xref: /netbsd-src/sys/arch/powerpc/ibm4xx/dev/if_emac.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: if_emac.c,v 1.48 2018/06/26 06:47:59 msaitoh Exp $	*/
2 
3 /*
4  * Copyright 2001, 2002 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Simon Burge and Jason Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * emac(4) supports following ibm4xx's EMACs.
40  *   XXXX: ZMII and 'TCP Accelaration Hardware' not support yet...
41  *
42  *            tested
43  *            ------
44  * 405EP	-  10/100 x2
45  * 405EX/EXr	o  10/100/1000 x2 (EXr x1), STA v2, 256bit hash-Table, RGMII
46  * 405GP/GPr	o  10/100
47  * 440EP	-  10/100 x2, ZMII
48  * 440GP	-  10/100 x2, ZMII
49  * 440GX	-  10/100/1000 x4, ZMII/RGMII(ch 2, 3), TAH(ch 2, 3)
50  * 440SP	-  10/100/1000
51  * 440SPe	-  10/100/1000, STA v2
52  */
53 
54 #include <sys/cdefs.h>
55 __KERNEL_RCSID(0, "$NetBSD: if_emac.c,v 1.48 2018/06/26 06:47:59 msaitoh Exp $");
56 
57 #include "opt_emac.h"
58 
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/mbuf.h>
62 #include <sys/kernel.h>
63 #include <sys/socket.h>
64 #include <sys/ioctl.h>
65 #include <sys/cpu.h>
66 #include <sys/device.h>
67 
68 #include <uvm/uvm_extern.h>		/* for PAGE_SIZE */
69 
70 #include <net/if.h>
71 #include <net/if_dl.h>
72 #include <net/if_media.h>
73 #include <net/if_ether.h>
74 
75 #include <net/bpf.h>
76 
77 #include <powerpc/ibm4xx/cpu.h>
78 #include <powerpc/ibm4xx/dcr4xx.h>
79 #include <powerpc/ibm4xx/mal405gp.h>
80 #include <powerpc/ibm4xx/dev/emacreg.h>
81 #include <powerpc/ibm4xx/dev/if_emacreg.h>
82 #include <powerpc/ibm4xx/dev/if_emacvar.h>
83 #include <powerpc/ibm4xx/dev/malvar.h>
84 #include <powerpc/ibm4xx/dev/opbreg.h>
85 #include <powerpc/ibm4xx/dev/opbvar.h>
86 #include <powerpc/ibm4xx/dev/plbvar.h>
87 #if defined(EMAC_ZMII_PHY) || defined(EMAC_RGMII_PHY)
88 #include <powerpc/ibm4xx/dev/rmiivar.h>
89 #endif
90 
91 #include <dev/mii/miivar.h>
92 
93 #include "locators.h"
94 
95 
96 /*
97  * Transmit descriptor list size.  There are two Tx channels, each with
98  * up to 256 hardware descriptors available.  We currently use one Tx
99  * channel.  We tell the upper layers that they can queue a lot of
100  * packets, and we go ahead and manage up to 64 of them at a time.  We
101  * allow up to 16 DMA segments per packet.
102  */
103 #define	EMAC_NTXSEGS		16
104 #define	EMAC_TXQUEUELEN		64
105 #define	EMAC_TXQUEUELEN_MASK	(EMAC_TXQUEUELEN - 1)
106 #define	EMAC_TXQUEUE_GC		(EMAC_TXQUEUELEN / 4)
107 #define	EMAC_NTXDESC		256
108 #define	EMAC_NTXDESC_MASK	(EMAC_NTXDESC - 1)
109 #define	EMAC_NEXTTX(x)		(((x) + 1) & EMAC_NTXDESC_MASK)
110 #define	EMAC_NEXTTXS(x)		(((x) + 1) & EMAC_TXQUEUELEN_MASK)
111 
112 /*
113  * Receive descriptor list size.  There is one Rx channel with up to 256
114  * hardware descriptors available.  We allocate 64 receive descriptors,
115  * each with a 2k buffer (MCLBYTES).
116  */
117 #define	EMAC_NRXDESC		64
118 #define	EMAC_NRXDESC_MASK	(EMAC_NRXDESC - 1)
119 #define	EMAC_NEXTRX(x)		(((x) + 1) & EMAC_NRXDESC_MASK)
120 #define	EMAC_PREVRX(x)		(((x) - 1) & EMAC_NRXDESC_MASK)
121 
122 /*
123  * Transmit/receive descriptors that are DMA'd to the EMAC.
124  */
125 struct emac_control_data {
126 	struct mal_descriptor ecd_txdesc[EMAC_NTXDESC];
127 	struct mal_descriptor ecd_rxdesc[EMAC_NRXDESC];
128 };
129 
130 #define	EMAC_CDOFF(x)		offsetof(struct emac_control_data, x)
131 #define	EMAC_CDTXOFF(x)		EMAC_CDOFF(ecd_txdesc[(x)])
132 #define	EMAC_CDRXOFF(x)		EMAC_CDOFF(ecd_rxdesc[(x)])
133 
134 /*
135  * Software state for transmit jobs.
136  */
137 struct emac_txsoft {
138 	struct mbuf *txs_mbuf;		/* head of mbuf chain */
139 	bus_dmamap_t txs_dmamap;	/* our DMA map */
140 	int txs_firstdesc;		/* first descriptor in packet */
141 	int txs_lastdesc;		/* last descriptor in packet */
142 	int txs_ndesc;			/* # of descriptors used */
143 };
144 
145 /*
146  * Software state for receive descriptors.
147  */
148 struct emac_rxsoft {
149 	struct mbuf *rxs_mbuf;		/* head of mbuf chain */
150 	bus_dmamap_t rxs_dmamap;	/* our DMA map */
151 };
152 
153 /*
154  * Software state per device.
