xref: /netbsd-src/sys/arch/arm/imx/if_enet.c (revision 404ee5b9334f618040b6cdef96a0ff35a6fc4636)
1 /*	$NetBSD: if_enet.c,v 1.28 2019/11/12 05:09:29 hkenken Exp $	*/
2 
3 /*
4  * Copyright (c) 2014 Ryo Shimizu <ryo@nerv.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * i.MX6,7 10/100/1000-Mbps ethernet MAC (ENET)
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: if_enet.c,v 1.28 2019/11/12 05:09:29 hkenken Exp $");
35 
36 #include "vlan.h"
37 
38 #include <sys/param.h>
39 #include <sys/bus.h>
40 #include <sys/mbuf.h>
41 #include <sys/device.h>
42 #include <sys/sockio.h>
43 #include <sys/kernel.h>
44 #include <sys/rndsource.h>
45 
46 #include <lib/libkern/libkern.h>
47 
48 #include <net/if.h>
49 #include <net/if_dl.h>
50 #include <net/if_media.h>
51 #include <net/if_ether.h>
52 #include <net/bpf.h>
53 #include <net/if_vlanvar.h>
54 
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 
59 #include <dev/mii/mii.h>
60 #include <dev/mii/miivar.h>
61 
62 #include <arm/imx/if_enetreg.h>
63 #include <arm/imx/if_enetvar.h>
64 
65 #undef DEBUG_ENET
66 #undef ENET_EVENT_COUNTER
67 
68 #define ENET_TICK	hz
69 
70 #ifdef DEBUG_ENET
71 int enet_debug = 0;
72 # define DEVICE_DPRINTF(args...)	\
73 	do { if (enet_debug) device_printf(sc->sc_dev, args); } while (0)
74 #else
75 # define DEVICE_DPRINTF(args...)
76 #endif
77 
78 
79 #define RXDESC_MAXBUFSIZE	0x07f0
80 				/* ENET does not work greather than 0x0800... */
81 
82 #undef ENET_SUPPORT_JUMBO	/* JUMBO FRAME SUPPORT is unstable */
83 #ifdef ENET_SUPPORT_JUMBO
84 # define ENET_MAX_PKT_LEN	4034	/* MAX FIFO LEN */
85 #else
86 # define ENET_MAX_PKT_LEN	1522
87 #endif
88 #define ENET_DEFAULT_PKT_LEN	1522	/* including VLAN tag */
89 #define MTU2FRAMESIZE(n)	\
90 	((n) + ETHER_HDR_LEN + ETHER_CRC_LEN + ETHER_VLAN_ENCAP_LEN)
91 
92 
93 #define ENET_MAX_PKT_NSEGS	64
94 
95 #define ENET_TX_NEXTIDX(idx)	\
96 	(((idx) >= (ENET_TX_RING_CNT - 1)) ? 0 : ((idx) + 1))
97 #define ENET_RX_NEXTIDX(idx)	\
98 	(((idx) >= (ENET_RX_RING_CNT - 1)) ? 0 : ((idx) + 1))
99 
100 #define TXDESC_WRITEOUT(idx)					\
101 	bus_dmamap_sync(sc->sc_dmat, sc->sc_txdesc_dmamap,	\
102 	    sizeof(struct enet_txdesc) * (idx),			\
103 	    sizeof(struct enet_txdesc),				\
104 	    BUS_DMASYNC_PREWRITE)
105 
106 #define TXDESC_READIN(idx)					\
107 	bus_dmamap_sync(sc->sc_dmat, sc->sc_txdesc_dmamap,	\
108 	    sizeof(struct enet_txdesc) * (idx),			\
109 	    sizeof(struct enet_txdesc),				\
110 	    BUS_DMASYNC_PREREAD)
111 
112 #define RXDESC_WRITEOUT(idx)					\
113 	bus_dmamap_sync(sc->sc_dmat, sc->sc_rxdesc_dmamap,	\
114 	    sizeof(struct enet_rxdesc) * (idx),			\
115 	    sizeof(struct enet_rxdesc),				\
116 	    BUS_DMASYNC_PREWRITE)
117 
118 #define RXDESC_READIN(idx)					\
119 	bus_dmamap_sync(sc->sc_dmat, sc->sc_rxdesc_dmamap,	\
120 	    sizeof(struct enet_rxdesc) * (idx),			\
121 	    sizeof(struct enet_rxdesc),				\
122 	    BUS_DMASYNC_PREREAD)
123 
124 #define ENET_REG_READ(sc, reg)					\
125 	bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, reg)
126 
127 #define ENET_REG_WRITE(sc, reg, value)				\
128 	bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, reg, value)
129 
130 #ifdef ENET_EVENT_COUNTER
131 static void enet_attach_evcnt(struct enet_softc *);
132 static void enet_update_evcnt(struct enet_softc *);
133 #endif
134 
135 static void enet_tick(void *);
136 static int enet_tx_intr(void *);
137 static int enet_rx_intr(void *);
138 static void enet_rx_csum(struct enet_softc *, struct ifnet *, struct mbuf *,
139 			 int);
140 
141 static void enet_start(struct ifnet *);
142 static int enet_ifflags_cb(struct ethercom *);
143 static int enet_ioctl(struct ifnet *, u_long, void *);
144 static int enet_init(struct ifnet *);
145 static void enet_stop(struct ifnet *, int);
146 static void enet_watchdog(struct ifnet *);
147 static void enet_mediastatus(struct ifnet *, struct ifmediareq *);
148 
149 static int enet_miibus_readreg(device_t, int, int, uint16_t *);
150 static int enet_miibus_writereg(device_t, int, int, uint16_t);
151 static void enet_miibus_statchg(struct ifnet *);
152 
153 static void enet_gethwaddr(struct enet_softc *, uint8_t *);
154 static void enet_sethwaddr(struct enet_softc *, uint8_t *);
155 static void enet_setmulti(struct enet_softc *);
156 static int enet_encap_mbufalign(struct mbuf **);
157 static int enet_encap_txring(struct enet_softc *, struct mbuf **);
158 static int enet_init_regs(struct enet_softc *, int);
159 static int enet_alloc_ring(struct enet_softc *);
160 static void enet_init_txring(struct enet_softc *);
161 static int enet_init_rxring(struct enet_softc *);
162 static void enet_reset_rxdesc(struct enet_softc *, int);
163 static int enet_alloc_rxbuf(struct enet_softc *, int);
164 static void enet_drain_txbuf(struct enet_softc *);
165 static void enet_drain_rxbuf(struct enet_softc *);
166 static int enet_alloc_dma(struct enet_softc *, size_t, void **,
167 			  bus_dmamap_t *);
168 
169 int
170 enet_attach_common(device_t self)
171 {
172 	struct enet_softc *sc = device_private(self);
173 	struct ifnet *ifp;
174 	struct mii_data * const mii = &sc->sc_mii;
175 
176 	/* allocate dma buffer */
177 	if (enet_alloc_ring(sc))
178 		return -1;
179 
180 #define IS_ENADDR_ZERO(enaddr)				\
181 	((enaddr[0] | enaddr[1] | enaddr[2] |		\
182 	 enaddr[3] | enaddr[4] | enaddr[5]) == 0)
183 
184 	if (IS_ENADDR_ZERO(sc->sc_enaddr)) {
185 		/* by any chance, mac-address is already set by bootloader? */
186 		enet_gethwaddr(sc, sc->sc_enaddr);
187 		if (IS_ENADDR_ZERO(sc->sc_enaddr)) {
188 			/* give up. set randomly */
189 			uint32_t eaddr = random();
190 			/* not multicast */
191 			sc->sc_enaddr[0] = (eaddr >> 24) & 0xfc;
192 			sc->sc_enaddr[1] = eaddr >> 16;
193 			sc->sc_enaddr[2] = eaddr >> 8;
194 			sc->sc_enaddr[3] = eaddr;
195 			eaddr = random();
196 			sc->sc_enaddr[4] = eaddr >> 8;
197 			sc->sc_enaddr[5] = eaddr;
198 
199 			aprint_error_dev(self,
200 			    "cannot get mac address. set randomly\n");
201 		}
202 	}
203 	enet_sethwaddr(sc, sc->sc_enaddr);
204 
205 	aprint_normal_dev(self, "Ethernet address %s\n",
206 	    ether_sprintf(sc->sc_enaddr));
207 
208 	enet_init_regs(sc, 1);
209 
210 	/* callout will be scheduled from enet_init() */
211 	callout_init(&sc->sc_tick_ch, 0);
212 	callout_setfunc(&sc->sc_tick_ch, enet_tick, sc);
213 
214 	/* setup ifp */
215 	ifp = &sc->sc_ethercom.ec_if;
216 	strlcpy(ifp->if_xname, device_xname(sc->sc_dev), IFNAMSIZ);
217 	ifp->if_softc = sc;
218 	ifp->if_mtu = ETHERMTU;
219 	ifp->if_baudrate = IF_Gbps(1);
220 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
221 	ifp->if_ioctl = enet_ioctl;
222 	ifp->if_start = enet_start;
223 	ifp->if_init = enet_init;
224 	ifp->if_stop = enet_stop;
225 	ifp->if_watchdog = enet_watchdog;
