1 /*
2  * Copyright (c) 2010-2011 Atheros Communications Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "htc.h"
18 
19 /******/
20 /* TX */
21 /******/
22 
23 static const int subtype_txq_to_hwq[] = {
24 	[IEEE80211_AC_BE] = ATH_TXQ_AC_BE,
25 	[IEEE80211_AC_BK] = ATH_TXQ_AC_BK,
26 	[IEEE80211_AC_VI] = ATH_TXQ_AC_VI,
27 	[IEEE80211_AC_VO] = ATH_TXQ_AC_VO,
28 };
29 
30 #define ATH9K_HTC_INIT_TXQ(subtype) do {			\
31 		qi.tqi_subtype = subtype_txq_to_hwq[subtype];	\
32 		qi.tqi_aifs = ATH9K_TXQ_USEDEFAULT;		\
33 		qi.tqi_cwmin = ATH9K_TXQ_USEDEFAULT;		\
34 		qi.tqi_cwmax = ATH9K_TXQ_USEDEFAULT;		\
35 		qi.tqi_physCompBuf = 0;				\
36 		qi.tqi_qflags = TXQ_FLAG_TXEOLINT_ENABLE |	\
37 			TXQ_FLAG_TXDESCINT_ENABLE;		\
38 	} while (0)
39 
40 int get_hw_qnum(u16 queue, int *hwq_map)
41 {
42 	switch (queue) {
43 	case 0:
44 		return hwq_map[IEEE80211_AC_VO];
45 	case 1:
46 		return hwq_map[IEEE80211_AC_VI];
47 	case 2:
48 		return hwq_map[IEEE80211_AC_BE];
49 	case 3:
50 		return hwq_map[IEEE80211_AC_BK];
51 	default:
52 		return hwq_map[IEEE80211_AC_BE];
53 	}
54 }
55 
56 void ath9k_htc_check_stop_queues(struct ath9k_htc_priv *priv)
57 {
58 	spin_lock_bh(&priv->tx.tx_lock);
59 	priv->tx.queued_cnt++;
60 	if ((priv->tx.queued_cnt >= ATH9K_HTC_TX_THRESHOLD) &&
61 	    !(priv->tx.flags & ATH9K_HTC_OP_TX_QUEUES_STOP)) {
62 		priv->tx.flags |= ATH9K_HTC_OP_TX_QUEUES_STOP;
63 		ieee80211_stop_queues(priv->hw);
64 	}
65 	spin_unlock_bh(&priv->tx.tx_lock);
66 }
67 
68 void ath9k_htc_check_wake_queues(struct ath9k_htc_priv *priv)
69 {
70 	spin_lock_bh(&priv->tx.tx_lock);
71 	if ((priv->tx.queued_cnt < ATH9K_HTC_TX_THRESHOLD) &&
72 	    (priv->tx.flags & ATH9K_HTC_OP_TX_QUEUES_STOP)) {
73 		priv->tx.flags &= ~ATH9K_HTC_OP_TX_QUEUES_STOP;
74 		ieee80211_wake_queues(priv->hw);
75 	}
76 	spin_unlock_bh(&priv->tx.tx_lock);
77 }
78 
79 int ath9k_htc_tx_get_slot(struct ath9k_htc_priv *priv)
80 {
81 	int slot;
82 
83 	spin_lock_bh(&priv->tx.tx_lock);
84 	slot = find_first_zero_bit(priv->tx.tx_slot, MAX_TX_BUF_NUM);
85 	if (slot >= MAX_TX_BUF_NUM) {
86 		spin_unlock_bh(&priv->tx.tx_lock);
87 		return -ENOBUFS;
88 	}
89 	__set_bit(slot, priv->tx.tx_slot);
90 	spin_unlock_bh(&priv->tx.tx_lock);
91 
92 	return slot;
93 }
94 
95 void ath9k_htc_tx_clear_slot(struct ath9k_htc_priv *priv, int slot)
96 {
97 	spin_lock_bh(&priv->tx.tx_lock);
98 	__clear_bit(slot, priv->tx.tx_slot);
99 	spin_unlock_bh(&priv->tx.tx_lock);
100 }
101 
102 static inline enum htc_endpoint_id get_htc_epid(struct ath9k_htc_priv *priv,
103 						u16 qnum)
104 {
105 	enum htc_endpoint_id epid;
106 
107 	switch (qnum) {
108 	case 0:
109 		TX_QSTAT_INC(priv, IEEE80211_AC_VO);
110 		epid = priv->data_vo_ep;
111 		break;
112 	case 1:
113 		TX_QSTAT_INC(priv, IEEE80211_AC_VI);
114 		epid = priv->data_vi_ep;
115 		break;
116 	case 2:
117 		TX_QSTAT_INC(priv, IEEE80211_AC_BE);
118 		epid = priv->data_be_ep;
119 		break;
120 	case 3:
121 	default:
122 		TX_QSTAT_INC(priv, IEEE80211_AC_BK);
123 		epid = priv->data_bk_ep;
124 		break;
125 	}
126 
127 	return epid;
128 }
129 
130 static inline struct sk_buff_head*
131 get_htc_epid_queue(struct ath9k_htc_priv *priv, u8 epid)
132 {
133 	struct ath_common *common = ath9k_hw_common(priv->ah);
134 	struct sk_buff_head *epid_queue = NULL;
135 
136 	if (epid == priv->mgmt_ep)
137 		epid_queue = &priv->tx.mgmt_ep_queue;
138 	else if (epid == priv->cab_ep)
139 		epid_queue = &priv->tx.cab_ep_queue;
140 	else if (epid == priv->data_be_ep)
141 		epid_queue = &priv->tx.data_be_queue;
142 	else if (epid == priv->data_bk_ep)
143 		epid_queue = &priv->tx.data_bk_queue;
144 	else if (epid == priv->data_vi_ep)
145 		epid_queue = &priv->tx.data_vi_queue;
146 	else if (epid == priv->data_vo_ep)
147 		epid_queue = &priv->tx.data_vo_queue;
148 	else
149 		ath_err(common, "Invalid EPID: %d\n", epid);
150 
151 	return epid_queue;
152 }
153 
154 /*
155  * Removes the driver header and returns the TX slot number
156  */
157 static inline int strip_drv_header(struct ath9k_htc_priv *priv,
158 				   struct sk_buff *skb)
159 {
160 	struct ath_common *common = ath9k_hw_common(priv->ah);
161 	struct ath9k_htc_tx_ctl *tx_ctl;
162 	int slot;
163 
164 	tx_ctl = HTC_SKB_CB(skb);
165 
166 	if (tx_ctl->epid == priv->mgmt_ep) {
167 		struct tx_mgmt_hdr *tx_mhdr =
