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1/*
2 * Copyright (c) 2008-2011 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 <linux/dma-mapping.h>
18#include "ath9k.h"
19#include "ar9003_mac.h"
20
21#define SKB_CB_ATHBUF(__skb)	(*((struct ath_rxbuf **)__skb->cb))
22
23static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
24{
25	return sc->ps_enabled &&
26	       (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
27}
28
29/*
30 * Setup and link descriptors.
31 *
32 * 11N: we can no longer afford to self link the last descriptor.
33 * MAC acknowledges BA status as long as it copies frames to host
34 * buffer (or rx fifo). This can incorrectly acknowledge packets
35 * to a sender if last desc is self-linked.
36 */
37static void ath_rx_buf_link(struct ath_softc *sc, struct ath_rxbuf *bf,
38			    bool flush)
39{
40	struct ath_hw *ah = sc->sc_ah;
41	struct ath_common *common = ath9k_hw_common(ah);
42	struct ath_desc *ds;
43	struct sk_buff *skb;
44
45	ds = bf->bf_desc;
46	ds->ds_link = 0; /* link to null */
47	ds->ds_data = bf->bf_buf_addr;
48
49	/* virtual addr of the beginning of the buffer. */
50	skb = bf->bf_mpdu;
51	BUG_ON(skb == NULL);
52	ds->ds_vdata = skb->data;
53
54	/*
55	 * setup rx descriptors. The rx_bufsize here tells the hardware
56	 * how much data it can DMA to us and that we are prepared
57	 * to process
58	 */
59	ath9k_hw_setuprxdesc(ah, ds,
60			     common->rx_bufsize,
61			     0);
62
63	if (sc->rx.rxlink)
64		*sc->rx.rxlink = bf->bf_daddr;
65	else if (!flush)
66		ath9k_hw_putrxbuf(ah, bf->bf_daddr);
67
68	sc->rx.rxlink = &ds->ds_link;
69}
70
71static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_rxbuf *bf,
72			      bool flush)
73{
74	if (sc->rx.buf_hold)
75		ath_rx_buf_link(sc, sc->rx.buf_hold, flush);
76
77	sc->rx.buf_hold = bf;
78}
79
80static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
81{
82	/* XXX block beacon interrupts */
83	ath9k_hw_setantenna(sc->sc_ah, antenna);
84	sc->rx.defant = antenna;
85	sc->rx.rxotherant = 0;
86}
87
88static void ath_opmode_init(struct ath_softc *sc)
89{
90	struct ath_hw *ah = sc->sc_ah;
91	struct ath_common *common = ath9k_hw_common(ah);
92
93	u32 rfilt, mfilt[2];
94
95	/* configure rx filter */
96	rfilt = ath_calcrxfilter(sc);
97	ath9k_hw_setrxfilter(ah, rfilt);
98
99	/* configure bssid mask */
100	ath_hw_setbssidmask(common);
101
102	/* configure operational mode */
103	ath9k_hw_setopmode(ah);
104
105	/* calculate and install multicast filter */
106	mfilt[0] = mfilt[1] = ~0;
107	ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
108}
109
110static bool ath_rx_edma_buf_link(struct ath_softc *sc,
111				 enum ath9k_rx_qtype qtype)
112{
113	struct ath_hw *ah = sc->sc_ah;
114	struct ath_rx_edma *rx_edma;
115	struct sk_buff *skb;
116	struct ath_rxbuf *bf;
117
118	rx_edma = &sc->rx.rx_edma[qtype];
119	if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
120		return false;
121
122	bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
123	list_del_init(&bf->list);
124
125	skb = bf->bf_mpdu;
126
127	memset(skb->data, 0, ah->caps.rx_status_len);
128	dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
129				ah->caps.rx_status_len, DMA_TO_DEVICE);
130
131	SKB_CB_ATHBUF(skb) = bf;
132	ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
133	__skb_queue_tail(&rx_edma->rx_fifo, skb);
134
135	return true;
136}
137
138static void ath_rx_addbuffer_edma(struct ath_softc *sc,
139				  enum ath9k_rx_qtype qtype)
140{
141	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
142	struct ath_rxbuf *bf, *tbf;
143
144	if (list_empty(&sc->rx.rxbuf)) {
145		ath_dbg(common, QUEUE, "No free rx buf available\n");
146		return;
147	}
148
149	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list)
150		if (!ath_rx_edma_buf_link(sc, qtype))
151			break;
152
153}
154
155static void ath_rx_remove_buffer(struct ath_softc *sc,
156				 enum ath9k_rx_qtype qtype)
157{
158	struct ath_rxbuf *bf;
159	struct ath_rx_edma *rx_edma;
160	struct sk_buff *skb;
161
162	rx_edma = &sc->rx.rx_edma[qtype];
163
164	while ((skb = __skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
165		bf = SKB_CB_ATHBUF(skb);
166		BUG_ON(!bf);
167		list_add_tail(&bf->list, &sc->rx.rxbuf);
168	}
169}
170
