xref: /freebsd/sys/dev/ath/if_ath_rx.c (revision 49dae58b287906be26f56ba3e3dc693c3ba8cf37)
1 /*-
2  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13  *    redistribution must be conditioned upon including a substantially
14  *    similar Disclaimer requirement for further binary redistribution.
15  *
16  * NO WARRANTY
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGES.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 /*
34  * Driver for the Atheros Wireless LAN controller.
35  *
36  * This software is derived from work of Atsushi Onoe; his contribution
37  * is greatly appreciated.
38  */
39 
40 #include "opt_inet.h"
41 #include "opt_ath.h"
42 /*
43  * This is needed for register operations which are performed
44  * by the driver - eg, calls to ath_hal_gettsf32().
45  *
46  * It's also required for any AH_DEBUG checks in here, eg the
47  * module dependencies.
48  */
49 #include "opt_ah.h"
50 #include "opt_wlan.h"
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/sysctl.h>
55 #include <sys/mbuf.h>
56 #include <sys/malloc.h>
57 #include <sys/lock.h>
58 #include <sys/mutex.h>
59 #include <sys/kernel.h>
60 #include <sys/socket.h>
61 #include <sys/sockio.h>
62 #include <sys/errno.h>
63 #include <sys/callout.h>
64 #include <sys/bus.h>
65 #include <sys/endian.h>
66 #include <sys/kthread.h>
67 #include <sys/taskqueue.h>
68 #include <sys/priv.h>
69 #include <sys/module.h>
70 #include <sys/ktr.h>
71 #include <sys/smp.h>	/* for mp_ncpus */
72 
73 #include <machine/bus.h>
74 
75 #include <net/if.h>
76 #include <net/if_var.h>
77 #include <net/if_dl.h>
78 #include <net/if_media.h>
79 #include <net/if_types.h>
80 #include <net/if_arp.h>
81 #include <net/ethernet.h>
82 #include <net/if_llc.h>
83 
84 #include <net80211/ieee80211_var.h>
85 #include <net80211/ieee80211_regdomain.h>
86 #ifdef IEEE80211_SUPPORT_SUPERG
87 #include <net80211/ieee80211_superg.h>
88 #endif
89 #ifdef IEEE80211_SUPPORT_TDMA
90 #include <net80211/ieee80211_tdma.h>
91 #endif
92 
93 #include <net/bpf.h>
94 
95 #ifdef INET
96 #include <netinet/in.h>
97 #include <netinet/if_ether.h>
98 #endif
99 
100 #include <dev/ath/if_athvar.h>
101 #include <dev/ath/ath_hal/ah_devid.h>		/* XXX for softled */
102 #include <dev/ath/ath_hal/ah_diagcodes.h>
103 
104 #include <dev/ath/if_ath_debug.h>
105 #include <dev/ath/if_ath_misc.h>
106 #include <dev/ath/if_ath_tsf.h>
107 #include <dev/ath/if_ath_tx.h>
108 #include <dev/ath/if_ath_sysctl.h>
109 #include <dev/ath/if_ath_led.h>
110 #include <dev/ath/if_ath_keycache.h>
111 #include <dev/ath/if_ath_rx.h>
112 #include <dev/ath/if_ath_beacon.h>
113 #include <dev/ath/if_athdfs.h>
114 #include <dev/ath/if_ath_descdma.h>
115 
116 #ifdef ATH_TX99_DIAG
117 #include <dev/ath/ath_tx99/ath_tx99.h>
118 #endif
119 
120 #ifdef	ATH_DEBUG_ALQ
121 #include <dev/ath/if_ath_alq.h>
122 #endif
123 
124 #include <dev/ath/if_ath_lna_div.h>
125 
126 /*
127  * Calculate the receive filter according to the
128  * operating mode and state:
129  *
130  * o always accept unicast, broadcast, and multicast traffic
131  * o accept PHY error frames when hardware doesn't have MIB support
132  *   to count and we need them for ANI (sta mode only until recently)
133  *   and we are not scanning (ANI is disabled)
134  *   NB: older hal's add rx filter bits out of sight and we need to
135  *	 blindly preserve them
136  * o probe request frames are accepted only when operating in
137  *   hostap, adhoc, mesh, or monitor modes
138  * o enable promiscuous mode
139  *   - when in monitor mode
140  *   - if interface marked PROMISC (assumes bridge setting is filtered)
141  * o accept beacons:
142  *   - when operating in station mode for collecting rssi data when
143  *     the station is otherwise quiet, or
144  *   - when operating in adhoc mode so the 802.11 layer creates
145  *     node table entries for peers,
146  *   - when scanning
147  *   - when doing s/w beacon miss (e.g. for ap+sta)
148  *   - when operating in ap mode in 11g to detect overlapping bss that
149  *     require protection
150  *   - when operating in mesh mode to detect neighbors
151  * o accept control frames:
152  *   - when in monitor mode
153  * XXX HT protection for 11n
154  */
155 u_int32_t
156 ath_calcrxfilter(struct ath_softc *sc)
157 {
158 	struct ieee80211com *ic = &sc->sc_ic;
159 	u_int32_t rfilt;
160 
161 	rfilt = HAL_RX_FILTER_UCAST | HAL_RX_FILTER_BCAST | HAL_RX_FILTER_MCAST;
162 	if (!sc->sc_needmib && !sc->sc_scanning)
163 		rfilt |= HAL_RX_FILTER_PHYERR;
164 	if (ic->ic_opmode != IEEE80211_M_STA)
165 		rfilt |= HAL_RX_FILTER_PROBEREQ;
166 	/* XXX ic->ic_monvaps != 0? */
167 	if (ic->ic_opmode == IEEE80211_M_MONITOR || ic->ic_promisc > 0)
168 		rfilt |= HAL_RX_FILTER_PROM;
169 
170 	/*
171 	 * Only listen to all beacons if we're scanning.
172 	 *
173 	 * Otherwise we only really need to hear beacons from
174 	 * our own BSSID.
175 	 *
176 	 * IBSS? software beacon miss? Just receive all beacons.
177 	 * We need to hear beacons/probe requests from everyone so
178 	 * we can merge ibss.
179 	 */
180 	if (ic->ic_opmode == IEEE80211_M_IBSS || sc->sc_swbmiss) {
181 		rfilt |= HAL_RX_FILTER_BEACON;
182 	} else if (ic->ic_opmode == IEEE80211_M_STA) {
183 		if (sc->sc_do_mybeacon && ! sc->sc_scanning) {
184 			rfilt |= HAL_RX_FILTER_MYBEACON;
185 		} else { /* scanning, non-mybeacon chips */
186 			rfilt |= HAL_RX_FILTER_BEACON;
187 		}
188 	}
189 
190 	/*
191 	 * NB: We don't recalculate the rx filter when
192 	 * ic_protmode changes; otherwise we could do
193 	 * this only when ic_protmode != NONE.
194 	 */
195 	if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
196 	    IEEE80211_IS_CHAN_ANYG(ic->ic_curchan))
197 		rfilt |= HAL_RX_FILTER_BEACON;
198 
199 	/*
200 	 * Enable hardware PS-POLL RX only for hostap mode;
201 	 * STA mode sends PS-POLL frames but never
202 	 * receives them.
203 	 */
204 	if (ath_hal_getcapability(sc->sc_ah, HAL_CAP_PSPOLL,
205 	    0, NULL) == HAL_OK &&
206 	    ic->ic_opmode == IEEE80211_M_HOSTAP)
207 		rfilt |= HAL_RX_FILTER_PSPOLL;
208 
209 	if (sc->sc_nmeshvaps) {
210 		rfilt |= HAL_RX_FILTER_BEACON;
211 		if (sc->sc_hasbmatch)
212 			rfilt |= HAL_RX_FILTER_BSSID;
213 		else
214 			rfilt |= HAL_RX_FILTER_PROM;
215 	}
216 	if (ic->ic_opmode == IEEE80211_M_MONITOR)
217 		rfilt |= HAL_RX_FILTER_CONTROL;
218 
219 	/*
220 	 * Enable RX of compressed BAR frames only when doing
221 	 * 802.11n. Required for A-MPDU.