168 			(struct tx_mgmt_hdr *)skb->data;
169 		slot = tx_mhdr->cookie;
170 		skb_pull(skb, sizeof(struct tx_mgmt_hdr));
171 	} else if ((tx_ctl->epid == priv->data_bk_ep) ||
172 		   (tx_ctl->epid == priv->data_be_ep) ||
173 		   (tx_ctl->epid == priv->data_vi_ep) ||
174 		   (tx_ctl->epid == priv->data_vo_ep) ||
175 		   (tx_ctl->epid == priv->cab_ep)) {
176 		struct tx_frame_hdr *tx_fhdr =
177 			(struct tx_frame_hdr *)skb->data;
178 		slot = tx_fhdr->cookie;
179 		skb_pull(skb, sizeof(struct tx_frame_hdr));
180 	} else {
181 		ath_err(common, "Unsupported EPID: %d\n", tx_ctl->epid);
182 		slot = -EINVAL;
183 	}
184 
185 	return slot;
186 }
187 
188 int ath_htc_txq_update(struct ath9k_htc_priv *priv, int qnum,
189 		       struct ath9k_tx_queue_info *qinfo)
190 {
191 	struct ath_hw *ah = priv->ah;
192 	int error = 0;
193 	struct ath9k_tx_queue_info qi;
194 
195 	ath9k_hw_get_txq_props(ah, qnum, &qi);
196 
197 	qi.tqi_aifs = qinfo->tqi_aifs;
198 	qi.tqi_cwmin = qinfo->tqi_cwmin / 2; /* XXX */
199 	qi.tqi_cwmax = qinfo->tqi_cwmax;
200 	qi.tqi_burstTime = qinfo->tqi_burstTime;
201 	qi.tqi_readyTime = qinfo->tqi_readyTime;
202 
203 	if (!ath9k_hw_set_txq_props(ah, qnum, &qi)) {
204 		ath_err(ath9k_hw_common(ah),
205 			"Unable to update hardware queue %u!\n", qnum);
206 		error = -EIO;
207 	} else {
208 		ath9k_hw_resettxqueue(ah, qnum);
209 	}
210 
211 	return error;
212 }
213 
214 static void ath9k_htc_tx_mgmt(struct ath9k_htc_priv *priv,
215 			      struct ath9k_htc_vif *avp,
216 			      struct sk_buff *skb,
217 			      u8 sta_idx, u8 vif_idx, u8 slot)
218 {
219 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
220 	struct ieee80211_mgmt *mgmt;
221 	struct ieee80211_hdr *hdr;
222 	struct tx_mgmt_hdr mgmt_hdr;
223 	struct ath9k_htc_tx_ctl *tx_ctl;
224 	u8 *tx_fhdr;
225 
226 	tx_ctl = HTC_SKB_CB(skb);
227 	hdr = (struct ieee80211_hdr *) skb->data;
228 
229 	memset(tx_ctl, 0, sizeof(*tx_ctl));
230 	memset(&mgmt_hdr, 0, sizeof(struct tx_mgmt_hdr));
231 
232 	/*
233 	 * Set the TSF adjust value for probe response
234 	 * frame also.
235 	 */
236 	if (avp && unlikely(ieee80211_is_probe_resp(hdr->frame_control))) {
237 		mgmt = (struct ieee80211_mgmt *)skb->data;
238 		mgmt->u.probe_resp.timestamp = avp->tsfadjust;
239 	}
240 
241 	tx_ctl->type = ATH9K_HTC_MGMT;
242 
243 	mgmt_hdr.node_idx = sta_idx;
244 	mgmt_hdr.vif_idx = vif_idx;
245 	mgmt_hdr.tidno = 0;
246 	mgmt_hdr.flags = 0;
247 	mgmt_hdr.cookie = slot;
248 
249 	mgmt_hdr.key_type = ath9k_cmn_get_hw_crypto_keytype(skb);
250 	if (mgmt_hdr.key_type == ATH9K_KEY_TYPE_CLEAR)
251 		mgmt_hdr.keyix = (u8) ATH9K_TXKEYIX_INVALID;
252 	else
253 		mgmt_hdr.keyix = tx_info->control.hw_key->hw_key_idx;
254 
255 	tx_fhdr = skb_push(skb, sizeof(mgmt_hdr));
256 	memcpy(tx_fhdr, (u8 *) &mgmt_hdr, sizeof(mgmt_hdr));
257 	tx_ctl->epid = priv->mgmt_ep;
258 }
259 
260 static void ath9k_htc_tx_data(struct ath9k_htc_priv *priv,
261 			      struct ieee80211_vif *vif,
262 			      struct sk_buff *skb,
263 			      u8 sta_idx, u8 vif_idx, u8 slot,
264 			      bool is_cab)
265 {
266 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
267 	struct ieee80211_hdr *hdr;
268 	struct ath9k_htc_tx_ctl *tx_ctl;
269 	struct tx_frame_hdr tx_hdr;
270 	u32 flags = 0;
271 	u8 *qc, *tx_fhdr;
272 	u16 qnum;
273 
274 	tx_ctl = HTC_SKB_CB(skb);
275 	hdr = (struct ieee80211_hdr *) skb->data;
276 
277 	memset(tx_ctl, 0, sizeof(*tx_ctl));
278 	memset(&tx_hdr, 0, sizeof(struct tx_frame_hdr));
279 
280 	tx_hdr.node_idx = sta_idx;
281 	tx_hdr.vif_idx = vif_idx;
282 	tx_hdr.cookie = slot;
283 
284 	/*
285 	 * This is a bit redundant but it helps to get
286 	 * the per-packet index quickly when draining the
287 	 * TX queue in the HIF layer. Otherwise we would
288 	 * have to parse the packet contents ...
289 	 */
290 	tx_ctl->sta_idx = sta_idx;
291 
292 	if (tx_info->flags & IEEE80211_TX_CTL_AMPDU) {
293 		tx_ctl->type = ATH9K_HTC_AMPDU;
294 		tx_hdr.data_type = ATH9K_HTC_AMPDU;
295 	} else {
296 		tx_ctl->type = ATH9K_HTC_NORMAL;
297 		tx_hdr.data_type = ATH9K_HTC_NORMAL;
298 	}
299 
300 	/* Transmit all frames that should not be reordered relative
301 	 * to each other using the same priority. For other QoS data
302 	 * frames extract the priority from the header.
