recv.c revision 22e66a4c15b063aee5d03991c4b9629a3b0c4556
1/*
2 * Copyright (c) 2008-2009 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 "ath9k.h"
18
19static struct ieee80211_hw * ath_get_virt_hw(struct ath_softc *sc,
20					     struct ieee80211_hdr *hdr)
21{
22	struct ieee80211_hw *hw = sc->pri_wiphy->hw;
23	int i;
24
25	spin_lock_bh(&sc->wiphy_lock);
26	for (i = 0; i < sc->num_sec_wiphy; i++) {
27		struct ath_wiphy *aphy = sc->sec_wiphy[i];
28		if (aphy == NULL)
29			continue;
30		if (compare_ether_addr(hdr->addr1, aphy->hw->wiphy->perm_addr)
31		    == 0) {
32			hw = aphy->hw;
33			break;
34		}
35	}
36	spin_unlock_bh(&sc->wiphy_lock);
37	return hw;
38}
39
40/*
41 * Setup and link descriptors.
42 *
43 * 11N: we can no longer afford to self link the last descriptor.
44 * MAC acknowledges BA status as long as it copies frames to host
45 * buffer (or rx fifo). This can incorrectly acknowledge packets
46 * to a sender if last desc is self-linked.
47 */
48static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
49{
50	struct ath_hw *ah = sc->sc_ah;
51	struct ath_desc *ds;
52	struct sk_buff *skb;
53
54	ATH_RXBUF_RESET(bf);
55
56	ds = bf->bf_desc;
57	ds->ds_link = 0; /* link to null */
58	ds->ds_data = bf->bf_buf_addr;
59
60	/* virtual addr of the beginning of the buffer. */
61	skb = bf->bf_mpdu;
62	ASSERT(skb != NULL);
63	ds->ds_vdata = skb->data;
64
65	/* setup rx descriptors. The rx.bufsize here tells the harware
66	 * how much data it can DMA to us and that we are prepared
67	 * to process */
68	ath9k_hw_setuprxdesc(ah, ds,
69			     sc->rx.bufsize,
70			     0);
71
72	if (sc->rx.rxlink == NULL)
73		ath9k_hw_putrxbuf(ah, bf->bf_daddr);
74	else
75		*sc->rx.rxlink = bf->bf_daddr;
76
77	sc->rx.rxlink = &ds->ds_link;
78	ath9k_hw_rxena(ah);
79}
80
81static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
82{
83	/* XXX block beacon interrupts */
84	ath9k_hw_setantenna(sc->sc_ah, antenna);
85	sc->rx.defant = antenna;
86	sc->rx.rxotherant = 0;
87}
88
89/*
90 *  Extend 15-bit time stamp from rx descriptor to
91 *  a full 64-bit TSF using the current h/w TSF.
92*/
93static u64 ath_extend_tsf(struct ath_softc *sc, u32 rstamp)
94{
95	u64 tsf;
96
97	tsf = ath9k_hw_gettsf64(sc->sc_ah);
98	if ((tsf & 0x7fff) < rstamp)
99		tsf -= 0x8000;
100	return (tsf & ~0x7fff) | rstamp;
101}
102
103/*
104 * For Decrypt or Demic errors, we only mark packet status here and always push
105 * up the frame up to let mac80211 handle the actual error case, be it no
106 * decryption key or real decryption error. This let us keep statistics there.
107 */
108static int ath_rx_prepare(struct sk_buff *skb, struct ath_desc *ds,
109			  struct ieee80211_rx_status *rx_status, bool *decrypt_error,
110			  struct ath_softc *sc)
111{
112	struct ieee80211_hdr *hdr;
113	u8 ratecode;
114	__le16 fc;
115	struct ieee80211_hw *hw;
116	struct ieee80211_sta *sta;
117	struct ath_node *an;
118	int last_rssi = ATH_RSSI_DUMMY_MARKER;
119
120
121	hdr = (struct ieee80211_hdr *)skb->data;
122	fc = hdr->frame_control;
123	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
124	hw = ath_get_virt_hw(sc, hdr);
125
126	if (ds->ds_rxstat.rs_more) {
127		/*
128		 * Frame spans multiple descriptors; this cannot happen yet
129		 * as we don't support jumbograms. If not in monitor mode,
130		 * discard the frame. Enable this if you want to see
131		 * error frames in Monitor mode.
