xref: /freebsd/sys/dev/ath/if_ath_rx_edma.c (revision c243e4902be8df1e643c76b5f18b68bb77cc5268)
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 __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_dl.h>
77 #include <net/if_media.h>
78 #include <net/if_types.h>
79 #include <net/if_arp.h>
80 #include <net/ethernet.h>
81 #include <net/if_llc.h>
82 
83 #include <net80211/ieee80211_var.h>
84 #include <net80211/ieee80211_regdomain.h>
85 #ifdef IEEE80211_SUPPORT_SUPERG
86 #include <net80211/ieee80211_superg.h>
87 #endif
88 #ifdef IEEE80211_SUPPORT_TDMA
89 #include <net80211/ieee80211_tdma.h>
90 #endif
91 
92 #include <net/bpf.h>
93 
94 #ifdef INET
95 #include <netinet/in.h>
96 #include <netinet/if_ether.h>
97 #endif
98 
99 #include <dev/ath/if_athvar.h>
100 #include <dev/ath/ath_hal/ah_devid.h>		/* XXX for softled */
101 #include <dev/ath/ath_hal/ah_diagcodes.h>
102 
103 #include <dev/ath/if_ath_debug.h>
104 #include <dev/ath/if_ath_misc.h>
105 #include <dev/ath/if_ath_tsf.h>
106 #include <dev/ath/if_ath_tx.h>
107 #include <dev/ath/if_ath_sysctl.h>
108 #include <dev/ath/if_ath_led.h>
109 #include <dev/ath/if_ath_keycache.h>
110 #include <dev/ath/if_ath_rx.h>
111 #include <dev/ath/if_ath_beacon.h>
112 #include <dev/ath/if_athdfs.h>
113 
114 #ifdef ATH_TX99_DIAG
115 #include <dev/ath/ath_tx99/ath_tx99.h>
116 #endif
117 
118 #include <dev/ath/if_ath_rx_edma.h>
119 
120 /*
121  * some general macros
122   */
123 #define	INCR(_l, _sz)		(_l) ++; (_l) &= ((_sz) - 1)
124 #define	DECR(_l, _sz)		(_l) --; (_l) &= ((_sz) - 1)
125 
126 MALLOC_DECLARE(M_ATHDEV);
127 
128 /*
129  * XXX TODO:
130  *
131  * + Add an RX lock, just to ensure we don't have things clash;
132  * + Make sure the FIFO is correctly flushed and reinitialised
133  *   through a reset;
134  * + Handle the "kickpcu" state where the FIFO overflows.
135  * + Implement a "flush" routine, which doesn't push any
136  *   new frames into the FIFO.
137  * + Verify multi-descriptor frames work!
138  * + There's a "memory use after free" which needs to be tracked down
139  *   and fixed ASAP.  I've seen this in the legacy path too, so it
140  *   may be a generic RX path issue.
141  */
142 
143 /*
144  * XXX shuffle the function orders so these pre-declarations aren't
145  * required!
146  */
147 static	int ath_edma_rxfifo_alloc(struct ath_softc *sc, HAL_RX_QUEUE qtype,
148 	    int nbufs);
149 static	int ath_edma_rxfifo_flush(struct ath_softc *sc, HAL_RX_QUEUE qtype);
150 static	void ath_edma_rxbuf_free(struct ath_softc *sc, struct ath_buf *bf);
151 static	int ath_edma_recv_proc_queue(struct ath_softc *sc,
152 	    HAL_RX_QUEUE qtype, int dosched);
153 
154 static void
155 ath_edma_stoprecv(struct ath_softc *sc, int dodelay)
156 {
157 	struct ath_hal *ah = sc->sc_ah;
158 
159 	ATH_RX_LOCK(sc);
160 	ath_hal_stoppcurecv(ah);
161 	ath_hal_setrxfilter(ah, 0);
162 	ath_hal_stopdmarecv(ah);
163 
164 	DELAY(3000);
165 
166 	/* Flush RX pending for each queue */
167 	/* XXX should generic-ify this */
168 	if (sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending) {
169 		m_freem(sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending);
170 		sc->sc_rxedma[HAL_RX_QUEUE_HP].m_rxpending = NULL;
171 	}
172 
173 	if (sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending) {
174 		m_freem(sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending);
175 		sc->sc_rxedma[HAL_RX_QUEUE_LP].m_rxpending = NULL;
176 	}
177 	ATH_RX_UNLOCK(sc);
178 }
179 
180 /*
181  * Re-initialise the FIFO given the current buffer contents.
