xref: /dragonfly/sys/dev/netif/ath/ath/if_ath_rx_edma.c (revision f503b4c4)
1 /*-
2  * Copyright (c) 2012 Adrian Chadd <adrian@FreeBSD.org>
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 
32 /*
33  * Driver for the Atheros Wireless LAN controller.
34  *
35  * This software is derived from work of Atsushi Onoe; his contribution
36  * is greatly appreciated.
37  */
38 
39 #include "opt_inet.h"
40 #include "opt_ath.h"
41 /*
42  * This is needed for register operations which are performed
43  * by the driver - eg, calls to ath_hal_gettsf32().
44  *
45  * It's also required for any AH_DEBUG checks in here, eg the
46  * module dependencies.
47  */
48 #include "opt_ah.h"
49 #include "opt_wlan.h"
50 
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/sysctl.h>
54 #include <sys/mbuf.h>
55 #include <sys/malloc.h>
56 #include <sys/lock.h>
57 #include <sys/mutex.h>
58 #include <sys/kernel.h>
59 #include <sys/socket.h>
60 #include <sys/sockio.h>
61 #include <sys/errno.h>
62 #include <sys/callout.h>
63 #include <sys/bus.h>
64 #include <sys/endian.h>
65 #include <sys/kthread.h>
66 #include <sys/taskqueue.h>
67 #include <sys/priv.h>
68 #include <sys/module.h>
69 #include <sys/ktr.h>
70 #include <machine/pmap.h>
71 
72 #include <net/if.h>
73 #include <net/if_var.h>
74 #include <net/if_dl.h>
75 #include <net/if_media.h>
76 #include <net/if_types.h>
77 #include <net/if_arp.h>
78 #include <net/ethernet.h>
79 #include <net/if_llc.h>
80 #include <net/ifq_var.h>
81 
82 #include <netproto/802_11/ieee80211_var.h>
83 #include <netproto/802_11/ieee80211_regdomain.h>
84 #ifdef IEEE80211_SUPPORT_SUPERG
85 #include <netproto/802_11/ieee80211_superg.h>
86 #endif
87 #ifdef IEEE80211_SUPPORT_TDMA
88 #include <netproto/802_11/ieee80211_tdma.h>
89 #endif
90 
91 #include <net/bpf.h>
92 
93 #ifdef INET
94 #include <netinet/in.h>
95 #include <netinet/if_ether.h>
96 #endif
97 
98 #include <dev/netif/ath/ath/if_athvar.h>
99 #include <dev/netif/ath/ath_hal/ah_devid.h>		/* XXX for softled */
100 #include <dev/netif/ath/ath_hal/ah_diagcodes.h>
101 
102 #include <dev/netif/ath/ath/if_ath_debug.h>
103 #include <dev/netif/ath/ath/if_ath_misc.h>
104 #include <dev/netif/ath/ath/if_ath_tsf.h>
105 #include <dev/netif/ath/ath/if_ath_tx.h>
106 #include <dev/netif/ath/ath/if_ath_sysctl.h>
107 #include <dev/netif/ath/ath/if_ath_led.h>
108 #include <dev/netif/ath/ath/if_ath_keycache.h>
109 #include <dev/netif/ath/ath/if_ath_rx.h>
110 #include <dev/netif/ath/ath/if_ath_beacon.h>
111 #include <dev/netif/ath/ath/if_athdfs.h>
112 
113 #ifdef ATH_TX99_DIAG
114 #include <dev/netif/ath/ath_tx99/ath_tx99.h>
115 #endif
116 
117 #include <dev/netif/ath/ath/if_ath_rx_edma.h>
118 
119 #ifdef	ATH_DEBUG_ALQ
120 #include <dev/netif/ath/ath/if_ath_alq.h>
121 #endif
122 
123 /*
124  * some general macros
125   */
126 #define	INCR(_l, _sz)		(_l) ++; (_l) &= ((_sz) - 1)
127 #define	DECR(_l, _sz)		(_l) --; (_l) &= ((_sz) - 1)
128 
129 MALLOC_DECLARE(M_ATHDEV);
130 
131 /*
132  * XXX TODO:
133  *
134  * + Make sure the FIFO is correctly flushed and reinitialised
135  *   through a reset;
136  * + Verify multi-descriptor frames work!
137  * + There's a "memory use after free" which needs to be tracked down
138  *   and fixed ASAP.  I've seen this in the legacy path too, so it
139  *   may be a generic RX path issue.
140  */
141 
142 /*
143  * XXX shuffle the function orders so these pre-declarations aren't
144  * required!