132		 */
133		if (sc->sc_ah->opmode != NL80211_IFTYPE_MONITOR)
134			goto rx_next;
135	} else if (ds->ds_rxstat.rs_status != 0) {
136		if (ds->ds_rxstat.rs_status & ATH9K_RXERR_CRC)
137			rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
138		if (ds->ds_rxstat.rs_status & ATH9K_RXERR_PHY)
139			goto rx_next;
140
141		if (ds->ds_rxstat.rs_status & ATH9K_RXERR_DECRYPT) {
142			*decrypt_error = true;
143		} else if (ds->ds_rxstat.rs_status & ATH9K_RXERR_MIC) {
144			if (ieee80211_is_ctl(fc))
145				/*
146				 * Sometimes, we get invalid
147				 * MIC failures on valid control frames.
148				 * Remove these mic errors.
149				 */
150				ds->ds_rxstat.rs_status &= ~ATH9K_RXERR_MIC;
151			else
152				rx_status->flag |= RX_FLAG_MMIC_ERROR;
153		}
154		/*
155		 * Reject error frames with the exception of
156		 * decryption and MIC failures. For monitor mode,
157		 * we also ignore the CRC error.
158		 */
159		if (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR) {
160			if (ds->ds_rxstat.rs_status &
161			    ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
162			      ATH9K_RXERR_CRC))
163				goto rx_next;
164		} else {
165			if (ds->ds_rxstat.rs_status &
166			    ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
167				goto rx_next;
168			}
169		}
170	}
171
172	ratecode = ds->ds_rxstat.rs_rate;
173
174	if (ratecode & 0x80) {
175		/* HT rate */
176		rx_status->flag |= RX_FLAG_HT;
177		if (ds->ds_rxstat.rs_flags & ATH9K_RX_2040)
178			rx_status->flag |= RX_FLAG_40MHZ;
179		if (ds->ds_rxstat.rs_flags & ATH9K_RX_GI)
180			rx_status->flag |= RX_FLAG_SHORT_GI;
181		rx_status->rate_idx = ratecode & 0x7f;
182	} else {
183		int i = 0, cur_band, n_rates;
184
185		cur_band = hw->conf.channel->band;
186		n_rates = sc->sbands[cur_band].n_bitrates;
187
188		for (i = 0; i < n_rates; i++) {
189			if (sc->sbands[cur_band].bitrates[i].hw_value ==
190			    ratecode) {
191				rx_status->rate_idx = i;
192				break;
193			}
194
195			if (sc->sbands[cur_band].bitrates[i].hw_value_short ==
196			    ratecode) {
197				rx_status->rate_idx = i;
198				rx_status->flag |= RX_FLAG_SHORTPRE;
199				break;
200			}
201		}
202	}
203
204	rcu_read_lock();
205	sta = ieee80211_find_sta(sc->hw, hdr->addr2);
206	if (sta) {
207		an = (struct ath_node *) sta->drv_priv;
208		if (ds->ds_rxstat.rs_rssi != ATH9K_RSSI_BAD &&
209		   !ds->ds_rxstat.rs_moreaggr)
210			ATH_RSSI_LPF(an->last_rssi, ds->ds_rxstat.rs_rssi);
211		last_rssi = an->last_rssi;
212	}
213	rcu_read_unlock();
214
215	if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
216		ds->ds_rxstat.rs_rssi = ATH_EP_RND(last_rssi,
217					ATH_RSSI_EP_MULTIPLIER);
218	if (ds->ds_rxstat.rs_rssi < 0)
219		ds->ds_rxstat.rs_rssi = 0;
220	else if (ds->ds_rxstat.rs_rssi > 127)
221		ds->ds_rxstat.rs_rssi = 127;
222
223	/* Update Beacon RSSI, this is used by ANI. */
224	if (ieee80211_is_beacon(fc))
225		sc->sc_ah->stats.avgbrssi = ds->ds_rxstat.rs_rssi;
226
227	rx_status->mactime = ath_extend_tsf(sc, ds->ds_rxstat.rs_tstamp);
228	rx_status->band = hw->conf.channel->band;
229	rx_status->freq = hw->conf.channel->center_freq;
230	rx_status->noise = sc->ani.noise_floor;
231	rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + ds->ds_rxstat.rs_rssi;
232	rx_status->antenna = ds->ds_rxstat.rs_antenna;
233
234	/*
235	 * Theory for reporting quality:
236	 *
237	 * At a hardware RSSI of 45 you will be able to use MCS 7  reliably.