155  */
156 struct emac_softc {
157 	device_t sc_dev;		/* generic device information */
158 	int sc_instance;		/* instance no. */
159 	bus_space_tag_t sc_st;		/* bus space tag */
160 	bus_space_handle_t sc_sh;	/* bus space handle */
161 	bus_dma_tag_t sc_dmat;		/* bus DMA tag */
162 	struct ethercom sc_ethercom;	/* ethernet common data */
163 	void *sc_sdhook;		/* shutdown hook */
164 	void *sc_powerhook;		/* power management hook */
165 
166 	struct mii_data sc_mii;		/* MII/media information */
167 	struct callout sc_callout;	/* tick callout */
168 
169 	uint32_t sc_mr1;		/* copy of Mode Register 1 */
170 	uint32_t sc_stacr_read;		/* Read opcode of STAOPC of STACR */
171 	uint32_t sc_stacr_write;	/* Write opcode of STAOPC of STACR */
172 	uint32_t sc_stacr_bits;		/* misc bits of STACR */
173 	bool sc_stacr_completed;	/* Operation completed of STACR */
174 	int sc_htsize;			/* Hash Table size */
175 
176 	bus_dmamap_t sc_cddmamap;	/* control data dma map */
177 #define	sc_cddma	sc_cddmamap->dm_segs[0].ds_addr
178 
179 	/* Software state for transmit/receive descriptors. */
180 	struct emac_txsoft sc_txsoft[EMAC_TXQUEUELEN];
181 	struct emac_rxsoft sc_rxsoft[EMAC_NRXDESC];
182 
183 	/* Control data structures. */
184 	struct emac_control_data *sc_control_data;
185 #define	sc_txdescs	sc_control_data->ecd_txdesc
186 #define	sc_rxdescs	sc_control_data->ecd_rxdesc
187 
188 #ifdef EMAC_EVENT_COUNTERS
189 	struct evcnt sc_ev_rxintr;	/* Rx interrupts */
190 	struct evcnt sc_ev_txintr;	/* Tx interrupts */
191 	struct evcnt sc_ev_rxde;	/* Rx descriptor interrupts */
192 	struct evcnt sc_ev_txde;	/* Tx descriptor interrupts */
193 	struct evcnt sc_ev_intr;	/* General EMAC interrupts */
194 
195 	struct evcnt sc_ev_txreap;	/* Calls to Tx descriptor reaper */
196 	struct evcnt sc_ev_txsstall;	/* Tx stalled due to no txs */
197 	struct evcnt sc_ev_txdstall;	/* Tx stalled due to no txd */
198 	struct evcnt sc_ev_txdrop;	/* Tx packets dropped (too many segs) */
199 	struct evcnt sc_ev_tu;		/* Tx underrun */
200 #endif /* EMAC_EVENT_COUNTERS */
201 
202 	int sc_txfree;			/* number of free Tx descriptors */
203 	int sc_txnext;			/* next ready Tx descriptor */
204 
205 	int sc_txsfree;			/* number of free Tx jobs */
206 	int sc_txsnext;			/* next ready Tx job */
207 	int sc_txsdirty;		/* dirty Tx jobs */
208 
209 	int sc_rxptr;			/* next ready RX descriptor/descsoft */
210 
211 	void (*sc_rmii_enable)(device_t, int);		/* reduced MII enable */
212 	void (*sc_rmii_disable)(device_t, int);		/* reduced MII disable*/
213 	void (*sc_rmii_speed)(device_t, int, int);	/* reduced MII speed */
214 };
215 
216 #ifdef EMAC_EVENT_COUNTERS
217 #define	EMAC_EVCNT_INCR(ev)	(ev)->ev_count++
218 #else
219 #define	EMAC_EVCNT_INCR(ev)	/* nothing */
220 #endif
221 
222 #define	EMAC_CDTXADDR(sc, x)	((sc)->sc_cddma + EMAC_CDTXOFF((x)))
223 #define	EMAC_CDRXADDR(sc, x)	((sc)->sc_cddma + EMAC_CDRXOFF((x)))
224 
225 #define	EMAC_CDTXSYNC(sc, x, n, ops)					\
226 do {									\
227 	int __x, __n;							\
228 									\
229 	__x = (x);							\
230 	__n = (n);							\
231 									\
232 	/* If it will wrap around, sync to the end of the ring. */	\
233 	if ((__x + __n) > EMAC_NTXDESC) {				\
234 		bus_dmamap_sync((sc)->sc_dmat, (sc)->sc_cddmamap,	\
235 		    EMAC_CDTXOFF(__x), sizeof(struct mal_descriptor) *	\
236 		    (EMAC_NTXDESC - __x), (ops));			\
237 		__n -= (EMAC_NTXDESC - __x);				\
238 		__x = 0;						\
239 	}								\
240 									\
241 	/* Now sync whatever is left. */				\
242 	bus_dmamap_sync((sc)->sc_dmat, (sc)->sc_cddmamap,		\
243 	    EMAC_CDTXOFF(__x), sizeof(struct mal_descriptor) * __n, (ops)); \
244 } while (/*CONSTCOND*/0)
245 
246 #define	EMAC_CDRXSYNC(sc, x, ops)					\
247 do {									\
248 	bus_dmamap_sync((sc)->sc_dmat, (sc)->sc_cddmamap,		\
249 	    EMAC_CDRXOFF((x)), sizeof(struct mal_descriptor), (ops));	\
250 } while (/*CONSTCOND*/0)
251 
252 #define	EMAC_INIT_RXDESC(sc, x)						\
253 do {									\
254 	struct emac_rxsoft *__rxs = &(sc)->sc_rxsoft[(x)];		\
255 	struct mal_descriptor *__rxd = &(sc)->sc_rxdescs[(x)];		\
256 	struct mbuf *__m = __rxs->rxs_mbuf;				\
257 									\
258 	/*								\
259 	 * Note: We scoot the packet forward 2 bytes in the buffer	\
260 	 * so that the payload after the Ethernet header is aligned	\
261 	 * to a 4-byte boundary.					\
262 	 */								\
263 	__m->m_data = __m->m_ext.ext_buf + 2;				\
264 									\
265 	__rxd->md_data = __rxs->rxs_dmamap->dm_segs[0].ds_addr + 2;	\
266 	__rxd->md_data_len = __m->m_ext.ext_size - 2;			\
267 	__rxd->md_stat_ctrl = MAL_RX_EMPTY | MAL_RX_INTERRUPT |		\
268 	    /* Set wrap on last descriptor. */				\
269 	    (((x) == EMAC_NRXDESC - 1) ? MAL_RX_WRAP : 0);		\
270 	EMAC_CDRXSYNC((sc), (x), BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE); \
271 } while (/*CONSTCOND*/0)
272 
273 #define	EMAC_WRITE(sc, reg, val) \
274 	bus_space_write_stream_4((sc)->sc_st, (sc)->sc_sh, (reg), (val))
275 #define	EMAC_READ(sc, reg) \
276 	bus_space_read_stream_4((sc)->sc_st, (sc)->sc_sh, (reg))
277 
278 #define	EMAC_SET_FILTER(aht, crc) \
279 do {									\
280 	(aht)[3 - (((crc) >> 26) >> 4)] |= 1 << (((crc) >> 26) & 0xf);	\
281 } while (/*CONSTCOND*/0)
282 #define	EMAC_SET_FILTER256(aht, crc) \
283 do {									\
284 	(aht)[7 - (((crc) >> 24) >> 5)] |= 1 << (((crc) >> 24) & 0x1f);	\
285 } while (/*CONSTCOND*/0)
286 
287 static int	emac_match(device_t, cfdata_t, void *);
288 static void	emac_attach(device_t, device_t, void *);
289 
290 static int	emac_intr(void *);
291 static void	emac_shutdown(void *);
292 
293 static void	emac_start(struct ifnet *);
294 static int	emac_ioctl(struct ifnet *, u_long, void *);
295 static int	emac_init(struct ifnet *);
296 static void	emac_stop(struct ifnet *, int);
297 static void	emac_watchdog(struct ifnet *);
298 
299 static int	emac_add_rxbuf(struct emac_softc *, int);
300 static void	emac_rxdrain(struct emac_softc *);
301 static int	emac_set_filter(struct emac_softc *);
302 static int	emac_txreap(struct emac_softc *);
303 
304 static void	emac_soft_reset(struct emac_softc *);
305 static void	emac_smart_reset(struct emac_softc *);
306 
307 static int	emac_mii_readreg(device_t, int, int);
308 static void	emac_mii_writereg(device_t, int, int, int);
309 static void	emac_mii_statchg(struct ifnet *);
310 static uint32_t	emac_mii_wait(struct emac_softc *);
311 static void	emac_mii_tick(void *);
312 
313 int		emac_copy_small = 0;
314 
315 CFATTACH_DECL_NEW(emac, sizeof(struct emac_softc),
316     emac_match, emac_attach, NULL, NULL);
317 
318 
319 static int
320 emac_match(device_t parent, cfdata_t cf, void *aux)
321 {
322 	struct opb_attach_args *oaa = aux;
323 
324 	/* match only on-chip ethernet devices */
325 	if (strcmp(oaa->opb_name, cf->cf_name) == 0)
326 		return 1;
327 
328 	return 0;
329 }
330 
331 static void
332 emac_attach(device_t parent, device_t self, void *aux)
333 {
334 	struct opb_attach_args *oaa = aux;
335 	struct emac_softc *sc = device_private(self);
336 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
337 	struct mii_data *mii = &sc->sc_mii;
338 	const char * xname = device_xname(self);
339 	bus_dma_segment_t seg;
340 	int error, i, nseg, opb_freq, opbc, mii_phy = MII_PHY_ANY;
341 	const uint8_t *enaddr;
342 	prop_dictionary_t dict = device_properties(self);
343 	prop_data_t ea;
344 
345 	bus_space_map(oaa->opb_bt, oaa->opb_addr, EMAC_NREG, 0, &sc->sc_sh);
346 
347 	sc->sc_dev = self;
348 	sc->sc_instance = oaa->opb_instance;
349 	sc->sc_st = oaa->opb_bt;
350 	sc->sc_dmat = oaa->opb_dmat;
351 
352 	callout_init(&sc->sc_callout, 0);
353 
354 	aprint_naive("\n");
355 	aprint_normal(": Ethernet Media Access Controller\n");
356 
357 	/* Fetch the Ethernet address. */
358 	ea = prop_dictionary_get(dict, "mac-address");
359 	if (ea == NULL) {
360 		aprint_error_dev(self, "unable to get mac-address property\n");
361 		return;
362 	}
363 	KASSERT(prop_object_type(ea) == PROP_TYPE_DATA);
364 	KASSERT(prop_data_size(ea) == ETHER_ADDR_LEN);
365 	enaddr = prop_data_data_nocopy(ea);
366 	aprint_normal_dev(self, "Ethernet address %s\n", ether_sprintf(enaddr));
367 
368 #if defined(EMAC_ZMII_PHY) || defined(EMAC_RGMII_PHY)
369 	/* Fetch the MII offset. */
370 	prop_dictionary_get_uint32(dict, "mii-phy", &mii_phy);
371 
372 #ifdef EMAC_ZMII_PHY
373 	if (oaa->opb_flags & OPB_FLAGS_EMAC_RMII_ZMII)
374 		zmii_attach(parent, sc->sc_instance, &sc->sc_rmii_enable,
375 		    &sc->sc_rmii_disable, &sc->sc_rmii_speed);
376 #endif
377 #ifdef EMAC_RGMII_PHY
378 	if (oaa->opb_flags & OPB_FLAGS_EMAC_RMII_RGMII)
379 		rgmii_attach(parent, sc->sc_instance, &sc->sc_rmii_enable,
380 		    &sc->sc_rmii_disable, &sc->sc_rmii_speed);
381 #endif
382 #endif
383 
384 	/*
385 	 * Allocate the control data structures, and create and load the
386 	 * DMA map for it.