145  */
146 static	int ath_edma_rxfifo_alloc(struct ath_softc *sc, HAL_RX_QUEUE qtype,
147 	    int nbufs);
148 static	int ath_edma_rxfifo_flush(struct ath_softc *sc, HAL_RX_QUEUE qtype);
149 static	void ath_edma_rxbuf_free(struct ath_softc *sc, struct ath_buf *bf);
150 static	int ath_edma_recv_proc_queue(struct ath_softc *sc,
151 	    HAL_RX_QUEUE qtype, int dosched);
152 static	int ath_edma_recv_proc_deferred_queue(struct ath_softc *sc,
153 	    HAL_RX_QUEUE qtype, int dosched);
154 
155 static void
156 ath_edma_stoprecv(struct ath_softc *sc, int dodelay)
157 {
158 	struct ath_hal *ah = sc->sc_ah;
159 
160 	ATH_RX_LOCK(sc);
161 	ath_hal_stoppcurecv(ah);
162 	ath_hal_setrxfilter(ah, 0);
163 	ath_hal_stopdmarecv(ah);
164 
165 	DELAY(3000);
166 
167 	/* Flush RX pending for each queue */
168 	/* XXX should generic-ify this */
169 	if (sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending) {
170 		m_freem(sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending);
171 		sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending = NULL;
172 	}
173 
174 	if (sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending) {
175 		m_freem(sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending);
176 		sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending = NULL;
177 	}
178 	ATH_RX_UNLOCK(sc);
179 }
180 
181 /*
182  * Re-initialise the FIFO given the current buffer contents.
183  * Specifically, walk from head -> tail, pushing the FIFO contents
184  * back into the FIFO.
185  */
186 static void
187 ath_edma_reinit_fifo(struct ath_softc *sc, HAL_RX_QUEUE qtype)
188 {
189 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
190 	struct ath_buf *bf;
191 	int i, j;
192 
193 	ATH_RX_LOCK_ASSERT(sc);
194 
195 	i = re->m_fifo_head;
196 	for (j = 0; j < re->m_fifo_depth; j++) {
197 		bf = re->m_fifo[i];
198 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
199 		    "%s: Q%d: pos=%i, addr=0x%jx\n",
200 		    __func__,
201 		    qtype,
202 		    i,
203 		    (uintmax_t)bf->bf_daddr);
204 		ath_hal_putrxbuf(sc->sc_ah, bf->bf_daddr, qtype);
205 		INCR(i, re->m_fifolen);
206 	}
207 
208 	/* Ensure this worked out right */
209 	if (i != re->m_fifo_tail) {
210 		device_printf(sc->sc_dev, "%s: i (%d) != tail! (%d)\n",
211 		    __func__,
212 		    i,
213 		    re->m_fifo_tail);
214 	}
215 }
216 
217 static void
218 ath_edma_handle_rxfifo_reset(struct ath_softc *sc)
219 {
220 	if (sc->sc_rxfifo_state == ATH_RXFIFO_RESET) {
221 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
222 		    "%s: Re-initing HP FIFO\n", __func__);
223 		ath_edma_reinit_fifo(sc, HAL_RX_QUEUE_HP);
224 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
225 		    "%s: Re-initing LP FIFO\n", __func__);
226 		ath_edma_reinit_fifo(sc, HAL_RX_QUEUE_LP);
227 		sc->sc_rxfifo_state = ATH_RXFIFO_OK;
228 	}
229 }
230 
231 /*
232  * Start receive.
233  *
234  * XXX TODO: this needs to reallocate the FIFO entries when a reset
235  * occurs, in case the FIFO is filled up and no new descriptors get
236  * thrown into the FIFO.
237  */
238 static int
239 ath_edma_startrecv(struct ath_softc *sc)
240 {
241 	struct ath_hal *ah = sc->sc_ah;
242 
243 	ATH_RX_LOCK(sc);
244 
245 	/* Enable RX FIFO */
246 	ath_hal_rxena(ah);
247 	ath_edma_handle_rxfifo_reset(sc);
248 
249 	/* Add up to m_fifolen entries in each queue */
250 	/*
251 	 * These must occur after the above write so the FIFO buffers
252 	 * are pushed/tracked in the same order as the hardware will
253 	 * process them.