238	 * At a hardware RSSI of 45 you will be able to use MCS 15 reliably.
239	 * At a hardware RSSI of 35 you should be able use 54 Mbps reliably.
240	 *
241	 * MCS 7  is the highets MCS index usable by a 1-stream device.
242	 * MCS 15 is the highest MCS index usable by a 2-stream device.
243	 *
244	 * All ath9k devices are either 1-stream or 2-stream.
245	 *
246	 * How many bars you see is derived from the qual reporting.
247	 *
248	 * A more elaborate scheme can be used here but it requires tables
249	 * of SNR/throughput for each possible mode used. For the MCS table
250	 * you can refer to the wireless wiki:
251	 *
252	 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
253	 *
254	 */
255	if (conf_is_ht(&hw->conf))
256		rx_status->qual =  ds->ds_rxstat.rs_rssi * 100 / 45;
257	else
258		rx_status->qual =  ds->ds_rxstat.rs_rssi * 100 / 35;
259
260	/* rssi can be more than 45 though, anything above that
261	 * should be considered at 100% */
262	if (rx_status->qual > 100)
263		rx_status->qual = 100;
264
265	rx_status->flag |= RX_FLAG_TSFT;
266
267	return 1;
268rx_next:
269	return 0;
270}
271
272static void ath_opmode_init(struct ath_softc *sc)
273{
274	struct ath_hw *ah = sc->sc_ah;
275	u32 rfilt, mfilt[2];
276
277	/* configure rx filter */
278	rfilt = ath_calcrxfilter(sc);
279	ath9k_hw_setrxfilter(ah, rfilt);
280
281	/* configure bssid mask */
282	if (ah->caps.hw_caps & ATH9K_HW_CAP_BSSIDMASK)
283		ath9k_hw_setbssidmask(sc);
284
285	/* configure operational mode */
286	ath9k_hw_setopmode(ah);
287
288	/* Handle any link-level address change. */
289	ath9k_hw_setmac(ah, sc->sc_ah->macaddr);
290
291	/* calculate and install multicast filter */
292	mfilt[0] = mfilt[1] = ~0;
293	ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
294}
295
296int ath_rx_init(struct ath_softc *sc, int nbufs)
297{
298	struct sk_buff *skb;
299	struct ath_buf *bf;
300	int error = 0;
301
302	spin_lock_init(&sc->rx.rxflushlock);
303	sc->sc_flags &= ~SC_OP_RXFLUSH;
304	spin_lock_init(&sc->rx.rxbuflock);
305
306	sc->rx.bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
307				 min(sc->common.cachelsz, (u16)64));
308
309	DPRINTF(sc, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
310		sc->common.cachelsz, sc->rx.bufsize);
311
312	/* Initialize rx descriptors */
313
314	error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
315				  "rx", nbufs, 1);
316	if (error != 0) {
317		DPRINTF(sc, ATH_DBG_FATAL,
318			"failed to allocate rx descriptors: %d\n", error);
319		goto err;
320	}
321
322	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