387 	 */
388 	if ((error = bus_dmamem_alloc(sc->sc_dmat,
389 	    sizeof(struct emac_control_data), 0, 0, &seg, 1, &nseg, 0)) != 0) {
390 		aprint_error_dev(self,
391 		    "unable to allocate control data, error = %d\n", error);
392 		goto fail_0;
393 	}
394 
395 	if ((error = bus_dmamem_map(sc->sc_dmat, &seg, nseg,
396 	    sizeof(struct emac_control_data), (void **)&sc->sc_control_data,
397 	    BUS_DMA_COHERENT)) != 0) {
398 		aprint_error_dev(self,
399 		    "unable to map control data, error = %d\n", error);
400 		goto fail_1;
401 	}
402 
403 	if ((error = bus_dmamap_create(sc->sc_dmat,
404 	    sizeof(struct emac_control_data), 1,
405 	    sizeof(struct emac_control_data), 0, 0, &sc->sc_cddmamap)) != 0) {
406 		aprint_error_dev(self,
407 		    "unable to create control data DMA map, error = %d\n",
408 		    error);
409 		goto fail_2;
410 	}
411 
412 	if ((error = bus_dmamap_load(sc->sc_dmat, sc->sc_cddmamap,
413 	    sc->sc_control_data, sizeof(struct emac_control_data), NULL,
414 	    0)) != 0) {
415 		aprint_error_dev(self,
416 		    "unable to load control data DMA map, error = %d\n", error);
417 		goto fail_3;
418 	}
419 
420 	/*
421 	 * Create the transmit buffer DMA maps.
422 	 */
423 	for (i = 0; i < EMAC_TXQUEUELEN; i++) {
424 		if ((error = bus_dmamap_create(sc->sc_dmat, MCLBYTES,
425 		    EMAC_NTXSEGS, MCLBYTES, 0, 0,
426 		    &sc->sc_txsoft[i].txs_dmamap)) != 0) {
427 			aprint_error_dev(self,
428 			    "unable to create tx DMA map %d, error = %d\n",
429 			    i, error);
430 			goto fail_4;
431 		}
432 	}
433 
434 	/*
435 	 * Create the receive buffer DMA maps.
436 	 */
437 	for (i = 0; i < EMAC_NRXDESC; i++) {
438 		if ((error = bus_dmamap_create(sc->sc_dmat, MCLBYTES, 1,
439 		    MCLBYTES, 0, 0, &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
440 			aprint_error_dev(self,
441 			    "unable to create rx DMA map %d, error = %d\n",
442 			    i, error);
443 			goto fail_5;
444 		}
445 		sc->sc_rxsoft[i].rxs_mbuf = NULL;
446 	}
447 
448 	/* Soft Reset the EMAC.  The chip to a known state. */
449 	emac_soft_reset(sc);
450 
451 	opb_freq = opb_get_frequency();
452 	switch (opb_freq) {
453 	case  50000000: opbc =  STACR_OPBC_50MHZ; break;
454 	case  66666666: opbc =  STACR_OPBC_66MHZ; break;
455 	case  83333333: opbc =  STACR_OPBC_83MHZ; break;
456 	case 100000000: opbc = STACR_OPBC_100MHZ; break;
457 
458 	default:
459 		if (opb_freq > 100000000) {
460 			opbc = STACR_OPBC_A100MHZ;
461 			break;
462 		}
463 		aprint_error_dev(self, "unsupport OPB frequency %dMHz\n",
464 		    opb_freq / 1000 / 1000);
465 		goto fail_5;
466 	}
467 	if (oaa->opb_flags & OPB_FLAGS_EMAC_GBE) {
468 		sc->sc_mr1 =
469 		    MR1_RFS_GBE(MR1__FS_16KB)	|
470 		    MR1_TFS_GBE(MR1__FS_16KB)	|
471 		    MR1_TR0_MULTIPLE		|
472 		    MR1_OBCI(opbc);
473 		sc->sc_ethercom.ec_capabilities |= ETHERCAP_JUMBO_MTU;
474 
475 		if (oaa->opb_flags & OPB_FLAGS_EMAC_STACV2) {
476 			sc->sc_stacr_read = STACR_STAOPC_READ;
477 			sc->sc_stacr_write = STACR_STAOPC_WRITE;
478 			sc->sc_stacr_bits = STACR_OC;
479 			sc->sc_stacr_completed = false;
480 		} else {
481 			sc->sc_stacr_read = STACR_READ;
482 			sc->sc_stacr_write = STACR_WRITE;
483 			sc->sc_stacr_completed = true;
484 		}
485 	} else {
486 		/*
487 		 * Set up Mode Register 1 - set receive and transmit FIFOs to
488 		 * maximum size, allow transmit of multiple packets (only
489 		 * channel 0 is used).
490 		 *
491 		 * XXX: Allow pause packets??
492 		 */
493 		sc->sc_mr1 =
494 		    MR1_RFS(MR1__FS_4KB) |
495 		    MR1_TFS(MR1__FS_2KB) |
496 		    MR1_TR0_MULTIPLE;
497 
498 		sc->sc_stacr_read = STACR_READ;
499 		sc->sc_stacr_write = STACR_WRITE;
500 		sc->sc_stacr_bits = STACR_OPBC(opbc);
501 		sc->sc_stacr_completed = true;
502 	}
503 
504 	intr_establish(oaa->opb_irq, IST_LEVEL, IPL_NET, emac_intr, sc);
505 	mal_intr_establish(sc->sc_instance, sc);
506 
507 	if (oaa->opb_flags & OPB_FLAGS_EMAC_HT256)
508 		sc->sc_htsize = 256;
509 	else
510 		sc->sc_htsize = 64;
511 
512 	/* Clear all interrupts */
513 	EMAC_WRITE(sc, EMAC_ISR, ISR_ALL);
514 
515 	/*
516 	 * Initialise the media structures.
