inc(&ar->tx_ampdu_upload);
1187 			tid_info->snx = seq = SEQ_NEXT(seq);
1188 			__skb_unlink(skb, &tid_info->queue);
1189 
1190 			__skb_queue_tail(&agg, skb);
1191 
1192 			if (skb_queue_len(&agg) >= CARL9170_NUM_TX_AGG_MAX)
1193 				break;
1194 		}
1195 
1196 		if (skb_queue_empty(&tid_info->queue) ||
1197 		    carl9170_get_seq(skb_peek(&tid_info->queue)) !=
1198 		    tid_info->snx) {
1199 			/*
1200 			 * stop TID, if A-MPDU frames are still missing,
1201 			 * or whenever the queue is empty.
1202 			 */
1203 
1204 			tid_info->state = CARL9170_TID_STATE_IDLE;
1205 		}
1206 		done_ampdus++;
1207 
1208 processed:
1209 		spin_unlock_bh(&tid_info->lock);
1210 
1211 		if (skb_queue_empty(&agg))
1212 			continue;
1213 
1214 		/* apply ampdu spacing & factor settings */
1215 		carl9170_set_ampdu_params(ar, skb_peek(&agg));
1216 
1217 		/* set aggregation push bit */
1218 		carl9170_set_immba(ar, skb_peek_tail(&agg));
1219 
1220 		spin_lock_bh(&ar->tx_pending[queue].lock);
1221 		skb_queue_splice_tail_init(&agg, &ar->tx_pending[queue]);
1222 		spin_unlock_bh(&ar->tx_pending[queue].lock);
1223 		ar->tx_schedule = true;
1224 	}
1225 	if ((done_ampdus++ == 0) && (i++ == 0))
1226 		goto retry;
1227 
1228 	rcu_assign_pointer(ar->tx_ampdu_iter, tid_info);
1229 	rcu_read_unlock();
1230 }
1231 
1232 static struct sk_buff *carl9170_tx_pick_skb(struct ar9170 *ar,
1233 					    struct sk_buff_head *queue)
1234 {
1235 	struct sk_buff *skb;
1236 	struct ieee80211_tx_info *info;
1237 	struct carl9170_tx_info *arinfo;
1238 
1239 	BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
1240 
1241 	spin_lock_bh(&queue->lock);
1242 	skb = skb_peek(queue);
1243 	if (unlikely(!skb))
1244 		goto err_unlock;
1245 
1246 	if (carl9170_alloc_dev_space(ar, skb))
1247 		goto err_unlock;
1248 
1249 	__skb_unlink(skb, queue);
1250 	spin_unlock_bh(&queue->lock);
1251 
1252 	info = IEEE80211_SKB_CB(skb);
1253 	arinfo = (void *) info->rate_driver_data;
1254 
1255 	arinfo->timeout = jiffies;
1256 	return skb;
1257 
1258 err_unlock:
1259 	spin_unlock_bh(&queue->lock);
1260 	return NULL;
1261 }
1262 
1263 void carl9170_tx_drop(struct ar9170 *ar, struct sk_buff *skb)
1264 {
1265 	struct _carl9170_tx_superframe *super;
1266 	uint8_t q = 0;
1267 
1268 	ar->tx_dropped++;
1269 
1270 	super = (void *)skb->data;
1271 	SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, q,
1272 		ar9170_qmap[carl9170_get_queue(ar, skb)]);
1273 	__carl9170_tx_process_status(ar, super->s.cookie, q);
1274 }
1275 
1276 static bool carl9170_tx_ps_drop(struct ar9170 *ar, struct sk_buff *skb)
1277 {
1278 	struct ieee80211_sta *sta;
1279 	struct carl9170_sta_info *sta_info;
1280 	struct ieee80211_tx_info *tx_info;