323		skb = ath_rxbuf_alloc(&sc->common, sc->rx.bufsize, GFP_KERNEL);
324		if (skb == NULL) {
325			error = -ENOMEM;
326			goto err;
327		}
328
329		bf->bf_mpdu = skb;
330		bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
331						 sc->rx.bufsize,
332						 DMA_FROM_DEVICE);
333		if (unlikely(dma_mapping_error(sc->dev,
334					       bf->bf_buf_addr))) {
335			dev_kfree_skb_any(skb);
336			bf->bf_mpdu = NULL;
337			DPRINTF(sc, ATH_DBG_FATAL,
338				"dma_mapping_error() on RX init\n");
339			error = -ENOMEM;
340			goto err;
341		}
342		bf->bf_dmacontext = bf->bf_buf_addr;
343	}
344	sc->rx.rxlink = NULL;
345
346err:
347	if (error)
348		ath_rx_cleanup(sc);
349
350	return error;
351}
352
353void ath_rx_cleanup(struct ath_softc *sc)
354{
355	struct sk_buff *skb;
356	struct ath_buf *bf;
357
358	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
359		skb = bf->bf_mpdu;
360		if (skb) {
361			dma_unmap_single(sc->dev, bf->bf_buf_addr,
362					 sc->rx.bufsize, DMA_FROM_DEVICE);
363			dev_kfree_skb(skb);
364		}
365	}
366
367	if (sc->rx.rxdma.dd_desc_len != 0)
368		ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
369}
370
371/*
372 * Calculate the receive filter according to the
373 * operating mode and state:
374 *
375 * o always accept unicast, broadcast, and multicast traffic
376 * o maintain current state of phy error reception (the hal
377 *   may enable phy error frames for noise immunity work)
378 * o probe request frames are accepted only when operating in
379 *   hostap, adhoc, or monitor modes
380 * o enable promiscuous mode according to the interface state
381 * o accept beacons:
382 *   - when operating in adhoc mode so the 802.11 layer creates
383 *     node table entries for peers,
384 *   - when operating in station mode for collecting rssi data when
385 *     the station is otherwise quiet, or
386 *   - when operating as a repeater so we see repeater-sta beacons
387 *   - when scanning
388 */
389
390u32 ath_calcrxfilter(struct ath_softc *sc)
391{
392#define	RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
393
394	u32 rfilt;
395
396	rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
397		| ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
398		| ATH9K_RX_FILTER_MCAST;
399
400	/* If not a STA, enable processing of Probe Requests */
401	if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
402		rfilt |= ATH9K_RX_FILTER_PROBEREQ;
403
404	/*
405	 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
406	 * mode interface or when in monitor mode. AP mode does not need this
407	 * since it receives all in-BSS frames anyway.