517 	 */
518 	mii->mii_ifp = ifp;
519 	mii->mii_readreg = emac_mii_readreg;
520 	mii->mii_writereg = emac_mii_writereg;
521 	mii->mii_statchg = emac_mii_statchg;
522 
523 	sc->sc_ethercom.ec_mii = mii;
524 	ifmedia_init(&mii->mii_media, 0, ether_mediachange, ether_mediastatus);
525 	mii_attach(self, mii, 0xffffffff, mii_phy, MII_OFFSET_ANY,
526 	    MIIF_DOPAUSE);
527 	if (LIST_FIRST(&mii->mii_phys) == NULL) {
528 		ifmedia_add(&mii->mii_media, IFM_ETHER|IFM_NONE, 0, NULL);
529 		ifmedia_set(&mii->mii_media, IFM_ETHER|IFM_NONE);
530 	} else
531 		ifmedia_set(&mii->mii_media, IFM_ETHER|IFM_AUTO);
532 
533 	ifp = &sc->sc_ethercom.ec_if;
534 	strcpy(ifp->if_xname, xname);
535 	ifp->if_softc = sc;
536 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
537 	ifp->if_start = emac_start;
538 	ifp->if_ioctl = emac_ioctl;
539 	ifp->if_init = emac_init;
540 	ifp->if_stop = emac_stop;
541 	ifp->if_watchdog = emac_watchdog;
542 	IFQ_SET_READY(&ifp->if_snd);
543 
544 	/*
545 	 * We can support 802.1Q VLAN-sized frames.
546 	 */
547 	sc->sc_ethercom.ec_capabilities |= ETHERCAP_VLAN_MTU;
548 
549 	/*
550 	 * Attach the interface.
551 	 */
552 	if_attach(ifp);
553 	if_deferred_start_init(ifp, NULL);
554 	ether_ifattach(ifp, enaddr);
555 
556 #ifdef EMAC_EVENT_COUNTERS
557 	/*
558 	 * Attach the event counters.
559 	 */
560 	evcnt_attach_dynamic(&sc->sc_ev_txintr, EVCNT_TYPE_INTR,
561 	    NULL, xname, "txintr");
562 	evcnt_attach_dynamic(&sc->sc_ev_rxintr, EVCNT_TYPE_INTR,
563 	    NULL, xname, "rxintr");
564 	evcnt_attach_dynamic(&sc->sc_ev_txde, EVCNT_TYPE_INTR,
565 	    NULL, xname, "txde");
566 	evcnt_attach_dynamic(&sc->sc_ev_rxde, EVCNT_TYPE_INTR,
567 	    NULL, xname, "rxde");
568 	evcnt_attach_dynamic(&sc->sc_ev_intr, EVCNT_TYPE_INTR,
569 	    NULL, xname, "intr");
570 
571 	evcnt_attach_dynamic(&sc->sc_ev_txreap, EVCNT_TYPE_MISC,
572 	    NULL, xname, "txreap");
573 	evcnt_attach_dynamic(&sc->sc_ev_txsstall, EVCNT_TYPE_MISC,
574 	    NULL, xname, "txsstall");
575 	evcnt_attach_dynamic(&sc->sc_ev_txdstall, EVCNT_TYPE_MISC,
576 	    NULL, xname, "txdstall");
577 	evcnt_attach_dynamic(&sc->sc_ev_txdrop, EVCNT_TYPE_MISC,
578 	    NULL, xname, "txdrop");
579 	evcnt_attach_dynamic(&sc->sc_ev_tu, EVCNT_TYPE_MISC,
580 	    NULL, xname, "tu");
581 #endif /* EMAC_EVENT_COUNTERS */
582 
583 	/*
584 	 * Make sure the interface is shutdown during reboot.
585 	 */
586 	sc->sc_sdhook = shutdownhook_establish(emac_shutdown, sc);
587 	if (sc->sc_sdhook == NULL)
588 		aprint_error_dev(self,
589 		    "WARNING: unable to establish shutdown hook\n");
590 
591 	return;
592 
593 	/*
594 	 * Free any resources we've allocated during the failed attach
595 	 * attempt.  Do this in reverse order and fall through.
596 	 */
597 fail_5:
598 	for (i = 0; i < EMAC_NRXDESC; i++) {
599 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
600 			bus_dmamap_destroy(sc->sc_dmat,
601 			    sc->sc_rxsoft[i].rxs_dmamap);
602 	}
603 fail_4:
604 	for (i = 0; i < EMAC_TXQUEUELEN; i++) {
605 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
606 			bus_dmamap_destroy(sc->sc_dmat,
607 			    sc->sc_txsoft[i].txs_dmamap);
608 	}
609 	bus_dmamap_unload(sc->sc_dmat, sc->sc_cddmamap);
610 fail_3:
611 	bus_dmamap_destroy(sc->sc_dmat, sc->sc_cddmamap);
612 fail_2:
613 	bus_dmamem_unmap(sc->sc_dmat, (void *)sc->sc_control_data,
614 	    sizeof(struct emac_control_data));
615 fail_1:
616 	bus_dmamem_free(sc->sc_dmat, &seg, nseg);
617 fail_0:
618 	return;
619 }
620 
621 /*
622  * EMAC General interrupt handler
623  */
624 static int
625 emac_intr(void *arg)
626 {
627 	struct emac_softc *sc = arg;
628 	uint32_t status;
629 
630 	EMAC_EVCNT_INCR(&sc->sc_ev_intr);
631 	status = EMAC_READ(sc, EMAC_ISR);
632 
633 	/* Clear the interrupt status bits. */
634 	EMAC_WRITE(sc, EMAC_ISR, status);
635 
636 	return 1;
637 }
638 
639 static void
640 emac_shutdown(void *arg)
641 {
642 	struct emac_softc *sc = arg;
643 
644 	emac_stop(&sc->sc_ethercom.ec_if, 0);
645 }
646 
647 
648 /*
649  * ifnet interface functions
650  */
651 
652 static void
653 emac_start(struct ifnet *ifp)
654 {
655 	struct emac_softc *sc = ifp->if_softc;
656 	struct mbuf *m0;
657 	struct emac_txsoft *txs;
658 	bus_dmamap_t dmamap;
659 	int error, firsttx, nexttx, lasttx, ofree, seg;
660 
661 	lasttx = 0;	/* XXX gcc */
662 
663 	if ((ifp->if_flags & (IFF_RUNNING|IFF_OACTIVE)) != IFF_RUNNING)
664 		return;
665 
666 	/*
667 	 * Remember the previous number of free descriptors.
668 	 */
669 	ofree = sc->sc_txfree;
670 
671 	/*
672 	 * Loop through the send queue, setting up transmit descriptors
673 	 * until we drain the queue, or use up all available transmit
674 	 * descriptors.
675 	 */
676 	for (;;) {
677 		/* Grab a packet off the queue. */
678 		IFQ_POLL(&ifp->if_snd, m0);
679 		if (m0 == NULL)
680 			break;
681 
682 		/*
683 		 * Get a work queue entry.  Reclaim used Tx descriptors if
684 		 * we are running low.
685 		 */
686 		if (sc->sc_txsfree < EMAC_TXQUEUE_GC) {
687 			emac_txreap(sc);
688 			if (sc->sc_txsfree == 0) {
689 				EMAC_EVCNT_INCR(&sc->sc_ev_txsstall);
690 				break;
691 			}
692 		}
693 
694 		txs = &sc->sc_txsoft[sc->sc_txsnext];
695 		dmamap = txs->txs_dmamap;
696 
697 		/*
698 		 * Load the DMA map.  If this fails, the packet either
699 		 * didn't fit in the alloted number of segments, or we
700 		 * were short on resources.  In this case, we'll copy
701 		 * and try again.
