xref: /freebsd/sys/dev/dwc/dwc1000_dma.c (revision 2e620256bd76c449c835c604e404483437743011)
1 /*-
2  * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
3  *
4  * This software was developed by SRI International and the University of
5  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
6  * ("CTSRD"), as part of the DARPA CRASH research programme.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/mbuf.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/rman.h>
41 #include <sys/socket.h>
42 
43 #include <net/bpf.h>
44 #include <net/if.h>
45 #include <net/ethernet.h>
46 #include <net/if_dl.h>
47 #include <net/if_media.h>
48 #include <net/if_types.h>
49 #include <net/if_var.h>
50 
51 #include <machine/bus.h>
52 
53 #include <dev/extres/clk/clk.h>
54 #include <dev/extres/hwreset/hwreset.h>
55 
56 #include <dev/ofw/ofw_bus.h>
57 #include <dev/ofw/ofw_bus_subr.h>
58 
59 #include <dev/dwc/if_dwcvar.h>
60 #include <dev/dwc/dwc1000_reg.h>
61 #include <dev/dwc/dwc1000_dma.h>
62 
63 #define	WATCHDOG_TIMEOUT_SECS	5
64 #define	DMA_RESET_TIMEOUT	100
65 
66 /* TX descriptors - TDESC0 is almost unified */
67 #define	TDESC0_OWN		(1U << 31)
68 #define	TDESC0_IHE		(1U << 16)	/* IP Header Error */
69 #define	TDESC0_ES		(1U << 15)	/* Error Summary */
70 #define	TDESC0_JT		(1U << 14)	/* Jabber Timeout */
71 #define	TDESC0_FF		(1U << 13)	/* Frame Flushed */
72 #define	TDESC0_PCE		(1U << 12)	/* Payload Checksum Error */
73 #define	TDESC0_LOC		(1U << 11)	/* Loss of Carrier */
74 #define	TDESC0_NC		(1U << 10)	/* No Carrier */
75 #define	TDESC0_LC		(1U <<  9)	/* Late Collision */
76 #define	TDESC0_EC		(1U <<  8)	/* Excessive Collision */
77 #define	TDESC0_VF		(1U <<  7)	/* VLAN Frame */
78 #define	TDESC0_CC_MASK		0xf
79 #define	TDESC0_CC_SHIFT		3		/* Collision Count */
80 #define	TDESC0_ED		(1U <<  2)	/* Excessive Deferral */
81 #define	TDESC0_UF		(1U <<  1)	/* Underflow Error */
82 #define	TDESC0_DB		(1U <<  0)	/* Deferred Bit */
83 /* TX descriptors - TDESC0 extended format only */
84 #define	ETDESC0_IC		(1U << 30)	/* Interrupt on Completion */
85 #define	ETDESC0_LS		(1U << 29)	/* Last Segment */
86 #define	ETDESC0_FS		(1U << 28)	/* First Segment */
87 #define	ETDESC0_DC		(1U << 27)	/* Disable CRC */
88 #define	ETDESC0_DP		(1U << 26)	/* Disable Padding */
89 #define	ETDESC0_CIC_NONE	(0U << 22)	/* Checksum Insertion Control */
90 #define	ETDESC0_CIC_HDR		(1U << 22)
91 #define	ETDESC0_CIC_SEG 	(2U << 22)
92 #define	ETDESC0_CIC_FULL	(3U << 22)
93 #define	ETDESC0_TER		(1U << 21)	/* Transmit End of Ring */
94 #define	ETDESC0_TCH		(1U << 20)	/* Second Address Chained */
95 
96 /* TX descriptors - TDESC1 normal format */
97 #define	NTDESC1_IC		(1U << 31)	/* Interrupt on Completion */
98 #define	NTDESC1_LS		(1U << 30)	/* Last Segment */
99 #define	NTDESC1_FS		(1U << 29)	/* First Segment */
100 #define	NTDESC1_CIC_NONE	(0U << 27)	/* Checksum Insertion Control */