408	 */
409	if (((sc->sc_ah->opmode != NL80211_IFTYPE_AP) &&
410	     (sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
411	    (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR))
412		rfilt |= ATH9K_RX_FILTER_PROM;
413
414	if (sc->rx.rxfilter & FIF_CONTROL)
415		rfilt |= ATH9K_RX_FILTER_CONTROL;
416
417	if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
418	    !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
419		rfilt |= ATH9K_RX_FILTER_MYBEACON;
420	else
421		rfilt |= ATH9K_RX_FILTER_BEACON;
422
423	if (sc->rx.rxfilter & FIF_PSPOLL)
424		rfilt |= ATH9K_RX_FILTER_PSPOLL;
425
426	if (sc->sec_wiphy) {
427		/* TODO: only needed if more than one BSSID is in use in
428		 * station/adhoc mode */
429		/* TODO: for older chips, may need to add ATH9K_RX_FILTER_PROM
430		 */
431		rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
432	}
433
434	return rfilt;
435
436#undef RX_FILTER_PRESERVE
437}
438
439int ath_startrecv(struct ath_softc *sc)
440{
441	struct ath_hw *ah = sc->sc_ah;
442	struct ath_buf *bf, *tbf;
443
444	spin_lock_bh(&sc->rx.rxbuflock);
445	if (list_empty(&sc->rx.rxbuf))
446		goto start_recv;
447
448	sc->rx.rxlink = NULL;
449	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
450		ath_rx_buf_link(sc, bf);
451	}
452
453	/* We could have deleted elements so the list may be empty now */
454	if (list_empty(&sc->rx.rxbuf))
455		goto start_recv;
456
457	bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
458	ath9k_hw_putrxbuf(ah, bf->bf_daddr);
459	ath9k_hw_rxena(ah);
460
461start_recv:
462	spin_unlock_bh(&sc->rx.rxbuflock);
463	ath_opmode_init(sc);
464	ath9k_hw_startpcureceive(ah);
465
466	return 0;
467}
468
469bool ath_stoprecv(struct ath_softc *sc)
470{
471	struct ath_hw *ah = sc->sc_ah;
472	bool stopped;
473
474	ath9k_hw_stoppcurecv(ah);
475	ath9k_hw_setrxfilter(ah, 0);
476	stopped = ath9k_hw_stopdmarecv(ah);
477	sc->rx.rxlink = NULL;
478
479	return stopped;
480}
481
482void ath_flushrecv(struct ath_softc *sc)
483{
484	spin_lock_bh(&sc->rx.rxflushlock);
485	sc->sc_flags |= SC_OP_RXFLUSH;
486	ath_rx_tasklet(sc, 1);
487	sc->sc_flags &= ~SC_OP_RXFLUSH;
488	spin_unlock_bh(&sc->rx.rxflushlock);
489}
490
491static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
492{
493	/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
494	struct ieee80211_mgmt *mgmt;
495	u8 *pos, *end, id, elen;
496	struct ieee80211_tim_ie *tim;
497
498	mgmt = (struct ieee80211_mgmt *)skb->data;
499	pos = mgmt->u.beacon.variable;
500	end = skb->data + skb->len;
501
502	while (pos + 2 < end) {
503		id = *pos++;
504		elen = *pos++;
505		if (pos + elen > end)
506			break;
507
508		if (id == WLAN_EID_TIM) {
509			if (elen < sizeof(*tim))
510				break;
511			tim = (struct ieee80211_tim_ie *) pos;
512			if (tim->dtim_count != 0)
513				break;
514			return tim->bitmap_ctrl & 0x01;
515		}
516
517		pos += elen;
518	}
519
520	return false;
521}
522
523static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
524{
525	struct ieee80211_mgmt *mgmt;
526
527	if (skb->len < 24 + 8 + 2 + 2)
528		return;
529
530	mgmt = (struct ieee80211_mgmt *)skb->data;
531	if (memcmp(sc->curbssid, mgmt->bssid, ETH_ALEN) != 0)
532		return; /* not from our current AP */
533
534	sc->sc_flags &= ~SC_OP_WAIT_FOR_BEACON;
535
536	if (sc->sc_flags & SC_OP_BEACON_SYNC) {
537		sc->sc_flags &= ~SC_OP_BEACON_SYNC;
538		DPRINTF(sc, ATH_DBG_PS, "Reconfigure Beacon timers based on "
539			"timestamp from the AP\n");
540		ath_beacon_config(sc, NULL);
541	}
542
543	if (ath_beacon_dtim_pending_cab(skb)) {
544		/*
545		 * Remain awake waiting for buffered broadcast/multicast
546		 * frames. If the last broadcast/multicast frame is not
547		 * received properly, the next beacon frame will work as
548		 * a backup trigger for returning into NETWORK SLEEP state,
549		 * so we are waiting for it as well.