254 	 */
255 	ath_edma_rxfifo_alloc(sc, HAL_RX_QUEUE_HP,
256 	    sc->sc_rxedma[HAL_RX_QUEUE_HP].m_fifolen);
257 
258 	ath_edma_rxfifo_alloc(sc, HAL_RX_QUEUE_LP,
259 	    sc->sc_rxedma[HAL_RX_QUEUE_LP].m_fifolen);
260 
261 	ath_mode_init(sc);
262 	ath_hal_startpcurecv(ah);
263 
264 	ATH_RX_UNLOCK(sc);
265 
266 	return (0);
267 }
268 
269 static void
270 ath_edma_recv_sched_queue(struct ath_softc *sc, HAL_RX_QUEUE qtype,
271     int dosched)
272 {
273 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
274 	if (dosched)
275 		ath_edma_handle_rxfifo_reset(sc);
276 	ath_edma_recv_proc_queue(sc, qtype, dosched);
277 	ath_power_restore_power_state(sc);
278 
279 	taskqueue_enqueue(sc->sc_tq, &sc->sc_rxtask);
280 }
281 
282 static void
283 ath_edma_recv_sched(struct ath_softc *sc, int dosched)
284 {
285 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
286 	if (dosched)
287 		ath_edma_handle_rxfifo_reset(sc);
288 	ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_HP, dosched);
289 	ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_LP, dosched);
290 	ath_power_restore_power_state(sc);
291 
292 	taskqueue_enqueue(sc->sc_tq, &sc->sc_rxtask);
293 }
294 
295 static void
296 ath_edma_recv_flush(struct ath_softc *sc)
297 {
298 
299 	DPRINTF(sc, ATH_DEBUG_RECV, "%s: called\n", __func__);
300 
301 	ATH_PCU_LOCK(sc);
302 	sc->sc_rxproc_cnt++;
303 	ATH_PCU_UNLOCK(sc);
304 
305 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
306 
307 	/*
308 	 * Flush any active frames from FIFO -> deferred list
309 	 */
310 	ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_HP, 0);
311 	ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_LP, 0);
312 
313 	/*
314 	 * Process what's in the deferred queue
315 	 */
316 	/*
317 	 * XXX: If we read the tsf/channoise here and then pass it in,
318 	 * we could restore the power state before processing
319 	 * the deferred queue.
320 	 */
321 	ath_edma_recv_proc_deferred_queue(sc, HAL_RX_QUEUE_HP, 0);
322 	ath_edma_recv_proc_deferred_queue(sc, HAL_RX_QUEUE_LP, 0);
323 
324 	ath_power_restore_power_state(sc);
325 
326 	ATH_PCU_LOCK(sc);
327 	sc->sc_rxproc_cnt--;
328 	ATH_PCU_UNLOCK(sc);
329 }
330 
331 /*
332  * Process frames from the current queue into the deferred queue.
333  */
334 static int
335 ath_edma_recv_proc_queue(struct ath_softc *sc, HAL_RX_QUEUE qtype,
336     int dosched)
337 {
338 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
339 	struct ath_rx_status *rs;
340 	struct ath_desc *ds;
341 	struct ath_buf *bf;
342 	struct mbuf *m;
343 	struct ath_hal *ah = sc->sc_ah;
344 	uint64_t tsf;
345 	uint16_t nf;
346 	int npkts = 0;
347 	int n = 0;
348 
349 	tsf = ath_hal_gettsf64(ah);
350 	nf = ath_hal_getchannoise(ah, sc->sc_curchan);
351 	sc->sc_stats.ast_rx_noise = nf;
352 
353 	ATH_RX_LOCK(sc);
354 
355 	do {
356 		bf = re->m_fifo[re->m_fifo_head];
357 		/* This shouldn't occur! */
358 		if (bf == NULL) {
359 			device_printf(sc->sc_dev, "%s: Q%d: NULL bf?\n",
360 			    __func__,
361 			    qtype);
362 			break;
363 		}
364 		m = bf->bf_m;
365 		ds = bf->bf_desc;
366 
367 		/*
368 		 * Sync descriptor memory - this also syncs the buffer for us.
369 		 * EDMA descriptors are in cached memory.
370 		 */
371 		cpu_lfence();
372 		bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap,
373 				BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
374 		rs = &bf->bf_status.ds_rxstat;
375 		bf->bf_rxstatus = ath_hal_rxprocdesc(ah, ds, bf->bf_daddr,
376 		    NULL, rs);
377 #ifdef	ATH_DEBUG
378 		if (sc->sc_debug & ATH_DEBUG_RECV_DESC)
379 			ath_printrxbuf(sc, bf, 0, bf->bf_rxstatus == HAL_OK);
380 #endif /* ATH_DEBUG */
381 #ifdef	ATH_DEBUG_ALQ
382 		if (if_ath_alq_checkdebug(&sc->sc_alq, ATH_ALQ_EDMA_RXSTATUS))
383 			if_ath_alq_post(&sc->sc_alq, ATH_ALQ_EDMA_RXSTATUS,
384 			    sc->sc_rx_statuslen, (char *) ds);
385 #endif /* ATH_DEBUG */
386 		if (bf->bf_rxstatus == HAL_EINPROGRESS) {
387 			DPRINTF(sc, ATH_DEBUG_EDMA_RX,
388 			    "%s: Q%d: still in-prog!\n", __func__, qtype);
389 			break;
390 		}
391 
392 		/*
393 		 * Completed descriptor.