182  * Specifically, walk from head -> tail, pushing the FIFO contents
183  * back into the FIFO.
184  */
185 static void
186 ath_edma_reinit_fifo(struct ath_softc *sc, HAL_RX_QUEUE qtype)
187 {
188 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
189 	struct ath_buf *bf;
190 	int i, j;
191 
192 	ATH_RX_LOCK_ASSERT(sc);
193 
194 	i = re->m_fifo_head;
195 	for (j = 0; j < re->m_fifo_depth; j++) {
196 		bf = re->m_fifo[i];
197 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
198 		    "%s: Q%d: pos=%i, addr=0x%jx\n",
199 		    __func__,
200 		    qtype,
201 		    i,
202 		    (uintmax_t)bf->bf_daddr);
203 		ath_hal_putrxbuf(sc->sc_ah, bf->bf_daddr, qtype);
204 		INCR(i, re->m_fifolen);
205 	}
206 
207 	/* Ensure this worked out right */
208 	if (i != re->m_fifo_tail) {
209 		device_printf(sc->sc_dev, "%s: i (%d) != tail! (%d)\n",
210 		    __func__,
211 		    i,
212 		    re->m_fifo_tail);
213 	}
214 }
215 
216 /*
217  * Start receive.
218  *
219  * XXX TODO: this needs to reallocate the FIFO entries when a reset
220  * occurs, in case the FIFO is filled up and no new descriptors get
221  * thrown into the FIFO.
222  */
223 static int
224 ath_edma_startrecv(struct ath_softc *sc)
225 {
226 	struct ath_hal *ah = sc->sc_ah;
227 
228 	ATH_RX_LOCK(sc);
229 
230 	/* Enable RX FIFO */
231 	ath_hal_rxena(ah);
232 
233 	/*
234 	 * Entries should only be written out if the
235 	 * FIFO is empty.
236 	 *
237 	 * XXX This isn't correct. I should be looking
238 	 * at the value of AR_RXDP_SIZE (0x0070) to determine
239 	 * how many entries are in here.
240 	 *
241 	 * A warm reset will clear the registers but not the FIFO.
242 	 *
243 	 * And I believe this is actually the address of the last
244 	 * handled buffer rather than the current FIFO pointer.
245 	 * So if no frames have been (yet) seen, we'll reinit the
246 	 * FIFO.
247 	 *
248 	 * I'll chase that up at some point.
249 	 */
250 	if (ath_hal_getrxbuf(sc->sc_ah, HAL_RX_QUEUE_HP) == 0) {
251 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
252 		    "%s: Re-initing HP FIFO\n", __func__);
253 		ath_edma_reinit_fifo(sc, HAL_RX_QUEUE_HP);
254 	}
255 	if (ath_hal_getrxbuf(sc->sc_ah, HAL_RX_QUEUE_LP) == 0) {
256 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
257 		    "%s: Re-initing LP FIFO\n", __func__);
258 		ath_edma_reinit_fifo(sc, HAL_RX_QUEUE_LP);
259 	}
260 
261 	/* Add up to m_fifolen entries in each queue */
262 	/*
263 	 * These must occur after the above write so the FIFO buffers
264 	 * are pushed/tracked in the same order as the hardware will
265 	 * process them.
266 	 */
267 	ath_edma_rxfifo_alloc(sc, HAL_RX_QUEUE_HP,
268 	    sc->sc_rxedma[HAL_RX_QUEUE_HP].m_fifolen);
269 
270 	ath_edma_rxfifo_alloc(sc, HAL_RX_QUEUE_LP,
271 	    sc->sc_rxedma[HAL_RX_QUEUE_LP].m_fifolen);
272 
273 	ath_mode_init(sc);
274 	ath_hal_startpcurecv(ah);
275 
276 	ATH_RX_UNLOCK(sc);
277 
278 	return (0);
279 }
280 
281 static void
282 ath_edma_recv_flush(struct ath_softc *sc)
283 {
284 
285 	device_printf(sc->sc_dev, "%s: called\n", __func__);
286 
287 	ATH_PCU_LOCK(sc);
288 	sc->sc_rxproc_cnt++;
289 	ATH_PCU_UNLOCK(sc);
290 
291 	ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_HP, 0);
292 	ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_LP, 0);
293 
294 	ATH_PCU_LOCK(sc);
295 	sc->sc_rxproc_cnt--;
296 	ATH_PCU_UNLOCK(sc);
297 }
298 
299 /*
300  * Process frames from the current queue.