550		 */
551		DPRINTF(sc, ATH_DBG_PS, "Received DTIM beacon indicating "
552			"buffered broadcast/multicast frame(s)\n");
553		sc->sc_flags |= SC_OP_WAIT_FOR_CAB | SC_OP_WAIT_FOR_BEACON;
554		return;
555	}
556
557	if (sc->sc_flags & SC_OP_WAIT_FOR_CAB) {
558		/*
559		 * This can happen if a broadcast frame is dropped or the AP
560		 * fails to send a frame indicating that all CAB frames have
561		 * been delivered.
562		 */
563		sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
564		DPRINTF(sc, ATH_DBG_PS, "PS wait for CAB frames timed out\n");
565	}
566}
567
568static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
569{
570	struct ieee80211_hdr *hdr;
571
572	hdr = (struct ieee80211_hdr *)skb->data;
573
574	/* Process Beacon and CAB receive in PS state */
575	if ((sc->sc_flags & SC_OP_WAIT_FOR_BEACON) &&
576	    ieee80211_is_beacon(hdr->frame_control))
577		ath_rx_ps_beacon(sc, skb);
578	else if ((sc->sc_flags & SC_OP_WAIT_FOR_CAB) &&
579		 (ieee80211_is_data(hdr->frame_control) ||
580		  ieee80211_is_action(hdr->frame_control)) &&
581		 is_multicast_ether_addr(hdr->addr1) &&
582		 !ieee80211_has_moredata(hdr->frame_control)) {
583		/*
584		 * No more broadcast/multicast frames to be received at this
585		 * point.
586		 */
587		sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
588		DPRINTF(sc, ATH_DBG_PS, "All PS CAB frames received, back to "
589			"sleep\n");
590	} else if ((sc->sc_flags & SC_OP_WAIT_FOR_PSPOLL_DATA) &&
591		   !is_multicast_ether_addr(hdr->addr1) &&
592		   !ieee80211_has_morefrags(hdr->frame_control)) {
593		sc->sc_flags &= ~SC_OP_WAIT_FOR_PSPOLL_DATA;
594		DPRINTF(sc, ATH_DBG_PS, "Going back to sleep after having "
595			"received PS-Poll data (0x%x)\n",
596			sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
597					SC_OP_WAIT_FOR_CAB |
598					SC_OP_WAIT_FOR_PSPOLL_DATA |
599					SC_OP_WAIT_FOR_TX_ACK));
600	}
601}
602
603static void ath_rx_send_to_mac80211(struct ath_softc *sc, struct sk_buff *skb,
604				    struct ieee80211_rx_status *rx_status)
605{
606	struct ieee80211_hdr *hdr;
607
608	hdr = (struct ieee80211_hdr *)skb->data;
609
610	/* Send the frame to mac80211 */
611	if (is_multicast_ether_addr(hdr->addr1)) {
612		int i;
613		/*
614		 * Deliver broadcast/multicast frames to all suitable
615		 * virtual wiphys.
