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	    AR_SREV_9561(sc->sc_ah))
430		rfilt |= ATH9K_RX_FILTER_4ADDRESS;
431
432	if (ath9k_is_chanctx_enabled() &&
433	    test_bit(ATH_OP_SCANNING, &common->op_flags))
434		rfilt |= ATH9K_RX_FILTER_BEACON;
435
436	spin_unlock_bh(&sc->chan_lock);
437
438	return rfilt;
439
440}
441
442void ath_startrecv(struct ath_softc *sc)
443{
444	struct ath_hw *ah = sc->sc_ah;
445	struct ath_rxbuf *bf, *tbf;
446
447	if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
448		ath_edma_start_recv(sc);
449		return;
450	}
451
452	if (list_empty(&sc->rx.rxbuf))
453		goto start_recv;
454
455	sc->rx.buf_hold = NULL;
456	sc->rx.rxlink = NULL;
457	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
458		ath_rx_buf_link(sc, bf, false);
459	}
460
461	/* We could have deleted elements so the list may be empty now */
462	if (list_empty(&sc->rx.rxbuf))
463		goto start_recv;
464
465	bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
466	ath9k_hw_putrxbuf(ah, bf->bf_daddr);
467	ath9k_hw_rxena(ah);
468
469start_recv:
470	ath_opmode_init(sc);
471	ath9k_hw_startpcureceive(ah, sc->cur_chan->offchannel);
472}
473
474static void ath_flushrecv(struct ath_softc *sc)
475{
476	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
477		ath_rx_tasklet(sc, 1, true);
478	ath_rx_tasklet(sc, 1, false);
479}
480
481bool ath_stoprecv(struct ath_softc *sc)
482{
483	struct ath_hw *ah = sc->sc_ah;
484	bool stopped, reset = false;
485
486	ath9k_hw_abortpcurecv(ah);
487	ath9k_hw_setrxfilter(ah, 0);
488	stopped = ath9k_hw_stopdmarecv(ah, &reset);
489
490	ath_flushrecv(sc);
491
492	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
493		ath_edma_stop_recv(sc);
494	else
495		sc->rx.rxlink = NULL;
496
497	if (!(ah->ah_flags & AH_UNPLUGGED) &&
498	    unlikely(!stopped)) {
499		ath_err(ath9k_hw_common(sc->sc_ah),
500			"Could not stop RX, we could be "
501			"confusing the DMA engine when we start RX up\n");
502		ATH_DBG_WARN_ON_ONCE(!stopped);
503	}
504	return stopped && !reset;
505}
506
507static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
508{
509	/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
510	struct ieee80211_mgmt *mgmt;
511	u8 *pos, *end, id, elen;
512	struct ieee80211_tim_ie *tim;
513
514	mgmt = (struct ieee80211_mgmt *)skb->data;
515	pos = mgmt->u.beacon.variable;
516	end = skb->data + skb->len;
517
518	while (pos + 2 < end) {
519		id = *pos++;
520		elen = *pos++;
521		if (pos + elen > end)
522			break;
523
524		if (id == WLAN_EID_TIM) {
525			if (elen < sizeof(*tim))
526				break;
527			tim = (struct ieee80211_tim_ie *) pos;
528			if (tim->dtim_count != 0)
529				break;
530			return tim->bitmap_ctrl & 0x01;
531		}
532
533		pos += elen;
534	}
535
536	return false;
537}
538
539static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
540{
541	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
542	bool skip_beacon = false;
543
544	if (skb->len < 24 + 8 + 2 + 2)
545		return;
546
547	sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
548
549	if (sc->ps_flags & PS_BEACON_SYNC) {
550		sc->ps_flags &= ~PS_BEACON_SYNC;
551		ath_dbg(common, PS,
552			"Reconfigure beacon timers based on synchronized timestamp\n");
553
554#ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
555		if (ath9k_is_chanctx_enabled()) {
556			if (sc->cur_chan == &sc->offchannel.chan)
557				skip_beacon = true;
558		}
559#endif
560
561		if (!skip_beacon &&
562		    !(WARN_ON_ONCE(sc->cur_chan->beacon.beacon_interval == 0)))
563			ath9k_set_beacon(sc);
564
565		ath9k_p2p_beacon_sync(sc);
566	}
567
568	if (ath_beacon_dtim_pending_cab(skb)) {
569		/*
570		 * Remain awake waiting for buffered broadcast/multicast
571		 * frames. If the last broadcast/multicast frame is not
572		 * received properly, the next beacon frame will work as
573		 * a backup trigger for returning into NETWORK SLEEP state,
574		 * so we are waiting for it as well.