301  *
302  * TODO:
303  *
304  * + Add a "dosched" flag, so we don't reschedule any FIFO frames
305  *   to the hardware or re-kick the PCU after 'kickpcu' is set.
306  *
307  * + Perhaps split "check FIFO contents" and "handle frames", so
308  *   we can run the "check FIFO contents" in ath_intr(), but
309  *   "handle frames" in the RX tasklet.
310  */
311 static int
312 ath_edma_recv_proc_queue(struct ath_softc *sc, HAL_RX_QUEUE qtype,
313     int dosched)
314 {
315 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
316 	struct ath_rx_status *rs;
317 	struct ath_desc *ds;
318 	struct ath_buf *bf;
319 	struct mbuf *m;
320 	struct ath_hal *ah = sc->sc_ah;
321 	uint64_t tsf;
322 	int16_t nf;
323 	int ngood = 0, npkts = 0;
324 	ath_bufhead rxlist;
325 	struct ath_buf *next;
326 
327 	TAILQ_INIT(&rxlist);
328 
329 	tsf = ath_hal_gettsf64(ah);
330 	nf = ath_hal_getchannoise(ah, sc->sc_curchan);
331 	sc->sc_stats.ast_rx_noise = nf;
332 
333 	ATH_RX_LOCK(sc);
334 
335 	do {
336 		bf = re->m_fifo[re->m_fifo_head];
337 		/* This shouldn't occur! */
338 		if (bf == NULL) {
339 			device_printf(sc->sc_dev, "%s: Q%d: NULL bf?\n",
340 			    __func__,
341 			    qtype);
342 			break;
343 		}
344 		m = bf->bf_m;
345 		ds = bf->bf_desc;
346 
347 		/*
348 		 * Sync descriptor memory - this also syncs the buffer for us.
349 		 *
350 		 * EDMA descriptors are in cached memory.
351 		 */
352 		bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap,
353 		    BUS_DMASYNC_POSTREAD);
354 		rs = &bf->bf_status.ds_rxstat;
355 		bf->bf_rxstatus = ath_hal_rxprocdesc(ah, ds, bf->bf_daddr,
356 		    NULL, rs);
357 #ifdef	ATH_DEBUG
358 		if (sc->sc_debug & ATH_DEBUG_RECV_DESC)
359 			ath_printrxbuf(sc, bf, 0, bf->bf_rxstatus == HAL_OK);
360 #endif
361 		if (bf->bf_rxstatus == HAL_EINPROGRESS)
362 			break;
363 
364 		/*
365 		 * Completed descriptor.
366 		 *
367 		 * In the future we'll call ath_rx_pkt(), but it first
368 		 * has to be taught about EDMA RX queues (so it can
369 		 * access sc_rxpending correctly.)
370 		 */
371 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
372 		    "%s: Q%d: completed!\n", __func__, qtype);
373 		npkts++;
374 
375 		/*
376 		 * Remove the FIFO entry and place it on the completion
377 		 * queue.
378 		 */
379 		re->m_fifo[re->m_fifo_head] = NULL;
380 		TAILQ_INSERT_TAIL(&rxlist, bf, bf_list);
381 
382 		/* Bump the descriptor FIFO stats */
383 		INCR(re->m_fifo_head, re->m_fifolen);
384 		re->m_fifo_depth--;
385 		/* XXX check it doesn't fall below 0 */
386 	} while (re->m_fifo_depth > 0);
387 
388 	/* Append some more fresh frames to the FIFO */
389 	if (dosched)
390 		ath_edma_rxfifo_alloc(sc, qtype, re->m_fifolen);
391 
392 	ATH_RX_UNLOCK(sc);
393 
394 	/* Handle the completed descriptors */
395 	TAILQ_FOREACH_SAFE(bf, &rxlist, bf_list, next) {
396 		/*
397 		 * Skip the RX descriptor status - start at the data offset
398 		 */
399 		m_adj(bf->bf_m, sc->sc_rx_statuslen);
400 
401 		/* Handle the frame */
402 		/*
403 		 * Note: this may or may not free bf->bf_m and sync/unmap
404 		 * the frame.