171static void ath_rx_edma_cleanup(struct ath_softc *sc)
172{
173	struct ath_hw *ah = sc->sc_ah;
174	struct ath_common *common = ath9k_hw_common(ah);
175	struct ath_rxbuf *bf;
176
177	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
178	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
179
180	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
181		if (bf->bf_mpdu) {
182			dma_unmap_single(sc->dev, bf->bf_buf_addr,
183					common->rx_bufsize,
184					DMA_BIDIRECTIONAL);
185			dev_kfree_skb_any(bf->bf_mpdu);
186			bf->bf_buf_addr = 0;
187			bf->bf_mpdu = NULL;
188		}
189	}
190}
191
192static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
193{
194	__skb_queue_head_init(&rx_edma->rx_fifo);
195	rx_edma->rx_fifo_hwsize = size;
196}
197
198static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
199{
200	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
201	struct ath_hw *ah = sc->sc_ah;
202	struct sk_buff *skb;
203	struct ath_rxbuf *bf;
204	int error = 0, i;
205	u32 size;
206
207	ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
208				    ah->caps.rx_status_len);
209
210	ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
211			       ah->caps.rx_lp_qdepth);
212	ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
213			       ah->caps.rx_hp_qdepth);
214
215	size = sizeof(struct ath_rxbuf) * nbufs;
216	bf = devm_kzalloc(sc->dev, size, GFP_KERNEL);
217	if (!bf)
218		return -ENOMEM;
219
220	INIT_LIST_HEAD(&sc->rx.rxbuf);
221
222	for (i = 0; i < nbufs; i++, bf++) {
223		skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
224		if (!skb) {
225			error = -ENOMEM;
226			goto rx_init_fail;
227		}
228
229		memset(skb->data, 0, common->rx_bufsize);
230		bf->bf_mpdu = skb;
231
232		bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
233						 common->rx_bufsize,
234						 DMA_BIDIRECTIONAL);
235		if (unlikely(dma_mapping_error(sc->dev,
236						bf->bf_buf_addr))) {
237				dev_kfree_skb_any(skb);
238				bf->bf_mpdu = NULL;
239				bf->bf_buf_addr = 0;
240				ath_err(common,
241					"dma_mapping_error() on RX init\n");
242				error = -ENOMEM;
243				goto rx_init_fail;
244		}
245
246		list_add_tail(&bf->list, &sc->rx.rxbuf);
247	}
248
249	return 0;
250
251rx_init_fail:
252	ath_rx_edma_cleanup(sc);
253	return error;
254}
255
256static void ath_edma_start_recv(struct ath_softc *sc)
257{
258	ath9k_hw_rxena(sc->sc_ah);
259	ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP);
260	ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP);
261	ath_opmode_init(sc);
262	ath9k_hw_startpcureceive(sc->sc_ah, sc->cur_chan->offchannel);
263}
264
265static void ath_edma_stop_recv(struct ath_softc *sc)
266{
267	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
268	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
269}
270
271int ath_rx_init(struct ath_softc *sc, int nbufs)
272{
273	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
274	struct sk_buff *skb;
275	struct ath_rxbuf *bf;
276	int error = 0;
277
278	spin_lock_init(&sc->sc_pcu_lock);
279
280	common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
281			     sc->sc_ah->caps.rx_status_len;
282
283	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
284		return ath_rx_edma_init(sc, nbufs);
285
286	ath_dbg(common, CONFIG, "cachelsz %u rxbufsize %u\n",
287		common->cachelsz, common->rx_bufsize);
288
289	/* Initialize rx descriptors */
290
291	error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
292				  "rx", nbufs, 1, 0);
293	if (error != 0) {
294		ath_err(common,
295			"failed to allocate rx descriptors: %d\n",
296			error);
297		goto err;
298	}
299
300	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
301		skb = ath_rxbuf_alloc(common, common->rx_bufsize,
302				      GFP_KERNEL);
303		if (skb == NULL) {
304			error = -ENOMEM;
305			goto err;
306		}
307
308		bf->bf_mpdu = skb;
309		bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
310						 common->rx_bufsize,
311						 DMA_FROM_DEVICE);
312		if (unlikely(dma_mapping_error(sc->dev,
313					       bf->bf_buf_addr))) {
314			dev_kfree_skb_any(skb);
315			bf->bf_mpdu = NULL;
316			bf->bf_buf_addr = 0;
317			ath_err(common,
318				"dma_mapping_error() on RX init\n");
319			error = -ENOMEM;
320			goto err;
321		}
322	}
