recv.c revision f0e9a8606ce60880249fd570fbebf4472c3d37c0
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
103static struct sk_buff *ath_rxbuf_alloc(struct ath_softc *sc, u32 len, gfp_t gfp_mask)
104{
105	struct sk_buff *skb;
106	u32 off;
107
108	/*
109	 * Cache-line-align.  This is important (for the
110	 * 5210 at least) as not doing so causes bogus data
111	 * in rx'd frames.
112	 */
113
114	/* Note: the kernel can allocate a value greater than
115	 * what we ask it to give us. We really only need 4 KB as that
116	 * is this hardware supports and in fact we need at least 3849
117	 * as that is the MAX AMSDU size this hardware supports.
118	 * Unfortunately this means we may get 8 KB here from the
119	 * kernel... and that is actually what is observed on some
120	 * systems :( */
121	skb = __dev_alloc_skb(len + sc->cachelsz - 1, gfp_mask);
122	if (skb != NULL) {
123		off = ((unsigned long) skb->data) % sc->cachelsz;
124		if (off != 0)
125			skb_reserve(skb, sc->cachelsz - off);
126	} else {
127		DPRINTF(sc, ATH_DBG_FATAL,
128			"skbuff alloc of size %u failed\n", len);
129		return NULL;
130	}
131
132	return skb;
133}
134
135/*
136 * For Decrypt or Demic errors, we only mark packet status here and always push
137 * up the frame up to let mac80211 handle the actual error case, be it no
138 * decryption key or real decryption error. This let us keep statistics there.
139 */
140static int ath_rx_prepare(struct sk_buff *skb, struct ath_desc *ds,
141			  struct ieee80211_rx_status *rx_status, bool *decrypt_error,
142			  struct ath_softc *sc)
143{
144	struct ieee80211_hdr *hdr;
145	u8 ratecode;
146	__le16 fc;
147	struct ieee80211_hw *hw;
148
149	hdr = (struct ieee80211_hdr *)skb->data;
150	fc = hdr->frame_control;
151	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
152	hw = ath_get_virt_hw(sc, hdr);
153
154	if (ds->ds_rxstat.rs_more) {
155		/*
156		 * Frame spans multiple descriptors; this cannot happen yet
157		 * as we don't support jumbograms. If not in monitor mode,
158		 * discard the frame. Enable this if you want to see
159		 * error frames in Monitor mode.
160		 */
161		if (sc->sc_ah->opmode != NL80211_IFTYPE_MONITOR)
162			goto rx_next;
163	} else if (ds->ds_rxstat.rs_status != 0) {
164		if (ds->ds_rxstat.rs_status & ATH9K_RXERR_CRC)
165			rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
166		if (ds->ds_rxstat.rs_status & ATH9K_RXERR_PHY)
167			goto rx_next;
168
169		if (ds->ds_rxstat.rs_status & ATH9K_RXERR_DECRYPT) {
170			*decrypt_error = true;
171		} else if (ds->ds_rxstat.rs_status & ATH9K_RXERR_MIC) {
172			if (ieee80211_is_ctl(fc))
173				/*
174				 * Sometimes, we get invalid
175				 * MIC failures on valid control frames.
176				 * Remove these mic errors.
177				 */
178				ds->ds_rxstat.rs_status &= ~ATH9K_RXERR_MIC;
179			else
180				rx_status->flag |= RX_FLAG_MMIC_ERROR;
181		}
182		/*
183		 * Reject error frames with the exception of
184		 * decryption and MIC failures. For monitor mode,
185		 * we also ignore the CRC error.