405 		 */
406 		rs = &bf->bf_status.ds_rxstat;
407 		if (ath_rx_pkt(sc, rs, bf->bf_rxstatus, tsf, nf, qtype, bf))
408 			ngood++;
409 	}
410 
411 	/* Free in one set, inside the lock */
412 	ATH_RX_LOCK(sc);
413 	TAILQ_FOREACH_SAFE(bf, &rxlist, bf_list, next) {
414 		/* Free the buffer/mbuf */
415 		ath_edma_rxbuf_free(sc, bf);
416 	}
417 	ATH_RX_UNLOCK(sc);
418 
419 	/* rx signal state monitoring */
420 	ath_hal_rxmonitor(ah, &sc->sc_halstats, sc->sc_curchan);
421 	if (ngood)
422 		sc->sc_lastrx = tsf;
423 
424 	CTR2(ATH_KTR_INTR, "ath edma rx proc: npkts=%d, ngood=%d",
425 	    npkts, ngood);
426 
427 	/* Handle resched and kickpcu appropriately */
428 	ATH_PCU_LOCK(sc);
429 	if (dosched && sc->sc_kickpcu) {
430 		CTR0(ATH_KTR_ERR, "ath_edma_recv_proc_queue(): kickpcu");
431 		device_printf(sc->sc_dev,
432 		    "%s: handled npkts %d ngood %d\n",
433 		    __func__, npkts, ngood);
434 
435 		/*
436 		 * XXX TODO: what should occur here? Just re-poke and
437 		 * re-enable the RX FIFO?
438 		 */
439 		sc->sc_kickpcu = 0;
440 	}
441 	ATH_PCU_UNLOCK(sc);
442 
443 	return (ngood);
444 }
445 
446 static void
447 ath_edma_recv_tasklet(void *arg, int npending)
448 {
449 	struct ath_softc *sc = (struct ath_softc *) arg;
450 	struct ifnet *ifp = sc->sc_ifp;
451 #ifdef	IEEE80211_SUPPORT_SUPERG
452 	struct ieee80211com *ic = ifp->if_l2com;
453 #endif
454 
455 	DPRINTF(sc, ATH_DEBUG_EDMA_RX, "%s: called; npending=%d\n",
456 	    __func__,
457 	    npending);
458 
459 	ATH_PCU_LOCK(sc);
460 	if (sc->sc_inreset_cnt > 0) {
461 		device_printf(sc->sc_dev, "%s: sc_inreset_cnt > 0; skipping\n",
462 		    __func__);
463 		ATH_PCU_UNLOCK(sc);
464 		return;
465 	}
466 	sc->sc_rxproc_cnt++;
467 	ATH_PCU_UNLOCK(sc);
468 
469 	ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_HP, 1);
470 	ath_edma_recv_proc_queue(sc, HAL_RX_QUEUE_LP, 1);
471 
472 	/* XXX inside IF_LOCK ? */
473 	if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0) {
474 #ifdef	IEEE80211_SUPPORT_SUPERG
475 		ieee80211_ff_age_all(ic, 100);
476 #endif
477 		if (! IFQ_IS_EMPTY(&ifp->if_snd))
478 			ath_tx_kick(sc);
479 	}
480 	if (ath_dfs_tasklet_needed(sc, sc->sc_curchan))
481 		taskqueue_enqueue(sc->sc_tq, &sc->sc_dfstask);
482 
483 	ATH_PCU_LOCK(sc);
484 	sc->sc_rxproc_cnt--;
485 	ATH_PCU_UNLOCK(sc);
486 }
487 
488 /*
489  * Allocate an RX mbuf for the given ath_buf and initialise
490  * it for EDMA.
491  *
492  * + Allocate a 4KB mbuf;
493  * + Setup the DMA map for the given buffer;
494  * + Keep a pointer to the start of the mbuf - that's where the
495  *   descriptor lies;
496  * + Take a pointer to the start of the RX buffer, set the
497  *   mbuf "start" to be there;
498  * + Return that.