101 #define	NTDESC1_CIC_HDR		(1U << 27)
102 #define	NTDESC1_CIC_SEG 	(2U << 27)
103 #define	NTDESC1_CIC_FULL	(3U << 27)
104 #define	NTDESC1_DC		(1U << 26)	/* Disable CRC */
105 #define	NTDESC1_TER		(1U << 25)	/* Transmit End of Ring */
106 #define	NTDESC1_TCH		(1U << 24)	/* Second Address Chained */
107 /* TX descriptors - TDESC1 extended format */
108 #define	ETDESC1_DP		(1U << 23)	/* Disable Padding */
109 #define	ETDESC1_TBS2_MASK	0x7ff
110 #define	ETDESC1_TBS2_SHIFT	11		/* Receive Buffer 2 Size */
111 #define	ETDESC1_TBS1_MASK	0x7ff
112 #define	ETDESC1_TBS1_SHIFT	0		/* Receive Buffer 1 Size */
113 
114 /* RX descriptor - RDESC0 is unified */
115 #define	RDESC0_OWN		(1U << 31)
116 #define	RDESC0_AFM		(1U << 30)	/* Dest. Address Filter Fail */
117 #define	RDESC0_FL_MASK		0x3fff
118 #define	RDESC0_FL_SHIFT		16		/* Frame Length */
119 #define	RDESC0_ES		(1U << 15)	/* Error Summary */
120 #define	RDESC0_DE		(1U << 14)	/* Descriptor Error */
121 #define	RDESC0_SAF		(1U << 13)	/* Source Address Filter Fail */
122 #define	RDESC0_LE		(1U << 12)	/* Length Error */
123 #define	RDESC0_OE		(1U << 11)	/* Overflow Error */
124 #define	RDESC0_VLAN		(1U << 10)	/* VLAN Tag */
125 #define	RDESC0_FS		(1U <<  9)	/* First Descriptor */
126 #define	RDESC0_LS		(1U <<  8)	/* Last Descriptor */
127 #define	RDESC0_ICE		(1U <<  7)	/* IPC Checksum Error */
128 #define	RDESC0_LC		(1U <<  6)	/* Late Collision */
129 #define	RDESC0_FT		(1U <<  5)	/* Frame Type */
130 #define	RDESC0_RWT		(1U <<  4)	/* Receive Watchdog Timeout */
131 #define	RDESC0_RE		(1U <<  3)	/* Receive Error */
132 #define	RDESC0_DBE		(1U <<  2)	/* Dribble Bit Error */
133 #define	RDESC0_CE		(1U <<  1)	/* CRC Error */
134 #define	RDESC0_PCE		(1U <<  0)	/* Payload Checksum Error */
135 #define	RDESC0_RXMA		(1U <<  0)	/* Rx MAC Address */
136 
137 /* RX descriptors - RDESC1 normal format */
138 #define	NRDESC1_DIC		(1U << 31)	/* Disable Intr on Completion */
139 #define	NRDESC1_RER		(1U << 25)	/* Receive End of Ring */
140 #define	NRDESC1_RCH		(1U << 24)	/* Second Address Chained */
141 #define	NRDESC1_RBS2_MASK	0x7ff
142 #define	NRDESC1_RBS2_SHIFT	11		/* Receive Buffer 2 Size */
143 #define	NRDESC1_RBS1_MASK	0x7ff
144 #define	NRDESC1_RBS1_SHIFT	0		/* Receive Buffer 1 Size */
145 
146 /* RX descriptors - RDESC1 enhanced format */
147 #define	ERDESC1_DIC		(1U << 31)	/* Disable Intr on Completion */
148 #define	ERDESC1_RBS2_MASK	0x7ffff
149 #define	ERDESC1_RBS2_SHIFT	16		/* Receive Buffer 2 Size */
150 #define	ERDESC1_RER		(1U << 15)	/* Receive End of Ring */
151 #define	ERDESC1_RCH		(1U << 14)	/* Second Address Chained */
152 #define	ERDESC1_RBS1_MASK	0x7ffff
153 #define	ERDESC1_RBS1_SHIFT	0		/* Receive Buffer 1 Size */
154 
155 /*
156  * The hardware imposes alignment restrictions on various objects involved in
157  * DMA transfers.  These values are expressed in bytes (not bits).