186		 */
187		if (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR) {
188			if (ds->ds_rxstat.rs_status &
189			    ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
190			      ATH9K_RXERR_CRC))
191				goto rx_next;
192		} else {
193			if (ds->ds_rxstat.rs_status &
194			    ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
195				goto rx_next;
196			}
197		}
198	}
199
200	ratecode = ds->ds_rxstat.rs_rate;
201
202	if (ratecode & 0x80) {
203		/* HT rate */
204		rx_status->flag |= RX_FLAG_HT;
205		if (ds->ds_rxstat.rs_flags & ATH9K_RX_2040)
206			rx_status->flag |= RX_FLAG_40MHZ;
207		if (ds->ds_rxstat.rs_flags & ATH9K_RX_GI)
208			rx_status->flag |= RX_FLAG_SHORT_GI;
209		rx_status->rate_idx = ratecode & 0x7f;
210	} else {
211		int i = 0, cur_band, n_rates;
212
213		cur_band = hw->conf.channel->band;
214		n_rates = sc->sbands[cur_band].n_bitrates;
215
216		for (i = 0; i < n_rates; i++) {
217			if (sc->sbands[cur_band].bitrates[i].hw_value ==
218			    ratecode) {
219				rx_status->rate_idx = i;
220				break;
221			}
222
223			if (sc->sbands[cur_band].bitrates[i].hw_value_short ==
224			    ratecode) {
225				rx_status->rate_idx = i;
226				rx_status->flag |= RX_FLAG_SHORTPRE;
227				break;
228			}
229		}
230	}
231
232	rx_status->mactime = ath_extend_tsf(sc, ds->ds_rxstat.rs_tstamp);
233	rx_status->band = hw->conf.channel->band;
234	rx_status->freq = hw->conf.channel->center_freq;
235	rx_status->noise = sc->ani.noise_floor;
236	rx_status->signal = rx_status->noise + ds->ds_rxstat.rs_rssi;
237	rx_status->antenna = ds->ds_rxstat.rs_antenna;
238
239	/* at 45 you will be able to use MCS 15 reliably. A more elaborate
240	 * scheme can be used here but it requires tables of SNR/throughput for
241	 * each possible mode used. */
242	rx_status->qual =  ds->ds_rxstat.rs_rssi * 100 / 45;
243
244	/* rssi can be more than 45 though, anything above that
245	 * should be considered at 100% */
246	if (rx_status->qual > 100)
247		rx_status->qual = 100;
248
249	rx_status->flag |= RX_FLAG_TSFT;
250
251	return 1;
252rx_next:
253	return 0;
254}
255
256static void ath_opmode_init(struct ath_softc *sc)
257{
258	struct ath_hw *ah = sc->sc_ah;
259	u32 rfilt, mfilt[2];
260
261	/* configure rx filter */
262	rfilt = ath_calcrxfilter(sc);
263	ath9k_hw_setrxfilter(ah, rfilt);
264
265	/* configure bssid mask */
266	if (ah->caps.hw_caps & ATH9K_HW_CAP_BSSIDMASK)
267		ath9k_hw_setbssidmask(sc);
268
269	/* configure operational mode */
270	ath9k_hw_setopmode(ah);
271
272	/* Handle any link-level address change. */
273	ath9k_hw_setmac(ah, sc->sc_ah->macaddr);
274
275	/* calculate and install multicast filter */
276	mfilt[0] = mfilt[1] = ~0;
277	ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
278}
279
280int ath_rx_init(struct ath_softc *sc, int nbufs)
281{
282	struct sk_buff *skb;
283	struct ath_buf *bf;
284	int error = 0;
285
286	spin_lock_init(&sc->rx.rxflushlock);
287	sc->sc_flags &= ~SC_OP_RXFLUSH;
288	spin_lock_init(&sc->rx.rxbuflock);
289
290	sc->rx.bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
291				 min(sc->cachelsz, (u16)64));
292
293	DPRINTF(sc, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
294		sc->cachelsz, sc->rx.bufsize);
295
296	/* Initialize rx descriptors */
297
298	error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
299				  "rx", nbufs, 1);
300	if (error != 0) {
301		DPRINTF(sc, ATH_DBG_FATAL,