499  */
500 static int
501 ath_edma_rxbuf_init(struct ath_softc *sc, struct ath_buf *bf)
502 {
503 
504 	struct mbuf *m;
505 	int error;
506 	int len;
507 
508 	ATH_RX_LOCK_ASSERT(sc);
509 
510 	m = m_getm(NULL, sc->sc_edma_bufsize, M_DONTWAIT, MT_DATA);
511 	if (! m)
512 		return (ENOBUFS);		/* XXX ?*/
513 
514 	/* XXX warn/enforce alignment */
515 
516 	len = m->m_ext.ext_size;
517 #if 0
518 	device_printf(sc->sc_dev, "%s: called: m=%p, size=%d, mtod=%p\n",
519 	    __func__,
520 	    m,
521 	    len,
522 	    mtod(m, char *));
523 #endif
524 
525 	m->m_pkthdr.len = m->m_len = m->m_ext.ext_size;
526 
527 	/*
528 	 * Create DMA mapping.
529 	 */
530 	error = bus_dmamap_load_mbuf_sg(sc->sc_dmat,
531 	    bf->bf_dmamap, m, bf->bf_segs, &bf->bf_nseg, BUS_DMA_NOWAIT);
532 	if (error != 0) {
533 		device_printf(sc->sc_dev, "%s: failed; error=%d\n",
534 		    __func__,
535 		    error);
536 		m_freem(m);
537 		return (error);
538 	}
539 
540 	/*
541 	 * Populate ath_buf fields.
542 	 */
543 
544 	bf->bf_desc = mtod(m, struct ath_desc *);
545 	bf->bf_daddr = bf->bf_segs[0].ds_addr;
546 	bf->bf_lastds = bf->bf_desc;	/* XXX only really for TX? */
547 	bf->bf_m = m;
548 
549 	/* Zero the descriptor */
550 	memset(bf->bf_desc, '\0', sc->sc_rx_statuslen);
551 
552 #if 0
553 	/*
554 	 * Adjust mbuf header and length/size to compensate for the
555 	 * descriptor size.
556 	 */
557 	m_adj(m, sc->sc_rx_statuslen);
558 #endif
559 
560 	/* Finish! */
561 
562 	return (0);
563 }
564 
565 static struct ath_buf *
566 ath_edma_rxbuf_alloc(struct ath_softc *sc)
567 {
568 	struct ath_buf *bf;
569 	int error;
570 
571 	ATH_RX_LOCK_ASSERT(sc);
572 
573 	/* Allocate buffer */
574 	bf = TAILQ_FIRST(&sc->sc_rxbuf);
575 	/* XXX shouldn't happen upon startup? */
576 	if (bf == NULL)
577 		return (NULL);
578 
579 	/* Remove it from the free list */
580 	TAILQ_REMOVE(&sc->sc_rxbuf, bf, bf_list);
581 
582 	/* Assign RX mbuf to it */
583 	error = ath_edma_rxbuf_init(sc, bf);
584 	if (error != 0) {
585 		device_printf(sc->sc_dev,
586 		    "%s: bf=%p, rxbuf alloc failed! error=%d\n",
587 		    __func__,
588 		    bf,
589 		    error);
590 		TAILQ_INSERT_TAIL(&sc->sc_rxbuf, bf, bf_list);
591 		return (NULL);
592 	}
593 
594 	return (bf);
595 }
596 
597 static void
598 ath_edma_rxbuf_free(struct ath_softc *sc, struct ath_buf *bf)
599 {
600 
601 	ATH_RX_LOCK_ASSERT(sc);
602 
603 	/* We're doing this multiple times? */
604 	bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
605 
606 	if (bf->bf_m) {
607 		m_freem(bf->bf_m);
608 		bf->bf_m = NULL;
609 	}
610 
611 	/* XXX lock? */
612 	TAILQ_INSERT_TAIL(&sc->sc_rxbuf, bf, bf_list);
613 }
614 
615 /*
616  * Allocate up to 'n' entries and push them onto the hardware FIFO.
617  *
618  * Return how many entries were successfully pushed onto the
619  * FIFO.
620  */
621 static int
622 ath_edma_rxfifo_alloc(struct ath_softc *sc, HAL_RX_QUEUE qtype, int nbufs)
623 {
624 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
625 	struct ath_buf *bf;
626 	int i;
627 
628 	ATH_RX_LOCK_ASSERT(sc);
629 
630 	/*
631 	 * Allocate buffers until the FIFO is full or nbufs is reached.