323	sc->rx.rxlink = NULL;
324err:
325	if (error)
326		ath_rx_cleanup(sc);
327
328	return error;
329}
330
331void ath_rx_cleanup(struct ath_softc *sc)
332{
333	struct ath_hw *ah = sc->sc_ah;
334	struct ath_common *common = ath9k_hw_common(ah);
335	struct sk_buff *skb;
336	struct ath_rxbuf *bf;
337
338	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
339		ath_rx_edma_cleanup(sc);
340		return;
341	}
342
343	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
344		skb = bf->bf_mpdu;
345		if (skb) {
346			dma_unmap_single(sc->dev, bf->bf_buf_addr,
347					 common->rx_bufsize,
348					 DMA_FROM_DEVICE);
349			dev_kfree_skb(skb);
350			bf->bf_buf_addr = 0;
351			bf->bf_mpdu = NULL;
352		}
353	}
354}
355
356/*
357 * Calculate the receive filter according to the
358 * operating mode and state:
359 *
360 * o always accept unicast, broadcast, and multicast traffic
361 * o maintain current state of phy error reception (the hal
362 *   may enable phy error frames for noise immunity work)
363 * o probe request frames are accepted only when operating in
364 *   hostap, adhoc, or monitor modes
365 * o enable promiscuous mode according to the interface state
366 * o accept beacons:
367 *   - when operating in adhoc mode so the 802.11 layer creates
368 *     node table entries for peers,
369 *   - when operating in station mode for collecting rssi data when
370 *     the station is otherwise quiet, or
371 *   - when operating as a repeater so we see repeater-sta beacons
372 *   - when scanning
373 */
374
375u32 ath_calcrxfilter(struct ath_softc *sc)
376{
377	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
378	u32 rfilt;
379
380	if (config_enabled(CONFIG_ATH9K_TX99))
381		return 0;
382
383	rfilt = ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
384		| ATH9K_RX_FILTER_MCAST;
385
386	/* if operating on a DFS channel, enable radar pulse detection */
387	if (sc->hw->conf.radar_enabled)
388		rfilt |= ATH9K_RX_FILTER_PHYRADAR | ATH9K_RX_FILTER_PHYERR;
389
390	spin_lock_bh(&sc->chan_lock);
391
392	if (sc->cur_chan->rxfilter & FIF_PROBE_REQ)
393		rfilt |= ATH9K_RX_FILTER_PROBEREQ;
394
395	/*
396	 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
397	 * mode interface or when in monitor mode. AP mode does not need this
398	 * since it receives all in-BSS frames anyway.
399	 */
400	if (sc->sc_ah->is_monitoring)
401		rfilt |= ATH9K_RX_FILTER_PROM;
402
403	if ((sc->cur_chan->rxfilter & FIF_CONTROL) ||
404	    sc->sc_ah->dynack.enabled)
405		rfilt |= ATH9K_RX_FILTER_CONTROL;
406
407	if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
408	    (sc->cur_chan->nvifs <= 1) &&
409	    !(sc->cur_chan->rxfilter & FIF_BCN_PRBRESP_PROMISC))
410		rfilt |= ATH9K_RX_FILTER_MYBEACON;
411	else
412		rfilt |= ATH9K_RX_FILTER_BEACON;
413
414	if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) ||
415	    (sc->cur_chan->rxfilter & FIF_PSPOLL))
416		rfilt |= ATH9K_RX_FILTER_PSPOLL;
417
418	if (sc->cur_chandef.width != NL80211_CHAN_WIDTH_20_NOHT)
419		rfilt |= ATH9K_RX_FILTER_COMP_BAR;
420
421	if (sc->cur_chan->nvifs > 1 || (sc->cur_chan->rxfilter & FIF_OTHER_BSS)) {
422		/* This is needed for older chips */
423		if (sc->sc_ah->hw_version.macVersion <= AR_SREV_VERSION_9160)
424			rfilt |= ATH9K_RX_FILTER_PROM;
425		rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
426	}
427
428	if (AR_SREV_9550(sc->sc_ah) || AR_SREV_9531(sc->sc_ah))
429		rfilt |= ATH9K_RX_FILTER_4ADDRESS;
430
431	if (ath9k_is_chanctx_enabled() &&
432	    test_bit(ATH_OP_SCANNING, &common->op_flags))
433		rfilt |= ATH9K_RX_FILTER_BEACON;
434
435	spin_unlock_bh(&sc->chan_lock);
436
437	return rfilt;
438
439}
440
441void ath_startrecv(struct ath_softc *sc)
442{
443	struct ath_hw *ah = sc->sc_ah;
444	struct ath_rxbuf *bf, *tbf;
445
446	if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
447		ath_edma_start_recv(sc);
448		return;
449	}
450
451	if (list_empty(&sc->rx.rxbuf))
452		goto start_recv;
453
454	sc->rx.buf_hold = NULL;
455	sc->rx.rxlink = NULL;
456	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
457		ath_rx_buf_link(sc, bf, false);
458	}
459
460	/* We could have deleted elements so the list may be empty now */
461	if (list_empty(&sc->rx.rxbuf))
462		goto start_recv;
463