226 
227 	sc->sc_ethercom.ec_capabilities |= ETHERCAP_VLAN_MTU;
228 #ifdef ENET_SUPPORT_JUMBO
229 	sc->sc_ethercom.ec_capabilities |= ETHERCAP_JUMBO_MTU;
230 #endif
231 
232 	ifp->if_capabilities = IFCAP_CSUM_IPv4_Tx | IFCAP_CSUM_IPv4_Rx |
233 	    IFCAP_CSUM_TCPv4_Tx | IFCAP_CSUM_UDPv4_Tx |
234 	    IFCAP_CSUM_TCPv4_Rx | IFCAP_CSUM_UDPv4_Rx |
235 	    IFCAP_CSUM_TCPv6_Tx | IFCAP_CSUM_UDPv6_Tx |
236 	    IFCAP_CSUM_TCPv6_Rx | IFCAP_CSUM_UDPv6_Rx;
237 
238 	IFQ_SET_MAXLEN(&ifp->if_snd, uimax(ENET_TX_RING_CNT, IFQ_MAXLEN));
239 	IFQ_SET_READY(&ifp->if_snd);
240 
241 	/* setup MII */
242 	sc->sc_ethercom.ec_mii = mii;
243 	mii->mii_ifp = ifp;
244 	mii->mii_readreg = enet_miibus_readreg;
245 	mii->mii_writereg = enet_miibus_writereg;
246 	mii->mii_statchg = enet_miibus_statchg;
247 	ifmedia_init(&mii->mii_media, 0, ether_mediachange, enet_mediastatus);
248 
249 	/* try to attach PHY */
250 	mii_attach(self, mii, 0xffffffff, MII_PHY_ANY, MII_OFFSET_ANY, 0);
251 	if (LIST_FIRST(&mii->mii_phys) == NULL) {
252 		ifmedia_add(&mii->mii_media, IFM_ETHER | IFM_MANUAL, 0, NULL);
253 		ifmedia_set(&mii->mii_media, IFM_ETHER | IFM_MANUAL);
254 	} else {
255 		ifmedia_set(&mii->mii_media, IFM_ETHER | IFM_AUTO);
256 	}
257 
258 	if_attach(ifp);
259 	ether_ifattach(ifp, sc->sc_enaddr);
260 	ether_set_ifflags_cb(&sc->sc_ethercom, enet_ifflags_cb);
261 
262 	rnd_attach_source(&sc->sc_rnd_source, device_xname(sc->sc_dev),
263 	    RND_TYPE_NET, RND_FLAG_DEFAULT);
264 
265 #ifdef ENET_EVENT_COUNTER
266 	enet_attach_evcnt(sc);
267 #endif
268 
269 	sc->sc_stopping = false;
270 
271 	return 0;
272 }
273 
274 #ifdef ENET_EVENT_COUNTER
275 static void
276 enet_attach_evcnt(struct enet_softc *sc)
277 {
278 	const char *xname;
279 
280 	xname = device_xname(sc->sc_dev);
281 
282 #define ENET_EVCNT_ATTACH(name)	\
283 	evcnt_attach_dynamic(&sc->sc_ev_ ## name, EVCNT_TYPE_MISC,	\
284 	    NULL, xname, #name);
285 
286 	ENET_EVCNT_ATTACH(t_drop);
287 	ENET_EVCNT_ATTACH(t_packets);
288 	ENET_EVCNT_ATTACH(t_bc_pkt);
289 	ENET_EVCNT_ATTACH(t_mc_pkt);
290 	ENET_EVCNT_ATTACH(t_crc_align);
291 	ENET_EVCNT_ATTACH(t_undersize);
292 	ENET_EVCNT_ATTACH(t_oversize);
293 	ENET_EVCNT_ATTACH(t_frag);
294 	ENET_EVCNT_ATTACH(t_jab);
295 	ENET_EVCNT_ATTACH(t_col);
296 	ENET_EVCNT_ATTACH(t_p64);
297 	ENET_EVCNT_ATTACH(t_p65to127n);
298 	ENET_EVCNT_ATTACH(t_p128to255n);
299 	ENET_EVCNT_ATTACH(t_p256to511);
300 	ENET_EVCNT_ATTACH(t_p512to1023);
301 	ENET_EVCNT_ATTACH(t_p1024to2047);
302 	ENET_EVCNT_ATTACH(t_p_gte2048);
303 	ENET_EVCNT_ATTACH(t_octets);
304 	ENET_EVCNT_ATTACH(r_packets);
305 	ENET_EVCNT_ATTACH(r_bc_pkt);
306 	ENET_EVCNT_ATTACH(r_mc_pkt);
307 	ENET_EVCNT_ATTACH(r_crc_align);
308 	ENET_EVCNT_ATTACH(r_undersize);
309 	ENET_EVCNT_ATTACH(r_oversize);
310 	ENET_EVCNT_ATTACH(r_frag);
311 	ENET_EVCNT_ATTACH(r_jab);
312 	ENET_EVCNT_ATTACH(r_p64);
313 	ENET_EVCNT_ATTACH(r_p65to127);
314 	ENET_EVCNT_ATTACH(r_p128to255);
315 	ENET_EVCNT_ATTACH(r_p256to511);
316 	ENET_EVCNT_ATTACH(r_p512to1023);
317 	ENET_EVCNT_ATTACH(r_p1024to2047);
318 	ENET_EVCNT_ATTACH(r_p_gte2048);
319 	ENET_EVCNT_ATTACH(r_octets);
320 }
321 
322 static void
323 enet_update_evcnt(struct enet_softc *sc)
324 {
325 	sc->sc_ev_t_drop.ev_count += ENET_REG_READ(sc, ENET_RMON_T_DROP);
326 	sc->sc_ev_t_packets.ev_count += ENET_REG_READ(sc, ENET_RMON_T_PACKETS);
327 	sc->sc_ev_t_bc_pkt.ev_count += ENET_REG_READ(sc, ENET_RMON_T_BC_PKT);
328 	sc->sc_ev_t_mc_pkt.ev_count += ENET_REG_READ(sc, ENET_RMON_T_MC_PKT);
329 	sc->sc_ev_t_crc_align.ev_count += ENET_REG_READ(sc, ENET_RMON_T_CRC_ALIGN);
330 	sc->sc_ev_t_undersize.ev_count += ENET_REG_READ(sc, ENET_RMON_T_UNDERSIZE);
331 	sc->sc_ev_t_oversize.ev_count += ENET_REG_READ(sc, ENET_RMON_T_OVERSIZE);
332 	sc->sc_ev_t_frag.ev_count += ENET_REG_READ(sc, ENET_RMON_T_FRAG);
333 	sc->sc_ev_t_jab.ev_count += ENET_REG_READ(sc, ENET_RMON_T_JAB);
334 	sc->sc_ev_t_col.ev_count += ENET_REG_READ(sc, ENET_RMON_T_COL);
335 	sc->sc_ev_t_p64.ev_count += ENET_REG_READ(sc, ENET_RMON_T_P64);
336 	sc->sc_ev_t_p65to127n.ev_count += ENET_REG_READ(sc, ENET_RMON_T_P65TO127N);
337 	sc->sc_ev_t_p128to255n.ev_count += ENET_REG_READ(sc, ENET_RMON_T_P128TO255N);
338 	sc->sc_ev_t_p256to511.ev_count += ENET_REG_READ(sc, ENET_RMON_T_P256TO511);
339 	sc->sc_ev_t_p512to1023.ev_count += ENET_REG_READ(sc, ENET_RMON_T_P512TO1023);
340 	sc->sc_ev_t_p1024to2047.ev_count += ENET_REG_READ(sc, ENET_RMON_T_P1024TO2047);
341 	sc->sc_ev_t_p_gte2048.ev_count += ENET_REG_READ(sc, ENET_RMON_T_P_GTE2048);
342 	sc->sc_ev_t_octets.ev_count += ENET_REG_READ(sc, ENET_RMON_T_OCTETS);
343 	sc->sc_ev_r_packets.ev_count += ENET_REG_READ(sc, ENET_RMON_R_PACKETS);
344 	sc->sc_ev_r_bc_pkt.ev_count += ENET_REG_READ(sc, ENET_RMON_R_BC_PKT);
345 	sc->sc_ev_r_mc_pkt.ev_count += ENET_REG_READ(sc, ENET_RMON_R_MC_PKT);
346 	sc->sc_ev_r_crc_align.ev_count += ENET_REG_READ(sc, ENET_RMON_R_CRC_ALIGN);
347 	sc->sc_ev_r_undersize.ev_count += ENET_REG_READ(sc, ENET_RMON_R_UNDERSIZE);
348 	sc->sc_ev_r_oversize.ev_count += ENET_REG_READ(sc, ENET_RMON_R_OVERSIZE);
349 	sc->sc_ev_r_frag.ev_count += ENET_REG_READ(sc, ENET_RMON_R_FRAG);
350 	sc->sc_ev_r_jab.ev_count += ENET_REG_READ(sc, ENET_RMON_R_JAB);
351 	sc->sc_ev_r_p64.ev_count += ENET_REG_READ(sc, ENET_RMON_R_P64);
352 	sc->sc_ev_r_p65to127.ev_count += ENET_REG_READ(sc, ENET_RMON_R_P65TO127);
353 	sc->sc_ev_r_p128to255.ev_count += ENET_REG_READ(sc, ENET_RMON_R_P128TO255);
354 	sc->sc_ev_r_p256to511.ev_count += ENET_REG_READ(sc, ENET_RMON_R_P256TO511);
355 	sc->sc_ev_r_p512to1023.ev_count += ENET_REG_READ(sc, ENET_RMON_R_P512TO1023);
356 	sc->sc_ev_r_p1024to2047.ev_count += ENET_REG_READ(sc, ENET_RMON_R_P1024TO2047);
357 	sc->sc_ev_r_p_gte2048.ev_count += ENET_REG_READ(sc, ENET_RMON_R_P_GTE2048);
358 	sc->sc_ev_r_octets.ev_count += ENET_REG_READ(sc, ENET_RMON_R_OCTETS);
359 }
360 #endif /* ENET_EVENT_COUNTER */
361 
362 static void
363 enet_tick(void *arg)
364 {
365 	struct enet_softc *sc;
366 	struct mii_data *mii;
367 	struct ifnet *ifp;
368 	int s;
369 
370 	sc = arg;
371 	mii = &sc->sc_mii;
372 	ifp = &sc->sc_ethercom.ec_if;
373 
374 	s = splnet();
375 
376 	if (sc->sc_stopping)
377 		goto out;
378 
379 #ifdef ENET_EVENT_COUNTER
380 	enet_update_evcnt(sc);
381 #endif
382 
383 	/* update counters */
384 	ifp->if_ierrors += ENET_REG_READ(sc, ENET_RMON_R_UNDERSIZE);
385 	ifp->if_ierrors += ENET_REG_READ(sc, ENET_RMON_R_FRAG);
386 	ifp->if_ierrors += ENET_REG_READ(sc, ENET_RMON_R_JAB);
387 
388 	/* clear counters */
389 	ENET_REG_WRITE(sc, ENET_MIBC, ENET_MIBC_MIB_CLEAR);
390 	ENET_REG_WRITE(sc, ENET_MIBC, 0);
391 
392 	mii_tick(mii);
393  out:
394 
395 	if (!sc->sc_stopping)
396 		callout_schedule(&sc->sc_tick_ch, ENET_TICK);
397 
398 	splx(s);
399 }
400 
401 int
402 enet_intr(void *arg)