632 	 */
633 	for (i = 0; i < nbufs && re->m_fifo_depth < re->m_fifolen; i++) {
634 		/* Ensure the FIFO is already blank, complain loudly! */
635 		if (re->m_fifo[re->m_fifo_tail] != NULL) {
636 			device_printf(sc->sc_dev,
637 			    "%s: Q%d: fifo[%d] != NULL (%p)\n",
638 			    __func__,
639 			    qtype,
640 			    re->m_fifo_tail,
641 			    re->m_fifo[re->m_fifo_tail]);
642 
643 			/* Free the slot */
644 			ath_edma_rxbuf_free(sc, re->m_fifo[re->m_fifo_tail]);
645 			re->m_fifo_depth--;
646 			/* XXX check it's not < 0 */
647 			re->m_fifo[re->m_fifo_tail] = NULL;
648 		}
649 
650 		bf = ath_edma_rxbuf_alloc(sc);
651 		/* XXX should ensure the FIFO is not NULL? */
652 		if (bf == NULL) {
653 			device_printf(sc->sc_dev, "%s: Q%d: alloc failed?\n",
654 			    __func__,
655 			    qtype);
656 			break;
657 		}
658 
659 		re->m_fifo[re->m_fifo_tail] = bf;
660 
661 		/*
662 		 * Flush the descriptor contents before it's handed to the
663 		 * hardware.
664 		 */
665 		bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap,
666 		    BUS_DMASYNC_PREREAD);
667 
668 		/* Write to the RX FIFO */
669 		DPRINTF(sc, ATH_DEBUG_EDMA_RX, "%s: Q%d: putrxbuf=%p\n",
670 		    __func__,
671 		    qtype,
672 		    bf->bf_desc);
673 		ath_hal_putrxbuf(sc->sc_ah, bf->bf_daddr, qtype);
674 
675 		re->m_fifo_depth++;
676 		INCR(re->m_fifo_tail, re->m_fifolen);
677 	}
678 
679 	/*
680 	 * Return how many were allocated.
681 	 */
682 	DPRINTF(sc, ATH_DEBUG_EDMA_RX, "%s: Q%d: nbufs=%d, nalloced=%d\n",
683 	    __func__,
684 	    qtype,
685 	    nbufs,
686 	    i);
687 	return (i);
688 }
689 
690 static int
691 ath_edma_rxfifo_flush(struct ath_softc *sc, HAL_RX_QUEUE qtype)
692 {
693 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
694 	int i;
695 
696 	ATH_RX_LOCK_ASSERT(sc);
697 
698 	for (i = 0; i < re->m_fifolen; i++) {
699 		if (re->m_fifo[i] != NULL) {
700 #ifdef	ATH_DEBUG
701 			struct ath_buf *bf = re->m_fifo[i];
702 
703 			if (sc->sc_debug & ATH_DEBUG_RECV_DESC)
704 				ath_printrxbuf(sc, bf, 0, HAL_OK);
705 #endif
706 			ath_edma_rxbuf_free(sc, re->m_fifo[i]);
707 			re->m_fifo[i] = NULL;
708 			re->m_fifo_depth--;
709 		}
710 	}
711 
712 	if (re->m_rxpending != NULL) {
713 		m_freem(re->m_rxpending);
714 		re->m_rxpending = NULL;
715 	}
716 	re->m_fifo_head = re->m_fifo_tail = re->m_fifo_depth = 0;
717 
718 	return (0);
719 }
720 
721 /*
722  * Setup the initial RX FIFO structure.
723  */
724 static int
725 ath_edma_setup_rxfifo(struct ath_softc *sc, HAL_RX_QUEUE qtype)
726 {
727 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
728 
729 	ATH_RX_LOCK_ASSERT(sc);
730 
731 	if (! ath_hal_getrxfifodepth(sc->sc_ah, qtype, &re->m_fifolen)) {
732 		device_printf(sc->sc_dev, "%s: qtype=%d, failed\n",
733 		    __func__,
734 		    qtype);
735 		return (-EINVAL);
736 	}
737 	device_printf(sc->sc_dev, "%s: type=%d, FIFO depth = %d entries\n",
738 	    __func__,
739 	    qtype,
740 	    re->m_fifolen);
741 
742 	/* Allocate ath_buf FIFO array, pre-zero'ed */
743 	re->m_fifo = malloc(sizeof(struct ath_buf *) * re->m_fifolen,
744 	    M_ATHDEV,
745 	    M_NOWAIT | M_ZERO);
746 	if (re->m_fifo == NULL) {
747 		device_printf(sc->sc_dev, "%s: malloc failed\n",
748 		    __func__);
749 		return (-ENOMEM);
750 	}
751 
752 	/*
753 	 * Set initial "empty" state.