303 	 */
304 	if (!(tx_info->control.flags & IEEE80211_TX_CTRL_DONT_REORDER) &&
305 	    ieee80211_is_data_qos(hdr->frame_control)) {
306 		qc = ieee80211_get_qos_ctl(hdr);
307 		tx_hdr.tidno = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
308 	}
309 
310 	/* Check for RTS protection */
311 	if (priv->hw->wiphy->rts_threshold != (u32) -1)
312 		if (skb->len > priv->hw->wiphy->rts_threshold)
313 			flags |= ATH9K_HTC_TX_RTSCTS;
314 
315 	/* CTS-to-self */
316 	if (!(flags & ATH9K_HTC_TX_RTSCTS) &&
317 	    (vif && vif->bss_conf.use_cts_prot))
318 		flags |= ATH9K_HTC_TX_CTSONLY;
319 
320 	tx_hdr.flags = cpu_to_be32(flags);
321 	tx_hdr.key_type = ath9k_cmn_get_hw_crypto_keytype(skb);
322 	if (tx_hdr.key_type == ATH9K_KEY_TYPE_CLEAR)
323 		tx_hdr.keyix = (u8) ATH9K_TXKEYIX_INVALID;
324 	else
325 		tx_hdr.keyix = tx_info->control.hw_key->hw_key_idx;
326 
327 	tx_fhdr = skb_push(skb, sizeof(tx_hdr));
328 	memcpy(tx_fhdr, (u8 *) &tx_hdr, sizeof(tx_hdr));
329 
330 	if (is_cab) {
331 		CAB_STAT_INC(priv);
332 		tx_ctl->epid = priv->cab_ep;
333 		return;
334 	}
335 
336 	qnum = skb_get_queue_mapping(skb);
337 	tx_ctl->epid = get_htc_epid(priv, qnum);
338 }
339 
340 int ath9k_htc_tx_start(struct ath9k_htc_priv *priv,
341 		       struct ieee80211_sta *sta,
342 		       struct sk_buff *skb,
343 		       u8 slot, bool is_cab)
344 {
345 	struct ieee80211_hdr *hdr;
346 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
347 	struct ieee80211_vif *vif = tx_info->control.vif;
348 	struct ath9k_htc_sta *ista;
349 	struct ath9k_htc_vif *avp = NULL;
350 	u8 sta_idx, vif_idx;
351 
352 	hdr = (struct ieee80211_hdr *) skb->data;
353 
354 	/*
355 	 * Find out on which interface this packet has to be
356 	 * sent out.
357 	 */
358 	if (vif) {
359 		avp = (struct ath9k_htc_vif *) vif->drv_priv;
360 		vif_idx = avp->index;
361 	} else {
362 		if (!priv->ah->is_monitoring) {
363 			ath_dbg(ath9k_hw_common(priv->ah), XMIT,
364 				"VIF is null, but no monitor interface !\n");
365 			return -EINVAL;
366 		}
367 
368 		vif_idx = priv->mon_vif_idx;
369 	}
370 
371 	/*
372 	 * Find out which station this packet is destined for.
373 	 */
374 	if (sta) {
375 		ista = (struct ath9k_htc_sta *) sta->drv_priv;
376 		sta_idx = ista->index;
377 	} else {
378 		sta_idx = priv->vif_sta_pos[vif_idx];
379 	}
380 
381 	if (ieee80211_is_data(hdr->frame_control))
382 		ath9k_htc_tx_data(priv, vif, skb,
383 				  sta_idx, vif_idx, slot, is_cab);
384 	else
385 		ath9k_htc_tx_mgmt(priv, avp, skb,
386 				  sta_idx, vif_idx, slot);
387 
388 
389 	return htc_send(priv->htc, skb);
390 }
391 
392 static inline bool __ath9k_htc_check_tx_aggr(struct ath9k_htc_priv *priv,
393 					     struct ath9k_htc_sta *ista, u8 tid)
394 {
395 	bool ret = false;
396 
397 	spin_lock_bh(&priv->tx.tx_lock);
398 	if ((tid < ATH9K_HTC_MAX_TID) && (ista->tid_state[tid] == AGGR_STOP))
399 		ret = true;
400 	spin_unlock_bh(&priv->tx.tx_lock);
401 
402 	return ret;
403 }
404 
405 static void ath9k_htc_check_tx_aggr(struct ath9k_htc_priv *priv,
406 				    struct ieee80211_vif *vif,
407 				    struct sk_buff *skb)
408 {
409 	struct ieee80211_sta *sta;
410 	struct ieee80211_hdr *hdr;
411 	__le16 fc;
412 
413 	hdr = (struct ieee80211_hdr *) skb->data;
414 	fc = hdr->frame_control;
415 
416 	rcu_read_lock();
417 
418 	sta = ieee80211_find_sta(vif, hdr->addr1);
419 	if (!sta) {
420 		rcu_read_unlock();
421 		return;
422 	}
423 
424 	if (sta && conf_is_ht(&priv->hw->conf) &&
425 	    !(skb->protocol == cpu_to_be16(ETH_P_PAE))) {
426 		if (ieee80211_is_data_qos(fc)) {
427 			u8 *qc, tid;
428 			struct ath9k_htc_sta *ista;
429 
430 			qc = ieee80211_get_qos_ctl(hdr);
431 			tid = qc[0] & 0xf;
432 			ista = (struct ath9k_htc_sta *)sta->drv_priv;
433 			if (__ath9k_htc_check_tx_aggr(priv, ista, tid)) {
434 				ieee80211_start_tx_ba_session(sta, tid, 0);
435 				spin_lock_bh(&priv->tx.tx_lock);
436 				ista->tid_state[tid] = AGGR_PROGRESS;
437 				spin_unlock_bh(&priv->tx.tx_lock);
438 			}
439 		}
440 	}
441 
442 	rcu_read_unlock();
443 }
444 
445 static void ath9k_htc_tx_process(struct ath9k_htc_priv *priv,
446 				 struct sk_buff *skb,
447 				 struct __wmi_event_txstatus *txs)
448 {
449 	struct ieee80211_vif *vif;
450 	struct ath9k_htc_tx_ctl *tx_ctl;
451 	struct ieee80211_tx_info *tx_info;
452 	struct ieee80211_tx_rate *rate;
453 	struct ieee80211_conf *cur_conf = &priv->hw->conf;
454 	bool txok;
455 	int slot;
456 	int hdrlen, padsize;
457 
458 	slot = strip_drv_header(priv, skb);
459 	if (slot < 0) {
460 		dev_kfree_skb_any(skb);
461 		return;
462 	}
463 
464 	tx_ctl = HTC_SKB_CB(skb);
465 	txok = tx_ctl->txok;
466 	tx_info = IEEE80211_SKB_CB(skb);
467 	vif = tx_info->control.vif;
468 	rate = &tx_info->status.rates[0];
469 
470 	memset(&tx_info->status, 0, sizeof(tx_info->status));
471 
472 	/*
473 	 * URB submission failed for this frame, it never reached
474 	 * the target.