403 {
404 	struct enet_softc *sc;
405 	struct ifnet *ifp;
406 	uint32_t status;
407 
408 	sc = arg;
409 	status = ENET_REG_READ(sc, ENET_EIR);
410 
411 	if (sc->sc_imxtype == 7) {
412 		if (status & (ENET_EIR_TXF | ENET_EIR_TXF1 | ENET_EIR_TXF2))
413 			enet_tx_intr(arg);
414 		if (status & (ENET_EIR_RXF | ENET_EIR_RXF1 | ENET_EIR_RXF2))
415 			enet_rx_intr(arg);
416 	} else {
417 		if (status & ENET_EIR_TXF)
418 			enet_tx_intr(arg);
419 		if (status & ENET_EIR_RXF)
420 			enet_rx_intr(arg);
421 	}
422 
423 	if (status & ENET_EIR_EBERR) {
424 		device_printf(sc->sc_dev, "Ethernet Bus Error\n");
425 		ifp = &sc->sc_ethercom.ec_if;
426 		enet_stop(ifp, 1);
427 		enet_init(ifp);
428 	} else {
429 		ENET_REG_WRITE(sc, ENET_EIR, status);
430 	}
431 
432 	rnd_add_uint32(&sc->sc_rnd_source, status);
433 
434 	return 1;
435 }
436 
437 static int
438 enet_tx_intr(void *arg)
439 {
440 	struct enet_softc *sc;
441 	struct ifnet *ifp;
442 	struct enet_txsoft *txs;
443 	int idx;
444 
445 	sc = (struct enet_softc *)arg;
446 	ifp = &sc->sc_ethercom.ec_if;
447 
448 	for (idx = sc->sc_tx_considx; idx != sc->sc_tx_prodidx;
449 	    idx = ENET_TX_NEXTIDX(idx)) {
450 
451 		txs = &sc->sc_txsoft[idx];
452 
453 		TXDESC_READIN(idx);
454 		if (sc->sc_txdesc_ring[idx].tx_flags1_len & TXFLAGS1_R) {
455 			/* This TX Descriptor has not been transmitted yet */
456 			break;
457 		}
458 
459 		/* txsoft is available on first segment (TXFLAGS1_T1) */
460 		if (sc->sc_txdesc_ring[idx].tx_flags1_len & TXFLAGS1_T1) {
461 			bus_dmamap_unload(sc->sc_dmat,
462 			    txs->txs_dmamap);
463 			m_freem(txs->txs_mbuf);
464 			ifp->if_opackets++;
465 		}
466 
467 		/* checking error */
468 		if (sc->sc_txdesc_ring[idx].tx_flags1_len & TXFLAGS1_L) {
469 			uint32_t flags2;
470 
471 			flags2 = sc->sc_txdesc_ring[idx].tx_flags2;
472 
473 			if (flags2 & (TXFLAGS2_TXE |
474 			    TXFLAGS2_UE | TXFLAGS2_EE | TXFLAGS2_FE |
475 			    TXFLAGS2_LCE | TXFLAGS2_OE | TXFLAGS2_TSE)) {
476 #ifdef DEBUG_ENET
477 				if (enet_debug) {
478 					char flagsbuf[128];
479 
480 					snprintb(flagsbuf, sizeof(flagsbuf),
481 					    "\20" "\20TRANSMIT" "\16UNDERFLOW"
482 					    "\15COLLISION" "\14FRAME"
483 					    "\13LATECOLLISION" "\12OVERFLOW",
484 					    flags2);
485 
486 					device_printf(sc->sc_dev,
487 					    "txdesc[%d]: transmit error: "
488 					    "flags2=%s\n", idx, flagsbuf);
489 				}
490 #endif /* DEBUG_ENET */
491 				ifp->if_oerrors++;
492 			}
493 		}
494 
495 		sc->sc_tx_free++;
496 	}
497 	sc->sc_tx_considx = idx;
498 
499 	if (sc->sc_tx_free > 0)
500 		ifp->if_flags &= ~IFF_OACTIVE;
501 
502 	/*
503 	 * No more pending TX descriptor,
504 	 * cancel the watchdog timer.
505 	 */
506 	if (sc->sc_tx_free == ENET_TX_RING_CNT)
507 		ifp->if_timer = 0;
508 
509 	return 1;
510 }
511 
512 static int
513 enet_rx_intr(void *arg)
514 {
515 	struct enet_softc *sc;
516 	struct ifnet *ifp;
517 	struct enet_rxsoft *rxs;
518 	int idx, len, amount;
519 	uint32_t flags1, flags2;
520 	struct mbuf *m, *m0, *mprev;
521 
522 	sc = arg;
523 	ifp = &sc->sc_ethercom.ec_if;
524 
525 	m0 = mprev = NULL;
526 	amount = 0;
527 	for (idx = sc->sc_rx_readidx; ; idx = ENET_RX_NEXTIDX(idx)) {
528 
529 		rxs = &sc->sc_rxsoft[idx];
530 
531 		RXDESC_READIN(idx);
532 		if (sc->sc_rxdesc_ring[idx].rx_flags1_len & RXFLAGS1_E) {
533 			/* This RX Descriptor has not been received yet */
534 			break;
535 		}
536 
537 		/*
538 		 * build mbuf from RX Descriptor if needed
539 		 */
540 		m = rxs->rxs_mbuf;
541 		rxs->rxs_mbuf = NULL;
542 
543 		flags1 = sc->sc_rxdesc_ring[idx].rx_flags1_len;
544 		len = RXFLAGS1_LEN(flags1);
545 
546 #define RACC_SHIFT16	2
547 		if (m0 == NULL) {
548 			m0 = m;
549 			m_adj(m0, RACC_SHIFT16);
550 			len -= RACC_SHIFT16;
551 			m->m_len = len;
552 			amount = len;
553 		} else {
554 			if (flags1 & RXFLAGS1_L)
555 				len = len - amount - RACC_SHIFT16;
556 
557 			m->m_len = len;
558 			amount += len;
559 			if (m->m_flags & M_PKTHDR)
560 				m_remove_pkthdr(m);
561 			mprev->m_next = m;
562 		}
563 		mprev = m;
564 
565 		flags2 = sc->sc_rxdesc_ring[idx].rx_flags2;
566 
567 		if (flags1 & RXFLAGS1_L) {
568 			/* last buffer */
569 			if ((amount < ETHER_HDR_LEN) ||
570 			    ((flags1 & (RXFLAGS1_LG | RXFLAGS1_NO |
571 			    RXFLAGS1_CR | RXFLAGS1_OV | RXFLAGS1_TR)) ||
572 			    (flags2 & (RXFLAGS2_ME | RXFLAGS2_PE |
573 			    RXFLAGS2_CE)))) {
574 
575 #ifdef DEBUG_ENET
576 				if (enet_debug) {
577 					char flags1buf[128], flags2buf[128];
578 					snprintb(flags1buf, sizeof(flags1buf),
579 					    "\20" "\31MISS" "\26LENGTHVIOLATION"
580 					    "\25NONOCTET" "\23CRC" "\22OVERRUN"
581 					    "\21TRUNCATED", flags1);
582 					snprintb(flags2buf, sizeof(flags2buf),
583 					    "\20" "\40MAC" "\33PHY"
584 					    "\32COLLISION", flags2);
585 
586 					DEVICE_DPRINTF(
587 					    "rxdesc[%d]: receive error: "
588 					    "flags1=%s,flags2=%s,len=%d\n",
589 					    idx, flags1buf, flags2buf, amount);
590 				}
591 #endif /* DEBUG_ENET */
592 				ifp->if_ierrors++;
593 				m_freem(m0);
594 
595 			} else {
596 				/* packet receive ok */
597 				m_set_rcvif(m0, ifp);
598 				m0->m_pkthdr.len = amount;
599 
600 				bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
601 				    rxs->rxs_dmamap->dm_mapsize,
602 				    BUS_DMASYNC_PREREAD);
603 
604 				if (ifp->if_csum_flags_rx & (M_CSUM_IPv4 |
605 				    M_CSUM_TCPv4 | M_CSUM_UDPv4 |
606 				    M_CSUM_TCPv6 | M_CSUM_UDPv6))
607 					enet_rx_csum(sc, ifp, m0, idx);
608 
609 				if_percpuq_enqueue(ifp->if_percpuq, m0);
610 			}
611 
612 			m0 = NULL;
613 			mprev = NULL;
614 			amount = 0;
615 
616 		} else {
617 			/* continued from previous buffer */
618 			bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
619 			    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
620 		}
621 
622 		bus_dmamap_unload(sc->sc_dmat, rxs->rxs_dmamap);
623 		if (enet_alloc_rxbuf(sc, idx) != 0) {
624 			panic("enet_alloc_rxbuf NULL\n");
625 		}
626 	}
627 	sc->sc_rx_readidx = idx;
628 
629 	/* re-enable RX DMA to make sure */
630 	ENET_REG_WRITE(sc, ENET_RDAR, ENET_RDAR_ACTIVE);
631 
632 	return 1;
633 }
634 
635 static void
636 enet_rx_csum(struct enet_softc *sc, struct ifnet *ifp, struct mbuf *m, int idx)
637 {
638 	uint32_t flags2;
639 	uint8_t proto;
640 
641 	flags2 = sc->sc_rxdesc_ring[idx].rx_flags2;
642 
643 	if (flags2 & RXFLAGS2_IPV6) {
644 		proto = sc->sc_rxdesc_ring[idx].rx_proto;
645 
646 		/* RXFLAGS2_PCR is valid when IPv6 and TCP/UDP */
647 		if ((proto == IPPROTO_TCP) &&
648 		    (ifp->if_csum_flags_rx & M_CSUM_TCPv6))
649 			m->m_pkthdr.csum_flags |= M_CSUM_TCPv6;
650 		else if ((proto == IPPROTO_UDP) &&
651 		    (ifp->if_csum_flags_rx & M_CSUM_UDPv6))
652 			m->m_pkthdr.csum_flags |= M_CSUM_UDPv6;