394 		 */
395 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
396 		    "%s: Q%d: completed!\n", __func__, qtype);
397 		npkts++;
398 
399 		/*
400 		 * We've been synced already, so unmap.
401 		 */
402 		bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
403 
404 		/*
405 		 * Remove the FIFO entry and place it on the completion
406 		 * queue.
407 		 */
408 		re->m_fifo[re->m_fifo_head] = NULL;
409 		TAILQ_INSERT_TAIL(&sc->sc_rx_rxlist[qtype], bf, bf_list);
410 
411 		/* Bump the descriptor FIFO stats */
412 		INCR(re->m_fifo_head, re->m_fifolen);
413 		re->m_fifo_depth--;
414 		/* XXX check it doesn't fall below 0 */
415 	} while (re->m_fifo_depth > 0);
416 
417 	/* Append some more fresh frames to the FIFO */
418 	/* (kick already handled when dosched != 0) */
419 	if (dosched)
420 		n = ath_edma_rxfifo_alloc(sc, qtype, re->m_fifolen);
421 
422 	ATH_RX_UNLOCK(sc);
423 
424 	/* rx signal state monitoring */
425 	ath_hal_rxmonitor(ah, &sc->sc_halstats, sc->sc_curchan);
426 
427 	ATH_KTR(sc, ATH_KTR_INTERRUPTS, 1,
428 	    "ath edma rx proc: npkts=%d\n",
429 	    npkts);
430 
431 	return n;
432 }
433 
434 /*
435  * Flush the deferred queue.
436  *
437  * This destructively flushes the deferred queue - it doesn't
438  * call the wireless stack on each mbuf.
439  */
440 static void
441 ath_edma_flush_deferred_queue(struct ath_softc *sc)
442 {
443 	struct ath_buf *bf;
444 
445 	ATH_RX_LOCK_ASSERT(sc);
446 
447 	/* Free in one set, inside the lock */
448 	while ((bf = TAILQ_FIRST(&sc->sc_rx_rxlist[HAL_RX_QUEUE_LP])) != NULL) {
449 		TAILQ_REMOVE(&sc->sc_rx_rxlist[HAL_RX_QUEUE_LP], bf, bf_list);
450 		ath_edma_rxbuf_free(sc, bf);
451 	}
452 	while ((bf = TAILQ_FIRST(&sc->sc_rx_rxlist[HAL_RX_QUEUE_HP])) != NULL) {
453 		TAILQ_REMOVE(&sc->sc_rx_rxlist[HAL_RX_QUEUE_HP], bf, bf_list);
454 		ath_edma_rxbuf_free(sc, bf);
455 	}
456 }
457 
458 static int
459 ath_edma_recv_proc_deferred_queue(struct ath_softc *sc, HAL_RX_QUEUE qtype,
460     int dosched)
461 {
462 	int ngood = 0;
463 	uint64_t tsf;
464 	struct ath_buf *bf;
465 	struct ath_buf *next;
466 	struct ath_rx_status *rs;
467 	int16_t nf;
468 	ath_bufhead rxlist;
469 	struct mbuf *m;
470 
471 	TAILQ_INIT(&rxlist);
472 
473 	nf = ath_hal_getchannoise(sc->sc_ah, sc->sc_curchan);
474 	/*
475 	 * XXX TODO: the NF/TSF should be stamped on the bufs themselves,
476 	 * otherwise we may end up adding in the wrong values if this
477 	 * is delayed too far..