575		 */
576		ath_dbg(common, PS,
577			"Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
578		sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
579		return;
580	}
581
582	if (sc->ps_flags & PS_WAIT_FOR_CAB) {
583		/*
584		 * This can happen if a broadcast frame is dropped or the AP
585		 * fails to send a frame indicating that all CAB frames have
586		 * been delivered.
587		 */
588		sc->ps_flags &= ~PS_WAIT_FOR_CAB;
589		ath_dbg(common, PS, "PS wait for CAB frames timed out\n");
590	}
591}
592
593static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb, bool mybeacon)
594{
595	struct ieee80211_hdr *hdr;
596	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
597
598	hdr = (struct ieee80211_hdr *)skb->data;
599
600	/* Process Beacon and CAB receive in PS state */
601	if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
602	    && mybeacon) {
603		ath_rx_ps_beacon(sc, skb);
604	} else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
605		   (ieee80211_is_data(hdr->frame_control) ||
606		    ieee80211_is_action(hdr->frame_control)) &&
607		   is_multicast_ether_addr(hdr->addr1) &&
608		   !ieee80211_has_moredata(hdr->frame_control)) {
609		/*
610		 * No more broadcast/multicast frames to be received at this
611		 * point.
612		 */
613		sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
614		ath_dbg(common, PS,
615			"All PS CAB frames received, back to sleep\n");
616	} else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
617		   !is_multicast_ether_addr(hdr->addr1) &&
618		   !ieee80211_has_morefrags(hdr->frame_control)) {
619		sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
620		ath_dbg(common, PS,
621			"Going back to sleep after having received PS-Poll data (0x%lx)\n",
622			sc->ps_flags & (PS_WAIT_FOR_BEACON |
623					PS_WAIT_FOR_CAB |
624					PS_WAIT_FOR_PSPOLL_DATA |
625					PS_WAIT_FOR_TX_ACK));
626	}
627}
628
629static bool ath_edma_get_buffers(struct ath_softc *sc,
630				 enum ath9k_rx_qtype qtype,
631				 struct ath_rx_status *rs,
632				 struct ath_rxbuf **dest)
633{
634	struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
635	struct ath_hw *ah = sc->sc_ah;
636	struct ath_common *common = ath9k_hw_common(ah);
637	struct sk_buff *skb;
638	struct ath_rxbuf *bf;
639	int ret;
640
641	skb = skb_peek(&rx_edma->rx_fifo);
642	if (!skb)
643		return false;
644
645	bf = SKB_CB_ATHBUF(skb);
646	BUG_ON(!bf);
647
648	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
649				common->rx_bufsize, DMA_FROM_DEVICE);
650
651	ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data);
652	if (ret == -EINPROGRESS) {
653		/*let device gain the buffer again*/
654		dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
655				common->rx_bufsize, DMA_FROM_DEVICE);
656		return false;
657	}
658
659	__skb_unlink(skb, &rx_edma->rx_fifo);
660	if (ret == -EINVAL) {
661		/* corrupt descriptor, skip this one and the following one */
662		list_add_tail(&bf->list, &sc->rx.rxbuf);
663		ath_rx_edma_buf_link(sc, qtype);
664
665		skb = skb_peek(&rx_edma->rx_fifo);
666		if (skb) {
667			bf = SKB_CB_ATHBUF(skb);
668			BUG_ON(!bf);
669
670			__skb_unlink(skb, &rx_edma->rx_fifo);
671			list_add_tail(&bf->list, &sc->rx.rxbuf);
672			ath_rx_edma_buf_link(sc, qtype);
673		}
674
675		bf = NULL;
676	}
677
678	*dest = bf;
679	return true;
680}
681
682static struct ath_rxbuf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
683						struct ath_rx_status *rs,
684						enum ath9k_rx_qtype qtype)
685{
686	struct ath_rxbuf *bf = NULL;
687
688	while (ath_edma_get_buffers(sc, qtype, rs, &bf)) {
689		if (!bf)
690			continue;
691
692		return bf;
693	}
694	return NULL;
695}
696
697static struct ath_rxbuf *ath_get_next_rx_buf(struct ath_softc *sc,
698					   struct ath_rx_status *rs)
699{
700	struct ath_hw *ah = sc->sc_ah;
701	struct ath_common *common = ath9k_hw_common(ah);
702	struct ath_desc *ds;
703	struct ath_rxbuf *bf;
704	int ret;
705
706	if (list_empty(&sc->rx.rxbuf)) {
707		sc->rx.rxlink = NULL;
708		return NULL;
709	}
710
711	bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
712	if (bf == sc->rx.buf_hold)
713		return NULL;
714
715	ds = bf->bf_desc;
716
717	/*
718	 * Must provide the virtual address of the current
719	 * descriptor, the physical address, and the virtual
720	 * address of the next descriptor in the h/w chain.