464	bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
465	ath9k_hw_putrxbuf(ah, bf->bf_daddr);
466	ath9k_hw_rxena(ah);
467
468start_recv:
469	ath_opmode_init(sc);
470	ath9k_hw_startpcureceive(ah, sc->cur_chan->offchannel);
471}
472
473static void ath_flushrecv(struct ath_softc *sc)
474{
475	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
476		ath_rx_tasklet(sc, 1, true);
477	ath_rx_tasklet(sc, 1, false);
478}
479
480bool ath_stoprecv(struct ath_softc *sc)
481{
482	struct ath_hw *ah = sc->sc_ah;
483	bool stopped, reset = false;
484
485	ath9k_hw_abortpcurecv(ah);
486	ath9k_hw_setrxfilter(ah, 0);
487	stopped = ath9k_hw_stopdmarecv(ah, &reset);
488
489	ath_flushrecv(sc);
490
491	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
492		ath_edma_stop_recv(sc);
493	else
494		sc->rx.rxlink = NULL;
495
496	if (!(ah->ah_flags & AH_UNPLUGGED) &&
497	    unlikely(!stopped)) {
498		ath_err(ath9k_hw_common(sc->sc_ah),
499			"Could not stop RX, we could be "
500			"confusing the DMA engine when we start RX up\n");
501		ATH_DBG_WARN_ON_ONCE(!stopped);
502	}
503	return stopped && !reset;
504}
505
506static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
507{
508	/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
509	struct ieee80211_mgmt *mgmt;
510	u8 *pos, *end, id, elen;
511	struct ieee80211_tim_ie *tim;
512
513	mgmt = (struct ieee80211_mgmt *)skb->data;
514	pos = mgmt->u.beacon.variable;
515	end = skb->data + skb->len;
516
517	while (pos + 2 < end) {
518		id = *pos++;
519		elen = *pos++;
520		if (pos + elen > end)
521			break;
522
523		if (id == WLAN_EID_TIM) {
524			if (elen < sizeof(*tim))
525				break;
526			tim = (struct ieee80211_tim_ie *) pos;
527			if (tim->dtim_count != 0)
528				break;
529			return tim->bitmap_ctrl & 0x01;
530		}
531
532		pos += elen;
533	}
534
535	return false;
536}
537
538static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
539{
540	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
541	bool skip_beacon = false;
542
543	if (skb->len < 24 + 8 + 2 + 2)
544		return;
545
546	sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
547
548	if (sc->ps_flags & PS_BEACON_SYNC) {
549		sc->ps_flags &= ~PS_BEACON_SYNC;
550		ath_dbg(common, PS,
551			"Reconfigure beacon timers based on synchronized timestamp\n");
552
553#ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
554		if (ath9k_is_chanctx_enabled()) {
555			if (sc->cur_chan == &sc->offchannel.chan)
556				skip_beacon = true;
557		}
558#endif
559
560		if (!skip_beacon &&
561		    !(WARN_ON_ONCE(sc->cur_chan->beacon.beacon_interval == 0)))
562			ath9k_set_beacon(sc);
563
564		ath9k_p2p_beacon_sync(sc);
565	}
566
567	if (ath_beacon_dtim_pending_cab(skb)) {
568		/*
569		 * Remain awake waiting for buffered broadcast/multicast
570		 * frames. If the last broadcast/multicast frame is not
571		 * received properly, the next beacon frame will work as
572		 * a backup trigger for returning into NETWORK SLEEP state,
573		 * so we are waiting for it as well.
574		 */
575		ath_dbg(common, PS,
576			"Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
577		sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
578		return;
579	}
580
581	if (sc->ps_flags & PS_WAIT_FOR_CAB) {
582		/*
583		 * This can happen if a broadcast frame is dropped or the AP
584		 * fails to send a frame indicating that all CAB frames have
585		 * been delivered.
586		 */
587		sc->ps_flags &= ~PS_WAIT_FOR_CAB;
588		ath_dbg(common, PS, "PS wait for CAB frames timed out\n");
589	}
590}
591
592static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb, bool mybeacon)
593{
594	struct ieee80211_hdr *hdr;
595	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
596
597	hdr = (struct ieee80211_hdr *)skb->data;
598
599	/* Process Beacon and CAB receive in PS state */
600	if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
601	    && mybeacon) {
602		ath_rx_ps_beacon(sc, skb);
603	} else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
604		   (ieee80211_is_data(hdr->frame_control) ||
605		    ieee80211_is_action(hdr->frame_control)) &&
606		   is_multicast_ether_addr(hdr->addr1) &&
607		   !ieee80211_has_moredata(hdr->frame_control)) {
608		/*
609		 * No more broadcast/multicast frames to be received at this
610		 * point.