478 	 */
479 	tsf = ath_hal_gettsf64(sc->sc_ah);
480 
481 	/* Copy the list over */
482 	ATH_RX_LOCK(sc);
483 	TAILQ_CONCAT(&rxlist, &sc->sc_rx_rxlist[qtype], bf_list);
484 	ATH_RX_UNLOCK(sc);
485 
486 	/* Handle the completed descriptors */
487 	TAILQ_FOREACH_MUTABLE(bf, &rxlist, bf_list, next) {
488 		/*
489 		 * Skip the RX descriptor status - start at the data offset
490 		 */
491 		m_adj(bf->bf_m, sc->sc_rx_statuslen);
492 
493 		/* Handle the frame */
494 
495 		rs = &bf->bf_status.ds_rxstat;
496 		m = bf->bf_m;
497 		bf->bf_m = NULL;
498 		if (ath_rx_pkt(sc, rs, bf->bf_rxstatus, tsf, nf, qtype, bf, m))
499 			ngood++;
500 	}
501 
502 	if (ngood) {
503 		sc->sc_lastrx = tsf;
504 	}
505 
506 	ATH_KTR(sc, ATH_KTR_INTERRUPTS, 1,
507 	    "ath edma rx deferred proc: ngood=%d\n",
508 	    ngood);
509 
510 	/* Free in one set, inside the lock */
511 	ATH_RX_LOCK(sc);
512 
513 	while ((bf = TAILQ_FIRST(&rxlist)) != NULL) {
514 		/* Free the buffer/mbuf */
515 		TAILQ_REMOVE(&rxlist, bf, bf_list);
516 		ath_edma_rxbuf_free(sc, bf);
517 	}
518 	ATH_RX_UNLOCK(sc);
519 
520 	return (ngood);
521 }
522 
523 static void
524 ath_edma_recv_tasklet(void *arg, int npending)
525 {
526 	struct ath_softc *sc = (struct ath_softc *) arg;
527 	struct ifnet *ifp = sc->sc_ifp;
528 #ifdef	IEEE80211_SUPPORT_SUPERG
529 	struct ieee80211com *ic = ifp->if_l2com;
530 #endif
531 	int n1;
532 	int n2;
533 
534 	DPRINTF(sc, ATH_DEBUG_EDMA_RX, "%s: called; npending=%d\n",
535 	    __func__,
536 	    npending);
537 
538 	wlan_serialize_enter();
539 	ATH_PCU_LOCK(sc);
540 	if (sc->sc_inreset_cnt > 0) {
541 		device_printf(sc->sc_dev, "%s: sc_inreset_cnt > 0; skipping\n",
542 		    __func__);
543 		ATH_PCU_UNLOCK(sc);
544 		wlan_serialize_exit();
545 		return;
546 	}
547 	sc->sc_rxproc_cnt++;
548 	ATH_PCU_UNLOCK(sc);
549 
550 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
551 
552 	ath_edma_handle_rxfifo_reset(sc);
553 	n1 = ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_HP, 1);
554 	n2 = ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_LP, 1);
555 
556 	ath_edma_recv_proc_deferred_queue(sc, HAL_RX_QUEUE_HP, 1);
557 	ath_edma_recv_proc_deferred_queue(sc, HAL_RX_QUEUE_LP, 1);
558 
559 	/* Handle resched and kickpcu appropriately */
560 	ATH_PCU_LOCK(sc);
561 	if (sc->sc_kickpcu) {
562 #ifdef ATH_DEBUG
563 		if (sc->sc_debug & ATH_DEBUG_RECV_DESC)
564 			kprintf("k(%d,%d)", n1, n2);
565 #endif
566 		sc->sc_kickpcu = 0;
567 		/* reload imask XXX */
568 		if (n1 || n2)
569 			ath_hal_intrset(sc->sc_ah, sc->sc_imask);
570 	}
571 	ATH_PCU_UNLOCK(sc);
572 
573 	/*
574 	 * XXX: If we read the tsf/channoise here and then pass it in,
575 	 * we could restore the power state before processing
576 	 * the deferred queue.
577 	 */
578 	ath_power_restore_power_state(sc);
579 
580 	/* XXX inside IF_LOCK ? */
581 	if (!ifq_is_oactive(&ifp->if_snd)) {
582 #ifdef	IEEE80211_SUPPORT_SUPERG
583 		ieee80211_ff_age_all(ic, 100);
584 #endif
585 		if (!ifq_is_empty(&ifp->if_snd))
586 			ath_tx_kick(sc);
587 	}
588 	if (ath_dfs_tasklet_needed(sc, sc->sc_curchan))
589 		taskqueue_enqueue(sc->sc_tq, &sc->sc_dfstask);
590 
591 	ATH_PCU_LOCK(sc);
592 	sc->sc_rxproc_cnt--;
593 	ATH_PCU_UNLOCK(sc);
594 	wlan_serialize_exit();
595 }
596 
597 /*
598  * Allocate an RX mbuf for the given ath_buf and initialise
599  * it for EDMA.
600  *
601  * + Allocate a 4KB mbuf;
602  * + Setup the DMA map for the given buffer;
603  * + Return that.