721	 * This allows the HAL to look ahead to see if the
722	 * hardware is done with a descriptor by checking the
723	 * done bit in the following descriptor and the address
724	 * of the current descriptor the DMA engine is working
725	 * on.  All this is necessary because of our use of
726	 * a self-linked list to avoid rx overruns.
727	 */
728	ret = ath9k_hw_rxprocdesc(ah, ds, rs);
729	if (ret == -EINPROGRESS) {
730		struct ath_rx_status trs;
731		struct ath_rxbuf *tbf;
732		struct ath_desc *tds;
733
734		memset(&trs, 0, sizeof(trs));
735		if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
736			sc->rx.rxlink = NULL;
737			return NULL;
738		}
739
740		tbf = list_entry(bf->list.next, struct ath_rxbuf, list);
741
742		/*
743		 * On some hardware the descriptor status words could
744		 * get corrupted, including the done bit. Because of
745		 * this, check if the next descriptor's done bit is
746		 * set or not.
747		 *
748		 * If the next descriptor's done bit is set, the current
749		 * descriptor has been corrupted. Force s/w to discard
750		 * this descriptor and continue...
751		 */
752
753		tds = tbf->bf_desc;
754		ret = ath9k_hw_rxprocdesc(ah, tds, &trs);
755		if (ret == -EINPROGRESS)
756			return NULL;
757
758		/*
759		 * Re-check previous descriptor, in case it has been filled
760		 * in the mean time.
761		 */
762		ret = ath9k_hw_rxprocdesc(ah, ds, rs);
763		if (ret == -EINPROGRESS) {
764			/*
765			 * mark descriptor as zero-length and set the 'more'
766			 * flag to ensure that both buffers get discarded
767			 */
768			rs->rs_datalen = 0;
769			rs->rs_more = true;
770		}
771	}
772
773	list_del(&bf->list);
774	if (!bf->bf_mpdu)
775		return bf;
776
777	/*
778	 * Synchronize the DMA transfer with CPU before
779	 * 1. accessing the frame
780	 * 2. requeueing the same buffer to h/w
781	 */
782	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
783			common->rx_bufsize,
784			DMA_FROM_DEVICE);
785
786	return bf;
787}
788
789static void ath9k_process_tsf(struct ath_rx_status *rs,
790			      struct ieee80211_rx_status *rxs,
791			      u64 tsf)
792{
793	u32 tsf_lower = tsf & 0xffffffff;
794
795	rxs->mactime = (tsf & ~0xffffffffULL) | rs->rs_tstamp;
796	if (rs->rs_tstamp > tsf_lower &&
797	    unlikely(rs->rs_tstamp - tsf_lower > 0x10000000))
798		rxs->mactime -= 0x100000000ULL;
799
800	if (rs->rs_tstamp < tsf_lower &&
801	    unlikely(tsf_lower - rs->rs_tstamp > 0x10000000))
802		rxs->mactime += 0x100000000ULL;
803}
804
805/*
806 * For Decrypt or Demic errors, we only mark packet status here and always push
807 * up the frame up to let mac80211 handle the actual error case, be it no
808 * decryption key or real decryption error. This let us keep statistics there.