475 	 */
476 	if (!txok || !vif || !txs)
477 		goto send_mac80211;
478 
479 	if (txs->ts_flags & ATH9K_HTC_TXSTAT_ACK) {
480 		tx_info->flags |= IEEE80211_TX_STAT_ACK;
481 		if (tx_info->flags & IEEE80211_TX_CTL_AMPDU)
482 			tx_info->flags |= IEEE80211_TX_STAT_AMPDU;
483 	}
484 
485 	if (txs->ts_flags & ATH9K_HTC_TXSTAT_FILT)
486 		tx_info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
487 
488 	if (txs->ts_flags & ATH9K_HTC_TXSTAT_RTC_CTS)
489 		rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
490 
491 	rate->count = 1;
492 	rate->idx = MS(txs->ts_rate, ATH9K_HTC_TXSTAT_RATE);
493 
494 	if (txs->ts_flags & ATH9K_HTC_TXSTAT_MCS) {
495 		rate->flags |= IEEE80211_TX_RC_MCS;
496 
497 		if (txs->ts_flags & ATH9K_HTC_TXSTAT_CW40)
498 			rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
499 		if (txs->ts_flags & ATH9K_HTC_TXSTAT_SGI)
500 			rate->flags |= IEEE80211_TX_RC_SHORT_GI;
501 	} else {
502 		if (cur_conf->chandef.chan->band == NL80211_BAND_5GHZ)
503 			rate->idx += 4; /* No CCK rates */
504 	}
505 
506 	ath9k_htc_check_tx_aggr(priv, vif, skb);
507 
508 send_mac80211:
509 	spin_lock_bh(&priv->tx.tx_lock);
510 	if (WARN_ON(--priv->tx.queued_cnt < 0))
511 		priv->tx.queued_cnt = 0;
512 	spin_unlock_bh(&priv->tx.tx_lock);
513 
514 	ath9k_htc_tx_clear_slot(priv, slot);
515 
516 	/* Remove padding before handing frame back to mac80211 */
517 	hdrlen = ieee80211_get_hdrlen_from_skb(skb);
518 
519 	padsize = hdrlen & 3;
520 	if (padsize && skb->len > hdrlen + padsize) {
521 		memmove(skb->data + padsize, skb->data, hdrlen);
522 		skb_pull(skb, padsize);
523 	}
524 
525 	/* Send status to mac80211 */
526 	ieee80211_tx_status(priv->hw, skb);
527 }
528 
529 static inline void ath9k_htc_tx_drainq(struct ath9k_htc_priv *priv,
530 				       struct sk_buff_head *queue)
531 {
532 	struct sk_buff *skb;
533 
534 	while ((skb = skb_dequeue(queue)) != NULL) {
535 		ath9k_htc_tx_process(priv, skb, NULL);
536 	}
537 }
538 
539 void ath9k_htc_tx_drain(struct ath9k_htc_priv *priv)
540 {
541 	struct ath9k_htc_tx_event *event, *tmp;
542 
543 	spin_lock_bh(&priv->tx.tx_lock);
544 	priv->tx.flags |= ATH9K_HTC_OP_TX_DRAIN;
545 	spin_unlock_bh(&priv->tx.tx_lock);
546 
547 	/*
548 	 * Ensure that all pending TX frames are flushed,
549 	 * and that the TX completion/failed tasklets is killed.
550 	 */
551 	htc_stop(priv->htc);
552 	tasklet_kill(&priv->wmi->wmi_event_tasklet);
553 	tasklet_kill(&priv->tx_failed_tasklet);
554 
555 	ath9k_htc_tx_drainq(priv, &priv->tx.mgmt_ep_queue);
556 	ath9k_htc_tx_drainq(priv, &priv->tx.cab_ep_queue);
557 	ath9k_htc_tx_drainq(priv, &priv->tx.data_be_queue);
558 	ath9k_htc_tx_drainq(priv, &priv->tx.data_bk_queue);
559 	ath9k_htc_tx_drainq(priv, &priv->tx.data_vi_queue);
560 	ath9k_htc_tx_drainq(priv, &priv->tx.data_vo_queue);
561 	ath9k_htc_tx_drainq(priv, &priv->tx.tx_failed);
562 
563 	/*
564 	 * The TX cleanup timer has already been killed.