158  */
159 #define	DWC_DESC_RING_ALIGN	2048
160 
161 static inline uint32_t
162 next_txidx(struct dwc_softc *sc, uint32_t curidx)
163 {
164 
165 	return ((curidx + 1) % TX_DESC_COUNT);
166 }
167 
168 static inline uint32_t
169 next_rxidx(struct dwc_softc *sc, uint32_t curidx)
170 {
171 
172 	return ((curidx + 1) % RX_DESC_COUNT);
173 }
174 
175 static void
176 dwc_get1paddr(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
177 {
178 
179 	if (error != 0)
180 		return;
181 	*(bus_addr_t *)arg = segs[0].ds_addr;
182 }
183 
184 inline static void
185 txdesc_clear(struct dwc_softc *sc, int idx)
186 {
187 
188 	sc->tx_desccount--;
189 	sc->txdesc_ring[idx].addr1 = (uint32_t)(0);
190 	sc->txdesc_ring[idx].desc0 = 0;
191 	sc->txdesc_ring[idx].desc1 = 0;
192 }
193 
194 inline static void
195 txdesc_setup(struct dwc_softc *sc, int idx, bus_addr_t paddr,
196   uint32_t len, uint32_t flags, bool first, bool last)
197 {
198 	uint32_t desc0, desc1;
199 
200 	if (!sc->dma_ext_desc) {
201 		desc0 = 0;
202 		desc1 = NTDESC1_TCH | len | flags;
203 		if (first)
204 			desc1 |=  NTDESC1_FS;
205 		if (last)
206 			desc1 |= NTDESC1_LS | NTDESC1_IC;
207 	} else {
208 		desc0 = ETDESC0_TCH | flags;
209 		if (first)
210 			desc0 |= ETDESC0_FS;
211 		if (last)
212 			desc0 |= ETDESC0_LS | ETDESC0_IC;
213 		desc1 = len;
214 	}
215 	++sc->tx_desccount;
216 	sc->txdesc_ring[idx].addr1 = (uint32_t)(paddr);
217 	sc->txdesc_ring[idx].desc0 = desc0;
218 	sc->txdesc_ring[idx].desc1 = desc1;
219 	wmb();
220 	sc->txdesc_ring[idx].desc0 |= TDESC0_OWN;
221 }
222 
223 inline static uint32_t
224 rxdesc_setup(struct dwc_softc *sc, int idx, bus_addr_t paddr)
225 {
226 	uint32_t nidx;
227 
228 	sc->rxdesc_ring[idx].addr1 = (uint32_t)paddr;
229 	nidx = next_rxidx(sc, idx);
230 	sc->rxdesc_ring[idx].addr2 = sc->rxdesc_ring_paddr +
231 	    (nidx * sizeof(struct dwc_hwdesc));
232 	if (!sc->dma_ext_desc)
233 		sc->rxdesc_ring[idx].desc1 = NRDESC1_RCH |
234 		    MIN(MCLBYTES, NRDESC1_RBS1_MASK);
235 	else
236 		sc->rxdesc_ring[idx].desc1 = ERDESC1_RCH |
237 		    MIN(MCLBYTES, ERDESC1_RBS1_MASK);
238 
239 	wmb();
240 	sc->rxdesc_ring[idx].desc0 = RDESC0_OWN;
241 	return (nidx);
242 }
243 
244 int
245 dma1000_setup_txbuf(struct dwc_softc *sc, int idx, struct mbuf **mp)
246 {
247 	struct bus_dma_segment segs[TX_MAP_MAX_SEGS];
248 	int error, nsegs;
249 	struct mbuf * m;
250 	uint32_t flags = 0;
251 	int i;
252 	int last;
253 
254 	error = bus_dmamap_load_mbuf_sg(sc->txbuf_tag, sc->txbuf_map[idx].map,
255 	    *mp, segs, &nsegs, 0);
256 	if (error == EFBIG) {
257 		/*
258 		 * The map may be partially mapped from the first call.
259 		 * Make sure to reset it.
260 		 */
261 		bus_dmamap_unload(sc->txbuf_tag, sc->txbuf_map[idx].map);
262 		if ((m = m_defrag(*mp, M_NOWAIT)) == NULL)
263 			return (ENOMEM);
264 		*mp = m;
265 		error = bus_dmamap_load_mbuf_sg(sc->txbuf_tag, sc->txbuf_map[idx].map,
266 		    *mp, segs, &nsegs, 0);
267 	}
268 	if (error != 0)
269 		return (ENOMEM);
270 
271 	if (sc->tx_desccount + nsegs > TX_DESC_COUNT) {
272 		bus_dmamap_unload(sc->txbuf_tag, sc->txbuf_map[idx].map);
273 		return (ENOMEM);
274 	}
275 
276 	m = *mp;
277 