809 */
810static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
811				   struct sk_buff *skb,
812				   struct ath_rx_status *rx_stats,
813				   struct ieee80211_rx_status *rx_status,
814				   bool *decrypt_error, u64 tsf)
815{
816	struct ieee80211_hw *hw = sc->hw;
817	struct ath_hw *ah = sc->sc_ah;
818	struct ath_common *common = ath9k_hw_common(ah);
819	struct ieee80211_hdr *hdr;
820	bool discard_current = sc->rx.discard_next;
821
822	/*
823	 * Discard corrupt descriptors which are marked in
824	 * ath_get_next_rx_buf().
825	 */
826	if (discard_current)
827		goto corrupt;
828
829	sc->rx.discard_next = false;
830
831	/*
832	 * Discard zero-length packets.
833	 */
834	if (!rx_stats->rs_datalen) {
835		RX_STAT_INC(rx_len_err);
836		goto corrupt;
837	}
838
839	/*
840	 * rs_status follows rs_datalen so if rs_datalen is too large
841	 * we can take a hint that hardware corrupted it, so ignore
842	 * those frames.
843	 */
844	if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) {
845		RX_STAT_INC(rx_len_err);
846		goto corrupt;
847	}
848
849	/* Only use status info from the last fragment */
850	if (rx_stats->rs_more)
851		return 0;
852
853	/*
854	 * Return immediately if the RX descriptor has been marked
855	 * as corrupt based on the various error bits.
856	 *
857	 * This is different from the other corrupt descriptor
858	 * condition handled above.
859	 */
860	if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC)
861		goto corrupt;
862
863	hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len);
864
865	ath9k_process_tsf(rx_stats, rx_status, tsf);
866	ath_debug_stat_rx(sc, rx_stats);
867
868	/*
869	 * Process PHY errors and return so that the packet
870	 * can be dropped.
871	 */
872	if (rx_stats->rs_status & ATH9K_RXERR_PHY) {
873		ath9k_dfs_process_phyerr(sc, hdr, rx_stats, rx_status->mactime);
874		if (ath_cmn_process_fft(&sc->spec_priv, hdr, rx_stats, rx_status->mactime))
875			RX_STAT_INC(rx_spectral);
876
877		return -EINVAL;
878	}
879
880	/*
881	 * everything but the rate is checked here, the rate check is done
882	 * separately to avoid doing two lookups for a rate for each frame.
883	 */
884	spin_lock_bh(&sc->chan_lock);
885	if (!ath9k_cmn_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error,
886				 sc->cur_chan->rxfilter)) {
887		spin_unlock_bh(&sc->chan_lock);
888		return -EINVAL;
889	}
890	spin_unlock_bh(&sc->chan_lock);
891
892	if (ath_is_mybeacon(common, hdr)) {
893		RX_STAT_INC(rx_beacons);
894		rx_stats->is_mybeacon = true;
895	}
896
897	/*
898	 * This shouldn't happen, but have a safety check anyway.
899	 */
900	if (WARN_ON(!ah->curchan))
901		return -EINVAL;
902
903	if (ath9k_cmn_process_rate(common, hw, rx_stats, rx_status)) {
904		/*
905		 * No valid hardware bitrate found -- we should not get here
906		 * because hardware has already validated this frame as OK.
907		 */
908		ath_dbg(common, ANY, "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
909			rx_stats->rs_rate);
910		RX_STAT_INC(rx_rate_err);
911		return -EINVAL;
912	}
913
914	if (ath9k_is_chanctx_enabled()) {
915		if (rx_stats->is_mybeacon)
916			ath_chanctx_beacon_recv_ev(sc,
917					   ATH_CHANCTX_EVENT_BEACON_RECEIVED);
918	}
919
920	ath9k_cmn_process_rssi(common, hw, rx_stats, rx_status);
921
922	rx_status->band = ah->curchan->chan->band;
923	rx_status->freq = ah->curchan->chan->center_freq;
924	rx_status->antenna = rx_stats->rs_antenna;
925	rx_status->flag |= RX_FLAG_MACTIME_END;
926
927#ifdef CONFIG_ATH9K_BTCOEX_SUPPORT
928	if (ieee80211_is_data_present(hdr->frame_control) &&
929	    !ieee80211_is_qos_nullfunc(hdr->frame_control))
930		sc->rx.num_pkts++;
931#endif
932
933	return 0;
934
935corrupt:
936	sc->rx.discard_next = rx_stats->rs_more;
937	return -EINVAL;
938}
939
940/*
941 * Run the LNA combining algorithm only in these cases:
942 *
943 * Standalone WLAN cards with both LNA/Antenna diversity
944 * enabled in the EEPROM.