565 	 */
566 	spin_lock_bh(&priv->wmi->event_lock);
567 	list_for_each_entry_safe(event, tmp, &priv->wmi->pending_tx_events, list) {
568 		list_del(&event->list);
569 		kfree(event);
570 	}
571 	spin_unlock_bh(&priv->wmi->event_lock);
572 
573 	spin_lock_bh(&priv->tx.tx_lock);
574 	priv->tx.flags &= ~ATH9K_HTC_OP_TX_DRAIN;
575 	spin_unlock_bh(&priv->tx.tx_lock);
576 }
577 
578 void ath9k_tx_failed_tasklet(struct tasklet_struct *t)
579 {
580 	struct ath9k_htc_priv *priv = from_tasklet(priv, t, tx_failed_tasklet);
581 
582 	spin_lock(&priv->tx.tx_lock);
583 	if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) {
584 		spin_unlock(&priv->tx.tx_lock);
585 		return;
586 	}
587 	spin_unlock(&priv->tx.tx_lock);
588 
589 	ath9k_htc_tx_drainq(priv, &priv->tx.tx_failed);
590 }
591 
592 static inline bool check_cookie(struct ath9k_htc_priv *priv,
593 				struct sk_buff *skb,
594 				u8 cookie, u8 epid)
595 {
596 	u8 fcookie = 0;
597 
598 	if (epid == priv->mgmt_ep) {
599 		struct tx_mgmt_hdr *hdr;
600 		hdr = (struct tx_mgmt_hdr *) skb->data;
601 		fcookie = hdr->cookie;
602 	} else if ((epid == priv->data_bk_ep) ||
603 		   (epid == priv->data_be_ep) ||
604 		   (epid == priv->data_vi_ep) ||
605 		   (epid == priv->data_vo_ep) ||
606 		   (epid == priv->cab_ep)) {
607 		struct tx_frame_hdr *hdr;
608 		hdr = (struct tx_frame_hdr *) skb->data;
609 		fcookie = hdr->cookie;
610 	}
611 
612 	if (fcookie == cookie)
613 		return true;
614 
615 	return false;
616 }
617 
618 static struct sk_buff* ath9k_htc_tx_get_packet(struct ath9k_htc_priv *priv,
619 					       struct __wmi_event_txstatus *txs)
620 {
621 	struct ath_common *common = ath9k_hw_common(priv->ah);
622 	struct sk_buff_head *epid_queue;
623 	struct sk_buff *skb, *tmp;
624 	unsigned long flags;
625 	u8 epid = MS(txs->ts_rate, ATH9K_HTC_TXSTAT_EPID);
626 
627 	epid_queue = get_htc_epid_queue(priv, epid);
628 	if (!epid_queue)
629 		return NULL;
630 
631 	spin_lock_irqsave(&epid_queue->lock, flags);
632 	skb_queue_walk_safe(epid_queue, skb, tmp) {
633 		if (check_cookie(priv, skb, txs->cookie, epid)) {
634 			__skb_unlink(skb, epid_queue);
635 			spin_unlock_irqrestore(&epid_queue->lock, flags);
636 			return skb;
637 		}
638 	}
639 	spin_unlock_irqrestore(&epid_queue->lock, flags);
640 
641 	ath_dbg(common, XMIT, "No matching packet for cookie: %d, epid: %d\n",
642 		txs->cookie, epid);
643 
644 	return NULL;
645 }
646 
647 void ath9k_htc_txstatus(struct ath9k_htc_priv *priv, void *wmi_event)
648 {
649 	struct wmi_event_txstatus *txs = wmi_event;
650 	struct __wmi_event_txstatus *__txs;
651 	struct sk_buff *skb;
652 	struct ath9k_htc_tx_event *tx_pend;
653 	int i;
654 
655 	for (i = 0; i < txs->cnt; i++) {
656 		WARN_ON(txs->cnt > HTC_MAX_TX_STATUS);
657 
658 		__txs = &txs->txstatus[i];
659 
660 		skb = ath9k_htc_tx_get_packet(priv, __txs);
661 		if (!skb) {
662 			/*
663 			 * Store this event, so that the TX cleanup
664 			 * routine can check later for the needed packet.
665 			 */
666 			tx_pend = kzalloc(sizeof(struct ath9k_htc_tx_event),
667 					  GFP_ATOMIC);
668 			if (!tx_pend)
669 				continue;
670 
671 			memcpy(&tx_pend->txs, __txs,
672 			       sizeof(struct __wmi_event_txstatus));
673 
674 			spin_lock(&priv->wmi->event_lock);
675 			list_add_tail(&tx_pend->list,
676 				      &priv->wmi->pending_tx_events);
677 			spin_unlock(&priv->wmi->event_lock);
678 
679 			continue;
680 		}
681 
682 		ath9k_htc_tx_process(priv, skb, __txs);
683 	}
684 
685 	/* Wake TX queues if needed */
686 	ath9k_htc_check_wake_queues(priv);
687 }
688 
689 void ath9k_htc_txep(void *drv_priv, struct sk_buff *skb,
690 		    enum htc_endpoint_id ep_id, bool txok)
691 {
692 	struct ath9k_htc_priv *priv = drv_priv;
693 	struct ath9k_htc_tx_ctl *tx_ctl;
694 	struct sk_buff_head *epid_queue;
695 
696 	tx_ctl = HTC_SKB_CB(skb);
697 	tx_ctl->txok = txok;
698 	tx_ctl->timestamp = jiffies;
699 
700 	if (!txok) {
701 		skb_queue_tail(&priv->tx.tx_failed, skb);
702 		tasklet_schedule(&priv->tx_failed_tasklet);
703 		return;
704 	}
705 
706 	epid_queue = get_htc_epid_queue(priv, ep_id);
707 	if (!epid_queue) {
708 		dev_kfree_skb_any(skb);
709 		return;
710 	}
711 
712 	skb_queue_tail(epid_queue, skb);
713 }
714 
715 static inline bool check_packet(struct ath9k_htc_priv *priv, struct sk_buff *skb)
716 {
717 	struct ath_common *common = ath9k_hw_common(priv->ah);
718 	struct ath9k_htc_tx_ctl *tx_ctl;
719 
720 	tx_ctl = HTC_SKB_CB(skb);
721 
722 	if (time_after(jiffies,
723 		       tx_ctl->timestamp +
724 		       msecs_to_jiffies(ATH9K_HTC_TX_TIMEOUT_INTERVAL))) {
725 		ath_dbg(common, XMIT, "Dropping a packet due to TX timeout\n");
726 		return true;
727 	}
728 
729 	return false;
730 }
731 
732 static void ath9k_htc_tx_cleanup_queue(struct ath9k_htc_priv *priv,
733 				       struct sk_buff_head *epid_queue)
734 {
735 	bool process = false;
736 	unsigned long flags;
737 	struct sk_buff *skb, *tmp;
738 	struct sk_buff_head queue;
739 
740 	skb_queue_head_init(&queue);
741 
742 	spin_lock_irqsave(&epid_queue->lock, flags);
743 	skb_queue_walk_safe(epid_queue, skb, tmp) {
744 		if (check_packet(priv, skb)) {
745 			__skb_unlink(skb, epid_queue);
746 			__skb_queue_tail(&queue, skb);
747 			process = true;
748 		}
749 	}
750 	spin_unlock_irqrestore(&epid_queue->lock, flags);
751 
752 	if (process) {
753 		skb_queue_walk_safe(&queue, skb, tmp) {
754 			__skb_unlink(skb, &queue);
755 			ath9k_htc_tx_process(priv, skb, NULL);
756 		}
757 	}
758 }
759 
760 void ath9k_htc_tx_cleanup_timer(struct timer_list *t)
761 {
762 	struct ath9k_htc_priv *priv = from_timer(priv, t, tx.cleanup_timer);
763 	struct ath_common *common = ath9k_hw_common(priv->ah);
764 	struct ath9k_htc_tx_event *event, *tmp;
765 	struct sk_buff *skb;
766 
767 	spin_lock(&priv->wmi->event_lock);
768 	list_for_each_entry_safe(event, tmp, &priv->wmi->pending_tx_events, list) {
769 
770 		skb = ath9k_htc_tx_get_packet(priv, &event->txs);
771 		if (skb) {
772 			ath_dbg(common, XMIT,
773 				"Found packet for cookie: %d, epid: %d\n",
774 				event->txs.cookie,
775 				MS(event->txs.ts_rate, ATH9K_HTC_TXSTAT_EPID));
776 
777 			ath9k_htc_tx_process(priv, skb, &event->txs);
778 			list_del(&event->list);
779 			kfree(event);
780 			continue;
781 		}
782 
783 		if (++event->count >= ATH9K_HTC_TX_TIMEOUT_COUNT) {
784 			list_del(&event->list);
785 			kfree(event);
786 		}
787 	}
788 	spin_unlock(&priv->wmi->event_lock);
789 
790 	/*
791 	 * Check if status-pending packets have to be cleaned up.