653 		else
654 			return;
655 
656 		/* IPv6 protocol checksum error */
657 		if (flags2 & RXFLAGS2_PCR)
658 			m->m_pkthdr.csum_flags |= M_CSUM_TCP_UDP_BAD;
659 
660 	} else {
661 		struct ether_header *eh;
662 		uint8_t *ip;
663 
664 		eh = mtod(m, struct ether_header *);
665 
666 		/* XXX: is an IPv4? */
667 		if (ntohs(eh->ether_type) != ETHERTYPE_IP)
668 			return;
669 		ip = (uint8_t *)(eh + 1);
670 		if ((ip[0] & 0xf0) == 0x40)
671 			return;
672 
673 		proto = sc->sc_rxdesc_ring[idx].rx_proto;
674 		if (flags2 & RXFLAGS2_ICE) {
675 			if (ifp->if_csum_flags_rx & M_CSUM_IPv4) {
676 				m->m_pkthdr.csum_flags |=
677 				    M_CSUM_IPv4 | M_CSUM_IPv4_BAD;
678 			}
679 		} else {
680 			if (ifp->if_csum_flags_rx & M_CSUM_IPv4) {
681 				m->m_pkthdr.csum_flags |= M_CSUM_IPv4;
682 			}
683 
684 			/*
685 			 * PCR is valid when
686 			 * ICE == 0 and FRAG == 0
687 			 */
688 			if (flags2 & RXFLAGS2_FRAG)
689 				return;
690 
691 			/*
692 			 * PCR is valid when proto is TCP or UDP
693 			 */
694 			if ((proto == IPPROTO_TCP) &&
695 			    (ifp->if_csum_flags_rx & M_CSUM_TCPv4))
696 				m->m_pkthdr.csum_flags |= M_CSUM_TCPv4;
697 			else if ((proto == IPPROTO_UDP) &&
698 			    (ifp->if_csum_flags_rx & M_CSUM_UDPv4))
699 				m->m_pkthdr.csum_flags |= M_CSUM_UDPv4;
700 			else
701 				return;
702 
703 			/* IPv4 protocol cksum error */
704 			if (flags2 & RXFLAGS2_PCR)
705 				m->m_pkthdr.csum_flags |= M_CSUM_TCP_UDP_BAD;
706 		}
707 	}
708 }
709 
710 static void
711 enet_setmulti(struct enet_softc *sc)
712 {
713 	struct ethercom *ec = &sc->sc_ethercom;
714 	struct ifnet *ifp = &ec->ec_if;
715 	struct ether_multi *enm;
716 	struct ether_multistep step;
717 	int promisc;
718 	uint32_t crc;
719 	uint32_t gaddr[2];
720 
721 	promisc = 0;
722 	if ((ifp->if_flags & IFF_PROMISC) || ec->ec_multicnt > 0) {
723 		ifp->if_flags |= IFF_ALLMULTI;
724 		if (ifp->if_flags & IFF_PROMISC)
725 			promisc = 1;
726 		gaddr[0] = gaddr[1] = 0xffffffff;
727 	} else {
728 		gaddr[0] = gaddr[1] = 0;
729 
730 		ETHER_LOCK(ec);
731 		ETHER_FIRST_MULTI(step, ec, enm);
732 		while (enm != NULL) {
733 			crc = ether_crc32_le(enm->enm_addrlo, ETHER_ADDR_LEN);
734 			gaddr[crc >> 31] |= 1 << ((crc >> 26) & 0x1f);
735 			ETHER_NEXT_MULTI(step, enm);
736 		}
737 		ETHER_UNLOCK(ec);
738 	}
739 
740 	ENET_REG_WRITE(sc, ENET_GAUR, gaddr[0]);
741 	ENET_REG_WRITE(sc, ENET_GALR, gaddr[1]);
742 
743 	if (promisc) {
744 		/* match all packet */
745 		ENET_REG_WRITE(sc, ENET_IAUR, 0xffffffff);
746 		ENET_REG_WRITE(sc, ENET_IALR, 0xffffffff);
747 	} else {
748 		/* don't match any packet */
749 		ENET_REG_WRITE(sc, ENET_IAUR, 0);
750 		ENET_REG_WRITE(sc, ENET_IALR, 0);
751 	}
752 }
753 
754 static void
755 enet_gethwaddr(struct enet_softc *sc, uint8_t *hwaddr)
756 {
757 	uint32_t paddr;
758 
759 	paddr = ENET_REG_READ(sc, ENET_PALR);
760 	hwaddr[0] = paddr >> 24;
761 	hwaddr[1] = paddr >> 16;
762 	hwaddr[2] = paddr >> 8;
763 	hwaddr[3] = paddr;
764 
765 	paddr = ENET_REG_READ(sc, ENET_PAUR);
766 	hwaddr[4] = paddr >> 24;
767 	hwaddr[5] = paddr >> 16;
768 }
769 
770 static void
771 enet_sethwaddr(struct enet_softc *sc, uint8_t *hwaddr)
772 {
773 	uint32_t paddr;
774 
775 	paddr = (hwaddr[0] << 24) | (hwaddr[1] << 16) | (hwaddr[2] << 8) |
776 	    hwaddr[3];
777 	ENET_REG_WRITE(sc, ENET_PALR, paddr);
778 	paddr = (hwaddr[4] << 24) | (hwaddr[5] << 16);
779 	ENET_REG_WRITE(sc, ENET_PAUR, paddr);
780 }
781 
782 /*
783  * ifnet interfaces
784  */
785 static int
786 enet_init(struct ifnet *ifp)
787 {
788 	struct enet_softc *sc;
789 	int s, error;
790 
791 	sc = ifp->if_softc;
792 
793 	s = splnet();
794 
795 	enet_init_regs(sc, 0);
796 	enet_init_txring(sc);
797 	error = enet_init_rxring(sc);
798 	if (error != 0) {
799 		enet_drain_rxbuf(sc);
800 		device_printf(sc->sc_dev, "Cannot allocate mbuf cluster\n");
801 		goto init_failure;
802 	}
803 
804 	/* reload mac address */
805 	memcpy(sc->sc_enaddr, CLLADDR(ifp->if_sadl), ETHER_ADDR_LEN);
806 	enet_sethwaddr(sc, sc->sc_enaddr);
807 
808 	/* program multicast address */
809 	enet_setmulti(sc);
810 
811 	/* update if_flags */
812 	ifp->if_flags |= IFF_RUNNING;
813 	ifp->if_flags &= ~IFF_OACTIVE;
814 
815 	/* update local copy of if_flags */
816 	sc->sc_if_flags = ifp->if_flags;
817 
818 	/* mii */
819 	mii_mediachg(&sc->sc_mii);
820 
821 	/* enable RX DMA */
822 	ENET_REG_WRITE(sc, ENET_RDAR, ENET_RDAR_ACTIVE);
823 
824 	sc->sc_stopping = false;
825 	callout_schedule(&sc->sc_tick_ch, ENET_TICK);
826 
827  init_failure:
828 	splx(s);
829 
830 	return error;
831 }
832 
833 static void
834 enet_start(struct ifnet *ifp)
835 {
836 	struct enet_softc *sc;
837 	struct mbuf *m;
838 	int npkt;
839 
840 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
841 		return;
842 
843 	sc = ifp->if_softc;
844 	for (npkt = 0; ; npkt++) {
845 		IFQ_POLL(&ifp->if_snd, m);
846 		if (m == NULL)
847 			break;
848 
849 		if (sc->sc_tx_free <= 0) {
850 			/* no tx descriptor now... */
851 			ifp->if_flags |= IFF_OACTIVE;
852 			DEVICE_DPRINTF("TX descriptor is full\n");
853 			break;
854 		}
855 
856 		IFQ_DEQUEUE(&ifp->if_snd, m);
857 
858 		if (enet_encap_txring(sc, &m) != 0) {
859 			/* too many mbuf chains? */
860 			ifp->if_flags |= IFF_OACTIVE;
861 			DEVICE_DPRINTF(
862 			    "TX descriptor is full. dropping packet\n");
863 			m_freem(m);
864 			ifp->if_oerrors++;
865 			break;
866 		}
867 
868 		/* Pass the packet to any BPF listeners */
869 		bpf_mtap(ifp, m, BPF_D_OUT);
870 	}
871 
872 	if (npkt) {
873 		/* enable TX DMA */
874 		ENET_REG_WRITE(sc, ENET_TDAR, ENET_TDAR_ACTIVE);
875 
876 		ifp->if_timer = 5;
877 	}
878 }
879 
880 static void
881 enet_stop(struct ifnet *ifp, int disable)
882 {
883 	struct enet_softc *sc;
884 	int s;
885 	uint32_t v;
886 
887 	sc = ifp->if_softc;
888 
889 	s = splnet();
890 
891 	sc->sc_stopping = true;
892 	callout_stop(&sc->sc_tick_ch);
893 
894 	/* clear ENET_ECR[ETHEREN] to abort receive and transmit */
895 	v = ENET_REG_READ(sc, ENET_ECR);
896 	ENET_REG_WRITE(sc, ENET_ECR, v & ~ENET_ECR_ETHEREN);
897 
898 	/* Mark the interface as down and cancel the watchdog timer. */
899 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
900 	ifp->if_timer = 0;
901 
902 	if (disable) {
903 		enet_drain_txbuf(sc);
904 		enet_drain_rxbuf(sc);
905 	}
906 
907 	splx(s);
908 }
909 
910 static void
911 enet_watchdog(struct ifnet *ifp)
912 {
913 	struct enet_softc *sc;
914 	int s;
915 
916 	sc = ifp->if_softc;
917 	s = splnet();
918 
919 	device_printf(sc->sc_dev, "watchdog timeout\n");
920 	ifp->if_oerrors++;
921 
922 	/* salvage packets left in descriptors */
923 	enet_tx_intr(sc);
924 	enet_rx_intr(sc);
925 
926 	/* reset */
927 	enet_stop(ifp, 1);
928 	enet_init(ifp);
929 
930 	splx(s);
931 }
932 