611		 */
612		sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
613		ath_dbg(common, PS,
614			"All PS CAB frames received, back to sleep\n");
615	} else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
616		   !is_multicast_ether_addr(hdr->addr1) &&
617		   !ieee80211_has_morefrags(hdr->frame_control)) {
618		sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
619		ath_dbg(common, PS,
620			"Going back to sleep after having received PS-Poll data (0x%lx)\n",
621			sc->ps_flags & (PS_WAIT_FOR_BEACON |
622					PS_WAIT_FOR_CAB |
623					PS_WAIT_FOR_PSPOLL_DATA |
624					PS_WAIT_FOR_TX_ACK));
625	}
626}
627
628static bool ath_edma_get_buffers(struct ath_softc *sc,
629				 enum ath9k_rx_qtype qtype,
630				 struct ath_rx_status *rs,
631				 struct ath_rxbuf **dest)
632{
633	struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
634	struct ath_hw *ah = sc->sc_ah;
635	struct ath_common *common = ath9k_hw_common(ah);
636	struct sk_buff *skb;
637	struct ath_rxbuf *bf;
638	int ret;
639
640	skb = skb_peek(&rx_edma->rx_fifo);
641	if (!skb)
642		return false;
643
644	bf = SKB_CB_ATHBUF(skb);
645	BUG_ON(!bf);
646
647	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
648				common->rx_bufsize, DMA_FROM_DEVICE);
649
650	ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data);
651	if (ret == -EINPROGRESS) {
652		/*let device gain the buffer again*/
653		dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
654				common->rx_bufsize, DMA_FROM_DEVICE);
655		return false;
656	}
657
658	__skb_unlink(skb, &rx_edma->rx_fifo);
659	if (ret == -EINVAL) {
660		/* corrupt descriptor, skip this one and the following one */
661		list_add_tail(&bf->list, &sc->rx.rxbuf);
662		ath_rx_edma_buf_link(sc, qtype);
663
664		skb = skb_peek(&rx_edma->rx_fifo);
665		if (skb) {
666			bf = SKB_CB_ATHBUF(skb);
667			BUG_ON(!bf);
668
669			__skb_unlink(skb, &rx_edma->rx_fifo);
670			list_add_tail(&bf->list, &sc->rx.rxbuf);
671			ath_rx_edma_buf_link(sc, qtype);
672		}
673
674		bf = NULL;
675	}
676
677	*dest = bf;
678	return true;
679}
680
681static struct ath_rxbuf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
682						struct ath_rx_status *rs,
683						enum ath9k_rx_qtype qtype)
684{
685	struct ath_rxbuf *bf = NULL;
686
687	while (ath_edma_get_buffers(sc, qtype, rs, &bf)) {
688		if (!bf)
689			continue;
690
691		return bf;
692	}
693	return NULL;
694}
695
696static struct ath_rxbuf *ath_get_next_rx_buf(struct ath_softc *sc,
697					   struct ath_rx_status *rs)
698{
699	struct ath_hw *ah = sc->sc_ah;
700	struct ath_common *common = ath9k_hw_common(ah);
701	struct ath_desc *ds;
702	struct ath_rxbuf *bf;
703	int ret;
704
705	if (list_empty(&sc->rx.rxbuf)) {
706		sc->rx.rxlink = NULL;
707		return NULL;
708	}
709
710	bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
711	if (bf == sc->rx.buf_hold)
712		return NULL;
713
714	ds = bf->bf_desc;
715
716	/*
717	 * Must provide the virtual address of the current
718	 * descriptor, the physical address, and the virtual
719	 * address of the next descriptor in the h/w chain.
720	 * This allows the HAL to look ahead to see if the
721	 * hardware is done with a descriptor by checking the
722	 * done bit in the following descriptor and the address
723	 * of the current descriptor the DMA engine is working
724	 * on.  All this is necessary because of our use of
725	 * a self-linked list to avoid rx overruns.
726	 */
727	ret = ath9k_hw_rxprocdesc(ah, ds, rs);
728	if (ret == -EINPROGRESS) {
729		struct ath_rx_status trs;
730		struct ath_rxbuf *tbf;
731		struct ath_desc *tds;
732
733		memset(&trs, 0, sizeof(trs));
734		if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
735			sc->rx.rxlink = NULL;
736			return NULL;
737		}
738
739		tbf = list_entry(bf->list.next, struct ath_rxbuf, list);
740
741		/*
742		 * On some hardware the descriptor status words could
743		 * get corrupted, including the done bit. Because of
744		 * this, check if the next descriptor's done bit is
745		 * set or not.
746		 *
747		 * If the next descriptor's done bit is set, the current
748		 * descriptor has been corrupted. Force s/w to discard
749		 * this descriptor and continue...
750		 */
751
752		tds = tbf->bf_desc;
753		ret = ath9k_hw_rxprocdesc(ah, tds, &trs);
754		if (ret == -EINPROGRESS)
755			return NULL;
756
757		/*
758		 * Re-check previous descriptor, in case it has been filled
759		 * in the mean time.