302			"failed to allocate rx descriptors: %d\n", error);
303		goto err;
304	}
305
306	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
307		skb = ath_rxbuf_alloc(sc, sc->rx.bufsize, GFP_KERNEL);
308		if (skb == NULL) {
309			error = -ENOMEM;
310			goto err;
311		}
312
313		bf->bf_mpdu = skb;
314		bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
315						 sc->rx.bufsize,
316						 DMA_FROM_DEVICE);
317		if (unlikely(dma_mapping_error(sc->dev,
318					       bf->bf_buf_addr))) {
319			dev_kfree_skb_any(skb);
320			bf->bf_mpdu = NULL;
321			DPRINTF(sc, ATH_DBG_FATAL,
322				"dma_mapping_error() on RX init\n");
323			error = -ENOMEM;
324			goto err;
325		}
326		bf->bf_dmacontext = bf->bf_buf_addr;
327	}
328	sc->rx.rxlink = NULL;
329
330err:
331	if (error)
332		ath_rx_cleanup(sc);
333
334	return error;
335}
336
337void ath_rx_cleanup(struct ath_softc *sc)
338{
339	struct sk_buff *skb;
340	struct ath_buf *bf;
341
342	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
343		skb = bf->bf_mpdu;
344		if (skb) {
345			dma_unmap_single(sc->dev, bf->bf_buf_addr,
346					 sc->rx.bufsize, DMA_FROM_DEVICE);
347			dev_kfree_skb(skb);
348		}
349	}
350
351	if (sc->rx.rxdma.dd_desc_len != 0)
352		ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
353}
354
355/*
356 * Calculate the receive filter according to the
357 * operating mode and state:
358 *
359 * o always accept unicast, broadcast, and multicast traffic
360 * o maintain current state of phy error reception (the hal
361 *   may enable phy error frames for noise immunity work)
362 * o probe request frames are accepted only when operating in
363 *   hostap, adhoc, or monitor modes
364 * o enable promiscuous mode according to the interface state
365 * o accept beacons:
366 *   - when operating in adhoc mode so the 802.11 layer creates
367 *     node table entries for peers,
368 *   - when operating in station mode for collecting rssi data when
369 *     the station is otherwise quiet, or
370 *   - when operating as a repeater so we see repeater-sta beacons
371 *   - when scanning
372 */
373
374u32 ath_calcrxfilter(struct ath_softc *sc)
375{
376#define	RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
377
378	u32 rfilt;
379
380	rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
381		| ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
382		| ATH9K_RX_FILTER_MCAST;
383
384	/* If not a STA, enable processing of Probe Requests */
385	if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
386		rfilt |= ATH9K_RX_FILTER_PROBEREQ;
387
388	/*
389	 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
390	 * mode interface or when in monitor mode. AP mode does not need this
391	 * since it receives all in-BSS frames anyway.
392	 */
393	if (((sc->sc_ah->opmode != NL80211_IFTYPE_AP) &&
394	     (sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
395	    (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR))
396		rfilt |= ATH9K_RX_FILTER_PROM;
397
398	if (sc->rx.rxfilter & FIF_CONTROL)
399		rfilt |= ATH9K_RX_FILTER_CONTROL;
400
401	if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
402	    !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
403		rfilt |= ATH9K_RX_FILTER_MYBEACON;
404	else
405		rfilt |= ATH9K_RX_FILTER_BEACON;
406
407	/* If in HOSTAP mode, want to enable reception of PSPOLL frames */
408	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP)
409		rfilt |= ATH9K_RX_FILTER_PSPOLL;