702 		 */
703 		error = bus_dmamap_load_mbuf(sc->sc_dmat, dmamap, m0,
704 		    BUS_DMA_WRITE|BUS_DMA_NOWAIT);
705 		if (error) {
706 			if (error == EFBIG) {
707 				EMAC_EVCNT_INCR(&sc->sc_ev_txdrop);
708 				aprint_error_ifnet(ifp,
709 				    "Tx packet consumes too many "
710 				    "DMA segments, dropping...\n");
711 				    IFQ_DEQUEUE(&ifp->if_snd, m0);
712 				    m_freem(m0);
713 				    continue;
714 			}
715 			/* Short on resources, just stop for now. */
716 			break;
717 		}
718 
719 		/*
720 		 * Ensure we have enough descriptors free to describe
721 		 * the packet.
722 		 */
723 		if (dmamap->dm_nsegs > sc->sc_txfree) {
724 			/*
725 			 * Not enough free descriptors to transmit this
726 			 * packet.  We haven't committed anything yet,
727 			 * so just unload the DMA map, put the packet
728 			 * back on the queue, and punt.  Notify the upper
729 			 * layer that there are not more slots left.
730 			 *
731 			 */
732 			ifp->if_flags |= IFF_OACTIVE;
733 			bus_dmamap_unload(sc->sc_dmat, dmamap);
734 			EMAC_EVCNT_INCR(&sc->sc_ev_txdstall);
735 			break;
736 		}
737 
738 		IFQ_DEQUEUE(&ifp->if_snd, m0);
739 
740 		/*
741 		 * WE ARE NOW COMMITTED TO TRANSMITTING THE PACKET.
742 		 */
743 
744 		/* Sync the DMA map. */
745 		bus_dmamap_sync(sc->sc_dmat, dmamap, 0, dmamap->dm_mapsize,
746 		    BUS_DMASYNC_PREWRITE);
747 
748 		/*
749 		 * Store a pointer to the packet so that we can free it
750 		 * later.
751 		 */
752 		txs->txs_mbuf = m0;
753 		txs->txs_firstdesc = sc->sc_txnext;
754 		txs->txs_ndesc = dmamap->dm_nsegs;
755 
756 		/*
757 		 * Initialize the transmit descriptor.
758 		 */
759 		firsttx = sc->sc_txnext;
760 		for (nexttx = sc->sc_txnext, seg = 0;
761 		     seg < dmamap->dm_nsegs;
762 		     seg++, nexttx = EMAC_NEXTTX(nexttx)) {
763 			struct mal_descriptor *txdesc =
764 			    &sc->sc_txdescs[nexttx];
765 
766 			/*
767 			 * If this is the first descriptor we're
768 			 * enqueueing, don't set the TX_READY bit just
769 			 * yet.  That could cause a race condition.
770 			 * We'll do it below.
771 			 */
772 			txdesc->md_data = dmamap->dm_segs[seg].ds_addr;
773 			txdesc->md_data_len = dmamap->dm_segs[seg].ds_len;
774 			txdesc->md_stat_ctrl =
775 			    (txdesc->md_stat_ctrl & MAL_TX_WRAP) |
776 			    (nexttx == firsttx ? 0 : MAL_TX_READY) |
777 			    EMAC_TXC_GFCS | EMAC_TXC_GPAD;
778 			lasttx = nexttx;
779 		}
780 
781 		/* Set the LAST bit on the last segment. */
782 		sc->sc_txdescs[lasttx].md_stat_ctrl |= MAL_TX_LAST;
783 
784 		/*
785 		 * Set up last segment descriptor to send an interrupt after
786 		 * that descriptor is transmitted, and bypass existing Tx
787 		 * descriptor reaping method (for now...).
788 		 */
789 		sc->sc_txdescs[lasttx].md_stat_ctrl |= MAL_TX_INTERRUPT;
790 
791 
792 		txs->txs_lastdesc = lasttx;
793 
794 		/* Sync the descriptors we're using. */
795 		EMAC_CDTXSYNC(sc, sc->sc_txnext, dmamap->dm_nsegs,
796 		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
797 
798 		/*
799 		 * The entire packet chain is set up.  Give the
800 		 * first descriptor to the chip now.
801 		 */
802 		sc->sc_txdescs[firsttx].md_stat_ctrl |= MAL_TX_READY;
803 		EMAC_CDTXSYNC(sc, firsttx, 1,
804 		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
805 		/*
806 		 * Tell the EMAC that a new packet is available.
807 		 */
808 		EMAC_WRITE(sc, EMAC_TMR0, TMR0_GNP0 | TMR0_TFAE_2);
809 
810 		/* Advance the tx pointer. */
811 		sc->sc_txfree -= txs->txs_ndesc;
812 		sc->sc_txnext = nexttx;
813 
814 		sc->sc_txsfree--;
815 		sc->sc_txsnext = EMAC_NEXTTXS(sc->sc_txsnext);
816 
817 		/*
818 		 * Pass the packet to any BPF listeners.
819 		 */
820 		bpf_mtap(ifp, m0, BPF_D_OUT);
821 	}
822 
823 	if (sc->sc_txfree == 0)
824 		/* No more slots left; notify upper layer. */
825 		ifp->if_flags |= IFF_OACTIVE;
826 
827 	if (sc->sc_txfree != ofree)
828 		/* Set a watchdog timer in case the chip flakes out. */
829 		ifp->if_timer = 5;
830 }
831 
832 static int
833 emac_ioctl(struct ifnet *ifp, u_long cmd, void *data)
834 {
835 	struct emac_softc *sc = ifp->if_softc;
836 	int s, error;
837 
838 	s = splnet();
839 
840 	switch (cmd) {
841 	case SIOCSIFMTU:
842 	{
843 		struct ifreq *ifr = (struct ifreq *)data;
844 		int maxmtu;
845 
846 		if (sc->sc_ethercom.ec_capabilities & ETHERCAP_JUMBO_MTU)
847 			maxmtu = EMAC_MAX_MTU;
848 		else
849 			maxmtu = ETHERMTU;
850 
851 		if (ifr->ifr_mtu < ETHERMIN || ifr->ifr_mtu > maxmtu)
852 			error = EINVAL;
853 		else if ((error = ifioctl_common(ifp, cmd, data)) != ENETRESET)
854 			break;
855 		else if (ifp->if_flags & IFF_UP)
856 			error = emac_init(ifp);
857 		else
858 			error = 0;
859 		break;
860 	}
861 
862 	default:
863 		error = ether_ioctl(ifp, cmd, data);
864 		if (error == ENETRESET) {
865 			/*
866 			 * Multicast list has changed; set the hardware filter
867 			 * accordingly.
868 			 */
869 			if (ifp->if_flags & IFF_RUNNING)
870 				error = emac_set_filter(sc);
871 			else
872 				error = 0;
873 		}
874 	}
875 
876 	/* try to get more packets going */
877 	emac_start(ifp);
878 
879 	splx(s);
880 	return error;
881 }
882 
883 static int
884 emac_init(struct ifnet *ifp)
885 {
886 	struct emac_softc *sc = ifp->if_softc;
887 	struct emac_rxsoft *rxs;
888 	const uint8_t *enaddr = CLLADDR(ifp->if_sadl);
889 	int error, i;
890 
891 	error = 0;
892 
893 	/* Cancel any pending I/O. */
894 	emac_stop(ifp, 0);
895 
896 	/* Reset the chip to a known state. */
897 	emac_soft_reset(sc);
898 
899 	/*
900 	 * Initialise the transmit descriptor ring.
901 	 */
902 	memset(sc->sc_txdescs, 0, sizeof(sc->sc_txdescs));
903 	/* set wrap on last descriptor */
904 	sc->sc_txdescs[EMAC_NTXDESC - 1].md_stat_ctrl |= MAL_TX_WRAP;
905 	EMAC_CDTXSYNC(sc, 0, EMAC_NTXDESC,
906 	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
907 	sc->sc_txfree = EMAC_NTXDESC;
908 	sc->sc_txnext = 0;
909 
910 	/*
911 	 * Initialise the transmit job descriptors.