792 	 */
793 	ath9k_htc_tx_cleanup_queue(priv, &priv->tx.mgmt_ep_queue);
794 	ath9k_htc_tx_cleanup_queue(priv, &priv->tx.cab_ep_queue);
795 	ath9k_htc_tx_cleanup_queue(priv, &priv->tx.data_be_queue);
796 	ath9k_htc_tx_cleanup_queue(priv, &priv->tx.data_bk_queue);
797 	ath9k_htc_tx_cleanup_queue(priv, &priv->tx.data_vi_queue);
798 	ath9k_htc_tx_cleanup_queue(priv, &priv->tx.data_vo_queue);
799 
800 	/* Wake TX queues if needed */
801 	ath9k_htc_check_wake_queues(priv);
802 
803 	mod_timer(&priv->tx.cleanup_timer,
804 		  jiffies + msecs_to_jiffies(ATH9K_HTC_TX_CLEANUP_INTERVAL));
805 }
806 
807 int ath9k_tx_init(struct ath9k_htc_priv *priv)
808 {
809 	skb_queue_head_init(&priv->tx.mgmt_ep_queue);
810 	skb_queue_head_init(&priv->tx.cab_ep_queue);
811 	skb_queue_head_init(&priv->tx.data_be_queue);
812 	skb_queue_head_init(&priv->tx.data_bk_queue);
813 	skb_queue_head_init(&priv->tx.data_vi_queue);
814 	skb_queue_head_init(&priv->tx.data_vo_queue);
815 	skb_queue_head_init(&priv->tx.tx_failed);
816 
817 	/* Allow ath9k_wmi_event_tasklet(WMI_TXSTATUS_EVENTID) to operate. */
818 	smp_wmb();
819 	priv->tx.initialized = true;
820 
821 	return 0;
822 }
823 
824 void ath9k_tx_cleanup(struct ath9k_htc_priv *priv)
825 {
826 
827 }
828 
829 bool ath9k_htc_txq_setup(struct ath9k_htc_priv *priv, int subtype)
830 {
831 	struct ath_hw *ah = priv->ah;
832 	struct ath_common *common = ath9k_hw_common(ah);
833 	struct ath9k_tx_queue_info qi;
834 	int qnum;
835 
836 	memset(&qi, 0, sizeof(qi));
837 	ATH9K_HTC_INIT_TXQ(subtype);
838 
839 	qnum = ath9k_hw_setuptxqueue(priv->ah, ATH9K_TX_QUEUE_DATA, &qi);
840 	if (qnum == -1)
841 		return false;
842 
843 	if (qnum >= ARRAY_SIZE(priv->hwq_map)) {
844 		ath_err(common, "qnum %u out of range, max %zu!\n",
845 			qnum, ARRAY_SIZE(priv->hwq_map));
846 		ath9k_hw_releasetxqueue(ah, qnum);
847 		return false;
848 	}
849 
850 	priv->hwq_map[subtype] = qnum;
851 	return true;
852 }
853 
854 int ath9k_htc_cabq_setup(struct ath9k_htc_priv *priv)
855 {
856 	struct ath9k_tx_queue_info qi;
857 
858 	memset(&qi, 0, sizeof(qi));
859 	ATH9K_HTC_INIT_TXQ(0);
860 
861 	return ath9k_hw_setuptxqueue(priv->ah, ATH9K_TX_QUEUE_CAB, &qi);
862 }
863 
864 /******/
865 /* RX */
866 /******/
867 
868 /*
869  * Calculate the RX filter to be set in the HW.
870  */
871 u32 ath9k_htc_calcrxfilter(struct ath9k_htc_priv *priv)
872 {
873 #define	RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
874 
875 	struct ath_hw *ah = priv->ah;
876 	u32 rfilt;
877 
878 	rfilt = (ath9k_hw_getrxfilter(ah) & RX_FILTER_PRESERVE)
879 		| ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
880 		| ATH9K_RX_FILTER_MCAST;
881 
882 	if (priv->rxfilter & FIF_PROBE_REQ)
883 		rfilt |= ATH9K_RX_FILTER_PROBEREQ;
884 
885 	if (ah->is_monitoring)
886 		rfilt |= ATH9K_RX_FILTER_PROM;
887 
888 	if (priv->rxfilter & FIF_CONTROL)
889 		rfilt |= ATH9K_RX_FILTER_CONTROL;
890 
891 	if ((ah->opmode == NL80211_IFTYPE_STATION) &&
892 	    (priv->nvifs <= 1) &&
893 	    !(priv->rxfilter & FIF_BCN_PRBRESP_PROMISC))
894 		rfilt |= ATH9K_RX_FILTER_MYBEACON;
895 	else
896 		rfilt |= ATH9K_RX_FILTER_BEACON;
897 
898 	if (conf_is_ht(&priv->hw->conf)) {
899 		rfilt |= ATH9K_RX_FILTER_COMP_BAR;
900 		rfilt |= ATH9K_RX_FILTER_UNCOMP_BA_BAR;
901 	}
902 
903 	if (priv->rxfilter & FIF_PSPOLL)
904 		rfilt |= ATH9K_RX_FILTER_PSPOLL;
905 
906 	if (priv->nvifs > 1 ||
907 	    priv->rxfilter & (FIF_OTHER_BSS | FIF_MCAST_ACTION))
908 		rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
909 
910 	return rfilt;
911 
912 #undef RX_FILTER_PRESERVE
913 }
914 
915 /*
916  * Recv initialization for opmode change.