410
411	if (sc->sec_wiphy) {
412		/* TODO: only needed if more than one BSSID is in use in
413		 * station/adhoc mode */
414		/* TODO: for older chips, may need to add ATH9K_RX_FILTER_PROM
415		 */
416		rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
417	}
418
419	return rfilt;
420
421#undef RX_FILTER_PRESERVE
422}
423
424int ath_startrecv(struct ath_softc *sc)
425{
426	struct ath_hw *ah = sc->sc_ah;
427	struct ath_buf *bf, *tbf;
428
429	spin_lock_bh(&sc->rx.rxbuflock);
430	if (list_empty(&sc->rx.rxbuf))
431		goto start_recv;
432
433	sc->rx.rxlink = NULL;
434	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
435		ath_rx_buf_link(sc, bf);
436	}
437
438	/* We could have deleted elements so the list may be empty now */
439	if (list_empty(&sc->rx.rxbuf))
440		goto start_recv;
441
442	bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
443	ath9k_hw_putrxbuf(ah, bf->bf_daddr);
444	ath9k_hw_rxena(ah);
445
446start_recv:
447	spin_unlock_bh(&sc->rx.rxbuflock);
448	ath_opmode_init(sc);
449	ath9k_hw_startpcureceive(ah);
450
451	return 0;
452}
453
454bool ath_stoprecv(struct ath_softc *sc)
455{
456	struct ath_hw *ah = sc->sc_ah;
457	bool stopped;
458
459	ath9k_hw_stoppcurecv(ah);
460	ath9k_hw_setrxfilter(ah, 0);
461	stopped = ath9k_hw_stopdmarecv(ah);
462	sc->rx.rxlink = NULL;
463
464	return stopped;
465}
466
467void ath_flushrecv(struct ath_softc *sc)
468{
469	spin_lock_bh(&sc->rx.rxflushlock);
470	sc->sc_flags |= SC_OP_RXFLUSH;
471	ath_rx_tasklet(sc, 1);
472	sc->sc_flags &= ~SC_OP_RXFLUSH;
473	spin_unlock_bh(&sc->rx.rxflushlock);
474}
475
476static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
477{
478	/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
479	struct ieee80211_mgmt *mgmt;
480	u8 *pos, *end, id, elen;
481	struct ieee80211_tim_ie *tim;
482
483	mgmt = (struct ieee80211_mgmt *)skb->data;
484	pos = mgmt->u.beacon.variable;
485	end = skb->data + skb->len;
486
487	while (pos + 2 < end) {
488		id = *pos++;
489		elen = *pos++;
490		if (pos + elen > end)
491			break;
492
493		if (id == WLAN_EID_TIM) {
494			if (elen < sizeof(*tim))
495				break;
496			tim = (struct ieee80211_tim_ie *) pos;
497			if (tim->dtim_count != 0)
498				break;
499			return tim->bitmap_ctrl & 0x01;
500		}
501
502		pos += elen;
503	}
504
505	return false;
506}
507
508static void ath_rx_ps_back_to_sleep(struct ath_softc *sc)
509{
510	sc->sc_flags &= ~(SC_OP_WAIT_FOR_BEACON | SC_OP_WAIT_FOR_CAB);
511}
512
513static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
514{
515	struct ieee80211_mgmt *mgmt;
516
517	if (skb->len < 24 + 8 + 2 + 2)
518		return;
519
520	mgmt = (struct ieee80211_mgmt *)skb->data;
521	if (memcmp(sc->curbssid, mgmt->bssid, ETH_ALEN) != 0)
522		return; /* not from our current AP */
523
524	if (sc->sc_flags & SC_OP_BEACON_SYNC) {
525		sc->sc_flags &= ~SC_OP_BEACON_SYNC;
526		DPRINTF(sc, ATH_DBG_PS, "Reconfigure Beacon timers based on "
527			"timestamp from the AP\n");
528		ath_beacon_config(sc, NULL);
529	}
530
531	if (!(sc->hw->conf.flags & IEEE80211_CONF_PS)) {
532		/* We are not in PS mode anymore; remain awake */
533		DPRINTF(sc, ATH_DBG_PS, "Not in PS mode anymore, remain "
534			"awake\n");
535		sc->sc_flags &= ~(SC_OP_WAIT_FOR_BEACON | SC_OP_WAIT_FOR_CAB);
536		return;
537	}
538
539	if (ath_beacon_dtim_pending_cab(skb)) {
540		/*
541		 * Remain awake waiting for buffered broadcast/multicast
542		 * frames.