945 *
946 * WLAN+BT cards which are in the supported card list
947 * in ath_pci_id_table and the user has loaded the
948 * driver with "bt_ant_diversity" set to true.
949 */
950static void ath9k_antenna_check(struct ath_softc *sc,
951				struct ath_rx_status *rs)
952{
953	struct ath_hw *ah = sc->sc_ah;
954	struct ath9k_hw_capabilities *pCap = &ah->caps;
955	struct ath_common *common = ath9k_hw_common(ah);
956
957	if (!(ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB))
958		return;
959
960	/*
961	 * Change the default rx antenna if rx diversity
962	 * chooses the other antenna 3 times in a row.
963	 */
964	if (sc->rx.defant != rs->rs_antenna) {
965		if (++sc->rx.rxotherant >= 3)
966			ath_setdefantenna(sc, rs->rs_antenna);
967	} else {
968		sc->rx.rxotherant = 0;
969	}
970
971	if (pCap->hw_caps & ATH9K_HW_CAP_BT_ANT_DIV) {
972		if (common->bt_ant_diversity)
973			ath_ant_comb_scan(sc, rs);
974	} else {
975		ath_ant_comb_scan(sc, rs);
976	}
977}
978
979static void ath9k_apply_ampdu_details(struct ath_softc *sc,
980	struct ath_rx_status *rs, struct ieee80211_rx_status *rxs)
981{
982	if (rs->rs_isaggr) {
983		rxs->flag |= RX_FLAG_AMPDU_DETAILS | RX_FLAG_AMPDU_LAST_KNOWN;
984
985		rxs->ampdu_reference = sc->rx.ampdu_ref;
986
987		if (!rs->rs_moreaggr) {
988			rxs->flag |= RX_FLAG_AMPDU_IS_LAST;
989			sc->rx.ampdu_ref++;
990		}
991
992		if (rs->rs_flags & ATH9K_RX_DELIM_CRC_PRE)
993			rxs->flag |= RX_FLAG_AMPDU_DELIM_CRC_ERROR;
994	}
995}
996
997int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
998{
999	struct ath_rxbuf *bf;
1000	struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
1001	struct ieee80211_rx_status *rxs;
1002	struct ath_hw *ah = sc->sc_ah;
1003	struct ath_common *common = ath9k_hw_common(ah);
1004	struct ieee80211_hw *hw = sc->hw;
1005	int retval;
1006	struct ath_rx_status rs;
1007	enum ath9k_rx_qtype qtype;
1008	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1009	int dma_type;
1010	u64 tsf = 0;
1011	unsigned long flags;
1012	dma_addr_t new_buf_addr;
1013	unsigned int budget = 512;
1014	struct ieee80211_hdr *hdr;
1015
1016	if (edma)
1017		dma_type = DMA_BIDIRECTIONAL;
1018	else
1019		dma_type = DMA_FROM_DEVICE;
1020
1021	qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1022
1023	tsf = ath9k_hw_gettsf64(ah);
1024
1025	do {
1026		bool decrypt_error = false;
1027
1028		memset(&rs, 0, sizeof(rs));
1029		if (edma)
1030			bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1031		else
1032			bf = ath_get_next_rx_buf(sc, &rs);
1033
1034		if (!bf)
1035			break;
1036
1037		skb = bf->bf_mpdu;
1038		if (!skb)
1039			continue;
1040
1041		/*
1042		 * Take frame header from the first fragment and RX status from
1043		 * the last one.