604  */
605 static int
606 ath_edma_rxbuf_init(struct ath_softc *sc, struct ath_buf *bf)
607 {
608 
609 	struct mbuf *m;
610 	int error;
611 	int len;
612 
613 	ATH_RX_LOCK_ASSERT(sc);
614 
615 	m = m_getjcl(MB_DONTWAIT, MT_DATA, M_PKTHDR, sc->sc_edma_bufsize);
616 /*	m = m_getcl(MB_WAIT, MT_DATA, M_PKTHDR);*/
617 /*	m = m_getm(NULL, sc->sc_edma_bufsize, MB_WAIT, MT_DATA);*/
618 	if (! m)
619 		return (ENOBUFS);		/* XXX ?*/
620 
621 	/* XXX warn/enforce alignment */
622 
623 	len = m->m_ext.ext_size;
624 #if 0
625 	device_printf(sc->sc_dev, "%s: called: m=%p, size=%d, mtod=%p\n",
626 	    __func__,
627 	    m,
628 	    len,
629 	    mtod(m, char *));
630 #endif
631 
632 	m->m_pkthdr.len = m->m_len = m->m_ext.ext_size;
633 
634 	/*
635 	 * Populate ath_buf fields.
636 	 */
637 	KKASSERT(m->m_len >= sc->sc_rx_statuslen);
638 	bf->bf_desc = mtod(m, struct ath_desc *);
639 	bf->bf_lastds = bf->bf_desc;	/* XXX only really for TX? */
640 	bf->bf_m = m;
641 
642 	/*
643 	 * Zero the descriptor and ensure it makes it out to the
644 	 * bounce buffer if one is required.
645 	 *
646 	 * XXX PREWRITE will copy the whole buffer; we only needed it
647 	 * to sync the first 32 DWORDS.  Oh well.
648 	 */
649 	memset(bf->bf_desc, '\0', sc->sc_rx_statuslen);
650 
651 	/*
652 	 * Create DMA mapping.
653 	 */
654 	error = bus_dmamap_load_mbuf_segment(sc->sc_dmat,
655 	    bf->bf_dmamap, m, bf->bf_segs, 1, &bf->bf_nseg, BUS_DMA_NOWAIT);
656 
657 	if (error != 0) {
658 		device_printf(sc->sc_dev, "%s: failed; error=%d\n",
659 		    __func__,
660 		    error);
661 		m_freem(m);
662 		return (error);
663 	}
664 
665 	/*
666 	 * Set daddr to the physical mapping page.
667 	 */
668 	bf->bf_daddr = bf->bf_segs[0].ds_addr;
669 
670 	/*
671 	 * Prepare for the upcoming read.
672 	 *
673 	 * We need to both sync some data into the buffer (the zero'ed
674 	 * descriptor payload) and also prepare for the read that's going
675 	 * to occur.
676 	 */
677 	bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap,
678 			BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
679 
680 	/* Finish! */
681 	return (0);
682 }
683 
684 /*
685  * Allocate a RX buffer.
686  */
687 static struct ath_buf *
688 ath_edma_rxbuf_alloc(struct ath_softc *sc)
689 {
690 	struct ath_buf *bf;
691 	int error;
692 
693 	ATH_RX_LOCK_ASSERT(sc);
694 
695 	/* Allocate buffer */
696 	bf = TAILQ_FIRST(&sc->sc_rxbuf);
697 	/* XXX shouldn't happen upon startup? */
698 	if (bf == NULL) {
699 		device_printf(sc->sc_dev, "%s: nothing on rxbuf?!\n",
700 		    __func__);
701 		return (NULL);
702 	}
703 
704 	/* Remove it from the free list */
705 	TAILQ_REMOVE(&sc->sc_rxbuf, bf, bf_list);
706 
707 	/* Assign RX mbuf to it */
708 	error = ath_edma_rxbuf_init(sc, bf);
709 	if (error != 0) {
710 		device_printf(sc->sc_dev,
711 		    "%s: bf=%p, rxbuf alloc failed! error=%d\n",
712 		    __func__,
713 		    bf,
714 		    error);
715 		TAILQ_INSERT_TAIL(&sc->sc_rxbuf, bf, bf_list);
716 		return (NULL);
717 	}
718 
719 	return (bf);
720 }
721 
722 static void
723 ath_edma_rxbuf_free(struct ath_softc *sc, struct ath_buf *bf)
724 {
725 
726 	ATH_RX_LOCK_ASSERT(sc);
727 
728 	/*
729 	 * Only unload the frame if we haven't consumed
730 	 * the mbuf via ath_rx_pkt().
731 	 */
732 	if (bf->bf_m) {
733 		bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
734 		m_freem(bf->bf_m);
735 		bf->bf_m = NULL;
736 	}
737 
738 	/* XXX lock? */
739 	TAILQ_INSERT_TAIL(&sc->sc_rxbuf, bf, bf_list);
740 }
741 
742 /*
743  * Allocate up to 'n' entries and push them onto the hardware FIFO.