278 	if ((m->m_pkthdr.csum_flags & CSUM_IP) != 0) {
279 		if ((m->m_pkthdr.csum_flags & (CSUM_TCP|CSUM_UDP)) != 0) {
280 			if (!sc->dma_ext_desc)
281 				flags = NTDESC1_CIC_FULL;
282 			else
283 				flags = ETDESC0_CIC_FULL;
284 		} else {
285 			if (!sc->dma_ext_desc)
286 				flags = NTDESC1_CIC_HDR;
287 			else
288 				flags = ETDESC0_CIC_HDR;
289 		}
290 	}
291 
292 	bus_dmamap_sync(sc->txbuf_tag, sc->txbuf_map[idx].map,
293 	    BUS_DMASYNC_PREWRITE);
294 
295 	sc->txbuf_map[idx].mbuf = m;
296 
297 	for (i = 0; i < nsegs; i++) {
298 		txdesc_setup(sc, sc->tx_desc_head,
299 		    segs[i].ds_addr, segs[i].ds_len,
300 		    (i == 0) ? flags : 0, /* only first desc needs flags */
301 		    (i == 0),
302 		    (i == nsegs - 1));
303 		last = sc->tx_desc_head;
304 		sc->tx_desc_head = next_txidx(sc, sc->tx_desc_head);
305 	}
306 
307 	sc->txbuf_map[idx].last_desc_idx = last;
308 
309 	return (0);
310 }
311 
312 static int
313 dma1000_setup_rxbuf(struct dwc_softc *sc, int idx, struct mbuf *m)
314 {
315 	struct bus_dma_segment seg;
316 	int error, nsegs;
317 
318 	m_adj(m, ETHER_ALIGN);
319 
320 	error = bus_dmamap_load_mbuf_sg(sc->rxbuf_tag, sc->rxbuf_map[idx].map,
321 	    m, &seg, &nsegs, 0);
322 	if (error != 0)
323 		return (error);
324 
325 	KASSERT(nsegs == 1, ("%s: %d segments returned!", __func__, nsegs));
326 
327 	bus_dmamap_sync(sc->rxbuf_tag, sc->rxbuf_map[idx].map,
328 	    BUS_DMASYNC_PREREAD);
329 
330 	sc->rxbuf_map[idx].mbuf = m;
331 	rxdesc_setup(sc, idx, seg.ds_addr);
332 
333 	return (0);
334 }
335 
336 static struct mbuf *
337 dwc_alloc_mbufcl(struct dwc_softc *sc)
338 {
339 	struct mbuf *m;
340 
341 	m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
342 	if (m != NULL)
343 		m->m_pkthdr.len = m->m_len = m->m_ext.ext_size;
344 
345 	return (m);
346 }
347 
348 static struct mbuf *
349 dwc_rxfinish_one(struct dwc_softc *sc, struct dwc_hwdesc *desc,
350     struct dwc_bufmap *map)
351 {
352 	if_t ifp;
353 	struct mbuf *m, *m0;
354 	int len;
355 	uint32_t rdesc0;
356 
357 	m = map->mbuf;
358 	ifp = sc->ifp;
359 	rdesc0 = desc ->desc0;
360 
361 	if ((rdesc0 & (RDESC0_FS | RDESC0_LS)) !=
362 		    (RDESC0_FS | RDESC0_LS)) {
363 		/*
364 		 * Something very wrong happens. The whole packet should be
365 		 * recevied in one descriptr. Report problem.
366 		 */
367 		device_printf(sc->dev,
368 		    "%s: RX descriptor without FIRST and LAST bit set: 0x%08X",
369 		    __func__, rdesc0);
370 		return (NULL);
371 	}
372 
373 	len = (rdesc0 >> RDESC0_FL_SHIFT) & RDESC0_FL_MASK;
374 	if (len < 64) {
375 		/*
376 		 * Lenght is invalid, recycle old mbuf
377 		 * Probably impossible case
378 		 */
379 		return (NULL);
380 	}
381 
382 	/* Allocate new buffer */
383 	m0 = dwc_alloc_mbufcl(sc);
384 	if (m0 == NULL) {
385 		/* no new mbuf available, recycle old */
386 		if_inc_counter(sc->ifp, IFCOUNTER_IQDROPS, 1);
387 		return (NULL);
388 	}
389 	/* Do dmasync for newly received packet */
390 	bus_dmamap_sync(sc->rxbuf_tag, map->map, BUS_DMASYNC_POSTREAD);
391 	bus_dmamap_unload(sc->rxbuf_tag, map->map);
392 
393 	/* Received packet is valid, process it */
394 	m->m_pkthdr.rcvif = ifp;
395 	m->m_pkthdr.len = len;