1044		 */
1045		if (sc->rx.frag)
1046			hdr_skb = sc->rx.frag;
1047		else
1048			hdr_skb = skb;
1049
1050		rxs = IEEE80211_SKB_RXCB(hdr_skb);
1051		memset(rxs, 0, sizeof(struct ieee80211_rx_status));
1052
1053		retval = ath9k_rx_skb_preprocess(sc, hdr_skb, &rs, rxs,
1054						 &decrypt_error, tsf);
1055		if (retval)
1056			goto requeue_drop_frag;
1057
1058		/* Ensure we always have an skb to requeue once we are done
1059		 * processing the current buffer's skb */
1060		requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1061
1062		/* If there is no memory we ignore the current RX'd frame,
1063		 * tell hardware it can give us a new frame using the old
1064		 * skb and put it at the tail of the sc->rx.rxbuf list for
1065		 * processing. */
1066		if (!requeue_skb) {
1067			RX_STAT_INC(rx_oom_err);
1068			goto requeue_drop_frag;
1069		}
1070
1071		/* We will now give hardware our shiny new allocated skb */
1072		new_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1073					      common->rx_bufsize, dma_type);
1074		if (unlikely(dma_mapping_error(sc->dev, new_buf_addr))) {
1075			dev_kfree_skb_any(requeue_skb);
1076			goto requeue_drop_frag;
1077		}
1078
1079		/* Unmap the frame */
1080		dma_unmap_single(sc->dev, bf->bf_buf_addr,
1081				 common->rx_bufsize, dma_type);
1082
1083		bf->bf_mpdu = requeue_skb;
1084		bf->bf_buf_addr = new_buf_addr;
1085
1086		skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1087		if (ah->caps.rx_status_len)
1088			skb_pull(skb, ah->caps.rx_status_len);
1089
1090		if (!rs.rs_more)
1091			ath9k_cmn_rx_skb_postprocess(common, hdr_skb, &rs,
1092						     rxs, decrypt_error);
1093
1094		if (rs.rs_more) {
1095			RX_STAT_INC(rx_frags);
1096			/*
1097			 * rs_more indicates chained descriptors which can be
1098			 * used to link buffers together for a sort of
1099			 * scatter-gather operation.
1100			 */
1101			if (sc->rx.frag) {
1102				/* too many fragments - cannot handle frame */
1103				dev_kfree_skb_any(sc->rx.frag);
1104				dev_kfree_skb_any(skb);
1105				RX_STAT_INC(rx_too_many_frags_err);
1106				skb = NULL;
1107			}
1108			sc->rx.frag = skb;
1109			goto requeue;
1110		}
1111
1112		if (sc->rx.frag) {
1113			int space = skb->len - skb_tailroom(hdr_skb);
1114
1115			if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
1116				dev_kfree_skb(skb);
1117				RX_STAT_INC(rx_oom_err);
1118				goto requeue_drop_frag;
1119			}
1120
1121			sc->rx.frag = NULL;
1122
1123			skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
1124						  skb->len);
1125			dev_kfree_skb_any(skb);
1126			skb = hdr_skb;
1127		}
1128
1129		if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
1130			skb_trim(skb, skb->len - 8);
1131
1132		spin_lock_irqsave(&sc->sc_pm_lock, flags);
1133		if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1134				     PS_WAIT_FOR_CAB |
1135				     PS_WAIT_FOR_PSPOLL_DATA)) ||
1136		    ath9k_check_auto_sleep(sc))
1137			ath_rx_ps(sc, skb, rs.is_mybeacon);
1138		spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1139
1140		ath9k_antenna_check(sc, &rs);
1141		ath9k_apply_ampdu_details(sc, &rs, rxs);
1142		ath_debug_rate_stats(sc, &rs, skb);
1143
1144		hdr = (struct ieee80211_hdr *)skb->data;
1145		if (ieee80211_is_ack(hdr->frame_control))
1146			ath_dynack_sample_ack_ts(sc->sc_ah, skb, rs.rs_tstamp);
1147
1148		ieee80211_rx(hw, skb);
1149
1150requeue_drop_frag:
1151		if (sc->rx.frag) {
1152			dev_kfree_skb_any(sc->rx.frag);
1153			sc->rx.frag = NULL;
1154		}
1155requeue:
1156		list_add_tail(&bf->list, &sc->rx.rxbuf);
1157
1158		if (!edma) {
1159			ath_rx_buf_relink(sc, bf, flush);
1160			if (!flush)
1161				ath9k_hw_rxena(ah);
1162		} else if (!flush) {
1163			ath_rx_edma_buf_link(sc, qtype);
1164		}
1165
1166		if (!budget--)
1167			break;
1168	} while (1);
1169
1170	if (!(ah->imask & ATH9K_INT_RXEOL)) {
1171		ah->imask |= (ATH9K_INT_RXEOL | ATH9K_INT_RXORN);
1172		ath9k_hw_set_interrupts(ah);
1173	}
1174
1175	return 0;
1176}
1177