222 	 */
223 	if (IEEE80211_IS_CHAN_HT(ic->ic_curchan))
224 		rfilt |= HAL_RX_FILTER_COMPBAR;
225 
226 	/*
227 	 * Enable radar PHY errors if requested by the
228 	 * DFS module.
229 	 */
230 	if (sc->sc_dodfs)
231 		rfilt |= HAL_RX_FILTER_PHYRADAR;
232 
233 	/*
234 	 * Enable spectral PHY errors if requested by the
235 	 * spectral module.
236 	 */
237 	if (sc->sc_dospectral)
238 		rfilt |= HAL_RX_FILTER_PHYRADAR;
239 
240 	DPRINTF(sc, ATH_DEBUG_MODE, "%s: RX filter 0x%x, %s\n",
241 	    __func__, rfilt, ieee80211_opmode_name[ic->ic_opmode]);
242 	return rfilt;
243 }
244 
245 static int
246 ath_legacy_rxbuf_init(struct ath_softc *sc, struct ath_buf *bf)
247 {
248 	struct ath_hal *ah = sc->sc_ah;
249 	int error;
250 	struct mbuf *m;
251 	struct ath_desc *ds;
252 
253 	/* XXX TODO: ATH_RX_LOCK_ASSERT(sc); */
254 
255 	m = bf->bf_m;
256 	if (m == NULL) {
257 		/*
258 		 * NB: by assigning a page to the rx dma buffer we
259 		 * implicitly satisfy the Atheros requirement that
260 		 * this buffer be cache-line-aligned and sized to be
261 		 * multiple of the cache line size.  Not doing this
262 		 * causes weird stuff to happen (for the 5210 at least).
263 		 */
264 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
265 		if (m == NULL) {
266 			DPRINTF(sc, ATH_DEBUG_ANY,
267 				"%s: no mbuf/cluster\n", __func__);
268 			sc->sc_stats.ast_rx_nombuf++;
269 			return ENOMEM;
270 		}
271 		m->m_pkthdr.len = m->m_len = m->m_ext.ext_size;
272 
273 		error = bus_dmamap_load_mbuf_sg(sc->sc_dmat,
274 					     bf->bf_dmamap, m,
275 					     bf->bf_segs, &bf->bf_nseg,
276 					     BUS_DMA_NOWAIT);
277 		if (error != 0) {
278 			DPRINTF(sc, ATH_DEBUG_ANY,
279 			    "%s: bus_dmamap_load_mbuf_sg failed; error %d\n",
280 			    __func__, error);
281 			sc->sc_stats.ast_rx_busdma++;
282 			m_freem(m);
283 			return error;
284 		}
285 		KASSERT(bf->bf_nseg == 1,
286 			("multi-segment packet; nseg %u", bf->bf_nseg));
287 		bf->bf_m = m;
288 	}
289 	bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_PREREAD);
290 
291 	/*
292 	 * Setup descriptors.  For receive we always terminate
293 	 * the descriptor list with a self-linked entry so we'll
294 	 * not get overrun under high load (as can happen with a
295 	 * 5212 when ANI processing enables PHY error frames).
296 	 *
297 	 * To insure the last descriptor is self-linked we create
298 	 * each descriptor as self-linked and add it to the end.  As
299 	 * each additional descriptor is added the previous self-linked
300 	 * entry is ``fixed'' naturally.  This should be safe even
301 	 * if DMA is happening.  When processing RX interrupts we
302 	 * never remove/process the last, self-linked, entry on the
303 	 * descriptor list.  This insures the hardware always has
304 	 * someplace to write a new frame.
305 	 */
306 	/*
307 	 * 11N: we can no longer afford to self link the last descriptor.
308 	 * MAC acknowledges BA status as long as it copies frames to host
309 	 * buffer (or rx fifo). This can incorrectly acknowledge packets
310 	 * to a sender if last desc is self-linked.
311 	 */
312 	ds = bf->bf_desc;
313 	if (sc->sc_rxslink)
314 		ds->ds_link = bf->bf_daddr;	/* link to self */
315 	else
316 		ds->ds_link = 0;		/* terminate the list */
317 	ds->ds_data = bf->bf_segs[0].ds_addr;
318 	ath_hal_setuprxdesc(ah, ds
319 		, m->m_len		/* buffer size */
320 		, 0
321 	);
322 
323 	if (sc->sc_rxlink != NULL)
324 		*sc->sc_rxlink = bf->bf_daddr;
325 	sc->sc_rxlink = &ds->ds_link;
326 	return 0;
327 }
328 
329 /*
330  * Intercept management frames to collect beacon rssi data
331  * and to do ibss merges.
332  */
333 void
334 ath_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m,
335 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
336 {
337 	struct ieee80211vap *vap = ni->ni_vap;
338 	struct ath_softc *sc = vap->iv_ic->ic_softc;
339 	uint64_t tsf_beacon_old, tsf_beacon;
340 	uint64_t nexttbtt;
341 	int64_t tsf_delta;
342 	int32_t tsf_delta_bmiss;
343 	int32_t tsf_remainder;
344 	uint64_t tsf_beacon_target;
345 	int tsf_intval;
346 
347 	tsf_beacon_old = ((uint64_t) le32dec(ni->ni_tstamp.data + 4)) << 32;
348 	tsf_beacon_old |= le32dec(ni->ni_tstamp.data);
349 
350 #define	TU_TO_TSF(_tu)	(((u_int64_t)(_tu)) << 10)
351 	tsf_intval = 1;
352 	if (ni->ni_intval > 0) {
353 		tsf_intval = TU_TO_TSF(ni->ni_intval);
354 	}
355 #undef	TU_TO_TSF
356 
357 	/*
358 	 * Call up first so subsequent work can use information
359 	 * potentially stored in the node (e.g. for ibss merge).
360 	 */
361 	ATH_VAP(vap)->av_recv_mgmt(ni, m, subtype, rxs, rssi, nf);
362 	switch (subtype) {
363 	case IEEE80211_FC0_SUBTYPE_BEACON:
364 
365 		/*
366 		 * Only do the following processing if it's for
367 		 * the current BSS.
368 		 *
369 		 * In scan and IBSS mode we receive all beacons,
370 		 * which means we need to filter out stuff
371 		 * that isn't for us or we'll end up constantly
372 		 * trying to sync / merge to BSSes that aren't
373 		 * actually us.
374 		 */
375 		if (IEEE80211_ADDR_EQ(ni->ni_bssid, vap->iv_bss->ni_bssid)) {
376 			/* update rssi statistics for use by the hal */
377 			/* XXX unlocked check against vap->iv_bss? */
378 			ATH_RSSI_LPF(sc->sc_halstats.ns_avgbrssi, rssi);
379 
380 
381 			tsf_beacon = ((uint64_t) le32dec(ni->ni_tstamp.data + 4)) << 32;
382 			tsf_beacon |= le32dec(ni->ni_tstamp.data);
383 
384 			nexttbtt = ath_hal_getnexttbtt(sc->sc_ah);
385 
386 			/*
387 			 * Let's calculate the delta and remainder, so we can see
388 			 * if the beacon timer from the AP is varying by more than
389 			 * a few TU.  (Which would be a huge, huge problem.)
390 			 */
391 			tsf_delta = (long long) tsf_beacon - (long long) tsf_beacon_old;
392 
393 			tsf_delta_bmiss = tsf_delta / tsf_intval;
394 
395 			/*
396 			 * If our delta is greater than half the beacon interval,
397 			 * let's round the bmiss value up to the next beacon
398 			 * interval.  Ie, we're running really, really early
399 			 * on the next beacon.
400 			 */
401 			if (tsf_delta % tsf_intval > (tsf_intval / 2))
402 				tsf_delta_bmiss ++;
403 
404 			tsf_beacon_target = tsf_beacon_old +
405 			    (((unsigned long long) tsf_delta_bmiss) * (long long) tsf_intval);
406 
407 			/*
408 			 * The remainder using '%' is between 0 .. intval-1.
409 			 * If we're actually running too fast, then the remainder
410 			 * will be some large number just under intval-1.