1281 
1282 	rcu_read_lock();
1283 	sta = __carl9170_get_tx_sta(ar, skb);
1284 	if (!sta)
1285 		goto out_rcu;
1286 
1287 	sta_info = (void *) sta->drv_priv;
1288 	tx_info = IEEE80211_SKB_CB(skb);
1289 
1290 	if (unlikely(sta_info->sleeping) &&
1291 	    !(tx_info->flags & (IEEE80211_TX_CTL_NO_PS_BUFFER |
1292 				IEEE80211_TX_CTL_CLEAR_PS_FILT))) {
1293 		rcu_read_unlock();
1294 
1295 		if (tx_info->flags & IEEE80211_TX_CTL_AMPDU)
1296 			atomic_dec(&ar->tx_ampdu_upload);
1297 
1298 		tx_info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
1299 		carl9170_release_dev_space(ar, skb);
1300 		carl9170_tx_status(ar, skb, false);
1301 		return true;
1302 	}
1303 
1304 out_rcu:
1305 	rcu_read_unlock();
1306 	return false;
1307 }
1308 
1309 static void carl9170_bar_check(struct ar9170 *ar, struct sk_buff *skb)
1310 {
1311 	struct _carl9170_tx_superframe *super = (void *) skb->data;
1312 	struct ieee80211_bar *bar = (void *) super->frame_data;
1313 
1314 	if (unlikely(ieee80211_is_back_req(bar->frame_control)) &&
1315 	    skb->len >= sizeof(struct ieee80211_bar)) {
1316 		struct carl9170_bar_list_entry *entry;
1317 		unsigned int queue = skb_get_queue_mapping(skb);
1318 
1319 		entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
1320 		if (!WARN_ON_ONCE(!entry)) {
1321 			entry->skb = skb;
1322 			spin_lock_bh(&ar->bar_list_lock[queue]);
1323 			list_add_tail_rcu(&entry->list, &ar->bar_list[queue]);
1324 			spin_unlock_bh(&ar->bar_list_lock[queue]);
1325 		}
1326 	}
1327 }
1328 
1329 static void carl9170_tx(struct ar9170 *ar)
1330 {
1331 	struct sk_buff *skb;
1332 	unsigned int i, q;
1333 	bool schedule_garbagecollector = false;
1334 
1335 	ar->tx_schedule = false;
1336 
1337 	if (unlikely(!IS_STARTED(ar)))
1338 		return;
1339 
1340 	carl9170_usb_handle_tx_err(ar);
1341 
1342 	for (i = 0; i < ar->hw->queues; i++) {
1343 		while (!skb_queue_empty(&ar->tx_pending[i])) {
1344 			skb = carl9170_tx_pick_skb(ar, &ar->tx_pending[i]);
1345 			if (unlikely(!skb))
1346 				break;
1347 
1348 			if (unlikely(carl9170_tx_ps_drop(ar, skb)))
1349 				continue;
1350 
1351 			carl9170_bar_check(ar, skb);
1352 
1353 			atomic_inc(&ar->tx_total_pending);
1354 
1355 			q = __carl9170_get_queue(ar, i);
1356 			/*
1357 			 * NB: tx_status[i] vs. tx_status[q],
1358 			 * TODO: Move into pick_skb or alloc_dev_space.
1359 			 */
1360 			skb_queue_tail(&ar->tx_status[q], skb);
1361 
1362 			/*
1363 			 * increase ref count to "2".
1364 			 * Ref counting is the easiest way to solve the
1365 			 * race between the urb's completion routine:
1366 			 *	carl9170_tx_callback
1367 			 * and wlan tx status functions:
1368 			 *	carl9170_tx_status/janitor.