396 	m->m_len = len;
397 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
398 
399 	if ((if_getcapenable(ifp) & IFCAP_RXCSUM) != 0 &&
400 	  (rdesc0 & RDESC0_FT) != 0) {
401 		m->m_pkthdr.csum_flags = CSUM_IP_CHECKED;
402 		if ((rdesc0 & RDESC0_ICE) == 0)
403 			m->m_pkthdr.csum_flags |= CSUM_IP_VALID;
404 		if ((rdesc0 & RDESC0_PCE) == 0) {
405 			m->m_pkthdr.csum_flags |=
406 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
407 			m->m_pkthdr.csum_data = 0xffff;
408 		}
409 	}
410 
411 	/* Remove trailing FCS */
412 	m_adj(m, -ETHER_CRC_LEN);
413 
414 	DWC_UNLOCK(sc);
415 	if_input(ifp, m);
416 	DWC_LOCK(sc);
417 	return (m0);
418 }
419 
420 void
421 dma1000_txfinish_locked(struct dwc_softc *sc)
422 {
423 	struct dwc_bufmap *bmap;
424 	struct dwc_hwdesc *desc;
425 	if_t ifp;
426 	int idx, last_idx;
427 	bool map_finished;
428 
429 	DWC_ASSERT_LOCKED(sc);
430 
431 	ifp = sc->ifp;
432 	/* check if all descriptors of the map are done */
433 	while (sc->tx_map_tail != sc->tx_map_head) {
434 		map_finished = true;
435 		bmap = &sc->txbuf_map[sc->tx_map_tail];
436 		idx = sc->tx_desc_tail;
437 		last_idx = next_txidx(sc, bmap->last_desc_idx);
438 		while (idx != last_idx) {
439 			desc = &sc->txdesc_ring[idx];
440 			if ((desc->desc0 & TDESC0_OWN) != 0) {
441 				map_finished = false;
442 				break;
443 			}
444 			idx = next_txidx(sc, idx);
445 		}
446 
447 		if (!map_finished)
448 			break;
449 		bus_dmamap_sync(sc->txbuf_tag, bmap->map,
450 		    BUS_DMASYNC_POSTWRITE);
451 		bus_dmamap_unload(sc->txbuf_tag, bmap->map);
452 		m_freem(bmap->mbuf);
453 		bmap->mbuf = NULL;
454 		sc->tx_mapcount--;
455 		while (sc->tx_desc_tail != last_idx) {
456 			txdesc_clear(sc, sc->tx_desc_tail);
457 			sc->tx_desc_tail = next_txidx(sc, sc->tx_desc_tail);
458 		}
459 		sc->tx_map_tail = next_txidx(sc, sc->tx_map_tail);
460 		if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);
461 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
462 	}
463 
464 	/* If there are no buffers outstanding, muzzle the watchdog. */
465 	if (sc->tx_desc_tail == sc->tx_desc_head) {
466 		sc->tx_watchdog_count = 0;
467 	}
468 }
469 
470 void
471 dma1000_txstart(struct dwc_softc *sc)
472 {
473 	int enqueued;
474 	struct mbuf *m;
475 
476 	enqueued = 0;
477 
478 	for (;;) {
479 		if (sc->tx_desccount > (TX_DESC_COUNT - TX_MAP_MAX_SEGS  + 1)) {
480 			if_setdrvflagbits(sc->ifp, IFF_DRV_OACTIVE, 0);
481 			break;
482 		}
483 
484 		if (sc->tx_mapcount == (TX_MAP_COUNT - 1)) {
485 			if_setdrvflagbits(sc->ifp, IFF_DRV_OACTIVE, 0);
486 			break;
487 		}
488 
489 		m = if_dequeue(sc->ifp);
490 		if (m == NULL)
491 			break;
492 		if (dma1000_setup_txbuf(sc, sc->tx_map_head, &m) != 0) {
493 			if_sendq_prepend(sc->ifp, m);
494 			if_setdrvflagbits(sc->ifp, IFF_DRV_OACTIVE, 0);
495 			break;
496 		}
497 		bpf_mtap_if(sc->ifp, m);
498 		sc->tx_map_head = next_txidx(sc, sc->tx_map_head);
499 		sc->tx_mapcount++;
500 		++enqueued;
501 	}
502 
503 	if (enqueued != 0) {
504 		WRITE4(sc, TRANSMIT_POLL_DEMAND, 0x1);
505 		sc->tx_watchdog_count = WATCHDOG_TIMEOUT_SECS;
506 	}
507 }
508 
509 void
510 dma1000_rxfinish_locked(struct dwc_softc *sc)
511 {
512 	struct mbuf *m;