411 			 * So we need to look at whether we're running
412 			 * before or after the target beacon interval
413 			 * and if we are, modify how we do the remainder
414 			 * calculation.
415 			 */
416 			if (tsf_beacon < tsf_beacon_target) {
417 				tsf_remainder =
418 				    -(tsf_intval - ((tsf_beacon - tsf_beacon_old) % tsf_intval));
419 			} else {
420 				tsf_remainder = (tsf_beacon - tsf_beacon_old) % tsf_intval;
421 			}
422 
423 			DPRINTF(sc, ATH_DEBUG_BEACON, "%s: old_tsf=%llu, new_tsf=%llu, target_tsf=%llu, delta=%lld, bmiss=%d, remainder=%d\n",
424 			    __func__,
425 			    (unsigned long long) tsf_beacon_old,
426 			    (unsigned long long) tsf_beacon,
427 			    (unsigned long long) tsf_beacon_target,
428 			    (long long) tsf_delta,
429 			    tsf_delta_bmiss,
430 			    tsf_remainder);
431 
432 			DPRINTF(sc, ATH_DEBUG_BEACON, "%s: tsf=%llu, nexttbtt=%llu, delta=%d\n",
433 			    __func__,
434 			    (unsigned long long) tsf_beacon,
435 			    (unsigned long long) nexttbtt,
436 			    (int32_t) tsf_beacon - (int32_t) nexttbtt + tsf_intval);
437 
438 			/* We only do syncbeacon on STA VAPs; not on IBSS */
439 			if (vap->iv_opmode == IEEE80211_M_STA &&
440 			    sc->sc_syncbeacon &&
441 			    ni == vap->iv_bss &&
442 			    (vap->iv_state == IEEE80211_S_RUN || vap->iv_state == IEEE80211_S_SLEEP)) {
443 				DPRINTF(sc, ATH_DEBUG_BEACON,
444 				    "%s: syncbeacon=1; syncing\n",
445 				    __func__);
446 				/*
447 				 * Resync beacon timers using the tsf of the beacon
448 				 * frame we just received.
449 				 */
450 				ath_beacon_config(sc, vap);
451 				sc->sc_syncbeacon = 0;
452 			}
453 		}
454 
455 		/* fall thru... */
456 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
457 		if (vap->iv_opmode == IEEE80211_M_IBSS &&
458 		    vap->iv_state == IEEE80211_S_RUN &&
459 		    ieee80211_ibss_merge_check(ni)) {
460 			uint32_t rstamp = sc->sc_lastrs->rs_tstamp;
461 			uint64_t tsf = ath_extend_tsf(sc, rstamp,
462 				ath_hal_gettsf64(sc->sc_ah));
463 			/*
464 			 * Handle ibss merge as needed; check the tsf on the
465 			 * frame before attempting the merge.  The 802.11 spec
466 			 * says the station should change it's bssid to match
467 			 * the oldest station with the same ssid, where oldest
468 			 * is determined by the tsf.  Note that hardware
469 			 * reconfiguration happens through callback to
470 			 * ath_newstate as the state machine will go from
471 			 * RUN -> RUN when this happens.
472 			 */
473 			if (le64toh(ni->ni_tstamp.tsf) >= tsf) {
474 				DPRINTF(sc, ATH_DEBUG_STATE,
475 				    "ibss merge, rstamp %u tsf %ju "
476 				    "tstamp %ju\n", rstamp, (uintmax_t)tsf,
477 				    (uintmax_t)ni->ni_tstamp.tsf);
478 				(void) ieee80211_ibss_merge(ni);
479 			}
480 		}
481 		break;
482 	}
483 }
484 
485 #ifdef	ATH_ENABLE_RADIOTAP_VENDOR_EXT
486 static void
487 ath_rx_tap_vendor(struct ath_softc *sc, struct mbuf *m,
488     const struct ath_rx_status *rs, u_int64_t tsf, int16_t nf)
489 {
490 
491 	/* Fill in the extension bitmap */
492 	sc->sc_rx_th.wr_ext_bitmap = htole32(1 << ATH_RADIOTAP_VENDOR_HEADER);
493 
494 	/* Fill in the vendor header */
495 	sc->sc_rx_th.wr_vh.vh_oui[0] = 0x7f;
496 	sc->sc_rx_th.wr_vh.vh_oui[1] = 0x03;
497 	sc->sc_rx_th.wr_vh.vh_oui[2] = 0x00;
498 
499 	/* XXX what should this be? */
500 	sc->sc_rx_th.wr_vh.vh_sub_ns = 0;
501 	sc->sc_rx_th.wr_vh.vh_skip_len =
502 	    htole16(sizeof(struct ath_radiotap_vendor_hdr));
503 
504 	/* General version info */
505 	sc->sc_rx_th.wr_v.vh_version = 1;
506 
507 	sc->sc_rx_th.wr_v.vh_rx_chainmask = sc->sc_rxchainmask;
508 
509 	/* rssi */
510 	sc->sc_rx_th.wr_v.rssi_ctl[0] = rs->rs_rssi_ctl[0];
511 	sc->sc_rx_th.wr_v.rssi_ctl[1] = rs->rs_rssi_ctl[1];
512 	sc->sc_rx_th.wr_v.rssi_ctl[2] = rs->rs_rssi_ctl[2];
513 	sc->sc_rx_th.wr_v.rssi_ext[0] = rs->rs_rssi_ext[0];
514 	sc->sc_rx_th.wr_v.rssi_ext[1] = rs->rs_rssi_ext[1];
515 	sc->sc_rx_th.wr_v.rssi_ext[2] = rs->rs_rssi_ext[2];
516 
517 	/* evm */
518 	sc->sc_rx_th.wr_v.evm[0] = rs->rs_evm0;
519 	sc->sc_rx_th.wr_v.evm[1] = rs->rs_evm1;
520 	sc->sc_rx_th.wr_v.evm[2] = rs->rs_evm2;
521 	/* These are only populated from the AR9300 or later */
522 	sc->sc_rx_th.wr_v.evm[3] = rs->rs_evm3;
523 	sc->sc_rx_th.wr_v.evm[4] = rs->rs_evm4;
524 
525 	/* direction */
526 	sc->sc_rx_th.wr_v.vh_flags = ATH_VENDOR_PKT_RX;
527 
528 	/* RX rate */
529 	sc->sc_rx_th.wr_v.vh_rx_hwrate = rs->rs_rate;
530 
531 	/* RX flags */
532 	sc->sc_rx_th.wr_v.vh_rs_flags = rs->rs_flags;
533 
534 	if (rs->rs_isaggr)
535 		sc->sc_rx_th.wr_v.vh_flags |= ATH_VENDOR_PKT_ISAGGR;
536 	if (rs->rs_moreaggr)
537 		sc->sc_rx_th.wr_v.vh_flags |= ATH_VENDOR_PKT_MOREAGGR;
538 
539 	/* phyerr info */
540 	if (rs->rs_status & HAL_RXERR_PHY) {
541 		sc->sc_rx_th.wr_v.vh_phyerr_code = rs->rs_phyerr;
542 		sc->sc_rx_th.wr_v.vh_flags |= ATH_VENDOR_PKT_RXPHYERR;
543 	} else {
544 		sc->sc_rx_th.wr_v.vh_phyerr_code = 0xff;
545 	}
546 	sc->sc_rx_th.wr_v.vh_rs_status = rs->rs_status;
547 	sc->sc_rx_th.wr_v.vh_rssi = rs->rs_rssi;
548 }
549 #endif	/* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
550 
551 static void
552 ath_rx_tap(struct ath_softc *sc, struct mbuf *m,
553 	const struct ath_rx_status *rs, u_int64_t tsf, int16_t nf)
554 {
555 #define	CHAN_HT20	htole32(IEEE80211_CHAN_HT20)
556 #define	CHAN_HT40U	htole32(IEEE80211_CHAN_HT40U)
557 #define	CHAN_HT40D	htole32(IEEE80211_CHAN_HT40D)
558 #define	CHAN_HT		(CHAN_HT20|CHAN_HT40U|CHAN_HT40D)
559 	const HAL_RATE_TABLE *rt;
560 	uint8_t rix;
561 
562 	rt = sc->sc_currates;
563 	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
564 	rix = rt->rateCodeToIndex[rs->rs_rate];
565 	sc->sc_rx_th.wr_rate = sc->sc_hwmap[rix].ieeerate;
566 	sc->sc_rx_th.wr_flags = sc->sc_hwmap[rix].rxflags;
567 #ifdef AH_SUPPORT_AR5416
568 	sc->sc_rx_th.wr_chan_flags &= ~CHAN_HT;
569 	if (rs->rs_status & HAL_RXERR_PHY) {
570 		/*
571 		 * PHY error - make sure the channel flags
572 		 * reflect the actual channel configuration,
573 		 * not the received frame.