1369 			 */
1370 			carl9170_tx_get_skb(skb);
1371 
1372 			carl9170_usb_tx(ar, skb);
1373 			schedule_garbagecollector = true;
1374 		}
1375 	}
1376 
1377 	if (!schedule_garbagecollector)
1378 		return;
1379 
1380 	ieee80211_queue_delayed_work(ar->hw, &ar->tx_janitor,
1381 		msecs_to_jiffies(CARL9170_TX_TIMEOUT));
1382 }
1383 
1384 static bool carl9170_tx_ampdu_queue(struct ar9170 *ar,
1385 	struct ieee80211_sta *sta, struct sk_buff *skb)
1386 {
1387 	struct _carl9170_tx_superframe *super = (void *) skb->data;
1388 	struct carl9170_sta_info *sta_info;
1389 	struct carl9170_sta_tid *agg;
1390 	struct sk_buff *iter;
1391 	u16 tid, seq, qseq, off;
1392 	bool run = false;
1393 
1394 	tid = carl9170_get_tid(skb);
1395 	seq = carl9170_get_seq(skb);
1396 	sta_info = (void *) sta->drv_priv;
1397 
1398 	rcu_read_lock();
1399 	agg = rcu_dereference(sta_info->agg[tid]);
1400 
1401 	if (!agg)
1402 		goto err_unlock_rcu;
1403 
1404 	spin_lock_bh(&agg->lock);
1405 	if (unlikely(agg->state < CARL9170_TID_STATE_IDLE))
1406 		goto err_unlock;
1407 
1408 	/* check if sequence is within the BA window */
1409 	if (unlikely(!BAW_WITHIN(agg->bsn, CARL9170_BAW_BITS, seq)))
1410 		goto err_unlock;
1411 
1412 	if (WARN_ON_ONCE(!BAW_WITHIN(agg->snx, CARL9170_BAW_BITS, seq)))
1413 		goto err_unlock;
1414 
1415 	off = SEQ_DIFF(seq, agg->bsn);
1416 	if (WARN_ON_ONCE(test_and_set_bit(off, agg->bitmap)))
1417 		goto err_unlock;
1418 
1419 	if (likely(BAW_WITHIN(agg->hsn, CARL9170_BAW_BITS, seq))) {
1420 		__skb_queue_tail(&agg->queue, skb);
1421 		agg->hsn = seq;
1422 		goto queued;
1423 	}
1424 
1425 	skb_queue_reverse_walk(&agg->queue, iter) {
1426 		qseq = carl9170_get_seq(iter);
1427 
1428 		if (BAW_WITHIN(qseq, CARL9170_BAW_BITS, seq)) {
1429 			__skb_queue_after(&agg->queue, iter, skb);
1430 			goto queued;
1431 		}
1432 	}
1433 
1434 	__skb_queue_head(&agg->queue, skb);
1435 queued:
1436 
1437 	if (unlikely(agg->state != CARL9170_TID_STATE_XMIT)) {
1438 		if (agg->snx == carl9170_get_seq(skb_peek(&agg->queue))) {
1439 			agg->state = CARL9170_TID_STATE_XMIT;
1440 			run = true;
1441 		}
1442 	}
1443 
1444 	spin_unlock_bh(&agg->lock);
1445 	rcu_read_unlock();
1446 
1447 	return run;
1448 
1449 err_unlock:
1450 	spin_unlock_bh(&agg->lock);
1451 
1452 err_unlock_rcu:
1453 	rcu_read_unlock();
1454 	super->f.mac_control &= ~cpu_to_le16(AR9170_TX_MAC_AGGR);
1455 	carl9170_tx_status(ar, skb, false);
1456 	ar->tx_dropped++;
1457 	return false;
1458 }
1459 
1460 void carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
1461 {
1462 	struct ar9170 *ar = hw->priv;
1463 	struct ieee80211_tx_info *info;
1464 	struct ieee80211_sta *sta;
1465 	bool run;
1466 
1467 	if (unlikely(!IS_STARTED(ar)))
1468 		goto err_free;
1469 
1470 	info = IEEE80211_SKB_CB(skb);
1471 	sta = info->control.sta;
1472 
1473 	if (unlikely(carl9170_tx_prepare(ar, skb)))
1474 		goto err_free;
1475 
1476 	carl9170_tx_accounting(ar, skb);
1477 	/*
1478 	 * from now on, one has to use carl9170_tx_status to free
1479 	 * all ressouces which are associated with the frame.