513 	int error, idx;
514 	struct dwc_hwdesc *desc;
515 
516 	DWC_ASSERT_LOCKED(sc);
517 	for (;;) {
518 		idx = sc->rx_idx;
519 		desc = sc->rxdesc_ring + idx;
520 		if ((desc->desc0 & RDESC0_OWN) != 0)
521 			break;
522 
523 		m = dwc_rxfinish_one(sc, desc, sc->rxbuf_map + idx);
524 		if (m == NULL) {
525 			wmb();
526 			desc->desc0 = RDESC0_OWN;
527 		} else {
528 			/* We cannot create hole in RX ring */
529 			error = dma1000_setup_rxbuf(sc, idx, m);
530 			if (error != 0)
531 				panic("dma1000_setup_rxbuf failed:  error %d\n",
532 				    error);
533 
534 		}
535 		sc->rx_idx = next_rxidx(sc, sc->rx_idx);
536 	}
537 }
538 
539 /*
540  * Start the DMA controller
541  */
542 void
543 dma1000_start(struct dwc_softc *sc)
544 {
545 	uint32_t reg;
546 
547 	DWC_ASSERT_LOCKED(sc);
548 
549 	/* Initializa DMA and enable transmitters */
550 	reg = READ4(sc, OPERATION_MODE);
551 	reg |= (MODE_TSF | MODE_OSF | MODE_FUF);
552 	reg &= ~(MODE_RSF);
553 	reg |= (MODE_RTC_LEV32 << MODE_RTC_SHIFT);
554 	WRITE4(sc, OPERATION_MODE, reg);
555 
556 	WRITE4(sc, INTERRUPT_ENABLE, INT_EN_DEFAULT);
557 
558 	/* Start DMA */
559 	reg = READ4(sc, OPERATION_MODE);
560 	reg |= (MODE_ST | MODE_SR);
561 	WRITE4(sc, OPERATION_MODE, reg);
562 }
563 
564 /*
565  * Stop the DMA controller
566  */
567 void
568 dma1000_stop(struct dwc_softc *sc)
569 {
570 	uint32_t reg;
571 
572 	DWC_ASSERT_LOCKED(sc);
573 
574 	/* Stop DMA TX */
575 	reg = READ4(sc, OPERATION_MODE);
576 	reg &= ~(MODE_ST);
577 	WRITE4(sc, OPERATION_MODE, reg);
578 
579 	/* Flush TX */
580 	reg = READ4(sc, OPERATION_MODE);
581 	reg |= (MODE_FTF);
582 	WRITE4(sc, OPERATION_MODE, reg);
583 
584 	/* Stop DMA RX */
585 	reg = READ4(sc, OPERATION_MODE);
586 	reg &= ~(MODE_SR);
587 	WRITE4(sc, OPERATION_MODE, reg);
588 }
589 
590 int
591 dma1000_reset(struct dwc_softc *sc)
592 {
593 	uint32_t reg;
594 	int i;
595 
596 	reg = READ4(sc, BUS_MODE);
597 	reg |= (BUS_MODE_SWR);
598 	WRITE4(sc, BUS_MODE, reg);
599 
600 	for (i = 0; i < DMA_RESET_TIMEOUT; i++) {
601 		if ((READ4(sc, BUS_MODE) & BUS_MODE_SWR) == 0)
602 			break;
603 		DELAY(10);
604 	}
605 	if (i >= DMA_RESET_TIMEOUT) {
606 		return (ENXIO);
607 	}
608 
609 	return (0);
610 }
611 
612 /*
613  * Create the bus_dma resources
614  */
615 int
616 dma1000_init(struct dwc_softc *sc)
617 {
618 	struct mbuf *m;
619 	uint32_t reg;
620 	int error;
621 	int nidx;
622 	int idx;
623 
624 	reg = BUS_MODE_USP;
625 	if (!sc->nopblx8)
626 		reg |= BUS_MODE_EIGHTXPBL;
627 	reg |= (sc->txpbl << BUS_MODE_PBL_SHIFT);
628 	reg |= (sc->rxpbl << BUS_MODE_RPBL_SHIFT);
629 	if (sc->fixed_burst)
630 		reg |= BUS_MODE_FIXEDBURST;
631 	if (sc->mixed_burst)
632 		reg |= BUS_MODE_MIXEDBURST;
633 	if (sc->aal)
634 		reg |= BUS_MODE_AAL;
635 
636 	WRITE4(sc, BUS_MODE, reg);
637 
638 	reg = READ4(sc, HW_FEATURE);
639 	if (reg & HW_FEATURE_EXT_DESCRIPTOR)
640 		sc->dma_ext_desc = true;
641 
642 	/*
643 	 * DMA must be stop while changing descriptor list addresses.
644 	 */
645 	reg = READ4(sc, OPERATION_MODE);
646 	reg &= ~(MODE_ST | MODE_SR);
647 	WRITE4(sc, OPERATION_MODE, reg);
648 
649 	/*
650 	 * Set up TX descriptor ring, descriptors, and dma maps.