574 		 */
575 		if (IEEE80211_IS_CHAN_HT40U(sc->sc_curchan))
576 			sc->sc_rx_th.wr_chan_flags |= CHAN_HT40U;
577 		else if (IEEE80211_IS_CHAN_HT40D(sc->sc_curchan))
578 			sc->sc_rx_th.wr_chan_flags |= CHAN_HT40D;
579 		else if (IEEE80211_IS_CHAN_HT20(sc->sc_curchan))
580 			sc->sc_rx_th.wr_chan_flags |= CHAN_HT20;
581 	} else if (sc->sc_rx_th.wr_rate & IEEE80211_RATE_MCS) {	/* HT rate */
582 		struct ieee80211com *ic = &sc->sc_ic;
583 
584 		if ((rs->rs_flags & HAL_RX_2040) == 0)
585 			sc->sc_rx_th.wr_chan_flags |= CHAN_HT20;
586 		else if (IEEE80211_IS_CHAN_HT40U(ic->ic_curchan))
587 			sc->sc_rx_th.wr_chan_flags |= CHAN_HT40U;
588 		else
589 			sc->sc_rx_th.wr_chan_flags |= CHAN_HT40D;
590 		if ((rs->rs_flags & HAL_RX_GI) == 0)
591 			sc->sc_rx_th.wr_flags |= IEEE80211_RADIOTAP_F_SHORTGI;
592 	}
593 
594 #endif
595 	sc->sc_rx_th.wr_tsf = htole64(ath_extend_tsf(sc, rs->rs_tstamp, tsf));
596 	if (rs->rs_status & HAL_RXERR_CRC)
597 		sc->sc_rx_th.wr_flags |= IEEE80211_RADIOTAP_F_BADFCS;
598 	/* XXX propagate other error flags from descriptor */
599 	sc->sc_rx_th.wr_antnoise = nf;
600 	sc->sc_rx_th.wr_antsignal = nf + rs->rs_rssi;
601 	sc->sc_rx_th.wr_antenna = rs->rs_antenna;
602 #undef CHAN_HT
603 #undef CHAN_HT20
604 #undef CHAN_HT40U
605 #undef CHAN_HT40D
606 }
607 
608 static void
609 ath_handle_micerror(struct ieee80211com *ic,
610 	struct ieee80211_frame *wh, int keyix)
611 {
612 	struct ieee80211_node *ni;
613 
614 	/* XXX recheck MIC to deal w/ chips that lie */
615 	/* XXX discard MIC errors on !data frames */
616 	ni = ieee80211_find_rxnode(ic, (const struct ieee80211_frame_min *) wh);
617 	if (ni != NULL) {
618 		ieee80211_notify_michael_failure(ni->ni_vap, wh, keyix);
619 		ieee80211_free_node(ni);
620 	}
621 }
622 
623 /*
624  * Process a single packet.
625  *
626  * The mbuf must already be synced, unmapped and removed from bf->bf_m
627  * by this stage.
628  *
629  * The mbuf must be consumed by this routine - either passed up the
630  * net80211 stack, put on the holding queue, or freed.
631  */
632 int
633 ath_rx_pkt(struct ath_softc *sc, struct ath_rx_status *rs, HAL_STATUS status,
634     uint64_t tsf, int nf, HAL_RX_QUEUE qtype, struct ath_buf *bf,
635     struct mbuf *m)
636 {
637 	uint64_t rstamp;
638 	int len, type;
639 	struct ieee80211com *ic = &sc->sc_ic;
640 	struct ieee80211_node *ni;
641 	int is_good = 0;
642 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
643 
644 	/*
645 	 * Calculate the correct 64 bit TSF given
646 	 * the TSF64 register value and rs_tstamp.
647 	 */
648 	rstamp = ath_extend_tsf(sc, rs->rs_tstamp, tsf);
649 
650 	/* These aren't specifically errors */
651 #ifdef	AH_SUPPORT_AR5416
652 	if (rs->rs_flags & HAL_RX_GI)
653 		sc->sc_stats.ast_rx_halfgi++;
654 	if (rs->rs_flags & HAL_RX_2040)
655 		sc->sc_stats.ast_rx_2040++;
656 	if (rs->rs_flags & HAL_RX_DELIM_CRC_PRE)
657 		sc->sc_stats.ast_rx_pre_crc_err++;
658 	if (rs->rs_flags & HAL_RX_DELIM_CRC_POST)
659 		sc->sc_stats.ast_rx_post_crc_err++;
660 	if (rs->rs_flags & HAL_RX_DECRYPT_BUSY)
661 		sc->sc_stats.ast_rx_decrypt_busy_err++;
662 	if (rs->rs_flags & HAL_RX_HI_RX_CHAIN)
663 		sc->sc_stats.ast_rx_hi_rx_chain++;
664 	if (rs->rs_flags & HAL_RX_STBC)
665 		sc->sc_stats.ast_rx_stbc++;
666 #endif /* AH_SUPPORT_AR5416 */
667 
668 	if (rs->rs_status != 0) {
669 		if (rs->rs_status & HAL_RXERR_CRC)
670 			sc->sc_stats.ast_rx_crcerr++;
671 		if (rs->rs_status & HAL_RXERR_FIFO)
672 			sc->sc_stats.ast_rx_fifoerr++;
673 		if (rs->rs_status & HAL_RXERR_PHY) {
674 			sc->sc_stats.ast_rx_phyerr++;
675 			/* Process DFS radar events */
676 			if ((rs->rs_phyerr == HAL_PHYERR_RADAR) ||
677 			    (rs->rs_phyerr == HAL_PHYERR_FALSE_RADAR_EXT)) {
678 				/* Now pass it to the radar processing code */
679 				ath_dfs_process_phy_err(sc, m, rstamp, rs);
680 			}
681 
682 			/* Be suitably paranoid about receiving phy errors out of the stats array bounds */
683 			if (rs->rs_phyerr < 64)
684 				sc->sc_stats.ast_rx_phy[rs->rs_phyerr]++;
685 			goto rx_error;	/* NB: don't count in ierrors */
686 		}
687 		if (rs->rs_status & HAL_RXERR_DECRYPT) {
688 			/*
689 			 * Decrypt error.  If the error occurred
690 			 * because there was no hardware key, then
691 			 * let the frame through so the upper layers
692 			 * can process it.  This is necessary for 5210
693 			 * parts which have no way to setup a ``clear''
694 			 * key cache entry.
695 			 *
696 			 * XXX do key cache faulting
697 			 */
698 			if (rs->rs_keyix == HAL_RXKEYIX_INVALID)
699 				goto rx_accept;
700 			sc->sc_stats.ast_rx_badcrypt++;
701 		}
702 		/*
703 		 * Similar as above - if the failure was a keymiss
704 		 * just punt it up to the upper layers for now.
705 		 */
706 		if (rs->rs_status & HAL_RXERR_KEYMISS) {
707 			sc->sc_stats.ast_rx_keymiss++;
708 			goto rx_accept;
709 		}
710 		if (rs->rs_status & HAL_RXERR_MIC) {
711 			sc->sc_stats.ast_rx_badmic++;
712 			/*
713 			 * Do minimal work required to hand off
714 			 * the 802.11 header for notification.
715 			 */
716 			/* XXX frag's and qos frames */
717 			len = rs->rs_datalen;
718 			if (len >= sizeof (struct ieee80211_frame)) {
719 				ath_handle_micerror(ic,
720 				    mtod(m, struct ieee80211_frame *),
721 				    sc->sc_splitmic ?