543		 */
544		DPRINTF(sc, ATH_DBG_PS, "Received DTIM beacon indicating "
545			"buffered broadcast/multicast frame(s)\n");
546		sc->sc_flags |= SC_OP_WAIT_FOR_CAB;
547		return;
548	}
549
550	if (sc->sc_flags & SC_OP_WAIT_FOR_CAB) {
551		/*
552		 * This can happen if a broadcast frame is dropped or the AP
553		 * fails to send a frame indicating that all CAB frames have
554		 * been delivered.
555		 */
556		DPRINTF(sc, ATH_DBG_PS, "PS wait for CAB frames timed out\n");
557	}
558
559	/* No more broadcast/multicast frames to be received at this point. */
560	ath_rx_ps_back_to_sleep(sc);
561}
562
563static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
564{
565	struct ieee80211_hdr *hdr;
566
567	hdr = (struct ieee80211_hdr *)skb->data;
568
569	/* Process Beacon and CAB receive in PS state */
570	if ((sc->sc_flags & SC_OP_WAIT_FOR_BEACON) &&
571	    ieee80211_is_beacon(hdr->frame_control))
572		ath_rx_ps_beacon(sc, skb);
573	else if ((sc->sc_flags & SC_OP_WAIT_FOR_CAB) &&
574		 (ieee80211_is_data(hdr->frame_control) ||
575		  ieee80211_is_action(hdr->frame_control)) &&
576		 is_multicast_ether_addr(hdr->addr1) &&
577		 !ieee80211_has_moredata(hdr->frame_control)) {
578		DPRINTF(sc, ATH_DBG_PS, "All PS CAB frames received, back to "
579			"sleep\n");
580		/*
581		 * No more broadcast/multicast frames to be received at this
582		 * point.
583		 */
584		ath_rx_ps_back_to_sleep(sc);
585	} else if ((sc->sc_flags & SC_OP_WAIT_FOR_PSPOLL_DATA) &&
586		   !is_multicast_ether_addr(hdr->addr1) &&
587		   !ieee80211_has_morefrags(hdr->frame_control)) {
588		sc->sc_flags &= ~SC_OP_WAIT_FOR_PSPOLL_DATA;
589		DPRINTF(sc, ATH_DBG_PS, "Going back to sleep after having "
590			"received PS-Poll data (0x%x)\n",
591			sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
592					SC_OP_WAIT_FOR_CAB |
593					SC_OP_WAIT_FOR_PSPOLL_DATA |
594					SC_OP_WAIT_FOR_TX_ACK));
595	}
596}
597
598static void ath_rx_send_to_mac80211(struct ath_softc *sc, struct sk_buff *skb,
599				    struct ieee80211_rx_status *rx_status)
600{
601	struct ieee80211_hdr *hdr;
602
603	hdr = (struct ieee80211_hdr *)skb->data;
604
605	/* Send the frame to mac80211 */
606	if (is_multicast_ether_addr(hdr->addr1)) {
607		int i;
608		/*
609		 * Deliver broadcast/multicast frames to all suitable
610		 * virtual wiphys.