651 	 */
652 	error = bus_dma_tag_create(
653 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
654 	    DWC_DESC_RING_ALIGN, 0,	/* alignment, boundary */
655 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
656 	    BUS_SPACE_MAXADDR,		/* highaddr */
657 	    NULL, NULL,			/* filter, filterarg */
658 	    TX_DESC_SIZE, 1, 		/* maxsize, nsegments */
659 	    TX_DESC_SIZE,		/* maxsegsize */
660 	    0,				/* flags */
661 	    NULL, NULL,			/* lockfunc, lockarg */
662 	    &sc->txdesc_tag);
663 	if (error != 0) {
664 		device_printf(sc->dev,
665 		    "could not create TX ring DMA tag.\n");
666 		goto out;
667 	}
668 
669 	error = bus_dmamem_alloc(sc->txdesc_tag, (void**)&sc->txdesc_ring,
670 	    BUS_DMA_COHERENT | BUS_DMA_WAITOK | BUS_DMA_ZERO,
671 	    &sc->txdesc_map);
672 	if (error != 0) {
673 		device_printf(sc->dev,
674 		    "could not allocate TX descriptor ring.\n");
675 		goto out;
676 	}
677 
678 	error = bus_dmamap_load(sc->txdesc_tag, sc->txdesc_map,
679 	    sc->txdesc_ring, TX_DESC_SIZE, dwc_get1paddr,
680 	    &sc->txdesc_ring_paddr, 0);
681 	if (error != 0) {
682 		device_printf(sc->dev,
683 		    "could not load TX descriptor ring map.\n");
684 		goto out;
685 	}
686 
687 	for (idx = 0; idx < TX_DESC_COUNT; idx++) {
688 		nidx = next_txidx(sc, idx);
689 		sc->txdesc_ring[idx].addr2 = sc->txdesc_ring_paddr +
690 		    (nidx * sizeof(struct dwc_hwdesc));
691 	}
692 
693 	error = bus_dma_tag_create(
694 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
695 	    1, 0,			/* alignment, boundary */
696 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
697 	    BUS_SPACE_MAXADDR,		/* highaddr */
698 	    NULL, NULL,			/* filter, filterarg */
699 	    MCLBYTES*TX_MAP_MAX_SEGS,	/* maxsize */
700 	    TX_MAP_MAX_SEGS,		/* nsegments */
701 	    MCLBYTES,			/* maxsegsize */
702 	    0,				/* flags */
703 	    NULL, NULL,			/* lockfunc, lockarg */
704 	    &sc->txbuf_tag);
705 	if (error != 0) {
706 		device_printf(sc->dev,
707 		    "could not create TX ring DMA tag.\n");
708 		goto out;
709 	}
710 
711 	for (idx = 0; idx < TX_MAP_COUNT; idx++) {
712 		error = bus_dmamap_create(sc->txbuf_tag, BUS_DMA_COHERENT,
713 		    &sc->txbuf_map[idx].map);
714 		if (error != 0) {
715 			device_printf(sc->dev,
716 			    "could not create TX buffer DMA map.\n");
717 			goto out;
718 		}
719 	}
720 
721 	for (idx = 0; idx < TX_DESC_COUNT; idx++)
722 		txdesc_clear(sc, idx);
723 
724 	WRITE4(sc, TX_DESCR_LIST_ADDR, sc->txdesc_ring_paddr);
725 
726 	/*
727 	 * Set up RX descriptor ring, descriptors, dma maps, and mbufs.
728 	 */
729 	error = bus_dma_tag_create(
730 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
731 	    DWC_DESC_RING_ALIGN, 0,	/* alignment, boundary */
732 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
733 	    BUS_SPACE_MAXADDR,		/* highaddr */
734 	    NULL, NULL,			/* filter, filterarg */
735 	    RX_DESC_SIZE, 1, 		/* maxsize, nsegments */
736 	    RX_DESC_SIZE,		/* maxsegsize */
737 	    0,				/* flags */
738 	    NULL, NULL,			/* lockfunc, lockarg */
739 	    &sc->rxdesc_tag);
740 	if (error != 0) {
741 		device_printf(sc->dev,
742 		    "could not create RX ring DMA tag.\n");
743 		goto out;
744 	}
745 
746 	error = bus_dmamem_alloc(sc->rxdesc_tag, (void **)&sc->rxdesc_ring,
747 	    BUS_DMA_COHERENT | BUS_DMA_WAITOK | BUS_DMA_ZERO,
748 	    &sc->rxdesc_map);
749 	if (error != 0) {
750 		device_printf(sc->dev,
751 		    "could not allocate RX descriptor ring.\n");
752 		goto out;
753 	}
754 
755 	error = bus_dmamap_load(sc->rxdesc_tag, sc->rxdesc_map,