933 static void
934 enet_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
935 {
936 	struct enet_softc *sc = ifp->if_softc;
937 
938 	ether_mediastatus(ifp, ifmr);
939 	ifmr->ifm_active = (ifmr->ifm_active & ~IFM_ETH_FMASK)
940 	    | sc->sc_flowflags;
941 }
942 
943 static int
944 enet_ifflags_cb(struct ethercom *ec)
945 {
946 	struct ifnet *ifp = &ec->ec_if;
947 	struct enet_softc *sc = ifp->if_softc;
948 	u_short change = ifp->if_flags ^ sc->sc_if_flags;
949 
950 	if ((change & ~(IFF_CANTCHANGE | IFF_DEBUG)) != 0)
951 		return ENETRESET;
952 	else if ((change & (IFF_PROMISC | IFF_ALLMULTI)) == 0)
953 		return 0;
954 
955 	enet_setmulti(sc);
956 
957 	sc->sc_if_flags = ifp->if_flags;
958 	return 0;
959 }
960 
961 static int
962 enet_ioctl(struct ifnet *ifp, u_long command, void *data)
963 {
964 	struct enet_softc *sc;
965 	struct ifreq *ifr;
966 	int s, error;
967 	uint32_t v;
968 
969 	sc = ifp->if_softc;
970 	ifr = data;
971 
972 	error = 0;
973 
974 	s = splnet();
975 
976 	switch (command) {
977 	case SIOCSIFMTU:
978 		if (MTU2FRAMESIZE(ifr->ifr_mtu) > ENET_MAX_PKT_LEN) {
979 			error = EINVAL;
980 		} else {
981 			ifp->if_mtu = ifr->ifr_mtu;
982 
983 			/* set maximum frame length */
984 			v = MTU2FRAMESIZE(ifr->ifr_mtu);
985 			ENET_REG_WRITE(sc, ENET_FTRL, v);
986 			v = ENET_REG_READ(sc, ENET_RCR);
987 			v &= ~ENET_RCR_MAX_FL(0x3fff);
988 			v |= ENET_RCR_MAX_FL(ifp->if_mtu + ETHER_HDR_LEN +
989 			    ETHER_CRC_LEN + ETHER_VLAN_ENCAP_LEN);
990 			ENET_REG_WRITE(sc, ENET_RCR, v);
991 		}
992 		break;
993 	case SIOCSIFMEDIA:
994 		/* Flow control requires full-duplex mode. */
995 		if (IFM_SUBTYPE(ifr->ifr_media) == IFM_AUTO ||
996 		    (ifr->ifr_media & IFM_FDX) == 0)
997 			ifr->ifr_media &= ~IFM_ETH_FMASK;
998 		if (IFM_SUBTYPE(ifr->ifr_media) != IFM_AUTO) {
999 			if ((ifr->ifr_media & IFM_ETH_FMASK) == IFM_FLOW) {
1000 				/* We can do both TXPAUSE and RXPAUSE. */
1001 				ifr->ifr_media |=
1002 				    IFM_ETH_TXPAUSE | IFM_ETH_RXPAUSE;
1003 			}
1004 			sc->sc_flowflags = ifr->ifr_media & IFM_ETH_FMASK;
1005 		}
1006 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii.mii_media, command);
1007 		break;
1008 	default:
1009 		error = ether_ioctl(ifp, command, data);
1010 		if (error != ENETRESET)
1011 			break;
1012 
1013 		/* post-process */
1014 		error = 0;
1015 		switch (command) {
1016 		case SIOCSIFCAP:
1017 			error = (*ifp->if_init)(ifp);
1018 			break;
1019 		case SIOCADDMULTI:
1020 		case SIOCDELMULTI:
1021 			if (ifp->if_flags & IFF_RUNNING)
1022 				enet_setmulti(sc);
1023 			break;
1024 		}
1025 		break;
1026 	}
1027 
1028 	splx(s);
1029 
1030 	return error;
1031 }
1032 
1033 /*
1034  * for MII
1035  */
1036 static int
1037 enet_miibus_readreg(device_t dev, int phy, int reg, uint16_t *val)
1038 {
1039 	struct enet_softc *sc;
1040 	int timeout;
1041 	uint32_t status;
1042 
1043 	sc = device_private(dev);
1044 
1045 	/* clear MII update */
1046 	ENET_REG_WRITE(sc, ENET_EIR, ENET_EIR_MII);
1047 
1048 	/* read command */
1049 	ENET_REG_WRITE(sc, ENET_MMFR,
1050 	    ENET_MMFR_ST | ENET_MMFR_OP_READ | ENET_MMFR_TA |
1051 	    ENET_MMFR_PHY_REG(reg) | ENET_MMFR_PHY_ADDR(phy));
1052 
1053 	/* check MII update */
1054 	for (timeout = 5000; timeout > 0; --timeout) {
1055 		status = ENET_REG_READ(sc, ENET_EIR);
1056 		if (status & ENET_EIR_MII)
1057 			break;
1058 	}
1059 	if (timeout <= 0) {
1060 		DEVICE_DPRINTF("MII read timeout: reg=0x%02x\n",
1061 		    reg);
1062 		return ETIMEDOUT;
1063 	} else
1064 		*val = ENET_REG_READ(sc, ENET_MMFR) & ENET_MMFR_DATAMASK;
1065 
1066 	return 0;
1067 }
1068 
1069 static int
1070 enet_miibus_writereg(device_t dev, int phy, int reg, uint16_t val)
1071 {
1072 	struct enet_softc *sc;
1073 	int timeout;
1074 
1075 	sc = device_private(dev);
1076 
1077 	/* clear MII update */
1078 	ENET_REG_WRITE(sc, ENET_EIR, ENET_EIR_MII);
1079 
1080 	/* write command */
1081 	ENET_REG_WRITE(sc, ENET_MMFR,
1082 	    ENET_MMFR_ST | ENET_MMFR_OP_WRITE | ENET_MMFR_TA |
1083 	    ENET_MMFR_PHY_REG(reg) | ENET_MMFR_PHY_ADDR(phy) |
1084 	    (ENET_MMFR_DATAMASK & val));
1085 
1086 	/* check MII update */
1087 	for (timeout = 5000; timeout > 0; --timeout) {
1088 		if (ENET_REG_READ(sc, ENET_EIR) & ENET_EIR_MII)
1089 			break;
1090 	}
1091 	if (timeout <= 0) {
1092 		DEVICE_DPRINTF("MII write timeout: reg=0x%02x\n", reg);
1093 		return ETIMEDOUT;
1094 	}
1095 
1096 	return 0;
1097 }
1098 
1099 static void
1100 enet_miibus_statchg(struct ifnet *ifp)
1101 {
1102 	struct enet_softc *sc;
1103 	struct mii_data *mii;
1104 	struct ifmedia_entry *ife;
1105 	uint32_t ecr, ecr0;
1106 	uint32_t rcr, rcr0;
1107 	uint32_t tcr, tcr0;
1108 
1109 	sc = ifp->if_softc;
1110 	mii = &sc->sc_mii;
1111 	ife = mii->mii_media.ifm_cur;
1112 
1113 	/* get current status */
1114 	ecr0 = ecr = ENET_REG_READ(sc, ENET_ECR) & ~ENET_ECR_RESET;
1115 	rcr0 = rcr = ENET_REG_READ(sc, ENET_RCR);
1116 	tcr0 = tcr = ENET_REG_READ(sc, ENET_TCR);
1117 
1118 	if (IFM_SUBTYPE(mii->mii_media.ifm_cur->ifm_media) == IFM_AUTO &&
1119 	    (mii->mii_media_active & IFM_ETH_FMASK) != sc->sc_flowflags) {
1120 		sc->sc_flowflags = mii->mii_media_active & IFM_ETH_FMASK;
1121 		mii->mii_media_active &= ~IFM_ETH_FMASK;
1122 	}
1123 
1124 	if ((ife->ifm_media & IFM_FDX) != 0) {
1125 		tcr |= ENET_TCR_FDEN;	/* full duplex */
1126 		rcr &= ~ENET_RCR_DRT;;	/* enable receive on transmit */
1127 	} else {
1128 		tcr &= ~ENET_TCR_FDEN;	/* half duplex */
1129 		rcr |= ENET_RCR_DRT;	/* disable receive on transmit */
1130 	}
1131 
1132 	if ((tcr ^ tcr0) & ENET_TCR_FDEN) {
1133 		/*
1134 		 * need to reset because
1135 		 * FDEN can change when ECR[ETHEREN] is 0
1136 		 */
1137 		enet_init_regs(sc, 0);
1138 		return;
1139 	}
1140 
1141 	switch (IFM_SUBTYPE(ife->ifm_media)) {
1142 	case IFM_AUTO:
1143 	case IFM_1000_T:
1144 		ecr |= ENET_ECR_SPEED;		/* 1000Mbps mode */
1145 		rcr &= ~ENET_RCR_RMII_10T;
1146 		break;
1147 	case IFM_100_TX:
1148 		ecr &= ~ENET_ECR_SPEED;		/* 100Mbps mode */
1149 		rcr &= ~ENET_RCR_RMII_10T;	/* 100Mbps mode */
1150 		break;
1151 	case IFM_10_T:
1152 		ecr &= ~ENET_ECR_SPEED;		/* 10Mbps mode */
1153 		rcr |= ENET_RCR_RMII_10T;	/* 10Mbps mode */
1154 		break;
1155 	default:
1156 		ecr = ecr0;
1157 		rcr = rcr0;
1158 		tcr = tcr0;
1159 		break;
1160 	}
1161 
1162 	if (sc->sc_rgmii == 0)
1163 		ecr &= ~ENET_ECR_SPEED;
1164 
1165 	if (sc->sc_flowflags & IFM_FLOW)
1166 		rcr |= ENET_RCR_FCE;
1167 	else
1168 		rcr &= ~ENET_RCR_FCE;
1169 
1170 	/* update registers if need change */
1171 	if (ecr != ecr0)
1172 		ENET_REG_WRITE(sc, ENET_ECR, ecr);
1173 	if (rcr != rcr0)
1174 		ENET_REG_WRITE(sc, ENET_RCR, rcr);
1175 	if (tcr != tcr0)
1176 		ENET_REG_WRITE(sc, ENET_TCR, tcr);
1177 }
1178 
1179 /*
1180  * handling descriptors
1181  */