611		 */
612		/* TODO: filter based on channel configuration */
613		for (i = 0; i < sc->num_sec_wiphy; i++) {
614			struct ath_wiphy *aphy = sc->sec_wiphy[i];
615			struct sk_buff *nskb;
616			if (aphy == NULL)
617				continue;
618			nskb = skb_copy(skb, GFP_ATOMIC);
619			if (nskb)
620				__ieee80211_rx(aphy->hw, nskb, rx_status);
621		}
622		__ieee80211_rx(sc->hw, skb, rx_status);
623	} else {
624		/* Deliver unicast frames based on receiver address */
625		__ieee80211_rx(ath_get_virt_hw(sc, hdr), skb, rx_status);
626	}
627}
628
629int ath_rx_tasklet(struct ath_softc *sc, int flush)
630{
631#define PA2DESC(_sc, _pa)                                               \
632	((struct ath_desc *)((caddr_t)(_sc)->rx.rxdma.dd_desc +		\
633			     ((_pa) - (_sc)->rx.rxdma.dd_desc_paddr)))
634
635	struct ath_buf *bf;
636	struct ath_desc *ds;
637	struct sk_buff *skb = NULL, *requeue_skb;
638	struct ieee80211_rx_status rx_status;
639	struct ath_hw *ah = sc->sc_ah;
640	struct ieee80211_hdr *hdr;
641	int hdrlen, padsize, retval;
642	bool decrypt_error = false;
643	u8 keyix;
644	__le16 fc;
645
646	spin_lock_bh(&sc->rx.rxbuflock);
647
648	do {
649		/* If handling rx interrupt and flush is in progress => exit */
650		if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
651			break;
652
653		if (list_empty(&sc->rx.rxbuf)) {
654			sc->rx.rxlink = NULL;
655			break;
656		}
657
658		bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
659		ds = bf->bf_desc;
660
661		/*
662		 * Must provide the virtual address of the current
663		 * descriptor, the physical address, and the virtual
664		 * address of the next descriptor in the h/w chain.
665		 * This allows the HAL to look ahead to see if the
666		 * hardware is done with a descriptor by checking the
667		 * done bit in the following descriptor and the address
668		 * of the current descriptor the DMA engine is working
669		 * on.  All this is necessary because of our use of
670		 * a self-linked list to avoid rx overruns.
671		 */
672		retval = ath9k_hw_rxprocdesc(ah, ds,
673					     bf->bf_daddr,
674					     PA2DESC(sc, ds->ds_link),
675					     0);
676		if (retval == -EINPROGRESS) {
677			struct ath_buf *tbf;
678			struct ath_desc *tds;
679
680			if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
681				sc->rx.rxlink = NULL;
682				break;
683			}
684
685			tbf = list_entry(bf->list.next, struct ath_buf, list);
686
687			/*
688			 * On some hardware the descriptor status words could
689			 * get corrupted, including the done bit. Because of
690			 * this, check if the next descriptor's done bit is
691			 * set or not.
692			 *
693			 * If the next descriptor's done bit is set, the current
694			 * descriptor has been corrupted. Force s/w to discard
695			 * this descriptor and continue...
696			 */
697
698			tds = tbf->bf_desc;
699			retval = ath9k_hw_rxprocdesc(ah, tds, tbf->bf_daddr,
700					     PA2DESC(sc, tds->ds_link), 0);
701			if (retval == -EINPROGRESS) {
702				break;
703			}
704		}
705
706		skb = bf->bf_mpdu;
707		if (!skb)
708			continue;
709
710		/*
711		 * Synchronize the DMA transfer with CPU before
712		 * 1. accessing the frame
713		 * 2. requeueing the same buffer to h/w
714		 */
715		dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
716				sc->rx.bufsize,
717				DMA_FROM_DEVICE);
718
719		/*
720		 * If we're asked to flush receive queue, directly
721		 * chain it back at the queue without processing it.