744  *
745  * Return how many entries were successfully pushed onto the
746  * FIFO.
747  */
748 static int
749 ath_edma_rxfifo_alloc(struct ath_softc *sc, HAL_RX_QUEUE qtype, int nbufs)
750 {
751 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
752 	struct ath_buf *bf;
753 	int i;
754 
755 	ATH_RX_LOCK_ASSERT(sc);
756 
757 	/*
758 	 * Allocate buffers until the FIFO is full or nbufs is reached.
759 	 */
760 	for (i = 0; i < nbufs && re->m_fifo_depth < re->m_fifolen; i++) {
761 		/* Ensure the FIFO is already blank, complain loudly! */
762 		if (re->m_fifo[re->m_fifo_tail] != NULL) {
763 			device_printf(sc->sc_dev,
764 			    "%s: Q%d: fifo[%d] != NULL (%p)\n",
765 			    __func__,
766 			    qtype,
767 			    re->m_fifo_tail,
768 			    re->m_fifo[re->m_fifo_tail]);
769 
770 			/* Free the slot */
771 			ath_edma_rxbuf_free(sc, re->m_fifo[re->m_fifo_tail]);
772 			re->m_fifo_depth--;
773 			/* XXX check it's not < 0 */
774 			re->m_fifo[re->m_fifo_tail] = NULL;
775 		}
776 
777 		bf = ath_edma_rxbuf_alloc(sc);
778 		/* XXX should ensure the FIFO is not NULL? */
779 		if (bf == NULL) {
780 			device_printf(sc->sc_dev,
781 			    "%s: Q%d: alloc failed: i=%d, nbufs=%d?\n",
782 			    __func__,
783 			    qtype,
784 			    i,
785 			    nbufs);
786 			break;
787 		}
788 
789 		re->m_fifo[re->m_fifo_tail] = bf;
790 
791 		/* Write to the RX FIFO */
792 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
793 		    "%s: Q%d: putrxbuf=%p (0x%jx)\n",
794 		    __func__,
795 		    qtype,
796 		    bf->bf_desc,
797 		    (uintmax_t) bf->bf_daddr);
798 		ath_hal_putrxbuf(sc->sc_ah, bf->bf_daddr, qtype);
799 
800 		re->m_fifo_depth++;
801 		INCR(re->m_fifo_tail, re->m_fifolen);
802 	}
803 
804 	/*
805 	 * Return how many were allocated.
806 	 */
807 	DPRINTF(sc, ATH_DEBUG_EDMA_RX, "%s: Q%d: nbufs=%d, nalloced=%d\n",
808 	    __func__,
809 	    qtype,
810 	    nbufs,
811 	    i);
812 	return (i);
813 }
814 
815 static int
816 ath_edma_rxfifo_flush(struct ath_softc *sc, HAL_RX_QUEUE qtype)
817 {
818 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
819 	int i;
820 
821 	ATH_RX_LOCK_ASSERT(sc);
822 
823 	for (i = 0; i < re->m_fifolen; i++) {
824 		if (re->m_fifo[i] != NULL) {
825 #ifdef	ATH_DEBUG
826 			struct ath_buf *bf = re->m_fifo[i];
827 
828 			if (sc->sc_debug & ATH_DEBUG_RECV_DESC)
829 				ath_printrxbuf(sc, bf, 0, HAL_OK);
830 #endif
831 			ath_edma_rxbuf_free(sc, re->m_fifo[i]);
832 			re->m_fifo[i] = NULL;
833 			re->m_fifo_depth--;
834 		}
835 	}
836 
837 	if (re->m_rxpending != NULL) {
838 		m_freem(re->m_rxpending);
839 		re->m_rxpending = NULL;
840 	}
841 	re->m_fifo_head = re->m_fifo_tail = re->m_fifo_depth = 0;
842 
843 	return (0);
844 }
845 
846 /*
847  * Setup the initial RX FIFO structure.