722 					rs->rs_keyix-32 : rs->rs_keyix);
723 			}
724 		}
725 		counter_u64_add(ic->ic_ierrors, 1);
726 rx_error:
727 		/*
728 		 * Cleanup any pending partial frame.
729 		 */
730 		if (re->m_rxpending != NULL) {
731 			m_freem(re->m_rxpending);
732 			re->m_rxpending = NULL;
733 		}
734 		/*
735 		 * When a tap is present pass error frames
736 		 * that have been requested.  By default we
737 		 * pass decrypt+mic errors but others may be
738 		 * interesting (e.g. crc).
739 		 */
740 		if (ieee80211_radiotap_active(ic) &&
741 		    (rs->rs_status & sc->sc_monpass)) {
742 			/* NB: bpf needs the mbuf length setup */
743 			len = rs->rs_datalen;
744 			m->m_pkthdr.len = m->m_len = len;
745 			ath_rx_tap(sc, m, rs, rstamp, nf);
746 #ifdef	ATH_ENABLE_RADIOTAP_VENDOR_EXT
747 			ath_rx_tap_vendor(sc, m, rs, rstamp, nf);
748 #endif	/* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
749 			ieee80211_radiotap_rx_all(ic, m);
750 		}
751 		/* XXX pass MIC errors up for s/w reclaculation */
752 		m_freem(m); m = NULL;
753 		goto rx_next;
754 	}
755 rx_accept:
756 	len = rs->rs_datalen;
757 	m->m_len = len;
758 
759 	if (rs->rs_more) {
760 		/*
761 		 * Frame spans multiple descriptors; save
762 		 * it for the next completed descriptor, it
763 		 * will be used to construct a jumbogram.
764 		 */
765 		if (re->m_rxpending != NULL) {
766 			/* NB: max frame size is currently 2 clusters */
767 			sc->sc_stats.ast_rx_toobig++;
768 			m_freem(re->m_rxpending);
769 		}
770 		m->m_pkthdr.len = len;
771 		re->m_rxpending = m;
772 		m = NULL;
773 		goto rx_next;
774 	} else if (re->m_rxpending != NULL) {
775 		/*
776 		 * This is the second part of a jumbogram,
777 		 * chain it to the first mbuf, adjust the
778 		 * frame length, and clear the rxpending state.
779 		 */
780 		re->m_rxpending->m_next = m;
781 		re->m_rxpending->m_pkthdr.len += len;
782 		m = re->m_rxpending;
783 		re->m_rxpending = NULL;
784 	} else {
785 		/*
786 		 * Normal single-descriptor receive; setup packet length.
787 		 */
788 		m->m_pkthdr.len = len;
789 	}
790 
791 	/*
792 	 * Validate rs->rs_antenna.
793 	 *
794 	 * Some users w/ AR9285 NICs have reported crashes
795 	 * here because rs_antenna field is bogusly large.
796 	 * Let's enforce the maximum antenna limit of 8
797 	 * (and it shouldn't be hard coded, but that's a
798 	 * separate problem) and if there's an issue, print
799 	 * out an error and adjust rs_antenna to something
800 	 * sensible.
801 	 *
802 	 * This code should be removed once the actual
803 	 * root cause of the issue has been identified.
804 	 * For example, it may be that the rs_antenna
805 	 * field is only valid for the lsat frame of
806 	 * an aggregate and it just happens that it is
807 	 * "mostly" right. (This is a general statement -
808 	 * the majority of the statistics are only valid
809 	 * for the last frame in an aggregate.
810 	 */
811 	if (rs->rs_antenna > 7) {
812 		device_printf(sc->sc_dev, "%s: rs_antenna > 7 (%d)\n",
813 		    __func__, rs->rs_antenna);
814 #ifdef	ATH_DEBUG
815 		ath_printrxbuf(sc, bf, 0, status == HAL_OK);
816 #endif /* ATH_DEBUG */
817 		rs->rs_antenna = 0;	/* XXX better than nothing */
818 	}
819 
820 	/*
821 	 * If this is an AR9285/AR9485, then the receive and LNA
822 	 * configuration is stored in RSSI[2] / EXTRSSI[2].
823 	 * We can extract this out to build a much better
824 	 * receive antenna profile.
825 	 *
826 	 * Yes, this just blurts over the above RX antenna field
827 	 * for now.  It's fine, the AR9285 doesn't really use
828 	 * that.
829 	 *
830 	 * Later on we should store away the fine grained LNA
831 	 * information and keep separate counters just for
832 	 * that.  It'll help when debugging the AR9285/AR9485
833 	 * combined diversity code.
834 	 */
835 	if (sc->sc_rx_lnamixer) {
836 		rs->rs_antenna = 0;
837 
838 		/* Bits 0:1 - the LNA configuration used */
839 		rs->rs_antenna |=
840 		    ((rs->rs_rssi_ctl[2] & HAL_RX_LNA_CFG_USED)
841 		      >> HAL_RX_LNA_CFG_USED_S);
842 
843 		/* Bit 2 - the external RX antenna switch */
844 		if (rs->rs_rssi_ctl[2] & HAL_RX_LNA_EXTCFG)
845 			rs->rs_antenna |= 0x4;
846 	}
847 
848 	sc->sc_stats.ast_ant_rx[rs->rs_antenna]++;
849 
850 	/*
851 	 * Populate the rx status block.  When there are bpf
852 	 * listeners we do the additional work to provide
853 	 * complete status.  Otherwise we fill in only the
854 	 * material required by ieee80211_input.  Note that
855 	 * noise setting is filled in above.
856 	 */
857 	if (ieee80211_radiotap_active(ic)) {
858 		ath_rx_tap(sc, m, rs, rstamp, nf);
859 #ifdef	ATH_ENABLE_RADIOTAP_VENDOR_EXT
860 		ath_rx_tap_vendor(sc, m, rs, rstamp, nf);
861 #endif	/* ATH_ENABLE_RADIOTAP_VENDOR_EXT */
862 	}
863 
864 	/*
865 	 * From this point on we assume the frame is at least
866 	 * as large as ieee80211_frame_min; verify that.
867 	 */
868 	if (len < IEEE80211_MIN_LEN) {
869 		if (!ieee80211_radiotap_active(ic)) {
870 			DPRINTF(sc, ATH_DEBUG_RECV,
871 			    "%s: short packet %d\n", __func__, len);
872 			sc->sc_stats.ast_rx_tooshort++;
873 		} else {
874 			/* NB: in particular this captures ack's */
875 			ieee80211_radiotap_rx_all(ic, m);
876 		}
877 		m_freem(m); m = NULL;
878 		goto rx_next;
879 	}
880 
881 	if (IFF_DUMPPKTS(sc, ATH_DEBUG_RECV)) {
882 		const HAL_RATE_TABLE *rt = sc->sc_currates;
883 		uint8_t rix = rt->rateCodeToIndex[rs->rs_rate];
884 
885 		ieee80211_dump_pkt(ic, mtod(m, caddr_t), len,
886 		    sc->sc_hwmap[rix].ieeerate, rs->rs_rssi);
887 	}
888 
889 	m_adj(m, -IEEE80211_CRC_LEN);
890 
891 	/*
892 	 * Locate the node for sender, track state, and then
893 	 * pass the (referenced) node up to the 802.11 layer
894 	 * for its use.
895 	 */
896 	ni = ieee80211_find_rxnode_withkey(ic,
897 		mtod(m, const struct ieee80211_frame_min *),
898 		rs->rs_keyix == HAL_RXKEYIX_INVALID ?
899 			IEEE80211_KEYIX_NONE : rs->rs_keyix);
900 	sc->sc_lastrs = rs;
901 
902 #ifdef	AH_SUPPORT_AR5416
903 	if (rs->rs_isaggr)
904 		sc->sc_stats.ast_rx_agg++;
905 #endif /* AH_SUPPORT_AR5416 */
906 
907 	if (ni != NULL) {
908 		/*
909 		 * Only punt packets for ampdu reorder processing for
910 		 * 11n nodes; net80211 enforces that M_AMPDU is only
911 		 * set for 11n nodes.