722		 */
723		if (flush)
724			goto requeue;
725
726		if (!ds->ds_rxstat.rs_datalen)
727			goto requeue;
728
729		/* The status portion of the descriptor could get corrupted. */
730		if (sc->rx.bufsize < ds->ds_rxstat.rs_datalen)
731			goto requeue;
732
733		if (!ath_rx_prepare(skb, ds, &rx_status, &decrypt_error, sc))
734			goto requeue;
735
736		/* Ensure we always have an skb to requeue once we are done
737		 * processing the current buffer's skb */
738		requeue_skb = ath_rxbuf_alloc(sc, sc->rx.bufsize, GFP_ATOMIC);
739
740		/* If there is no memory we ignore the current RX'd frame,
741		 * tell hardware it can give us a new frame using the old
742		 * skb and put it at the tail of the sc->rx.rxbuf list for
743		 * processing. */
744		if (!requeue_skb)
745			goto requeue;
746
747		/* Unmap the frame */
748		dma_unmap_single(sc->dev, bf->bf_buf_addr,
749				 sc->rx.bufsize,
750				 DMA_FROM_DEVICE);
751
752		skb_put(skb, ds->ds_rxstat.rs_datalen);
753		skb->protocol = cpu_to_be16(ETH_P_CONTROL);
754
755		/* see if any padding is done by the hw and remove it */
756		hdr = (struct ieee80211_hdr *)skb->data;
757		hdrlen = ieee80211_get_hdrlen_from_skb(skb);
758		fc = hdr->frame_control;
759
760		/* The MAC header is padded to have 32-bit boundary if the
761		 * packet payload is non-zero. The general calculation for
762		 * padsize would take into account odd header lengths:
763		 * padsize = (4 - hdrlen % 4) % 4; However, since only
764		 * even-length headers are used, padding can only be 0 or 2
765		 * bytes and we can optimize this a bit. In addition, we must
766		 * not try to remove padding from short control frames that do
767		 * not have payload. */
768		padsize = hdrlen & 3;
769		if (padsize && hdrlen >= 24) {
770			memmove(skb->data + padsize, skb->data, hdrlen);
771			skb_pull(skb, padsize);
772		}
773
774		keyix = ds->ds_rxstat.rs_keyix;
775
776		if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
777			rx_status.flag |= RX_FLAG_DECRYPTED;
778		} else if (ieee80211_has_protected(fc)
779			   && !decrypt_error && skb->len >= hdrlen + 4) {
780			keyix = skb->data[hdrlen + 3] >> 6;
781
782			if (test_bit(keyix, sc->keymap))
783				rx_status.flag |= RX_FLAG_DECRYPTED;
784		}
785		if (ah->sw_mgmt_crypto &&
786		    (rx_status.flag & RX_FLAG_DECRYPTED) &&
787		    ieee80211_is_mgmt(fc)) {
788			/* Use software decrypt for management frames. */
789			rx_status.flag &= ~RX_FLAG_DECRYPTED;
790		}
791
792		/* We will now give hardware our shiny new allocated skb */
793		bf->bf_mpdu = requeue_skb;
794		bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
795					 sc->rx.bufsize,
796					 DMA_FROM_DEVICE);
797		if (unlikely(dma_mapping_error(sc->dev,
798			  bf->bf_buf_addr))) {
799			dev_kfree_skb_any(requeue_skb);
800			bf->bf_mpdu = NULL;
801			DPRINTF(sc, ATH_DBG_FATAL,
802				"dma_mapping_error() on RX\n");
803			ath_rx_send_to_mac80211(sc, skb, &rx_status);
804			break;
805		}
806		bf->bf_dmacontext = bf->bf_buf_addr;
807
808		/*
809		 * change the default rx antenna if rx diversity chooses the
810		 * other antenna 3 times in a row.
811		 */
812		if (sc->rx.defant != ds->ds_rxstat.rs_antenna) {
813			if (++sc->rx.rxotherant >= 3)
814				ath_setdefantenna(sc, ds->ds_rxstat.rs_antenna);
815		} else {
816			sc->rx.rxotherant = 0;
817		}
818
819		if (unlikely(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
820					     SC_OP_WAIT_FOR_CAB |
821					     SC_OP_WAIT_FOR_PSPOLL_DATA)))
822			ath_rx_ps(sc, skb);
823
824		ath_rx_send_to_mac80211(sc, skb, &rx_status);
825
826requeue:
827		list_move_tail(&bf->list, &sc->rx.rxbuf);
828		ath_rx_buf_link(sc, bf);
829	} while (1);
830
831	spin_unlock_bh(&sc->rx.rxbuflock);
832
833	return 0;
834#undef PA2DESC
835}
836