917  */
918 static void ath9k_htc_opmode_init(struct ath9k_htc_priv *priv)
919 {
920 	struct ath_hw *ah = priv->ah;
921 	u32 rfilt, mfilt[2];
922 
923 	/* configure rx filter */
924 	rfilt = ath9k_htc_calcrxfilter(priv);
925 	ath9k_hw_setrxfilter(ah, rfilt);
926 
927 	/* calculate and install multicast filter */
928 	mfilt[0] = mfilt[1] = ~0;
929 	ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
930 }
931 
932 void ath9k_host_rx_init(struct ath9k_htc_priv *priv)
933 {
934 	struct ath_common *common = ath9k_hw_common(priv->ah);
935 	ath9k_hw_rxena(priv->ah);
936 	ath9k_htc_opmode_init(priv);
937 	ath9k_hw_startpcureceive(priv->ah, test_bit(ATH_OP_SCANNING, &common->op_flags));
938 }
939 
940 static inline void convert_htc_flag(struct ath_rx_status *rx_stats,
941 				   struct ath_htc_rx_status *rxstatus)
942 {
943 	rx_stats->enc_flags = 0;
944 	rx_stats->bw = RATE_INFO_BW_20;
945 	if (rxstatus->rs_flags & ATH9K_RX_2040)
946 		rx_stats->bw = RATE_INFO_BW_40;
947 	if (rxstatus->rs_flags & ATH9K_RX_GI)
948 		rx_stats->enc_flags |= RX_ENC_FLAG_SHORT_GI;
949 }
950 
951 static void rx_status_htc_to_ath(struct ath_rx_status *rx_stats,
952 				 struct ath_htc_rx_status *rxstatus)
953 {
954 	rx_stats->rs_datalen	= be16_to_cpu(rxstatus->rs_datalen);
955 	rx_stats->rs_status	= rxstatus->rs_status;
956 	rx_stats->rs_phyerr	= rxstatus->rs_phyerr;
957 	rx_stats->rs_rssi	= rxstatus->rs_rssi;
958 	rx_stats->rs_keyix	= rxstatus->rs_keyix;
959 	rx_stats->rs_rate	= rxstatus->rs_rate;
960 	rx_stats->rs_antenna	= rxstatus->rs_antenna;
961 	rx_stats->rs_more	= rxstatus->rs_more;
962 
963 	memcpy(rx_stats->rs_rssi_ctl, rxstatus->rs_rssi_ctl,
964 		sizeof(rx_stats->rs_rssi_ctl));
965 	memcpy(rx_stats->rs_rssi_ext, rxstatus->rs_rssi_ext,
966 		sizeof(rx_stats->rs_rssi_ext));
967 
968 	rx_stats->rs_isaggr	= rxstatus->rs_isaggr;
969 	rx_stats->rs_moreaggr	= rxstatus->rs_moreaggr;
970 	rx_stats->rs_num_delims	= rxstatus->rs_num_delims;
971 	convert_htc_flag(rx_stats, rxstatus);
972 }
973 
974 static bool ath9k_rx_prepare(struct ath9k_htc_priv *priv,
975 			     struct ath9k_htc_rxbuf *rxbuf,
976 			     struct ieee80211_rx_status *rx_status)
977 
978 {
979 	struct ieee80211_hdr *hdr;
980 	struct ieee80211_hw *hw = priv->hw;
981 	struct sk_buff *skb = rxbuf->skb;
982 	struct ath_common *common = ath9k_hw_common(priv->ah);
983 	struct ath_hw *ah = common->ah;
984 	struct ath_htc_rx_status *rxstatus;
985 	struct ath_rx_status rx_stats;
986 	bool decrypt_error = false;
987 	u16 rs_datalen;
988 	bool is_phyerr;
989 
990 	if (skb->len < HTC_RX_FRAME_HEADER_SIZE) {
991 		ath_err(common, "Corrupted RX frame, dropping (len: %d)\n",
992 			skb->len);
993 		goto rx_next;
994 	}
995 
996 	rxstatus = (struct ath_htc_rx_status *)skb->data;
997 
998 	rs_datalen = be16_to_cpu(rxstatus->rs_datalen);
999 	if (unlikely(rs_datalen -
1000 	    (skb->len - HTC_RX_FRAME_HEADER_SIZE) != 0)) {
1001 		ath_err(common,
1002 			"Corrupted RX data len, dropping (dlen: %d, skblen: %d)\n",
1003 			rs_datalen, skb->len);
1004 		goto rx_next;
1005 	}
1006 
1007 	is_phyerr = rxstatus->rs_status & ATH9K_RXERR_PHY;
1008 	/*
1009 	 * Discard zero-length packets and packets smaller than an ACK
1010 	 * which are not PHY_ERROR (short radar pulses have a length of 3)
1011 	 */
1012 	if (unlikely(!rs_datalen || (rs_datalen < 10 && !is_phyerr))) {
1013 		ath_dbg(common, ANY,
1014 			"Short RX data len, dropping (dlen: %d)\n",
1015 			rs_datalen);
1016 		goto rx_next;
1017 	}
1018 
1019 	if (rxstatus->rs_keyix >= ATH_KEYMAX &&
1020 	    rxstatus->rs_keyix != ATH9K_RXKEYIX_INVALID) {
1021 		ath_dbg(common, ANY,
1022 			"Invalid keyix, dropping (keyix: %d)\n",
1023 			rxstatus->rs_keyix);
1024 		goto rx_next;
1025 	}
1026 
1027 	/* Get the RX status information */
1028 
1029 	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
1030 
1031 	/* Copy everything from ath_htc_rx_status (HTC_RX_FRAME_HEADER).
1032 	 * After this, we can drop this part of skb. */
1033 	rx_status_htc_to_ath(&rx_stats, rxstatus);
1034 	ath9k_htc_err_stat_rx(priv, &rx_stats);
1035 	rx_status->mactime = be64_to_cpu(rxstatus->rs_tstamp);
1036 	skb_pull(skb, HTC_RX_FRAME_HEADER_SIZE);
1037 
1038 	/*
1039 	 * everything but the rate is checked here, the rate check is done
1040 	 * separately to avoid doing two lookups for a rate for each frame.
1041 	 */
1042 	hdr = (struct ieee80211_hdr *)skb->data;
1043 
1044 	/*
1045 	 * Process PHY errors and return so that the packet
1046 	 * can be dropped.