912 		 */
913 		if (ni->ni_flags & IEEE80211_NODE_HT)
914 			m->m_flags |= M_AMPDU;
915 
916 		/*
917 		 * Sending station is known, dispatch directly.
918 		 */
919 		type = ieee80211_input(ni, m, rs->rs_rssi, nf);
920 		ieee80211_free_node(ni);
921 		m = NULL;
922 		/*
923 		 * Arrange to update the last rx timestamp only for
924 		 * frames from our ap when operating in station mode.
925 		 * This assumes the rx key is always setup when
926 		 * associated.
927 		 */
928 		if (ic->ic_opmode == IEEE80211_M_STA &&
929 		    rs->rs_keyix != HAL_RXKEYIX_INVALID)
930 			is_good = 1;
931 	} else {
932 		type = ieee80211_input_all(ic, m, rs->rs_rssi, nf);
933 		m = NULL;
934 	}
935 
936 	/*
937 	 * At this point we have passed the frame up the stack; thus
938 	 * the mbuf is no longer ours.
939 	 */
940 
941 	/*
942 	 * Track rx rssi and do any rx antenna management.
943 	 */
944 	ATH_RSSI_LPF(sc->sc_halstats.ns_avgrssi, rs->rs_rssi);
945 	if (sc->sc_diversity) {
946 		/*
947 		 * When using fast diversity, change the default rx
948 		 * antenna if diversity chooses the other antenna 3
949 		 * times in a row.
950 		 */
951 		if (sc->sc_defant != rs->rs_antenna) {
952 			if (++sc->sc_rxotherant >= 3)
953 				ath_setdefantenna(sc, rs->rs_antenna);
954 		} else
955 			sc->sc_rxotherant = 0;
956 	}
957 
958 	/* Handle slow diversity if enabled */
959 	if (sc->sc_dolnadiv) {
960 		ath_lna_rx_comb_scan(sc, rs, ticks, hz);
961 	}
962 
963 	if (sc->sc_softled) {
964 		/*
965 		 * Blink for any data frame.  Otherwise do a
966 		 * heartbeat-style blink when idle.  The latter
967 		 * is mainly for station mode where we depend on
968 		 * periodic beacon frames to trigger the poll event.
969 		 */
970 		if (type == IEEE80211_FC0_TYPE_DATA) {
971 			const HAL_RATE_TABLE *rt = sc->sc_currates;
972 			ath_led_event(sc,
973 			    rt->rateCodeToIndex[rs->rs_rate]);
974 		} else if (ticks - sc->sc_ledevent >= sc->sc_ledidle)
975 			ath_led_event(sc, 0);
976 		}
977 rx_next:
978 	/*
979 	 * Debugging - complain if we didn't NULL the mbuf pointer
980 	 * here.
981 	 */
982 	if (m != NULL) {
983 		device_printf(sc->sc_dev,
984 		    "%s: mbuf %p should've been freed!\n",
985 		    __func__,
986 		    m);
987 	}
988 	return (is_good);
989 }
990 
991 #define	ATH_RX_MAX		128
992 
993 /*
994  * XXX TODO: break out the "get buffers" from "call ath_rx_pkt()" like
995  * the EDMA code does.
996  *
997  * XXX TODO: then, do all of the RX list management stuff inside
998  * ATH_RX_LOCK() so we don't end up potentially racing.  The EDMA
999  * code is doing it right.
1000  */
1001 static void
1002 ath_rx_proc(struct ath_softc *sc, int resched)
1003 {
1004 #define	PA2DESC(_sc, _pa) \
1005 	((struct ath_desc *)((caddr_t)(_sc)->sc_rxdma.dd_desc + \
1006 		((_pa) - (_sc)->sc_rxdma.dd_desc_paddr)))
1007 	struct ath_buf *bf;
1008 	struct ath_hal *ah = sc->sc_ah;
1009 #ifdef IEEE80211_SUPPORT_SUPERG
1010 	struct ieee80211com *ic = &sc->sc_ic;
1011 #endif
1012 	struct ath_desc *ds;
1013 	struct ath_rx_status *rs;
1014 	struct mbuf *m;
1015 	int ngood;
1016 	HAL_STATUS status;
1017 	int16_t nf;
1018 	u_int64_t tsf;
1019 	int npkts = 0;
1020 	int kickpcu = 0;
1021 	int ret;
1022 
1023 	/* XXX we must not hold the ATH_LOCK here */
1024 	ATH_UNLOCK_ASSERT(sc);
1025 	ATH_PCU_UNLOCK_ASSERT(sc);
1026 
1027 	ATH_PCU_LOCK(sc);
1028 	sc->sc_rxproc_cnt++;
1029 	kickpcu = sc->sc_kickpcu;
1030 	ATH_PCU_UNLOCK(sc);
1031 
1032 	ATH_LOCK(sc);
1033 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
1034 	ATH_UNLOCK(sc);
1035 
1036 	DPRINTF(sc, ATH_DEBUG_RX_PROC, "%s: called\n", __func__);
1037 	ngood = 0;
1038 	nf = ath_hal_getchannoise(ah, sc->sc_curchan);
1039 	sc->sc_stats.ast_rx_noise = nf;
1040 	tsf = ath_hal_gettsf64(ah);
1041 	do {
1042 		/*
1043 		 * Don't process too many packets at a time; give the
1044 		 * TX thread time to also run - otherwise the TX
1045 		 * latency can jump by quite a bit, causing throughput
1046 		 * degredation.
1047 		 */
1048 		if (!kickpcu && npkts >= ATH_RX_MAX)
1049 			break;
1050 
1051 		bf = TAILQ_FIRST(&sc->sc_rxbuf);
1052 		if (sc->sc_rxslink && bf == NULL) {	/* NB: shouldn't happen */
1053 			device_printf(sc->sc_dev, "%s: no buffer!\n", __func__);
1054 			break;
1055 		} else if (bf == NULL) {
1056 			/*
1057 			 * End of List:
1058 			 * this can happen for non-self-linked RX chains
1059 			 */
1060 			sc->sc_stats.ast_rx_hitqueueend++;
1061 			break;
1062 		}
1063 		m = bf->bf_m;
1064 		if (m == NULL) {		/* NB: shouldn't happen */
1065 			/*
1066 			 * If mbuf allocation failed previously there
1067 			 * will be no mbuf; try again to re-populate it.
1068 			 */
1069 			/* XXX make debug msg */
1070 			device_printf(sc->sc_dev, "%s: no mbuf!\n", __func__);
1071 			TAILQ_REMOVE(&sc->sc_rxbuf, bf, bf_list);
1072 			goto rx_proc_next;
1073 		}
1074 		ds = bf->bf_desc;
1075 		if (ds->ds_link == bf->bf_daddr) {
1076 			/* NB: never process the self-linked entry at the end */
1077 			sc->sc_stats.ast_rx_hitqueueend++;
1078 			break;
1079 		}
1080 		/* XXX sync descriptor memory */
1081 		/*
1082 		 * Must provide the virtual address of the current
1083 		 * descriptor, the physical address, and the virtual
1084 		 * address of the next descriptor in the h/w chain.
1085 		 * This allows the HAL to look ahead to see if the
1086 		 * hardware is done with a descriptor by checking the
1087 		 * done bit in the following descriptor and the address
1088 		 * of the current descriptor the DMA engine is working
1089 		 * on.  All this is necessary because of our use of
1090 		 * a self-linked list to avoid rx overruns.