760		 */
761		ret = ath9k_hw_rxprocdesc(ah, ds, rs);
762		if (ret == -EINPROGRESS) {
763			/*
764			 * mark descriptor as zero-length and set the 'more'
765			 * flag to ensure that both buffers get discarded
766			 */
767			rs->rs_datalen = 0;
768			rs->rs_more = true;
769		}
770	}
771
772	list_del(&bf->list);
773	if (!bf->bf_mpdu)
774		return bf;
775
776	/*
777	 * Synchronize the DMA transfer with CPU before
778	 * 1. accessing the frame
779	 * 2. requeueing the same buffer to h/w
780	 */
781	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
782			common->rx_bufsize,
783			DMA_FROM_DEVICE);
784
785	return bf;
786}
787
788static void ath9k_process_tsf(struct ath_rx_status *rs,
789			      struct ieee80211_rx_status *rxs,
790			      u64 tsf)
791{
792	u32 tsf_lower = tsf & 0xffffffff;
793
794	rxs->mactime = (tsf & ~0xffffffffULL) | rs->rs_tstamp;
795	if (rs->rs_tstamp > tsf_lower &&
796	    unlikely(rs->rs_tstamp - tsf_lower > 0x10000000))
797		rxs->mactime -= 0x100000000ULL;
798
799	if (rs->rs_tstamp < tsf_lower &&
800	    unlikely(tsf_lower - rs->rs_tstamp > 0x10000000))
801		rxs->mactime += 0x100000000ULL;
802}
803
804/*
805 * For Decrypt or Demic errors, we only mark packet status here and always push
806 * up the frame up to let mac80211 handle the actual error case, be it no
807 * decryption key or real decryption error. This let us keep statistics there.
808 */
809static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
810				   struct sk_buff *skb,
811				   struct ath_rx_status *rx_stats,
812				   struct ieee80211_rx_status *rx_status,
813				   bool *decrypt_error, u64 tsf)
814{
815	struct ieee80211_hw *hw = sc->hw;
816	struct ath_hw *ah = sc->sc_ah;
817	struct ath_common *common = ath9k_hw_common(ah);
818	struct ieee80211_hdr *hdr;
819	bool discard_current = sc->rx.discard_next;
820
821	/*
822	 * Discard corrupt descriptors which are marked in
823	 * ath_get_next_rx_buf().
824	 */
825	if (discard_current)
826		goto corrupt;
827
828	sc->rx.discard_next = false;
829
830	/*
831	 * Discard zero-length packets.
832	 */
833	if (!rx_stats->rs_datalen) {
834		RX_STAT_INC(rx_len_err);
835		goto corrupt;
836	}
837
838	/*
839	 * rs_status follows rs_datalen so if rs_datalen is too large
840	 * we can take a hint that hardware corrupted it, so ignore
841	 * those frames.
842	 */
843	if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) {
844		RX_STAT_INC(rx_len_err);
845		goto corrupt;
846	}
847
848	/* Only use status info from the last fragment */
849	if (rx_stats->rs_more)
850		return 0;
851
852	/*
853	 * Return immediately if the RX descriptor has been marked
854	 * as corrupt based on the various error bits.
855	 *
856	 * This is different from the other corrupt descriptor
857	 * condition handled above.
858	 */
859	if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC)
860		goto corrupt;
861
862	hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len);
863
864	ath9k_process_tsf(rx_stats, rx_status, tsf);
865	ath_debug_stat_rx(sc, rx_stats);
866
867	/*
868	 * Process PHY errors and return so that the packet
869	 * can be dropped.
870	 */
871	if (rx_stats->rs_status & ATH9K_RXERR_PHY) {
872		ath9k_dfs_process_phyerr(sc, hdr, rx_stats, rx_status->mactime);
873		if (ath_process_fft(sc, hdr, rx_stats, rx_status->mactime))
874			RX_STAT_INC(rx_spectral);
875
876		return -EINVAL;
877	}
878
879	/*
880	 * everything but the rate is checked here, the rate check is done
881	 * separately to avoid doing two lookups for a rate for each frame.
882	 */
883	spin_lock_bh(&sc->chan_lock);
884	if (!ath9k_cmn_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error,
885				 sc->cur_chan->rxfilter)) {
886		spin_unlock_bh(&sc->chan_lock);
887		return -EINVAL;
888	}
889	spin_unlock_bh(&sc->chan_lock);
890
891	if (ath_is_mybeacon(common, hdr)) {
892		RX_STAT_INC(rx_beacons);
893		rx_stats->is_mybeacon = true;
894	}
895
896	/*
897	 * This shouldn't happen, but have a safety check anyway.
898	 */
899	if (WARN_ON(!ah->curchan))
900		return -EINVAL;
901
902	if (ath9k_cmn_process_rate(common, hw, rx_stats, rx_status)) {
903		/*
904		 * No valid hardware bitrate found -- we should not get here
905		 * because hardware has already validated this frame as OK.