1047 	 */
1048 	if (unlikely(is_phyerr)) {
1049 		/* TODO: Not using DFS processing now. */
1050 		if (ath_cmn_process_fft(&priv->spec_priv, hdr,
1051 				    &rx_stats, rx_status->mactime)) {
1052 			/* TODO: Code to collect spectral scan statistics */
1053 		}
1054 		goto rx_next;
1055 	}
1056 
1057 	if (!ath9k_cmn_rx_accept(common, hdr, rx_status, &rx_stats,
1058 			&decrypt_error, priv->rxfilter))
1059 		goto rx_next;
1060 
1061 	ath9k_cmn_rx_skb_postprocess(common, skb, &rx_stats,
1062 				     rx_status, decrypt_error);
1063 
1064 	if (ath9k_cmn_process_rate(common, hw, &rx_stats, rx_status))
1065 		goto rx_next;
1066 
1067 	rx_stats.is_mybeacon = ath_is_mybeacon(common, hdr);
1068 	ath9k_cmn_process_rssi(common, hw, &rx_stats, rx_status);
1069 
1070 	rx_status->band = ah->curchan->chan->band;
1071 	rx_status->freq = ah->curchan->chan->center_freq;
1072 	rx_status->antenna = rx_stats.rs_antenna;
1073 	rx_status->flag |= RX_FLAG_MACTIME_END;
1074 
1075 	return true;
1076 rx_next:
1077 	return false;
1078 }
1079 
1080 /*
1081  * FIXME: Handle FLUSH later on.
1082  */
1083 void ath9k_rx_tasklet(struct tasklet_struct *t)
1084 {
1085 	struct ath9k_htc_priv *priv = from_tasklet(priv, t, rx_tasklet);
1086 	struct ath9k_htc_rxbuf *rxbuf = NULL, *tmp_buf = NULL;
1087 	struct ieee80211_rx_status rx_status;
1088 	struct sk_buff *skb;
1089 	unsigned long flags;
1090 	struct ieee80211_hdr *hdr;
1091 
1092 	do {
1093 		spin_lock_irqsave(&priv->rx.rxbuflock, flags);
1094 		list_for_each_entry(tmp_buf, &priv->rx.rxbuf, list) {
1095 			if (tmp_buf->in_process) {
1096 				rxbuf = tmp_buf;
1097 				break;
1098 			}
1099 		}
1100 
1101 		if (rxbuf == NULL) {
1102 			spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);
1103 			break;
1104 		}
1105 
1106 		if (!rxbuf->skb)
1107 			goto requeue;
1108 
1109 		if (!ath9k_rx_prepare(priv, rxbuf, &rx_status)) {
1110 			dev_kfree_skb_any(rxbuf->skb);
1111 			goto requeue;
1112 		}
1113 
1114 		memcpy(IEEE80211_SKB_RXCB(rxbuf->skb), &rx_status,
1115 		       sizeof(struct ieee80211_rx_status));
1116 		skb = rxbuf->skb;
1117 		hdr = (struct ieee80211_hdr *) skb->data;
1118 
1119 		if (ieee80211_is_beacon(hdr->frame_control) && priv->ps_enabled)
1120 				ieee80211_queue_work(priv->hw, &priv->ps_work);
1121 
1122 		spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);
1123 
1124 		ieee80211_rx(priv->hw, skb);
1125 
1126 		spin_lock_irqsave(&priv->rx.rxbuflock, flags);
1127 requeue:
1128 		rxbuf->in_process = false;
1129 		rxbuf->skb = NULL;
1130 		list_move_tail(&rxbuf->list, &priv->rx.rxbuf);
1131 		rxbuf = NULL;
1132 		spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);
1133 	} while (1);
1134 
1135 }
1136 
1137 void ath9k_htc_rxep(void *drv_priv, struct sk_buff *skb,
1138 		    enum htc_endpoint_id ep_id)
1139 {
1140 	struct ath9k_htc_priv *priv = drv_priv;
1141 	struct ath_hw *ah = priv->ah;
1142 	struct ath_common *common = ath9k_hw_common(ah);
1143 	struct ath9k_htc_rxbuf *rxbuf = NULL, *tmp_buf = NULL;
1144 	unsigned long flags;
1145 
1146 	/* Check if ath9k_rx_init() completed. */
1147 	if (!data_race(priv->rx.initialized))
1148 		goto err;
1149 
1150 	spin_lock_irqsave(&priv->rx.rxbuflock, flags);
1151 	list_for_each_entry(tmp_buf, &priv->rx.rxbuf, list) {
1152 		if (!tmp_buf->in_process) {
1153 			rxbuf = tmp_buf;
1154 			break;
1155 		}
1156 	}
1157 	spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);
1158 
1159 	if (rxbuf == NULL) {
1160 		ath_dbg(common, ANY, "No free RX buffer\n");
1161 		goto err;
1162 	}
1163 
1164 	spin_lock_irqsave(&priv->rx.rxbuflock, flags);
1165 	rxbuf->skb = skb;
1166 	rxbuf->in_process = true;
1167 	spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);
1168 
1169 	tasklet_schedule(&priv->rx_tasklet);
1170 	return;
1171 err:
1172 	dev_kfree_skb_any(skb);
1173 }
1174 
1175 /* FIXME: Locking for cleanup/init */
1176 
1177 void ath9k_rx_cleanup(struct ath9k_htc_priv *priv)
1178 {
1179 	struct ath9k_htc_rxbuf *rxbuf, *tbuf;
1180 
1181 	list_for_each_entry_safe(rxbuf, tbuf, &priv->rx.rxbuf, list) {
1182 		list_del(&rxbuf->list);
1183 		if (rxbuf->skb)
1184 			dev_kfree_skb_any(rxbuf->skb);
1185 		kfree(rxbuf);
1186 	}
1187 }
1188 
1189 int ath9k_rx_init(struct ath9k_htc_priv *priv)
1190 {
1191 	int i = 0;
1192 
1193 	INIT_LIST_HEAD(&priv->rx.rxbuf);
1194 	spin_lock_init(&priv->rx.rxbuflock);
1195 
1196 	for (i = 0; i < ATH9K_HTC_RXBUF; i++) {
1197 		struct ath9k_htc_rxbuf *rxbuf =
1198 			kzalloc(sizeof(struct ath9k_htc_rxbuf), GFP_KERNEL);
1199 		if (rxbuf == NULL)
1200 			goto err;
1201 
1202 		list_add_tail(&rxbuf->list, &priv->rx.rxbuf);
1203 	}
1204 
1205 	/* Allow ath9k_htc_rxep() to operate. */
1206 	smp_wmb();
1207 	priv->rx.initialized = true;
1208 
1209 	return 0;
1210 
1211 err:
1212 	ath9k_rx_cleanup(priv);
1213 	return -ENOMEM;
1214 }
1215