912 	 */
913 	for (i = 0; i < EMAC_TXQUEUELEN; i++)
914 		sc->sc_txsoft[i].txs_mbuf = NULL;
915 	sc->sc_txsfree = EMAC_TXQUEUELEN;
916 	sc->sc_txsnext = 0;
917 	sc->sc_txsdirty = 0;
918 
919 	/*
920 	 * Initialise the receiver descriptor and receive job
921 	 * descriptor rings.
922 	 */
923 	for (i = 0; i < EMAC_NRXDESC; i++) {
924 		rxs = &sc->sc_rxsoft[i];
925 		if (rxs->rxs_mbuf == NULL) {
926 			if ((error = emac_add_rxbuf(sc, i)) != 0) {
927 				aprint_error_ifnet(ifp,
928 				    "unable to allocate or map rx buffer %d,"
929 				    " error = %d\n",
930 				    i, error);
931 				/*
932 				 * XXX Should attempt to run with fewer receive
933 				 * XXX buffers instead of just failing.
934 				 */
935 				emac_rxdrain(sc);
936 				goto out;
937 			}
938 		} else
939 			EMAC_INIT_RXDESC(sc, i);
940 	}
941 	sc->sc_rxptr = 0;
942 
943 	/*
944 	 * Set the current media.
945 	 */
946 	if ((error = ether_mediachange(ifp)) != 0)
947 		goto out;
948 
949 	/*
950 	 * Load the MAC address.
951 	 */
952 	EMAC_WRITE(sc, EMAC_IAHR, enaddr[0] << 8 | enaddr[1]);
953 	EMAC_WRITE(sc, EMAC_IALR,
954 	    enaddr[2] << 24 | enaddr[3] << 16 | enaddr[4] << 8 | enaddr[5]);
955 
956 	/* Enable the transmit and receive channel on the MAL. */
957 	error = mal_start(sc->sc_instance,
958 	    EMAC_CDTXADDR(sc, 0), EMAC_CDRXADDR(sc, 0));
959 	if (error)
960 		goto out;
961 
962 	sc->sc_mr1 &= ~MR1_JPSM;
963 	if (ifp->if_mtu > ETHERMTU)
964 		/* Enable Jumbo Packet Support Mode */
965 		sc->sc_mr1 |= MR1_JPSM;
966 
967 	/* Set fifos, media modes. */
968 	EMAC_WRITE(sc, EMAC_MR1, sc->sc_mr1);
969 
970 	/*
971 	 * Enable Individual and (possibly) Broadcast Address modes,
972 	 * runt packets, and strip padding.
973 	 */
974 	EMAC_WRITE(sc, EMAC_RMR, RMR_IAE | RMR_RRP | RMR_SP | RMR_TFAE_2 |
975 	    (ifp->if_flags & IFF_PROMISC ? RMR_PME : 0) |
976 	    (ifp->if_flags & IFF_BROADCAST ? RMR_BAE : 0));
977 
978 	/*
979 	 * Set multicast filter.
980 	 */
981 	emac_set_filter(sc);
982 
983 	/*
984 	 * Set low- and urgent-priority request thresholds.
985 	 */
986 	EMAC_WRITE(sc, EMAC_TMR1,
987 	    ((7 << TMR1_TLR_SHIFT) & TMR1_TLR_MASK) | /* 16 word burst */
988 	    ((15 << TMR1_TUR_SHIFT) & TMR1_TUR_MASK));
989 	/*
990 	 * Set Transmit Request Threshold Register.
991 	 */
992 	EMAC_WRITE(sc, EMAC_TRTR, TRTR_256);
993 
994 	/*
995 	 * Set high and low receive watermarks.
996 	 */
997 	EMAC_WRITE(sc, EMAC_RWMR,
998 	    30 << RWMR_RLWM_SHIFT | 64 << RWMR_RLWM_SHIFT);
999 
1000 	/*
1001 	 * Set frame gap.
1002 	 */
1003 	EMAC_WRITE(sc, EMAC_IPGVR, 8);
1004 
1005 	/*
1006 	 * Set interrupt status enable bits for EMAC.
1007 	 */
1008 	EMAC_WRITE(sc, EMAC_ISER,
1009 	    ISR_TXPE |		/* TX Parity Error */
1010 	    ISR_RXPE |		/* RX Parity Error */
1011 	    ISR_TXUE |		/* TX Underrun Event */
1012 	    ISR_RXOE |		/* RX Overrun Event */
1013 	    ISR_OVR  |		/* Overrun Error */
1014 	    ISR_PP   |		/* Pause Packet */
1015 	    ISR_BP   |		/* Bad Packet */
1016 	    ISR_RP   |		/* Runt Packet */
1017 	    ISR_SE   |		/* Short Event */
1018 	    ISR_ALE  |		/* Alignment Error */
1019 	    ISR_BFCS |		/* Bad FCS */
1020 	    ISR_PTLE |		/* Packet Too Long Error */
1021 	    ISR_ORE  |		/* Out of Range Error */
1022 	    ISR_IRE  |		/* In Range Error */
1023 	    ISR_SE0  |		/* Signal Quality Error 0 (SQE) */
1024 	    ISR_TE0  |		/* Transmit Error 0 */
1025 	    ISR_MOS  |		/* MMA Operation Succeeded */
1026 	    ISR_MOF);		/* MMA Operation Failed */
1027 
1028 	/*
1029 	 * Enable the transmit and receive channel on the EMAC.
1030 	 */
1031 	EMAC_WRITE(sc, EMAC_MR0, MR0_TXE | MR0_RXE);
1032 
1033 	/*
1034 	 * Start the one second MII clock.
1035 	 */
1036 	callout_reset(&sc->sc_callout, hz, emac_mii_tick, sc);
1037 
1038 	/*
1039 	 * ... all done!
1040 	 */
1041 	ifp->if_flags |= IFF_RUNNING;
1042 	ifp->if_flags &= ~IFF_OACTIVE;
1043 
1044  out:
1045 	if (error) {
1046 		ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
1047 		ifp->if_timer = 0;
1048 		aprint_error_ifnet(ifp, "interface not running\n");
1049 	}
1050 	return error;
1051 }
1052 
1053 static void
1054 emac_stop(struct ifnet *ifp, int disable)
1055 {
1056 	struct emac_softc *sc = ifp->if_softc;
1057 	struct emac_txsoft *txs;
1058 	int i;
1059 
1060 	/* Stop the one second clock. */
1061 	callout_stop(&sc->sc_callout);
1062 
1063 	/* Down the MII */
1064 	mii_down(&sc->sc_mii);
1065 
1066 	/* Disable interrupts. */
1067 	EMAC_WRITE(sc, EMAC_ISER, 0);
1068 
1069 	/* Disable the receive and transmit channels. */
1070 	mal_stop(sc->sc_instance);
1071 
1072 	/* Disable the transmit enable and receive MACs. */
1073 	EMAC_WRITE(sc, EMAC_MR0,
1074 	    EMAC_READ(sc, EMAC_MR0) & ~(MR0_TXE | MR0_RXE));
1075 
1076 	/* Release any queued transmit buffers. */
1077 	for (i = 0; i < EMAC_TXQUEUELEN; i++) {
1078 		txs = &sc->sc_txsoft[i];
1079 		if (txs->txs_mbuf != NULL) {
1080 			bus_dmamap_unload(sc->sc_dmat, txs->txs_dmamap);
1081 			m_freem(txs->txs_mbuf);
1082 			txs->txs_mbuf = NULL;
1083 		}
1084 	}
1085 
1086 	if (disable)
1087 		emac_rxdrain(sc);
1088 
1089 	/*
1090 	 * Mark the interface down and cancel the watchdog timer.