906		 */
907		ath_dbg(common, ANY, "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
908			rx_stats->rs_rate);
909		RX_STAT_INC(rx_rate_err);
910		return -EINVAL;
911	}
912
913	if (ath9k_is_chanctx_enabled()) {
914		if (rx_stats->is_mybeacon)
915			ath_chanctx_beacon_recv_ev(sc,
916					   ATH_CHANCTX_EVENT_BEACON_RECEIVED);
917	}
918
919	ath9k_cmn_process_rssi(common, hw, rx_stats, rx_status);
920
921	rx_status->band = ah->curchan->chan->band;
922	rx_status->freq = ah->curchan->chan->center_freq;
923	rx_status->antenna = rx_stats->rs_antenna;
924	rx_status->flag |= RX_FLAG_MACTIME_END;
925
926#ifdef CONFIG_ATH9K_BTCOEX_SUPPORT
927	if (ieee80211_is_data_present(hdr->frame_control) &&
928	    !ieee80211_is_qos_nullfunc(hdr->frame_control))
929		sc->rx.num_pkts++;
930#endif
931
932	return 0;
933
934corrupt:
935	sc->rx.discard_next = rx_stats->rs_more;
936	return -EINVAL;
937}
938
939/*
940 * Run the LNA combining algorithm only in these cases:
941 *
942 * Standalone WLAN cards with both LNA/Antenna diversity
943 * enabled in the EEPROM.
944 *
945 * WLAN+BT cards which are in the supported card list
946 * in ath_pci_id_table and the user has loaded the
947 * driver with "bt_ant_diversity" set to true.
948 */
949static void ath9k_antenna_check(struct ath_softc *sc,
950				struct ath_rx_status *rs)
951{
952	struct ath_hw *ah = sc->sc_ah;
953	struct ath9k_hw_capabilities *pCap = &ah->caps;
954	struct ath_common *common = ath9k_hw_common(ah);
955
956	if (!(ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB))
957		return;
958
959	/*
960	 * Change the default rx antenna if rx diversity
961	 * chooses the other antenna 3 times in a row.
962	 */
963	if (sc->rx.defant != rs->rs_antenna) {
964		if (++sc->rx.rxotherant >= 3)
965			ath_setdefantenna(sc, rs->rs_antenna);
966	} else {
967		sc->rx.rxotherant = 0;
968	}
969
970	if (pCap->hw_caps & ATH9K_HW_CAP_BT_ANT_DIV) {
971		if (common->bt_ant_diversity)
972			ath_ant_comb_scan(sc, rs);
973	} else {
974		ath_ant_comb_scan(sc, rs);
975	}
976}
977
978static void ath9k_apply_ampdu_details(struct ath_softc *sc,
979	struct ath_rx_status *rs, struct ieee80211_rx_status *rxs)
980{
981	if (rs->rs_isaggr) {
982		rxs->flag |= RX_FLAG_AMPDU_DETAILS | RX_FLAG_AMPDU_LAST_KNOWN;
983
984		rxs->ampdu_reference = sc->rx.ampdu_ref;
985
986		if (!rs->rs_moreaggr) {
987			rxs->flag |= RX_FLAG_AMPDU_IS_LAST;
988			sc->rx.ampdu_ref++;
989		}
990
991		if (rs->rs_flags & ATH9K_RX_DELIM_CRC_PRE)
992			rxs->flag |= RX_FLAG_AMPDU_DELIM_CRC_ERROR;
993	}
994}
995
996int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
997{
998	struct ath_rxbuf *bf;
999	struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
1000	struct ieee80211_rx_status *rxs;
1001	struct ath_hw *ah = sc->sc_ah;
1002	struct ath_common *common = ath9k_hw_common(ah);
1003	struct ieee80211_hw *hw = sc->hw;
1004	int retval;
1005	struct ath_rx_status rs;
1006	enum ath9k_rx_qtype qtype;
1007	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1008	int dma_type;
1009	u64 tsf = 0;
1010	unsigned long flags;
1011	dma_addr_t new_buf_addr;
1012	unsigned int budget = 512;
1013	struct ieee80211_hdr *hdr;
1014
1015	if (edma)
1016		dma_type = DMA_BIDIRECTIONAL;
1017	else
1018		dma_type = DMA_FROM_DEVICE;
1019
1020	qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1021
1022	tsf = ath9k_hw_gettsf64(ah);
1023
1024	do {
1025		bool decrypt_error = false;
1026
1027		memset(&rs, 0, sizeof(rs));
1028		if (edma)
1029			bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1030		else
1031			bf = ath_get_next_rx_buf(sc, &rs);
1032
1033		if (!bf)
1034			break;
1035
1036		skb = bf->bf_mpdu;
1037		if (!skb)
1038			continue;
1039
1040		/*
1041		 * Take frame header from the first fragment and RX status from
1042		 * the last one.