848  */
849 static int
850 ath_edma_setup_rxfifo(struct ath_softc *sc, HAL_RX_QUEUE qtype)
851 {
852 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
853 
854 	ATH_RX_LOCK_ASSERT(sc);
855 
856 	if (! ath_hal_getrxfifodepth(sc->sc_ah, qtype, &re->m_fifolen)) {
857 		device_printf(sc->sc_dev, "%s: qtype=%d, failed\n",
858 		    __func__,
859 		    qtype);
860 		return (-EINVAL);
861 	}
862 	device_printf(sc->sc_dev, "%s: type=%d, FIFO depth = %d entries\n",
863 	    __func__,
864 	    qtype,
865 	    re->m_fifolen);
866 
867 	/* Allocate ath_buf FIFO array, pre-zero'ed */
868 	re->m_fifo = kmalloc(sizeof(struct ath_buf *) * re->m_fifolen,
869 	    M_ATHDEV,
870 	    M_INTWAIT | M_ZERO);
871 	if (re->m_fifo == NULL) {
872 		device_printf(sc->sc_dev, "%s: malloc failed\n",
873 		    __func__);
874 		return (-ENOMEM);
875 	}
876 
877 	/*
878 	 * Set initial "empty" state.
879 	 */
880 	re->m_rxpending = NULL;
881 	re->m_fifo_head = re->m_fifo_tail = re->m_fifo_depth = 0;
882 
883 	return (0);
884 }
885 
886 static int
887 ath_edma_rxfifo_free(struct ath_softc *sc, HAL_RX_QUEUE qtype)
888 {
889 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
890 
891 	device_printf(sc->sc_dev, "%s: called; qtype=%d\n",
892 	    __func__,
893 	    qtype);
894 
895 	kfree(re->m_fifo, M_ATHDEV);
896 
897 	return (0);
898 }
899 
900 static int
901 ath_edma_dma_rxsetup(struct ath_softc *sc)
902 {
903 	int error;
904 
905 	/*
906 	 * Create RX DMA tag and buffers.
907 	 */
908 	error = ath_descdma_setup_rx_edma(sc, &sc->sc_rxdma, &sc->sc_rxbuf,
909 	    "rx", ath_rxbuf, sc->sc_rx_statuslen);
910 	if (error != 0)
911 		return error;
912 
913 	ATH_RX_LOCK(sc);
914 	(void) ath_edma_setup_rxfifo(sc, HAL_RX_QUEUE_HP);
915 	(void) ath_edma_setup_rxfifo(sc, HAL_RX_QUEUE_LP);
916 	ATH_RX_UNLOCK(sc);
917 
918 	return (0);
919 }
920 
921 static int
922 ath_edma_dma_rxteardown(struct ath_softc *sc)
923 {
924 
925 	ATH_RX_LOCK(sc);
926 	ath_edma_flush_deferred_queue(sc);
927 	ath_edma_rxfifo_flush(sc, HAL_RX_QUEUE_HP);
928 	ath_edma_rxfifo_free(sc, HAL_RX_QUEUE_HP);
929 
930 	ath_edma_rxfifo_flush(sc, HAL_RX_QUEUE_LP);
931 	ath_edma_rxfifo_free(sc, HAL_RX_QUEUE_LP);
932 	ATH_RX_UNLOCK(sc);
933 
934 	/* Free RX ath_buf */
935 	/* Free RX DMA tag */
936 	if (sc->sc_rxdma.dd_desc_len != 0)
937 		ath_descdma_cleanup(sc, &sc->sc_rxdma, &sc->sc_rxbuf);
938 
939 	return (0);
940 }
941 
942 void
943 ath_recv_setup_edma(struct ath_softc *sc)
944 {
945 
946 	/* Set buffer size to 4k */
947 	sc->sc_edma_bufsize = 4096;
948 
949 	/* Fetch EDMA field and buffer sizes */
950 	(void) ath_hal_getrxstatuslen(sc->sc_ah, &sc->sc_rx_statuslen);
951 
952 	/* Configure the hardware with the RX buffer size */
953 	(void) ath_hal_setrxbufsize(sc->sc_ah, sc->sc_edma_bufsize -
954 	    sc->sc_rx_statuslen);
955 
956 	device_printf(sc->sc_dev, "RX status length: %d\n",
957 	    sc->sc_rx_statuslen);
958 	device_printf(sc->sc_dev, "RX buffer size: %d\n",
959 	    sc->sc_edma_bufsize);
960 
961 	sc->sc_rx.recv_stop = ath_edma_stoprecv;
962 	sc->sc_rx.recv_start = ath_edma_startrecv;
963 	sc->sc_rx.recv_flush = ath_edma_recv_flush;
964 	sc->sc_rx.recv_tasklet = ath_edma_recv_tasklet;
965 	sc->sc_rx.recv_rxbuf_init = ath_edma_rxbuf_init;
966 
967 	sc->sc_rx.recv_setup = ath_edma_dma_rxsetup;
968 	sc->sc_rx.recv_teardown = ath_edma_dma_rxteardown;
969 
970 	sc->sc_rx.recv_sched = ath_edma_recv_sched;
971 	sc->sc_rx.recv_sched_queue = ath_edma_recv_sched_queue;
972 }
973