1182 static void
1183 enet_init_txring(struct enet_softc *sc)
1184 {
1185 	int i;
1186 
1187 	/* build TX ring */
1188 	for (i = 0; i < ENET_TX_RING_CNT; i++) {
1189 		sc->sc_txdesc_ring[i].tx_flags1_len =
1190 		    ((i == (ENET_TX_RING_CNT - 1)) ? TXFLAGS1_W : 0);
1191 		sc->sc_txdesc_ring[i].tx_databuf = 0;
1192 		sc->sc_txdesc_ring[i].tx_flags2 = TXFLAGS2_INT;
1193 		sc->sc_txdesc_ring[i].tx__reserved1 = 0;
1194 		sc->sc_txdesc_ring[i].tx_flags3 = 0;
1195 		sc->sc_txdesc_ring[i].tx_1588timestamp = 0;
1196 		sc->sc_txdesc_ring[i].tx__reserved2 = 0;
1197 		sc->sc_txdesc_ring[i].tx__reserved3 = 0;
1198 
1199 		TXDESC_WRITEOUT(i);
1200 	}
1201 
1202 	sc->sc_tx_free = ENET_TX_RING_CNT;
1203 	sc->sc_tx_considx = 0;
1204 	sc->sc_tx_prodidx = 0;
1205 }
1206 
1207 static int
1208 enet_init_rxring(struct enet_softc *sc)
1209 {
1210 	int i, error;
1211 
1212 	/* build RX ring */
1213 	for (i = 0; i < ENET_RX_RING_CNT; i++) {
1214 		error = enet_alloc_rxbuf(sc, i);
1215 		if (error != 0)
1216 			return error;
1217 	}
1218 
1219 	sc->sc_rx_readidx = 0;
1220 
1221 	return 0;
1222 }
1223 
1224 static int
1225 enet_alloc_rxbuf(struct enet_softc *sc, int idx)
1226 {
1227 	struct mbuf *m;
1228 	int error;
1229 
1230 	KASSERT((idx >= 0) && (idx < ENET_RX_RING_CNT));
1231 
1232 	/* free mbuf if already allocated */
1233 	if (sc->sc_rxsoft[idx].rxs_mbuf != NULL) {
1234 		bus_dmamap_unload(sc->sc_dmat, sc->sc_rxsoft[idx].rxs_dmamap);
1235 		m_freem(sc->sc_rxsoft[idx].rxs_mbuf);
1236 		sc->sc_rxsoft[idx].rxs_mbuf = NULL;
1237 	}
1238 
1239 	/* allocate new mbuf cluster */
1240 	MGETHDR(m, M_DONTWAIT, MT_DATA);
1241 	if (m == NULL)
1242 		return ENOBUFS;
1243 	MCLGET(m, M_DONTWAIT);
1244 	if (!(m->m_flags & M_EXT)) {
1245 		m_freem(m);
1246 		return ENOBUFS;
1247 	}
1248 	m->m_len = MCLBYTES;
1249 	m->m_next = NULL;
1250 
1251 	error = bus_dmamap_load(sc->sc_dmat, sc->sc_rxsoft[idx].rxs_dmamap,
1252 	    m->m_ext.ext_buf, m->m_ext.ext_size, NULL,
1253 	    BUS_DMA_READ | BUS_DMA_NOWAIT);
1254 	if (error) {
1255 		m_freem(m);
1256 		return error;
1257 	}
1258 
1259 	bus_dmamap_sync(sc->sc_dmat, sc->sc_rxsoft[idx].rxs_dmamap, 0,
1260 	    sc->sc_rxsoft[idx].rxs_dmamap->dm_mapsize,
1261 	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1262 
1263 	sc->sc_rxsoft[idx].rxs_mbuf = m;
1264 	enet_reset_rxdesc(sc, idx);
1265 	return 0;
1266 }
1267 
1268 static void
1269 enet_reset_rxdesc(struct enet_softc *sc, int idx)
1270 {
1271 	uint32_t paddr;
1272 
1273 	paddr = sc->sc_rxsoft[idx].rxs_dmamap->dm_segs[0].ds_addr;
1274 
1275 	sc->sc_rxdesc_ring[idx].rx_flags1_len =
1276 	    RXFLAGS1_E |
1277 	    ((idx == (ENET_RX_RING_CNT - 1)) ? RXFLAGS1_W : 0);
1278 	sc->sc_rxdesc_ring[idx].rx_databuf = paddr;
1279 	sc->sc_rxdesc_ring[idx].rx_flags2 =
1280 	    RXFLAGS2_INT;
1281 	sc->sc_rxdesc_ring[idx].rx_hl = 0;
1282 	sc->sc_rxdesc_ring[idx].rx_proto = 0;
1283 	sc->sc_rxdesc_ring[idx].rx_cksum = 0;
1284 	sc->sc_rxdesc_ring[idx].rx_flags3 = 0;
1285 	sc->sc_rxdesc_ring[idx].rx_1588timestamp = 0;
1286 	sc->sc_rxdesc_ring[idx].rx__reserved2 = 0;
1287 	sc->sc_rxdesc_ring[idx].rx__reserved3 = 0;
1288 
1289 	RXDESC_WRITEOUT(idx);
1290 }
1291 
1292 static void
1293 enet_drain_txbuf(struct enet_softc *sc)
1294 {
1295 	int idx;
1296 	struct enet_txsoft *txs;
1297 	struct ifnet *ifp;
1298 
1299 	ifp = &sc->sc_ethercom.ec_if;
1300 
1301 	for (idx = sc->sc_tx_considx; idx != sc->sc_tx_prodidx;
1302 	    idx = ENET_TX_NEXTIDX(idx)) {
1303 
1304 		/* txsoft[] is used only first segment */
1305 		txs = &sc->sc_txsoft[idx];
1306 		TXDESC_READIN(idx);
1307 		if (sc->sc_txdesc_ring[idx].tx_flags1_len & TXFLAGS1_T1) {
1308 			sc->sc_txdesc_ring[idx].tx_flags1_len = 0;
1309 			bus_dmamap_unload(sc->sc_dmat,
1310 			    txs->txs_dmamap);
1311 			m_freem(txs->txs_mbuf);
1312 
1313 			ifp->if_oerrors++;
1314 		}
1315 		sc->sc_tx_free++;
1316 	}
1317 }
1318 
1319 static void
1320 enet_drain_rxbuf(struct enet_softc *sc)
1321 {
1322 	int i;
1323 
1324 	for (i = 0; i < ENET_RX_RING_CNT; i++) {
1325 		if (sc->sc_rxsoft[i].rxs_mbuf != NULL) {
1326 			sc->sc_rxdesc_ring[i].rx_flags1_len = 0;
1327 			bus_dmamap_unload(sc->sc_dmat,
1328 			    sc->sc_rxsoft[i].rxs_dmamap);
1329 			m_freem(sc->sc_rxsoft[i].rxs_mbuf);
1330 			sc->sc_rxsoft[i].rxs_mbuf = NULL;
1331 		}
1332 	}
1333 }
1334 
1335 static int
1336 enet_alloc_ring(struct enet_softc *sc)
1337 {
1338 	int i, error;
1339 
1340 	/*
1341 	 * build DMA maps for TX.
1342 	 * TX descriptor must be able to contain mbuf chains,
1343 	 * so, make up ENET_MAX_PKT_NSEGS dmamap.
1344 	 */
1345 	for (i = 0; i < ENET_TX_RING_CNT; i++) {
1346 		error = bus_dmamap_create(sc->sc_dmat, ENET_MAX_PKT_LEN,
1347 		    ENET_MAX_PKT_NSEGS, ENET_MAX_PKT_LEN, 0, BUS_DMA_NOWAIT,
1348 		    &sc->sc_txsoft[i].txs_dmamap);
1349 
1350 		if (error) {
1351 			aprint_error_dev(sc->sc_dev,
1352 			    "can't create DMA map for TX descs\n");
1353 			goto fail_1;
1354 		}
1355 	}
1356 
1357 	/*
1358 	 * build DMA maps for RX.
1359 	 * RX descripter contains An mbuf cluster,
1360 	 * and make up a dmamap.
1361 	 */
1362 	for (i = 0; i < ENET_RX_RING_CNT; i++) {
1363 		error = bus_dmamap_create(sc->sc_dmat, MCLBYTES,
1364 		    1, MCLBYTES, 0, BUS_DMA_NOWAIT,
1365 		    &sc->sc_rxsoft[i].rxs_dmamap);
1366 		if (error) {
1367 			aprint_error_dev(sc->sc_dev,
1368 			    "can't create DMA map for RX descs\n");
1369 			goto fail_2;
1370 		}
1371 	}
1372 
1373 	if (enet_alloc_dma(sc, sizeof(struct enet_txdesc) * ENET_TX_RING_CNT,
1374 	    (void **)&(sc->sc_txdesc_ring), &(sc->sc_txdesc_dmamap)) != 0)
1375 		return -1;
1376 	memset(sc->sc_txdesc_ring, 0,
1377 	    sizeof(struct enet_txdesc) * ENET_TX_RING_CNT);
1378 
1379 	if (enet_alloc_dma(sc, sizeof(struct enet_rxdesc) * ENET_RX_RING_CNT,
1380 	    (void **)&(sc->sc_rxdesc_ring), &(sc->sc_rxdesc_dmamap)) != 0)
1381 		return -1;
1382 	memset(sc->sc_rxdesc_ring, 0,
1383 	    sizeof(struct enet_rxdesc) * ENET_RX_RING_CNT);
1384 
1385 	return 0;
1386 
1387  fail_2:
1388 	for (i = 0; i < ENET_RX_RING_CNT; i++) {
1389 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
1390 			bus_dmamap_destroy(sc->sc_dmat,
1391 			    sc->sc_rxsoft[i].rxs_dmamap);
1392 	}
1393  fail_1:
1394 	for (i = 0; i < ENET_TX_RING_CNT; i++) {
1395 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
1396 			bus_dmamap_destroy(sc->sc_dmat,
1397 			    sc->sc_txsoft[i].txs_dmamap);
1398 	}
1399 	return error;
1400 }
1401 
1402 static int
1403 enet_encap_mbufalign(struct mbuf **mp)
1404 {
1405 	struct mbuf *m, *m0, *mt, *p, *x;
1406 	void *ap;
1407 	uint32_t alignoff, chiplen;
1408 
1409 	/*
1410 	 * iMX6 SoC ethernet controller requires
1411 	 * address of buffer must aligned 8, and
1412 	 * length of buffer must be greater than 10 (first fragment only?)