616		 */
617		/* TODO: filter based on channel configuration */
618		for (i = 0; i < sc->num_sec_wiphy; i++) {
619			struct ath_wiphy *aphy = sc->sec_wiphy[i];
620			struct sk_buff *nskb;
621			if (aphy == NULL)
622				continue;
623			nskb = skb_copy(skb, GFP_ATOMIC);
624			if (nskb) {
625				memcpy(IEEE80211_SKB_RXCB(nskb), rx_status,
626					sizeof(*rx_status));
627				ieee80211_rx(aphy->hw, nskb);
628			}
629		}
630		memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
631		ieee80211_rx(sc->hw, skb);
632	} else {
633		/* Deliver unicast frames based on receiver address */
634		memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
635		ieee80211_rx(ath_get_virt_hw(sc, hdr), skb);
636	}
637}
638
639int ath_rx_tasklet(struct ath_softc *sc, int flush)
640{
641#define PA2DESC(_sc, _pa)                                               \
642	((struct ath_desc *)((caddr_t)(_sc)->rx.rxdma.dd_desc +		\
643			     ((_pa) - (_sc)->rx.rxdma.dd_desc_paddr)))
644
645	struct ath_buf *bf;
646	struct ath_desc *ds;
647	struct sk_buff *skb = NULL, *requeue_skb;
648	struct ieee80211_rx_status rx_status;
649	struct ath_hw *ah = sc->sc_ah;
650	struct ieee80211_hdr *hdr;
651	int hdrlen, padsize, retval;
652	bool decrypt_error = false;
653	u8 keyix;
654	__le16 fc;
655
656	spin_lock_bh(&sc->rx.rxbuflock);
657
658	do {
659		/* If handling rx interrupt and flush is in progress => exit */
660		if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
661			break;
662
663		if (list_empty(&sc->rx.rxbuf)) {
664			sc->rx.rxlink = NULL;
665			break;
666		}
667
668		bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
669		ds = bf->bf_desc;
670
671		/*
672		 * Must provide the virtual address of the current
673		 * descriptor, the physical address, and the virtual
674		 * address of the next descriptor in the h/w chain.
675		 * This allows the HAL to look ahead to see if the
676		 * hardware is done with a descriptor by checking the
677		 * done bit in the following descriptor and the address
678		 * of the current descriptor the DMA engine is working
679		 * on.  All this is necessary because of our use of
680		 * a self-linked list to avoid rx overruns.
681		 */
682		retval = ath9k_hw_rxprocdesc(ah, ds,
683					     bf->bf_daddr,
684					     PA2DESC(sc, ds->ds_link),
685					     0);
686		if (retval == -EINPROGRESS) {
687			struct ath_buf *tbf;
688			struct ath_desc *tds;
689
690			if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
691				sc->rx.rxlink = NULL;
692				break;
693			}
694
695			tbf = list_entry(bf->list.next, struct ath_buf, list);
696
697			/*
698			 * On some hardware the descriptor status words could
699			 * get corrupted, including the done bit. Because of
700			 * this, check if the next descriptor's done bit is
701			 * set or not.
702			 *
703			 * If the next descriptor's done bit is set, the current
704			 * descriptor has been corrupted. Force s/w to discard
705			 * this descriptor and continue...
706			 */
707
708			tds = tbf->bf_desc;
709			retval = ath9k_hw_rxprocdesc(ah, tds, tbf->bf_daddr,
710					     PA2DESC(sc, tds->ds_link), 0);
711			if (retval == -EINPROGRESS) {
712				break;
713			}
714		}
715
716		skb = bf->bf_mpdu;
717		if (!skb)
718			continue;
719
720		/*
721		 * Synchronize the DMA transfer with CPU before
722		 * 1. accessing the frame
723		 * 2. requeueing the same buffer to h/w
724		 */
725		dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
726				sc->rx.bufsize,
727				DMA_FROM_DEVICE);
728
729		/*
730		 * If we're asked to flush receive queue, directly
731		 * chain it back at the queue without processing it.