1043		 */
1044		if (sc->rx.frag)
1045			hdr_skb = sc->rx.frag;
1046		else
1047			hdr_skb = skb;
1048
1049		rxs = IEEE80211_SKB_RXCB(hdr_skb);
1050		memset(rxs, 0, sizeof(struct ieee80211_rx_status));
1051
1052		retval = ath9k_rx_skb_preprocess(sc, hdr_skb, &rs, rxs,
1053						 &decrypt_error, tsf);
1054		if (retval)
1055			goto requeue_drop_frag;
1056
1057		/* Ensure we always have an skb to requeue once we are done
1058		 * processing the current buffer's skb */
1059		requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1060
1061		/* If there is no memory we ignore the current RX'd frame,
1062		 * tell hardware it can give us a new frame using the old
1063		 * skb and put it at the tail of the sc->rx.rxbuf list for
1064		 * processing. */
1065		if (!requeue_skb) {
1066			RX_STAT_INC(rx_oom_err);
1067			goto requeue_drop_frag;
1068		}
1069
1070		/* We will now give hardware our shiny new allocated skb */
1071		new_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1072					      common->rx_bufsize, dma_type);
1073		if (unlikely(dma_mapping_error(sc->dev, new_buf_addr))) {
1074			dev_kfree_skb_any(requeue_skb);
1075			goto requeue_drop_frag;
1076		}
1077
1078		/* Unmap the frame */
1079		dma_unmap_single(sc->dev, bf->bf_buf_addr,
1080				 common->rx_bufsize, dma_type);
1081
1082		bf->bf_mpdu = requeue_skb;
1083		bf->bf_buf_addr = new_buf_addr;
1084
1085		skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1086		if (ah->caps.rx_status_len)
1087			skb_pull(skb, ah->caps.rx_status_len);
1088
1089		if (!rs.rs_more)
1090			ath9k_cmn_rx_skb_postprocess(common, hdr_skb, &rs,
1091						     rxs, decrypt_error);
1092
1093		if (rs.rs_more) {
1094			RX_STAT_INC(rx_frags);
1095			/*
1096			 * rs_more indicates chained descriptors which can be
1097			 * used to link buffers together for a sort of
1098			 * scatter-gather operation.
1099			 */
1100			if (sc->rx.frag) {
1101				/* too many fragments - cannot handle frame */
1102				dev_kfree_skb_any(sc->rx.frag);
1103				dev_kfree_skb_any(skb);
1104				RX_STAT_INC(rx_too_many_frags_err);
1105				skb = NULL;
1106			}
1107			sc->rx.frag = skb;
1108			goto requeue;
1109		}
1110
1111		if (sc->rx.frag) {
1112			int space = skb->len - skb_tailroom(hdr_skb);
1113
1114			if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
1115				dev_kfree_skb(skb);
1116				RX_STAT_INC(rx_oom_err);
1117				goto requeue_drop_frag;
1118			}
1119
1120			sc->rx.frag = NULL;
1121
1122			skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
1123						  skb->len);
1124			dev_kfree_skb_any(skb);
1125			skb = hdr_skb;
1126		}
1127
1128		if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
1129			skb_trim(skb, skb->len - 8);
1130
1131		spin_lock_irqsave(&sc->sc_pm_lock, flags);
1132		if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1133				     PS_WAIT_FOR_CAB |
1134				     PS_WAIT_FOR_PSPOLL_DATA)) ||
1135		    ath9k_check_auto_sleep(sc))
1136			ath_rx_ps(sc, skb, rs.is_mybeacon);
1137		spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1138
1139		ath9k_antenna_check(sc, &rs);
1140		ath9k_apply_ampdu_details(sc, &rs, rxs);
1141		ath_debug_rate_stats(sc, &rs, skb);
1142
1143		hdr = (struct ieee80211_hdr *)skb->data;
1144		if (ieee80211_is_ack(hdr->frame_control))
1145			ath_dynack_sample_ack_ts(sc->sc_ah, skb, rs.rs_tstamp);
1146
1147		ieee80211_rx(hw, skb);
1148
1149requeue_drop_frag:
1150		if (sc->rx.frag) {
1151			dev_kfree_skb_any(sc->rx.frag);
1152			sc->rx.frag = NULL;
1153		}
1154requeue:
1155		list_add_tail(&bf->list, &sc->rx.rxbuf);
1156
1157		if (!edma) {
1158			ath_rx_buf_relink(sc, bf, flush);
1159			if (!flush)
1160				ath9k_hw_rxena(ah);
1161		} else if (!flush) {
1162			ath_rx_edma_buf_link(sc, qtype);
1163		}
1164
1165		if (!budget--)
1166			break;
1167	} while (1);
1168
1169	if (!(ah->imask & ATH9K_INT_RXEOL)) {
1170		ah->imask |= (ATH9K_INT_RXEOL | ATH9K_INT_RXORN);
1171		ath9k_hw_set_interrupts(ah);
1172	}
1173
1174	return 0;
1175}
1176