1091 		 */
1092 		rs = &bf->bf_status.ds_rxstat;
1093 		status = ath_hal_rxprocdesc(ah, ds,
1094 				bf->bf_daddr, PA2DESC(sc, ds->ds_link), rs);
1095 #ifdef ATH_DEBUG
1096 		if (sc->sc_debug & ATH_DEBUG_RECV_DESC)
1097 			ath_printrxbuf(sc, bf, 0, status == HAL_OK);
1098 #endif
1099 
1100 #ifdef	ATH_DEBUG_ALQ
1101 		if (if_ath_alq_checkdebug(&sc->sc_alq, ATH_ALQ_EDMA_RXSTATUS))
1102 		    if_ath_alq_post(&sc->sc_alq, ATH_ALQ_EDMA_RXSTATUS,
1103 		    sc->sc_rx_statuslen, (char *) ds);
1104 #endif	/* ATH_DEBUG_ALQ */
1105 
1106 		if (status == HAL_EINPROGRESS)
1107 			break;
1108 
1109 		TAILQ_REMOVE(&sc->sc_rxbuf, bf, bf_list);
1110 		npkts++;
1111 
1112 		/*
1113 		 * Process a single frame.
1114 		 */
1115 		bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_POSTREAD);
1116 		bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
1117 		bf->bf_m = NULL;
1118 		if (ath_rx_pkt(sc, rs, status, tsf, nf, HAL_RX_QUEUE_HP, bf, m))
1119 			ngood++;
1120 rx_proc_next:
1121 		/*
1122 		 * If there's a holding buffer, insert that onto
1123 		 * the RX list; the hardware is now definitely not pointing
1124 		 * to it now.
1125 		 */
1126 		ret = 0;
1127 		if (sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf != NULL) {
1128 			TAILQ_INSERT_TAIL(&sc->sc_rxbuf,
1129 			    sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf,
1130 			    bf_list);
1131 			ret = ath_rxbuf_init(sc,
1132 			    sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf);
1133 		}
1134 		/*
1135 		 * Next, throw our buffer into the holding entry.  The hardware
1136 		 * may use the descriptor to read the link pointer before
1137 		 * DMAing the next descriptor in to write out a packet.
1138 		 */
1139 		sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf = bf;
1140 	} while (ret == 0);
1141 
1142 	/* rx signal state monitoring */
1143 	ath_hal_rxmonitor(ah, &sc->sc_halstats, sc->sc_curchan);
1144 	if (ngood)
1145 		sc->sc_lastrx = tsf;
1146 
1147 	ATH_KTR(sc, ATH_KTR_RXPROC, 2, "ath_rx_proc: npkts=%d, ngood=%d", npkts, ngood);
1148 	/* Queue DFS tasklet if needed */
1149 	if (resched && ath_dfs_tasklet_needed(sc, sc->sc_curchan))
1150 		taskqueue_enqueue(sc->sc_tq, &sc->sc_dfstask);
1151 
1152 	/*
1153 	 * Now that all the RX frames were handled that
1154 	 * need to be handled, kick the PCU if there's
1155 	 * been an RXEOL condition.
1156 	 */
1157 	if (resched && kickpcu) {
1158 		ATH_PCU_LOCK(sc);
1159 		ATH_KTR(sc, ATH_KTR_ERROR, 0, "ath_rx_proc: kickpcu");
1160 		device_printf(sc->sc_dev, "%s: kickpcu; handled %d packets\n",
1161 		    __func__, npkts);
1162 
1163 		/*
1164 		 * Go through the process of fully tearing down
1165 		 * the RX buffers and reinitialising them.
1166 		 *
1167 		 * There's a hardware bug that causes the RX FIFO
1168 		 * to get confused under certain conditions and
1169 		 * constantly write over the same frame, leading
1170 		 * the RX driver code here to get heavily confused.
1171 		 */
1172 		/*
1173 		 * XXX Has RX DMA stopped enough here to just call
1174 		 *     ath_startrecv()?
1175 		 * XXX Do we need to use the holding buffer to restart
1176 		 *     RX DMA by appending entries to the final
1177 		 *     descriptor?  Quite likely.
1178 		 */
1179 #if 1
1180 		ath_startrecv(sc);
1181 #else
1182 		/*
1183 		 * Disabled for now - it'd be nice to be able to do
1184 		 * this in order to limit the amount of CPU time spent
1185 		 * reinitialising the RX side (and thus minimise RX
1186 		 * drops) however there's a hardware issue that
1187 		 * causes things to get too far out of whack.
1188 		 */
1189 		/*
1190 		 * XXX can we hold the PCU lock here?
1191 		 * Are there any net80211 buffer calls involved?
1192 		 */
1193 		bf = TAILQ_FIRST(&sc->sc_rxbuf);
1194 		ath_hal_putrxbuf(ah, bf->bf_daddr, HAL_RX_QUEUE_HP);
1195 		ath_hal_rxena(ah);		/* enable recv descriptors */
1196 		ath_mode_init(sc);		/* set filters, etc. */
1197 		ath_hal_startpcurecv(ah);	/* re-enable PCU/DMA engine */
1198 #endif
1199 
1200 		ath_hal_intrset(ah, sc->sc_imask);
1201 		sc->sc_kickpcu = 0;
1202 		ATH_PCU_UNLOCK(sc);
1203 	}
1204 
1205 #ifdef IEEE80211_SUPPORT_SUPERG
1206 	if (resched)
1207 		ieee80211_ff_age_all(ic, 100);
1208 #endif
1209 
1210 	/*
1211 	 * Put the hardware to sleep again if we're done with it.
1212 	 */
1213 	ATH_LOCK(sc);
1214 	ath_power_restore_power_state(sc);
1215 	ATH_UNLOCK(sc);
1216 
1217 	/*
1218 	 * If we hit the maximum number of frames in this round,
1219 	 * reschedule for another immediate pass.  This gives
1220 	 * the TX and TX completion routines time to run, which
1221 	 * will reduce latency.
1222 	 */
1223 	if (npkts >= ATH_RX_MAX)
1224 		sc->sc_rx.recv_sched(sc, resched);
1225 
1226 	ATH_PCU_LOCK(sc);
1227 	sc->sc_rxproc_cnt--;
1228 	ATH_PCU_UNLOCK(sc);
1229 }
1230 #undef	PA2DESC
1231 #undef	ATH_RX_MAX
1232 
1233 /*
1234  * Only run the RX proc if it's not already running.
1235  * Since this may get run as part of the reset/flush path,
1236  * the task can't clash with an existing, running tasklet.
1237  */
1238 static void
1239 ath_legacy_rx_tasklet(void *arg, int npending)
1240 {
1241 	struct ath_softc *sc = arg;
1242 
1243 	ATH_KTR(sc, ATH_KTR_RXPROC, 1, "ath_rx_proc: pending=%d", npending);
1244 	DPRINTF(sc, ATH_DEBUG_RX_PROC, "%s: pending %u\n", __func__, npending);
1245 	ATH_PCU_LOCK(sc);
1246 	if (sc->sc_inreset_cnt > 0) {
1247 		device_printf(sc->sc_dev,
1248 		    "%s: sc_inreset_cnt > 0; skipping\n", __func__);
1249 		ATH_PCU_UNLOCK(sc);
1250 		return;
1251 	}
1252 	ATH_PCU_UNLOCK(sc);
1253 
1254 	ath_rx_proc(sc, 1);
1255 }
1256 
1257 static void
1258 ath_legacy_flushrecv(struct ath_softc *sc)
1259 {
1260 
1261 	ath_rx_proc(sc, 0);
1262 }
1263 
1264 static void
1265 ath_legacy_flush_rxpending(struct ath_softc *sc)
1266 {
1267 
1268 	/* XXX ATH_RX_LOCK_ASSERT(sc); */
1269 
1270 	if (sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending != NULL) {
1271 		m_freem(sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending);
1272 		sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending = NULL;
1273 	}
1274 	if (sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending != NULL) {
1275 		m_freem(sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending);
1276 		sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending = NULL;
1277 	}
1278 }
1279 
1280 static int
1281 ath_legacy_flush_rxholdbf(struct ath_softc *sc)
1282 {
1283 	struct ath_buf *bf;
1284 
1285 	/* XXX ATH_RX_LOCK_ASSERT(sc); */
1286 	/*
1287 	 * If there are RX holding buffers, free them here and return
1288 	 * them to the list.
1289 	 *
1290 	 * XXX should just verify that bf->bf_m is NULL, as it must
1291 	 * be at this point!