1480 	 */
1481 
1482 	if (sta) {
1483 		struct carl9170_sta_info *stai = (void *) sta->drv_priv;
1484 		atomic_inc(&stai->pending_frames);
1485 	}
1486 
1487 	if (info->flags & IEEE80211_TX_CTL_AMPDU) {
1488 		run = carl9170_tx_ampdu_queue(ar, sta, skb);
1489 		if (run)
1490 			carl9170_tx_ampdu(ar);
1491 
1492 	} else {
1493 		unsigned int queue = skb_get_queue_mapping(skb);
1494 
1495 		skb_queue_tail(&ar->tx_pending[queue], skb);
1496 	}
1497 
1498 	carl9170_tx(ar);
1499 	return;
1500 
1501 err_free:
1502 	ar->tx_dropped++;
1503 	ieee80211_free_txskb(ar->hw, skb);
1504 }
1505 
1506 void carl9170_tx_scheduler(struct ar9170 *ar)
1507 {
1508 
1509 	if (ar->tx_ampdu_schedule)
1510 		carl9170_tx_ampdu(ar);
1511 
1512 	if (ar->tx_schedule)
1513 		carl9170_tx(ar);
1514 }
1515 
1516 int carl9170_update_beacon(struct ar9170 *ar, const bool submit)
1517 {
1518 	struct sk_buff *skb = NULL;
1519 	struct carl9170_vif_info *cvif;
1520 	struct ieee80211_tx_info *txinfo;
1521 	struct ieee80211_tx_rate *rate;
1522 	__le32 *data, *old = NULL;
1523 	unsigned int plcp, power, chains;
1524 	u32 word, ht1, off, addr, len;
1525 	int i = 0, err = 0;
1526 
1527 	rcu_read_lock();
1528 	cvif = rcu_dereference(ar->beacon_iter);
1529 retry:
1530 	if (ar->vifs == 0 || !cvif)
1531 		goto out_unlock;
1532 
1533 	list_for_each_entry_continue_rcu(cvif, &ar->vif_list, list) {
1534 		if (cvif->active && cvif->enable_beacon)
1535 			goto found;
1536 	}
1537 
1538 	if (!ar->beacon_enabled || i++)
1539 		goto out_unlock;
1540 
1541 	goto retry;
1542 
1543 found:
1544 	rcu_assign_pointer(ar->beacon_iter, cvif);
1545 
1546 	skb = ieee80211_beacon_get_tim(ar->hw, carl9170_get_vif(cvif),
1547 		NULL, NULL);
1548 
1549 	if (!skb) {
1550 		err = -ENOMEM;
1551 		goto err_free;
1552 	}
1553 
1554 	txinfo = IEEE80211_SKB_CB(skb);
1555 	spin_lock_bh(&ar->beacon_lock);
1556 	data = (__le32 *)skb->data;
1557 	if (cvif->beacon)
1558 		old = (__le32 *)cvif->beacon->data;
1559 
1560 	off = cvif->id * AR9170_MAC_BCN_LENGTH_MAX;
1561 	addr = ar->fw.beacon_addr + off;
1562 	len = roundup(skb->len + FCS_LEN, 4);
1563 
1564 	if ((off + len) > ar->fw.beacon_max_len) {
1565 		if (net_ratelimit()) {
1566 			wiphy_err(ar->hw->wiphy, "beacon does not "
1567 				  "fit into device memory!\n");
1568 		}
1569 		err = -EINVAL;
1570 		goto err_unlock;
1571 	}
1572 
1573 	if (len > AR9170_MAC_BCN_LENGTH_MAX) {
1574 		if (net_ratelimit()) {
1575 			wiphy_err(ar->hw->wiphy, "no support for beacons "
1576 				"bigger than %d (yours:%d).\n",
1577 				 AR9170_MAC_BCN_LENGTH_MAX, len);
1578 		}
1579 
1580 		err = -EMSGSIZE;