1091 	 */
1092 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
1093 	ifp->if_timer = 0;
1094 }
1095 
1096 static void
1097 emac_watchdog(struct ifnet *ifp)
1098 {
1099 	struct emac_softc *sc = ifp->if_softc;
1100 
1101 	/*
1102 	 * Since we're not interrupting every packet, sweep
1103 	 * up before we report an error.
1104 	 */
1105 	emac_txreap(sc);
1106 
1107 	if (sc->sc_txfree != EMAC_NTXDESC) {
1108 		aprint_error_ifnet(ifp,
1109 		    "device timeout (txfree %d txsfree %d txnext %d)\n",
1110 		    sc->sc_txfree, sc->sc_txsfree, sc->sc_txnext);
1111 		ifp->if_oerrors++;
1112 
1113 		/* Reset the interface. */
1114 		(void)emac_init(ifp);
1115 	} else if (ifp->if_flags & IFF_DEBUG)
1116 		aprint_error_ifnet(ifp, "recovered from device timeout\n");
1117 
1118 	/* try to get more packets going */
1119 	emac_start(ifp);
1120 }
1121 
1122 static int
1123 emac_add_rxbuf(struct emac_softc *sc, int idx)
1124 {
1125 	struct emac_rxsoft *rxs = &sc->sc_rxsoft[idx];
1126 	struct mbuf *m;
1127 	int error;
1128 
1129 	MGETHDR(m, M_DONTWAIT, MT_DATA);
1130 	if (m == NULL)
1131 		return ENOBUFS;
1132 
1133 	MCLGET(m, M_DONTWAIT);
1134 	if ((m->m_flags & M_EXT) == 0) {
1135 		m_freem(m);
1136 		return ENOBUFS;
1137 	}
1138 
1139 	if (rxs->rxs_mbuf != NULL)
1140 		bus_dmamap_unload(sc->sc_dmat, rxs->rxs_dmamap);
1141 
1142 	rxs->rxs_mbuf = m;
1143 
1144 	error = bus_dmamap_load(sc->sc_dmat, rxs->rxs_dmamap,
1145 	    m->m_ext.ext_buf, m->m_ext.ext_size, NULL, BUS_DMA_NOWAIT);
1146 	if (error) {
1147 		aprint_error_dev(sc->sc_dev,
1148 		    "can't load rx DMA map %d, error = %d\n", idx, error);
1149 		panic("emac_add_rxbuf");		/* XXX */
1150 	}
1151 
1152 	bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1153 	    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
1154 
1155 	EMAC_INIT_RXDESC(sc, idx);
1156 
1157 	return 0;
1158 }
1159 
1160 static void
1161 emac_rxdrain(struct emac_softc *sc)
1162 {
1163 	struct emac_rxsoft *rxs;
1164 	int i;
1165 
1166 	for (i = 0; i < EMAC_NRXDESC; i++) {
1167 		rxs = &sc->sc_rxsoft[i];
1168 		if (rxs->rxs_mbuf != NULL) {
1169 			bus_dmamap_unload(sc->sc_dmat, rxs->rxs_dmamap);
1170 			m_freem(rxs->rxs_mbuf);
1171 			rxs->rxs_mbuf = NULL;
1172 		}
1173 	}
1174 }
1175 
1176 static int
1177 emac_set_filter(struct emac_softc *sc)
1178 {
1179 	struct ether_multistep step;
1180 	struct ether_multi *enm;
1181 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1182 	uint32_t rmr, crc, mask, tmp, reg, gaht[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
1183 	int regs, cnt = 0, i;
1184 
1185 	if (sc->sc_htsize == 256) {
1186 		reg = EMAC_GAHT256(0);
1187 		regs = 8;
1188 	} else {
1189 		reg = EMAC_GAHT64(0);
1190 		regs = 4;
1191 	}
1192 	mask = (1ULL << (sc->sc_htsize / regs)) - 1;
1193 
1194 	rmr = EMAC_READ(sc, EMAC_RMR);
1195 	rmr &= ~(RMR_PMME | RMR_MAE);
1196 	ifp->if_flags &= ~IFF_ALLMULTI;
1197 
1198 	ETHER_FIRST_MULTI(step, &sc->sc_ethercom, enm);
1199 	while (enm != NULL) {
1200 		if (memcmp(enm->enm_addrlo,
1201 		    enm->enm_addrhi, ETHER_ADDR_LEN) != 0) {
1202 			/*
1203 			 * We must listen to a range of multicast addresses.
1204 			 * For now, just accept all multicasts, rather than
1205 			 * trying to set only those filter bits needed to match
1206 			 * the range.  (At this time, the only use of address
1207 			 * ranges is for IP multicast routing, for which the
1208 			 * range is big enough to require all bits set.)
1209 			 */
1210 			gaht[0] = gaht[1] = gaht[2] = gaht[3] =
1211 			    gaht[4] = gaht[5] = gaht[6] = gaht[7] = mask;
1212 			break;
1213 		}
1214 
1215 		crc = ether_crc32_be(enm->enm_addrlo, ETHER_ADDR_LEN);
1216 
1217 		if (sc->sc_htsize == 256)
1218 			EMAC_SET_FILTER256(gaht, crc);
1219 		else
1220 			EMAC_SET_FILTER(gaht, crc);
1221 
1222 		ETHER_NEXT_MULTI(step, enm);
1223 		cnt++;
1224 	}
1225 
1226 	for (i = 1, tmp = gaht[0]; i < regs; i++)
1227 		tmp &= gaht[i];
1228 	if (tmp == mask) {
1229 		/* All categories are true. */
1230 		ifp->if_flags |= IFF_ALLMULTI;
1231 		rmr |= RMR_PMME;
1232 	} else if (cnt != 0) {
1233 		/* Some categories are true. */
1234 		for (i = 0; i < regs; i++)
1235 			EMAC_WRITE(sc, reg + (i << 2), gaht[i]);
1236 		rmr |= RMR_MAE;
1237 	}
1238 	EMAC_WRITE(sc, EMAC_RMR, rmr);
1239 
1240 	return 0;
1241 }
1242 
1243 /*
1244  * Reap completed Tx descriptors.
1245  */
1246 static int
1247 emac_txreap(struct emac_softc *sc)
1248 {
1249 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1250 	struct emac_txsoft *txs;
1251 	int handled, i;
1252 	uint32_t txstat;
1253 
1254 	EMAC_EVCNT_INCR(&sc->sc_ev_txreap);
1255 	handled = 0;
1256 
1257 	ifp->if_flags &= ~IFF_OACTIVE;
1258 
1259 	/*
1260 	 * Go through our Tx list and free mbufs for those
1261 	 * frames that have been transmitted.
1262 	 */
1263 	for (i = sc->sc_txsdirty; sc->sc_txsfree != EMAC_TXQUEUELEN;
1264 	    i = EMAC_NEXTTXS(i), sc->sc_txsfree++) {
1265 		txs = &sc->sc_txsoft[i];
1266 
1267 		EMAC_CDTXSYNC(sc, txs->txs_lastdesc,
1268 		    txs->txs_dmamap->dm_nsegs,
1269 		    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
1270 
1271 		txstat = sc->sc_txdescs[txs->txs_lastdesc].md_stat_ctrl;
1272 		if (txstat & MAL_TX_READY)
1273 			break;
1274 
1275 		handled = 1;
1276 
1277 		/*
1278 		 * Check for errors and collisions.