1292 	 */
1293 	bf = sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf;
1294 	if (bf != NULL) {
1295 		if (bf->bf_m != NULL)
1296 			m_freem(bf->bf_m);
1297 		bf->bf_m = NULL;
1298 		TAILQ_INSERT_TAIL(&sc->sc_rxbuf, bf, bf_list);
1299 		(void) ath_rxbuf_init(sc, bf);
1300 	}
1301 	sc->sc_rxedma[HAL_RX_QUEUE_HP].m_holdbf = NULL;
1302 
1303 	bf = sc->sc_rxedma[HAL_RX_QUEUE_LP].m_holdbf;
1304 	if (bf != NULL) {
1305 		if (bf->bf_m != NULL)
1306 			m_freem(bf->bf_m);
1307 		bf->bf_m = NULL;
1308 		TAILQ_INSERT_TAIL(&sc->sc_rxbuf, bf, bf_list);
1309 		(void) ath_rxbuf_init(sc, bf);
1310 	}
1311 	sc->sc_rxedma[HAL_RX_QUEUE_LP].m_holdbf = NULL;
1312 
1313 	return (0);
1314 }
1315 
1316 /*
1317  * Disable the receive h/w in preparation for a reset.
1318  */
1319 static void
1320 ath_legacy_stoprecv(struct ath_softc *sc, int dodelay)
1321 {
1322 #define	PA2DESC(_sc, _pa) \
1323 	((struct ath_desc *)((caddr_t)(_sc)->sc_rxdma.dd_desc + \
1324 		((_pa) - (_sc)->sc_rxdma.dd_desc_paddr)))
1325 	struct ath_hal *ah = sc->sc_ah;
1326 
1327 	ATH_RX_LOCK(sc);
1328 
1329 	ath_hal_stoppcurecv(ah);	/* disable PCU */
1330 	ath_hal_setrxfilter(ah, 0);	/* clear recv filter */
1331 	ath_hal_stopdmarecv(ah);	/* disable DMA engine */
1332 	/*
1333 	 * TODO: see if this particular DELAY() is required; it may be
1334 	 * masking some missing FIFO flush or DMA sync.
1335 	 */
1336 #if 0
1337 	if (dodelay)
1338 #endif
1339 		DELAY(3000);		/* 3ms is long enough for 1 frame */
1340 #ifdef ATH_DEBUG
1341 	if (sc->sc_debug & (ATH_DEBUG_RESET | ATH_DEBUG_FATAL)) {
1342 		struct ath_buf *bf;
1343 		u_int ix;
1344 
1345 		device_printf(sc->sc_dev,
1346 		    "%s: rx queue %p, link %p\n",
1347 		    __func__,
1348 		    (caddr_t)(uintptr_t) ath_hal_getrxbuf(ah, HAL_RX_QUEUE_HP),
1349 		    sc->sc_rxlink);
1350 		ix = 0;
1351 		TAILQ_FOREACH(bf, &sc->sc_rxbuf, bf_list) {
1352 			struct ath_desc *ds = bf->bf_desc;
1353 			struct ath_rx_status *rs = &bf->bf_status.ds_rxstat;
1354 			HAL_STATUS status = ath_hal_rxprocdesc(ah, ds,
1355 				bf->bf_daddr, PA2DESC(sc, ds->ds_link), rs);
1356 			if (status == HAL_OK || (sc->sc_debug & ATH_DEBUG_FATAL))
1357 				ath_printrxbuf(sc, bf, ix, status == HAL_OK);
1358 			ix++;
1359 		}
1360 	}
1361 #endif
1362 
1363 	(void) ath_legacy_flush_rxpending(sc);
1364 	(void) ath_legacy_flush_rxholdbf(sc);
1365 
1366 	sc->sc_rxlink = NULL;		/* just in case */
1367 
1368 	ATH_RX_UNLOCK(sc);
1369 #undef PA2DESC
1370 }
1371 
1372 /*
1373  * XXX TODO: something was calling startrecv without calling
1374  * stoprecv.  Let's figure out what/why.  It was showing up
1375  * as a mbuf leak (rxpending) and ath_buf leak (holdbf.)
1376  */
1377 
1378 /*
1379  * Enable the receive h/w following a reset.
1380  */
1381 static int
1382 ath_legacy_startrecv(struct ath_softc *sc)
1383 {
1384 	struct ath_hal *ah = sc->sc_ah;
1385 	struct ath_buf *bf;
1386 
1387 	ATH_RX_LOCK(sc);
1388 
1389 	/*
1390 	 * XXX should verify these are already all NULL!
1391 	 */
1392 	sc->sc_rxlink = NULL;
1393 	(void) ath_legacy_flush_rxpending(sc);
1394 	(void) ath_legacy_flush_rxholdbf(sc);
1395 
1396 	/*
1397 	 * Re-chain all of the buffers in the RX buffer list.
1398 	 */
1399 	TAILQ_FOREACH(bf, &sc->sc_rxbuf, bf_list) {
1400 		int error = ath_rxbuf_init(sc, bf);
1401 		if (error != 0) {
1402 			DPRINTF(sc, ATH_DEBUG_RECV,
1403 				"%s: ath_rxbuf_init failed %d\n",
1404 				__func__, error);
1405 			return error;
1406 		}
1407 	}
1408 
1409 	bf = TAILQ_FIRST(&sc->sc_rxbuf);
1410 	ath_hal_putrxbuf(ah, bf->bf_daddr, HAL_RX_QUEUE_HP);
1411 	ath_hal_rxena(ah);		/* enable recv descriptors */
1412 	ath_mode_init(sc);		/* set filters, etc. */
1413 	ath_hal_startpcurecv(ah);	/* re-enable PCU/DMA engine */
1414 
1415 	ATH_RX_UNLOCK(sc);
1416 	return 0;
1417 }
1418 
1419 static int
1420 ath_legacy_dma_rxsetup(struct ath_softc *sc)
1421 {
1422 	int error;
1423 
1424 	error = ath_descdma_setup(sc, &sc->sc_rxdma, &sc->sc_rxbuf,
1425 	    "rx", sizeof(struct ath_desc), ath_rxbuf, 1);
1426 	if (error != 0)
1427 		return (error);
1428 
1429 	return (0);
1430 }
1431 
1432 static int
1433 ath_legacy_dma_rxteardown(struct ath_softc *sc)
1434 {
1435 
1436 	if (sc->sc_rxdma.dd_desc_len != 0)
1437 		ath_descdma_cleanup(sc, &sc->sc_rxdma, &sc->sc_rxbuf);
1438 	return (0);
1439 }
1440 
1441 static void
1442 ath_legacy_recv_sched(struct ath_softc *sc, int dosched)
1443 {
1444 
1445 	taskqueue_enqueue(sc->sc_tq, &sc->sc_rxtask);
1446 }
1447 
1448 static void
1449 ath_legacy_recv_sched_queue(struct ath_softc *sc, HAL_RX_QUEUE q,
1450     int dosched)
1451 {
1452 
1453 	taskqueue_enqueue(sc->sc_tq, &sc->sc_rxtask);
1454 }
1455 
1456 void
1457 ath_recv_setup_legacy(struct ath_softc *sc)
1458 {
1459 
1460 	/* Sensible legacy defaults */
1461 	/*
1462 	 * XXX this should be changed to properly support the
1463 	 * exact RX descriptor size for each HAL.
1464 	 */
1465 	sc->sc_rx_statuslen = sizeof(struct ath_desc);
1466 
1467 	sc->sc_rx.recv_start = ath_legacy_startrecv;
1468 	sc->sc_rx.recv_stop = ath_legacy_stoprecv;
1469 	sc->sc_rx.recv_flush = ath_legacy_flushrecv;
1470 	sc->sc_rx.recv_tasklet = ath_legacy_rx_tasklet;
1471 	sc->sc_rx.recv_rxbuf_init = ath_legacy_rxbuf_init;
1472 
1473 	sc->sc_rx.recv_setup = ath_legacy_dma_rxsetup;
1474 	sc->sc_rx.recv_teardown = ath_legacy_dma_rxteardown;
1475 	sc->sc_rx.recv_sched = ath_legacy_recv_sched;
1476 	sc->sc_rx.recv_sched_queue = ath_legacy_recv_sched_queue;
1477 }
1478