1581 		goto err_unlock;
1582 	}
1583 
1584 	ht1 = AR9170_MAC_BCN_HT1_TX_ANT0;
1585 	rate = &txinfo->control.rates[0];
1586 	carl9170_tx_rate_tpc_chains(ar, txinfo, rate, &plcp, &power, &chains);
1587 	if (!(txinfo->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
1588 		if (plcp <= AR9170_TX_PHY_RATE_CCK_11M)
1589 			plcp |= ((skb->len + FCS_LEN) << (3 + 16)) + 0x0400;
1590 		else
1591 			plcp |= ((skb->len + FCS_LEN) << 16) + 0x0010;
1592 	} else {
1593 		ht1 |= AR9170_MAC_BCN_HT1_HT_EN;
1594 		if (rate->flags & IEEE80211_TX_RC_SHORT_GI)
1595 			plcp |= AR9170_MAC_BCN_HT2_SGI;
1596 
1597 		if (rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1598 			ht1 |= AR9170_MAC_BCN_HT1_BWC_40M_SHARED;
1599 			plcp |= AR9170_MAC_BCN_HT2_BW40;
1600 		}
1601 		if (rate->flags & IEEE80211_TX_RC_DUP_DATA) {
1602 			ht1 |= AR9170_MAC_BCN_HT1_BWC_40M_DUP;
1603 			plcp |= AR9170_MAC_BCN_HT2_BW40;
1604 		}
1605 
1606 		SET_VAL(AR9170_MAC_BCN_HT2_LEN, plcp, skb->len + FCS_LEN);
1607 	}
1608 
1609 	SET_VAL(AR9170_MAC_BCN_HT1_PWR_CTRL, ht1, 7);
1610 	SET_VAL(AR9170_MAC_BCN_HT1_TPC, ht1, power);
1611 	SET_VAL(AR9170_MAC_BCN_HT1_CHAIN_MASK, ht1, chains);
1612 	if (chains == AR9170_TX_PHY_TXCHAIN_2)
1613 		ht1 |= AR9170_MAC_BCN_HT1_TX_ANT1;
1614 
1615 	carl9170_async_regwrite_begin(ar);
1616 	carl9170_async_regwrite(AR9170_MAC_REG_BCN_HT1, ht1);
1617 	if (!(txinfo->control.rates[0].flags & IEEE80211_TX_RC_MCS))
1618 		carl9170_async_regwrite(AR9170_MAC_REG_BCN_PLCP, plcp);
1619 	else
1620 		carl9170_async_regwrite(AR9170_MAC_REG_BCN_HT2, plcp);
1621 
1622 	for (i = 0; i < DIV_ROUND_UP(skb->len, 4); i++) {
1623 		/*
1624 		 * XXX: This accesses beyond skb data for up
1625 		 *	to the last 3 bytes!!
1626 		 */
1627 
1628 		if (old && (data[i] == old[i]))
1629 			continue;
1630 
1631 		word = le32_to_cpu(data[i]);
1632 		carl9170_async_regwrite(addr + 4 * i, word);
1633 	}
1634 	carl9170_async_regwrite_finish();
1635 
1636 	dev_kfree_skb_any(cvif->beacon);
1637 	cvif->beacon = NULL;
1638 
1639 	err = carl9170_async_regwrite_result();
1640 	if (!err)
1641 		cvif->beacon = skb;
1642 	spin_unlock_bh(&ar->beacon_lock);
1643 	if (err)
1644 		goto err_free;
1645 
1646 	if (submit) {
1647 		err = carl9170_bcn_ctrl(ar, cvif->id,
1648 					CARL9170_BCN_CTRL_CAB_TRIGGER,
1649 					addr, skb->len + FCS_LEN);
1650 
1651 		if (err)
1652 			goto err_free;
1653 	}
1654 out_unlock:
1655 	rcu_read_unlock();
1656 	return 0;
1657 
1658 err_unlock:
1659 	spin_unlock_bh(&ar->beacon_lock);
1660 
1661 err_free:
1662 	rcu_read_unlock();
1663 	dev_kfree_skb_any(skb);
1664 	return err;
1665 }
1666