756 	    sc->rxdesc_ring, RX_DESC_SIZE, dwc_get1paddr,
757 	    &sc->rxdesc_ring_paddr, 0);
758 	if (error != 0) {
759 		device_printf(sc->dev,
760 		    "could not load RX descriptor ring map.\n");
761 		goto out;
762 	}
763 
764 	error = bus_dma_tag_create(
765 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
766 	    1, 0,			/* alignment, boundary */
767 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
768 	    BUS_SPACE_MAXADDR,		/* highaddr */
769 	    NULL, NULL,			/* filter, filterarg */
770 	    MCLBYTES, 1, 		/* maxsize, nsegments */
771 	    MCLBYTES,			/* maxsegsize */
772 	    0,				/* flags */
773 	    NULL, NULL,			/* lockfunc, lockarg */
774 	    &sc->rxbuf_tag);
775 	if (error != 0) {
776 		device_printf(sc->dev,
777 		    "could not create RX buf DMA tag.\n");
778 		goto out;
779 	}
780 
781 	for (idx = 0; idx < RX_DESC_COUNT; idx++) {
782 		error = bus_dmamap_create(sc->rxbuf_tag, BUS_DMA_COHERENT,
783 		    &sc->rxbuf_map[idx].map);
784 		if (error != 0) {
785 			device_printf(sc->dev,
786 			    "could not create RX buffer DMA map.\n");
787 			goto out;
788 		}
789 		if ((m = dwc_alloc_mbufcl(sc)) == NULL) {
790 			device_printf(sc->dev, "Could not alloc mbuf\n");
791 			error = ENOMEM;
792 			goto out;
793 		}
794 		if ((error = dma1000_setup_rxbuf(sc, idx, m)) != 0) {
795 			device_printf(sc->dev,
796 			    "could not create new RX buffer.\n");
797 			goto out;
798 		}
799 	}
800 	WRITE4(sc, RX_DESCR_LIST_ADDR, sc->rxdesc_ring_paddr);
801 
802 out:
803 	if (error != 0)
804 		return (ENXIO);
805 
806 	return (0);
807 }
808 
809 /*
810  * Free the bus_dma resources
811  */
812 void
813 dma1000_free(struct dwc_softc *sc)
814 {
815 	bus_dmamap_t map;
816 	int idx;
817 
818 	/* Clean up RX DMA resources and free mbufs. */
819 	for (idx = 0; idx < RX_DESC_COUNT; ++idx) {
820 		if ((map = sc->rxbuf_map[idx].map) != NULL) {
821 			bus_dmamap_unload(sc->rxbuf_tag, map);
822 			bus_dmamap_destroy(sc->rxbuf_tag, map);
823 			m_freem(sc->rxbuf_map[idx].mbuf);
824 		}
825 	}
826 	if (sc->rxbuf_tag != NULL)
827 		bus_dma_tag_destroy(sc->rxbuf_tag);
828 	if (sc->rxdesc_map != NULL) {
829 		bus_dmamap_unload(sc->rxdesc_tag, sc->rxdesc_map);
830 		bus_dmamem_free(sc->rxdesc_tag, sc->rxdesc_ring,
831 		    sc->rxdesc_map);
832 	}
833 	if (sc->rxdesc_tag != NULL)
834 		bus_dma_tag_destroy(sc->rxdesc_tag);
835 
836 	/* Clean up TX DMA resources. */
837 	for (idx = 0; idx < TX_DESC_COUNT; ++idx) {
838 		if ((map = sc->txbuf_map[idx].map) != NULL) {
839 			/* TX maps are already unloaded. */
840 			bus_dmamap_destroy(sc->txbuf_tag, map);
841 		}
842 	}
843 	if (sc->txbuf_tag != NULL)
844 		bus_dma_tag_destroy(sc->txbuf_tag);
845 	if (sc->txdesc_map != NULL) {
846 		bus_dmamap_unload(sc->txdesc_tag, sc->txdesc_map);
847 		bus_dmamem_free(sc->txdesc_tag, sc->txdesc_ring,
848 		    sc->txdesc_map);
849 	}
850 	if (sc->txdesc_tag != NULL)
851 		bus_dma_tag_destroy(sc->txdesc_tag);
852 }
853 
854 /*
855  * Interrupt function
856  */
857 
858 int
859 dma1000_intr(struct dwc_softc *sc)
860 {
861 	uint32_t reg;
862 	int rv;
863 
864 	DWC_ASSERT_LOCKED(sc);
865 
866 	rv = 0;
867 	reg = READ4(sc, DMA_STATUS);
868 	if (reg & DMA_STATUS_NIS) {
869 		if (reg & DMA_STATUS_RI)
870 			dma1000_rxfinish_locked(sc);
871 
872 		if (reg & DMA_STATUS_TI) {
873 			dma1000_txfinish_locked(sc);
874 			dma1000_txstart(sc);
875 		}
876 	}
877 
878 	if (reg & DMA_STATUS_AIS) {
879 		if (reg & DMA_STATUS_FBI) {
880 			/* Fatal bus error */
881 			rv = EIO;
882 		}
883 	}
884 
885 	WRITE4(sc, DMA_STATUS, reg & DMA_STATUS_INTR_MASK);
886 	return (rv);
887 }
888