732		 */
733		if (flush)
734			goto requeue;
735
736		if (!ds->ds_rxstat.rs_datalen)
737			goto requeue;
738
739		/* The status portion of the descriptor could get corrupted. */
740		if (sc->rx.bufsize < ds->ds_rxstat.rs_datalen)
741			goto requeue;
742
743		if (!ath_rx_prepare(skb, ds, &rx_status, &decrypt_error, sc))
744			goto requeue;
745
746		/* Ensure we always have an skb to requeue once we are done
747		 * processing the current buffer's skb */
748		requeue_skb = ath_rxbuf_alloc(&sc->common, sc->rx.bufsize, GFP_ATOMIC);
749
750		/* If there is no memory we ignore the current RX'd frame,
751		 * tell hardware it can give us a new frame using the old
752		 * skb and put it at the tail of the sc->rx.rxbuf list for
753		 * processing. */
754		if (!requeue_skb)
755			goto requeue;
756
757		/* Unmap the frame */
758		dma_unmap_single(sc->dev, bf->bf_buf_addr,
759				 sc->rx.bufsize,
760				 DMA_FROM_DEVICE);
761
762		skb_put(skb, ds->ds_rxstat.rs_datalen);
763
764		/* see if any padding is done by the hw and remove it */
765		hdr = (struct ieee80211_hdr *)skb->data;
766		hdrlen = ieee80211_get_hdrlen_from_skb(skb);
767		fc = hdr->frame_control;
768
769		/* The MAC header is padded to have 32-bit boundary if the
770		 * packet payload is non-zero. The general calculation for
771		 * padsize would take into account odd header lengths:
772		 * padsize = (4 - hdrlen % 4) % 4; However, since only
773		 * even-length headers are used, padding can only be 0 or 2
774		 * bytes and we can optimize this a bit. In addition, we must
775		 * not try to remove padding from short control frames that do
776		 * not have payload. */
777		padsize = hdrlen & 3;
778		if (padsize && hdrlen >= 24) {
779			memmove(skb->data + padsize, skb->data, hdrlen);
780			skb_pull(skb, padsize);
781		}
782
783		keyix = ds->ds_rxstat.rs_keyix;
784
785		if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
786			rx_status.flag |= RX_FLAG_DECRYPTED;
787		} else if (ieee80211_has_protected(fc)
788			   && !decrypt_error && skb->len >= hdrlen + 4) {
789			keyix = skb->data[hdrlen + 3] >> 6;
790
791			if (test_bit(keyix, sc->keymap))
792				rx_status.flag |= RX_FLAG_DECRYPTED;
793		}
794		if (ah->sw_mgmt_crypto &&
795		    (rx_status.flag & RX_FLAG_DECRYPTED) &&
796		    ieee80211_is_mgmt(fc)) {
797			/* Use software decrypt for management frames. */
798			rx_status.flag &= ~RX_FLAG_DECRYPTED;
799		}
800
801		/* We will now give hardware our shiny new allocated skb */
802		bf->bf_mpdu = requeue_skb;
803		bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
804					 sc->rx.bufsize,
805					 DMA_FROM_DEVICE);
806		if (unlikely(dma_mapping_error(sc->dev,
807			  bf->bf_buf_addr))) {
808			dev_kfree_skb_any(requeue_skb);
809			bf->bf_mpdu = NULL;
810			DPRINTF(sc, ATH_DBG_FATAL,
811				"dma_mapping_error() on RX\n");
812			ath_rx_send_to_mac80211(sc, skb, &rx_status);
813			break;
814		}
815		bf->bf_dmacontext = bf->bf_buf_addr;
816
817		/*
818		 * change the default rx antenna if rx diversity chooses the
819		 * other antenna 3 times in a row.
820		 */
821		if (sc->rx.defant != ds->ds_rxstat.rs_antenna) {
822			if (++sc->rx.rxotherant >= 3)
823				ath_setdefantenna(sc, ds->ds_rxstat.rs_antenna);
824		} else {
825			sc->rx.rxotherant = 0;
826		}
827
828		if (unlikely(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
829					     SC_OP_WAIT_FOR_CAB |
830					     SC_OP_WAIT_FOR_PSPOLL_DATA)))
831			ath_rx_ps(sc, skb);
832
833		ath_rx_send_to_mac80211(sc, skb, &rx_status);
834
835requeue:
836		list_move_tail(&bf->list, &sc->rx.rxbuf);
837		ath_rx_buf_link(sc, bf);
838	} while (1);
839
840	spin_unlock_bh(&sc->rx.rxbuflock);
841
842	return 0;
843#undef PA2DESC
844}
845