754 	 */
755 	re->m_rxpending = NULL;
756 	re->m_fifo_head = re->m_fifo_tail = re->m_fifo_depth = 0;
757 
758 	return (0);
759 }
760 
761 static int
762 ath_edma_rxfifo_free(struct ath_softc *sc, HAL_RX_QUEUE qtype)
763 {
764 	struct ath_rx_edma *re = &sc->sc_rxedma[qtype];
765 
766 	device_printf(sc->sc_dev, "%s: called; qtype=%d\n",
767 	    __func__,
768 	    qtype);
769 
770 	free(re->m_fifo, M_ATHDEV);
771 
772 	return (0);
773 }
774 
775 static int
776 ath_edma_dma_rxsetup(struct ath_softc *sc)
777 {
778 	int error;
779 
780 	/*
781 	 * Create RX DMA tag and buffers.
782 	 */
783 	error = ath_descdma_setup_rx_edma(sc, &sc->sc_rxdma, &sc->sc_rxbuf,
784 	    "rx", ath_rxbuf, sc->sc_rx_statuslen);
785 	if (error != 0)
786 		return error;
787 
788 	ATH_RX_LOCK(sc);
789 	(void) ath_edma_setup_rxfifo(sc, HAL_RX_QUEUE_HP);
790 	(void) ath_edma_setup_rxfifo(sc, HAL_RX_QUEUE_LP);
791 	ATH_RX_UNLOCK(sc);
792 
793 	return (0);
794 }
795 
796 static int
797 ath_edma_dma_rxteardown(struct ath_softc *sc)
798 {
799 
800 	ATH_RX_LOCK(sc);
801 	ath_edma_rxfifo_flush(sc, HAL_RX_QUEUE_HP);
802 	ath_edma_rxfifo_free(sc, HAL_RX_QUEUE_HP);
803 
804 	ath_edma_rxfifo_flush(sc, HAL_RX_QUEUE_LP);
805 	ath_edma_rxfifo_free(sc, HAL_RX_QUEUE_LP);
806 	ATH_RX_UNLOCK(sc);
807 
808 	/* Free RX ath_buf */
809 	/* Free RX DMA tag */
810 	if (sc->sc_rxdma.dd_desc_len != 0)
811 		ath_descdma_cleanup(sc, &sc->sc_rxdma, &sc->sc_rxbuf);
812 
813 	return (0);
814 }
815 
816 void
817 ath_recv_setup_edma(struct ath_softc *sc)
818 {
819 
820 	/* Set buffer size to 4k */
821 	sc->sc_edma_bufsize = 4096;
822 
823 	/* Fetch EDMA field and buffer sizes */
824 	(void) ath_hal_getrxstatuslen(sc->sc_ah, &sc->sc_rx_statuslen);
825 
826 	/* Configure the hardware with the RX buffer size */
827 	(void) ath_hal_setrxbufsize(sc->sc_ah, sc->sc_edma_bufsize -
828 	    sc->sc_rx_statuslen);
829 
830 	device_printf(sc->sc_dev, "RX status length: %d\n",
831 	    sc->sc_rx_statuslen);
832 	device_printf(sc->sc_dev, "RX buffer size: %d\n",
833 	    sc->sc_edma_bufsize);
834 
835 	sc->sc_rx.recv_stop = ath_edma_stoprecv;
836 	sc->sc_rx.recv_start = ath_edma_startrecv;
837 	sc->sc_rx.recv_flush = ath_edma_recv_flush;
838 	sc->sc_rx.recv_tasklet = ath_edma_recv_tasklet;
839 	sc->sc_rx.recv_rxbuf_init = ath_edma_rxbuf_init;
840 
841 	sc->sc_rx.recv_setup = ath_edma_dma_rxsetup;
842 	sc->sc_rx.recv_teardown = ath_edma_dma_rxteardown;
843 }
844