1413 	 */
1414 #define ALIGNBYTE	8
1415 #define MINBUFSIZE	10
1416 #define ALIGN_PTR(p, align)	\
1417 	(void *)(((uintptr_t)(p) + ((align) - 1)) & -(align))
1418 
1419 	m0 = *mp;
1420 	mt = p = NULL;
1421 	for (m = m0; m != NULL; m = m->m_next) {
1422 		alignoff = (uintptr_t)m->m_data & (ALIGNBYTE - 1);
1423 		if (m->m_len < (ALIGNBYTE * 2)) {
1424 			/*
1425 			 * rearrange mbuf data aligned
1426 			 *
1427 			 *        align 8 *       *       *       *       *
1428 			 *               +0123456789abcdef0123456789abcdef0
1429 			 * FROM m->m_data[___________abcdefghijklmn_______]
1430 			 *
1431 			 *               +0123456789abcdef0123456789abcdef0
1432 			 * TO   m->m_data[________abcdefghijklm___________] or
1433 			 *      m->m_data[________________abcdefghijklmn__]
1434 			 */
1435 			if ((alignoff != 0) && (m->m_len != 0)) {
1436 				chiplen = ALIGNBYTE - alignoff;
1437 				if (M_LEADINGSPACE(m) >= alignoff) {
1438 					ap = m->m_data - alignoff;
1439 					memmove(ap, m->m_data, m->m_len);
1440 					m->m_data = ap;
1441 				} else if (M_TRAILINGSPACE(m) >= chiplen) {
1442 					ap = m->m_data + chiplen;
1443 					memmove(ap, m->m_data, m->m_len);
1444 					m->m_data = ap;
1445 				} else {
1446 					/*
1447 					 * no space to align data. (M_READONLY?)
1448 					 * allocate new mbuf aligned,
1449 					 * and copy to it.
1450 					 */
1451 					MGET(x, M_DONTWAIT, m->m_type);
1452 					if (x == NULL) {
1453 						m_freem(m);
1454 						return ENOBUFS;
1455 					}
1456 					MCLAIM(x, m->m_owner);
1457 					if (m->m_flags & M_PKTHDR)
1458 						m_move_pkthdr(x, m);
1459 					x->m_len = m->m_len;
1460 					x->m_data = ALIGN_PTR(x->m_data,
1461 					    ALIGNBYTE);
1462 					memcpy(mtod(x, void *), mtod(m, void *),
1463 					    m->m_len);
1464 					p->m_next = x;
1465 					x->m_next = m_free(m);
1466 					m = x;
1467 				}
1468 			}
1469 
1470 			/*
1471 			 * fill 1st mbuf at least 10byte
1472 			 *
1473 			 *        align 8 *       *       *       *       *
1474 			 *               +0123456789abcdef0123456789abcdef0
1475 			 * FROM m->m_data[________abcde___________________]
1476 			 *      m->m_data[__fg____________________________]
1477 			 *      m->m_data[_________________hi_____________]
1478 			 *      m->m_data[__________jk____________________]
1479 			 *      m->m_data[____l___________________________]
1480 			 *
1481 			 *               +0123456789abcdef0123456789abcdef0
1482 			 * TO   m->m_data[________abcdefghij______________]
1483 			 *      m->m_data[________________________________]
1484 			 *      m->m_data[________________________________]
1485 			 *      m->m_data[___________k____________________]
1486 			 *      m->m_data[____l___________________________]
1487 			 */
1488 			if (mt == NULL) {
1489 				mt = m;
1490 				while (mt->m_len == 0) {
1491 					mt = mt->m_next;
1492 					if (mt == NULL) {
1493 						m_freem(m);
1494 						return ENOBUFS;
1495 					}
1496 				}
1497 
1498 				/* mt = 1st mbuf, x = 2nd mbuf */
1499 				x = mt->m_next;
1500 				while (mt->m_len < MINBUFSIZE) {
1501 					if (x == NULL) {
1502 						m_freem(m);
1503 						return ENOBUFS;
1504 					}
1505 
1506 					alignoff = (uintptr_t)x->m_data &
1507 					    (ALIGNBYTE - 1);
1508 					chiplen = ALIGNBYTE - alignoff;
1509 					if (chiplen > x->m_len) {
1510 						chiplen = x->m_len;
1511 					} else if ((mt->m_len + chiplen) <
1512 					    MINBUFSIZE) {
1513 						/*
1514 						 * next mbuf should be greater
1515 						 * than ALIGNBYTE?
1516 						 */
1517 						if (x->m_len >= (chiplen +
1518 						    ALIGNBYTE * 2))
1519 							chiplen += ALIGNBYTE;
1520 						else
1521 							chiplen = x->m_len;
1522 					}
1523 
1524 					if (chiplen &&
1525 					    (M_TRAILINGSPACE(mt) < chiplen)) {
1526 						/*
1527 						 * move data to the begining of
1528 						 * m_dat[] (aligned) to en-
1529 						 * large trailingspace
1530 						 */
1531 						ap = M_BUFADDR(mt);
1532 						ap = ALIGN_PTR(ap, ALIGNBYTE);
1533 						memcpy(ap, mt->m_data,
1534 						    mt->m_len);
1535 						mt->m_data = ap;
1536 					}
1537 
1538 					if (chiplen &&
1539 					    (M_TRAILINGSPACE(mt) >= chiplen)) {
1540 						memcpy(mt->m_data + mt->m_len,
1541 						    x->m_data, chiplen);
1542 						mt->m_len += chiplen;
1543 						m_adj(x, chiplen);
1544 					}
1545 
1546 					x = x->m_next;
1547 				}
1548 			}
1549 
1550 		} else {
1551 			mt = m;
1552 
1553 			/*
1554 			 * allocate new mbuf x, and rearrange as below;
1555 			 *
1556 			 *        align 8 *       *       *       *       *
1557 			 *               +0123456789abcdef0123456789abcdef0
1558 			 * FROM m->m_data[____________abcdefghijklmnopq___]
1559 			 *
1560 			 *               +0123456789abcdef0123456789abcdef0
1561 			 * TO   x->m_data[________abcdefghijkl____________]
1562 			 *      m->m_data[________________________mnopq___]
1563 			 *
1564 			 */
1565 			if (alignoff != 0) {
1566 				/* at least ALIGNBYTE */
1567 				chiplen = ALIGNBYTE - alignoff + ALIGNBYTE;
1568 
1569 				MGET(x, M_DONTWAIT, m->m_type);
1570 				if (x == NULL) {
1571 					m_freem(m);
1572 					return ENOBUFS;
1573 				}
1574 				MCLAIM(x, m->m_owner);
1575 				if (m->m_flags & M_PKTHDR)
1576 					m_move_pkthdr(x, m);
1577 				x->m_data = ALIGN_PTR(x->m_data, ALIGNBYTE);
1578 				memcpy(mtod(x, void *), mtod(m, void *),
1579 				    chiplen);
1580 				x->m_len = chiplen;
1581 				x->m_next = m;
1582 				m_adj(m, chiplen);
1583 
1584 				if (p == NULL)
1585 					m0 = x;
1586 				else
1587 					p->m_next = x;
1588 			}
1589 		}
1590 		p = m;
1591 	}
1592 	*mp = m0;
1593 
1594 	return 0;
1595 }
1596 
1597 static int
1598 enet_encap_txring(struct enet_softc *sc, struct mbuf **mp)
1599 {
1600 	bus_dmamap_t map;
1601 	struct mbuf *m;
1602 	int csumflags, idx, i, error;
1603 	uint32_t flags1, flags2;
1604 
1605 	idx = sc->sc_tx_prodidx;
1606 	map = sc->sc_txsoft[idx].txs_dmamap;
1607 
1608 	/* align mbuf data for claim of ENET */
1609 	error = enet_encap_mbufalign(mp);
1610 	if (error != 0)
1611 		return error;
1612 
1613 	m = *mp;
1614 	csumflags = m->m_pkthdr.csum_flags;
1615 
1616 	error = bus_dmamap_load_mbuf(sc->sc_dmat, map, m,
1617 	    BUS_DMA_NOWAIT);
1618 	if (error != 0) {
1619 		device_printf(sc->sc_dev,
1620 		    "Error mapping mbuf into TX chain: error=%d\n", error);
1621 		m_freem(m);
1622 		return error;
1623 	}
1624 
1625 	if (map->dm_nsegs > sc->sc_tx_free) {
1626 		bus_dmamap_unload(sc->sc_dmat, map);
1627 		device_printf(sc->sc_dev,
1628 		    "too many mbuf chain %d\n", map->dm_nsegs);
1629 		m_freem(m);
1630 		return ENOBUFS;
1631 	}
1632 
1633 	/* fill protocol cksum zero beforehand */
1634 	if (csumflags & (M_CSUM_UDPv4 | M_CSUM_TCPv4 |
1635 	    M_CSUM_UDPv6 | M_CSUM_TCPv6)) {
1636 		int ehlen;
1637 		uint16_t etype;
1638 
1639 		m_copydata(m, ETHER_ADDR_LEN * 2, sizeof(etype), &etype);
1640 		switch (ntohs(etype)) {
1641 		case ETHERTYPE_IP:
1642 		case ETHERTYPE_IPV6:
1643 			ehlen = ETHER_HDR_LEN;
1644 			break;
1645 		case ETHERTYPE_VLAN:
1646 			ehlen = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
1647 			break;
1648 		default:
1649 			ehlen = 0;
1650 			break;
1651 		}
1652 
1653 		if (ehlen) {
1654 			const int off =
1655 			    M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) +
1656 			    M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data);
1657 			if (m->m_pkthdr.len >= ehlen + off + sizeof(uint16_t)) {
1658 				uint16_t zero = 0;
1659 				m_copyback(m, ehlen + off, sizeof(zero), &zero);
1660 			}
1661 		}
1662 	}
1663 
1664 	bus_dmamap_sync(sc->sc_dmat, map, 0, map->dm_mapsize,
1665 	    BUS_DMASYNC_PREWRITE);
1666 
1667 	for (i = 0; i < map->dm_nsegs; i++) {
1668 		flags1 = TXFLAGS1_R;
1669 		flags2 = 0;
1670 
1671 		if (i == 0) {
1672 			flags1 |= TXFLAGS1_T1;	/* mark as first segment */
1673 			sc->sc_txsoft[idx].txs_mbuf = m;
1674 		}
1675 
1676 		/* checksum offloading */
1677 		if (csumflags & (M_CSUM_UDPv4 | M_CSUM_TCPv4 |
1678 		    M_CSUM_UDPv6 | M_CSUM_TCPv6))
1679 			flags2 |= TXFLAGS2_PINS;
1680 		if (csumflags & (M_CSUM_IPv4))
1681 			flags2 |= TXFLAGS2_IINS;
1682 
1683 		if (i == map->dm_nsegs - 1) {
1684 			/* mark last segment */
1685 			flags1 |= TXFLAGS1_L | TXFLAGS1_TC;
1686 			flags2 |= TXFLAGS2_INT;
1687 		}
1688 		if (idx == ENET_TX_RING_CNT - 1) {
1689 			/* mark end of ring */
1690 			flags1 |= TXFLAGS1_W;
1691 		}
1692 
1693 		sc->sc_txdesc_ring[idx].tx_databuf = map->dm_segs[i].ds_addr;
1694 		sc->sc_txdesc_ring[idx].tx_flags2 = flags2;
1695 		sc->sc_txdesc_ring[idx].tx_flags3 = 0;
1696 		TXDESC_WRITEOUT(idx);
1697 
1698 		sc->sc_txdesc_ring[idx].tx_flags1_len =
1699 		    flags1 | TXFLAGS1_LEN(map->dm_segs[i].ds_len);
1700 		TXDESC_WRITEOUT(idx);
1701 
1702 		idx = ENET_TX_NEXTIDX(idx);
1703 		sc->sc_tx_free--;
1704 	}
1705 
1706 	sc->sc_tx_prodidx = idx;
1707 
1708 	return 0;
1709 }
1710 
1711 /*
1712  * device initialize
1713  */
1714 static int
1715 enet_init_regs(struct enet_softc *sc, int init)
1716 {
1717 	struct mii_data *mii;
1718 	struct ifmedia_entry *ife;
1719 	paddr_t paddr;
1720 	uint32_t val;
1721 	int miimode, fulldup, ecr_speed, rcr_speed, flowctrl;
1722 
1723 	if (init) {
1724 		fulldup = 1;
1725 		ecr_speed = ENET_ECR_SPEED;
1726 		rcr_speed = 0;
1727 		flowctrl = 0;
1728 	} else {
1729 		mii = &sc->sc_mii;
1730 		ife = mii->mii_media.ifm_cur;
1731 
1732 		if ((ife->ifm_media & IFM_FDX) != 0)
1733 			fulldup = 1;
1734 		else
1735 			fulldup = 0;
1736 
1737 		switch (IFM_SUBTYPE(ife->ifm_media)) {
1738 		case IFM_10_T:
1739 			ecr_speed = 0;
1740 			rcr_speed = ENET_RCR_RMII_10T;
1741 			break;
1742 		case IFM_100_TX:
1743 			ecr_speed = 0;
1744 			rcr_speed = 0;
1745 			break;
1746 		default:
1747 			ecr_speed = ENET_ECR_SPEED;
1748 			rcr_speed = 0;
1749 			break;
1750 		}
1751 
1752 		flowctrl = sc->sc_flowflags & IFM_FLOW;
1753 	}
1754 
1755 	if (sc->sc_rgmii == 0)
1756 		ecr_speed = 0;
1757 
1758 	/* reset */
1759 	ENET_REG_WRITE(sc, ENET_ECR, ecr_speed | ENET_ECR_RESET);
1760 
1761 	/* mask and clear all interrupt */
1762 	ENET_REG_WRITE(sc, ENET_EIMR, 0);
1763 	ENET_REG_WRITE(sc, ENET_EIR, 0xffffffff);
1764 
1765 	/* full duplex */
1766 	ENET_REG_WRITE(sc, ENET_TCR, fulldup ? ENET_TCR_FDEN : 0);
1767 
1768 	/* clear and enable MIB register */
1769 	ENET_REG_WRITE(sc, ENET_MIBC, ENET_MIBC_MIB_CLEAR);
1770 	ENET_REG_WRITE(sc, ENET_MIBC, 0);
1771 
1772 	/* MII speed setup. MDCclk(=2.5MHz) = (internal module clock)/((val+1)*2) */
1773 	val = (sc->sc_clock + (5000000 - 1)) / 5000000 - 1;
1774 	ENET_REG_WRITE(sc, ENET_MSCR, __SHIFTIN(val, ENET_MSCR_MII_SPEED));
1775 
1776 	/* Opcode/Pause Duration */
1777 	ENET_REG_WRITE(sc, ENET_OPD, 0x00010020);
1778 
1779 	/* Receive FIFO */
1780 	ENET_REG_WRITE(sc, ENET_RSFL, 16);	/* RxFIFO Section Full */
1781 	ENET_REG_WRITE(sc, ENET_RSEM, 0x84);	/* RxFIFO Section Empty */
1782 	ENET_REG_WRITE(sc, ENET_RAEM, 8);	/* RxFIFO Almost Empty */
1783 	ENET_REG_WRITE(sc, ENET_RAFL, 8);	/* RxFIFO Almost Full */
1784 
1785 	/* Transmit FIFO */
1786 	ENET_REG_WRITE(sc, ENET_TFWR, ENET_TFWR_STRFWD |
1787 	    ENET_TFWR_FIFO(128));		/* TxFIFO Watermark */
1788 	ENET_REG_WRITE(sc, ENET_TSEM, 0);	/* TxFIFO Section Empty */
1789 	ENET_REG_WRITE(sc, ENET_TAEM, 256);	/* TxFIFO Almost Empty */
1790 	ENET_REG_WRITE(sc, ENET_TAFL, 8);	/* TxFIFO Almost Full */
1791 	ENET_REG_WRITE(sc, ENET_TIPG, 12);	/* Tx Inter-Packet Gap */
1792 
1793 	/* hardware checksum is default off (override in TX descripter) */
1794 	ENET_REG_WRITE(sc, ENET_TACC, 0);
1795 
1796 	/*
1797 	 * align ethernet payload on 32bit, discard frames with MAC layer error,
1798 	 * and don't discard checksum error
1799 	 */
1800 	ENET_REG_WRITE(sc, ENET_RACC, ENET_RACC_SHIFT16 | ENET_RACC_LINEDIS);
1801 
1802 	/* maximum frame size */
1803 	val = ENET_DEFAULT_PKT_LEN;
1804 	ENET_REG_WRITE(sc, ENET_FTRL, val);	/* Frame Truncation Length */
1805 
1806 	if (sc->sc_rgmii == 0)
1807 		miimode = ENET_RCR_RMII_MODE | ENET_RCR_MII_MODE;
1808 	else
1809 		miimode = ENET_RCR_RGMII_EN;
1810 	ENET_REG_WRITE(sc, ENET_RCR,
1811 	    ENET_RCR_PADEN |			/* RX frame padding remove */
1812 	    miimode |
1813 	    (flowctrl ? ENET_RCR_FCE : 0) |	/* flow control enable */
1814 	    rcr_speed |
1815 	    (fulldup ? 0 : ENET_RCR_DRT) |
1816 	    ENET_RCR_MAX_FL(val));
1817 
1818 	/* Maximum Receive BufSize per one descriptor */
1819 	ENET_REG_WRITE(sc, ENET_MRBR, RXDESC_MAXBUFSIZE);
1820 
1821 
1822 	/* TX/RX Descriptor Physical Address */
1823 	paddr = sc->sc_txdesc_dmamap->dm_segs[0].ds_addr;
1824 	ENET_REG_WRITE(sc, ENET_TDSR, paddr);
1825 	paddr = sc->sc_rxdesc_dmamap->dm_segs[0].ds_addr;
1826 	ENET_REG_WRITE(sc, ENET_RDSR, paddr);
1827 	/* sync cache */
1828 	bus_dmamap_sync(sc->sc_dmat, sc->sc_txdesc_dmamap, 0,
1829 	    sc->sc_txdesc_dmamap->dm_mapsize, BUS_DMASYNC_PREWRITE);
1830 	bus_dmamap_sync(sc->sc_dmat, sc->sc_rxdesc_dmamap, 0,
1831 	    sc->sc_rxdesc_dmamap->dm_mapsize, BUS_DMASYNC_PREWRITE);
1832 
1833 	/* enable interrupts */
1834 	val = ENET_EIMR | ENET_EIR_TXF | ENET_EIR_RXF | ENET_EIR_EBERR;
1835 	if (sc->sc_imxtype == 7)
1836 		val |= ENET_EIR_TXF2 | ENET_EIR_RXF2 | ENET_EIR_TXF1 |
1837 		    ENET_EIR_RXF1;
1838 	ENET_REG_WRITE(sc, ENET_EIMR, val);
1839 
1840 	/* enable ether */
1841 	ENET_REG_WRITE(sc, ENET_ECR,
1842 #if _BYTE_ORDER == _LITTLE_ENDIAN
1843 	    ENET_ECR_DBSWP |
1844 #endif
1845 	    ecr_speed |
1846 	    ENET_ECR_EN1588 |	/* use enhanced TX/RX descriptor */
1847 	    ENET_ECR_ETHEREN);	/* Ethernet Enable */
1848 
1849 	return 0;
1850 }
1851 
1852 static int
1853 enet_alloc_dma(struct enet_softc *sc, size_t size, void **addrp,
1854     bus_dmamap_t *mapp)
1855 {
1856 	bus_dma_segment_t seglist[1];
1857 	int nsegs, error;
1858 
1859 	if ((error = bus_dmamem_alloc(sc->sc_dmat, size, PAGE_SIZE, 0, seglist,
1860 	    1, &nsegs, M_NOWAIT)) != 0) {
1861 		device_printf(sc->sc_dev,
1862 		    "unable to allocate DMA buffer, error=%d\n", error);
1863 		goto fail_alloc;
1864 	}
1865 
1866 	if ((error = bus_dmamem_map(sc->sc_dmat, seglist, 1, size, addrp,
1867 	    BUS_DMA_NOWAIT | BUS_DMA_COHERENT)) != 0) {
1868 		device_printf(sc->sc_dev,
1869 		    "unable to map DMA buffer, error=%d\n",
1870 		    error);
1871 		goto fail_map;
1872 	}
1873 
1874 	if ((error = bus_dmamap_create(sc->sc_dmat, size, 1, size, 0,
1875 	    BUS_DMA_NOWAIT, mapp)) != 0) {
1876 		device_printf(sc->sc_dev,
1877 		    "unable to create DMA map, error=%d\n", error);
1878 		goto fail_create;
1879 	}
1880 
1881 	if ((error = bus_dmamap_load(sc->sc_dmat, *mapp, *addrp, size, NULL,
1882 	    BUS_DMA_NOWAIT)) != 0) {
1883 		aprint_error_dev(sc->sc_dev,
1884 		    "unable to load DMA map, error=%d\n", error);
1885 		goto fail_load;
1886 	}
1887 
1888 	return 0;
1889 
1890  fail_load:
1891 	bus_dmamap_destroy(sc->sc_dmat, *mapp);
1892  fail_create:
1893 	bus_dmamem_unmap(sc->sc_dmat, *addrp, size);
1894  fail_map:
1895 	bus_dmamem_free(sc->sc_dmat, seglist, 1);
1896  fail_alloc:
1897 	return error;
1898 }
1899