1279 		 */
1280 		if (txstat & (EMAC_TXS_UR | EMAC_TXS_ED))
1281 			ifp->if_oerrors++;
1282 
1283 #ifdef EMAC_EVENT_COUNTERS
1284 		if (txstat & EMAC_TXS_UR)
1285 			EMAC_EVCNT_INCR(&sc->sc_ev_tu);
1286 #endif /* EMAC_EVENT_COUNTERS */
1287 
1288 		if (txstat &
1289 		    (EMAC_TXS_EC | EMAC_TXS_MC | EMAC_TXS_SC | EMAC_TXS_LC)) {
1290 			if (txstat & EMAC_TXS_EC)
1291 				ifp->if_collisions += 16;
1292 			else if (txstat & EMAC_TXS_MC)
1293 				ifp->if_collisions += 2;	/* XXX? */
1294 			else if (txstat & EMAC_TXS_SC)
1295 				ifp->if_collisions++;
1296 			if (txstat & EMAC_TXS_LC)
1297 				ifp->if_collisions++;
1298 		} else
1299 			ifp->if_opackets++;
1300 
1301 		if (ifp->if_flags & IFF_DEBUG) {
1302 			if (txstat & EMAC_TXS_ED)
1303 				aprint_error_ifnet(ifp, "excessive deferral\n");
1304 			if (txstat & EMAC_TXS_EC)
1305 				aprint_error_ifnet(ifp,
1306 				    "excessive collisions\n");
1307 		}
1308 
1309 		sc->sc_txfree += txs->txs_ndesc;
1310 		bus_dmamap_sync(sc->sc_dmat, txs->txs_dmamap,
1311 		    0, txs->txs_dmamap->dm_mapsize, BUS_DMASYNC_POSTWRITE);
1312 		bus_dmamap_unload(sc->sc_dmat, txs->txs_dmamap);
1313 		m_freem(txs->txs_mbuf);
1314 		txs->txs_mbuf = NULL;
1315 	}
1316 
1317 	/* Update the dirty transmit buffer pointer. */
1318 	sc->sc_txsdirty = i;
1319 
1320 	/*
1321 	 * If there are no more pending transmissions, cancel the watchdog
1322 	 * timer.
1323 	 */
1324 	if (sc->sc_txsfree == EMAC_TXQUEUELEN)
1325 		ifp->if_timer = 0;
1326 
1327 	return handled;
1328 }
1329 
1330 
1331 /*
1332  * Reset functions
1333  */
1334 
1335 static void
1336 emac_soft_reset(struct emac_softc *sc)
1337 {
1338 	uint32_t sdr;
1339 	int t = 0;
1340 
1341 	/*
1342 	 * The PHY must provide a TX Clk in order perform a soft reset the
1343 	 * EMAC.  If none is present, select the internal clock,
1344 	 * SDR0_MFR[E0CS,E1CS].  After the soft reset, select the external
1345 	 * clock.
1346 	 */
1347 
1348 	sdr = mfsdr(DCR_SDR0_MFR);
1349 	sdr |= SDR0_MFR_ECS(sc->sc_instance);
1350 	mtsdr(DCR_SDR0_MFR, sdr);
1351 
1352 	EMAC_WRITE(sc, EMAC_MR0, MR0_SRST);
1353 
1354 	sdr = mfsdr(DCR_SDR0_MFR);
1355 	sdr &= ~SDR0_MFR_ECS(sc->sc_instance);
1356 	mtsdr(DCR_SDR0_MFR, sdr);
1357 
1358 	delay(5);
1359 
1360 	/* wait finish */
1361 	while (EMAC_READ(sc, EMAC_MR0) & MR0_SRST) {
1362 		if (++t == 1000000 /* 1sec XXXXX */) {
1363 			aprint_error_dev(sc->sc_dev, "Soft Reset failed\n");
1364 			return;
1365 		}
1366 		delay(1);
1367 	}
1368 }
1369 
1370 static void
1371 emac_smart_reset(struct emac_softc *sc)
1372 {
1373 	uint32_t mr0;
1374 	int t = 0;
1375 
1376 	mr0 = EMAC_READ(sc, EMAC_MR0);
1377 	if (mr0 & (MR0_TXE | MR0_RXE)) {
1378 		mr0 &= ~(MR0_TXE | MR0_RXE);
1379 		EMAC_WRITE(sc, EMAC_MR0, mr0);
1380 
1381 		/* wait idel state */
1382 		while ((EMAC_READ(sc, EMAC_MR0) & (MR0_TXI | MR0_RXI)) !=
1383 		    (MR0_TXI | MR0_RXI)) {
1384 			if (++t == 1000000 /* 1sec XXXXX */) {
1385 				aprint_error_dev(sc->sc_dev,
1386 				    "Smart Reset failed\n");
1387 				return;
1388 			}
1389 			delay(1);
1390 		}
1391 	}
1392 }
1393 
1394 
1395 /*
1396  * MII related functions
1397  */
1398 
1399 static int
1400 emac_mii_readreg(device_t self, int phy, int reg)
1401 {
1402 	struct emac_softc *sc = device_private(self);
1403 	uint32_t sta_reg;
1404 
1405 	if (sc->sc_rmii_enable)
1406 		sc->sc_rmii_enable(device_parent(self), sc->sc_instance);
1407 
1408 	/* wait for PHY data transfer to complete */
1409 	if (emac_mii_wait(sc))
1410 		goto fail;
1411 
1412 	sta_reg =
1413 	    sc->sc_stacr_read		|
1414 	    (reg << STACR_PRA_SHIFT)	|
1415 	    (phy << STACR_PCDA_SHIFT)	|
1416 	    sc->sc_stacr_bits;
1417 	EMAC_WRITE(sc, EMAC_STACR, sta_reg);
1418 
1419 	if (emac_mii_wait(sc))
1420 		goto fail;
1421 	sta_reg = EMAC_READ(sc, EMAC_STACR);
1422 
1423 	if (sc->sc_rmii_disable)
1424 		sc->sc_rmii_disable(device_parent(self), sc->sc_instance);
1425 
1426 	if (sta_reg & STACR_PHYE)
1427 		return 0;
1428 	return sta_reg >> STACR_PHYD_SHIFT;
1429 
1430 fail:
1431 	if (sc->sc_rmii_disable)
1432 		sc->sc_rmii_disable(device_parent(self), sc->sc_instance);
1433 	return 0;
1434 }
1435 
1436 static void
1437 emac_mii_writereg(device_t self, int phy, int reg, int val)
1438 {
1439 	struct emac_softc *sc = device_private(self);
1440 	uint32_t sta_reg;
1441 
1442 	if (sc->sc_rmii_enable)
1443 		sc->sc_rmii_enable(device_parent(self), sc->sc_instance);
1444 
1445 	/* wait for PHY data transfer to complete */
1446 	if (emac_mii_wait(sc))
1447 		goto out;
1448 
1449 	sta_reg =
1450 	    (val << STACR_PHYD_SHIFT)	|
1451 	    sc->sc_stacr_write		|
1452 	    (reg << STACR_PRA_SHIFT)	|
1453 	    (phy << STACR_PCDA_SHIFT)	|
1454 	    sc->sc_stacr_bits;
1455 	EMAC_WRITE(sc, EMAC_STACR, sta_reg);
1456 
1457 	if (emac_mii_wait(sc))
1458 		goto out;
1459 	if (EMAC_READ(sc, EMAC_STACR) & STACR_PHYE)
1460 		aprint_error_dev(sc->sc_dev, "MII PHY Error\n");
1461 
1462 out:
1463 	if (sc->sc_rmii_disable)
1464 		sc->sc_rmii_disable(device_parent(self), sc->sc_instance);
1465 }
1466 
1467 static void
1468 emac_mii_statchg(struct ifnet *ifp)
1469 {
1470 	struct emac_softc *sc = ifp->if_softc;
1471 	struct mii_data *mii = &sc->sc_mii;
1472 
1473 	/*
1474 	 * MR1 can only be written immediately after a reset...
1475 	 */
1476 	emac_smart_reset(sc);
1477 
1478 	sc->sc_mr1 &= ~(MR1_FDE | MR1_ILE | MR1_EIFC | MR1_MF_MASK | MR1_IST);
1479 	if (mii->mii_media_active & IFM_FDX)
1480 		sc->sc_mr1 |= (MR1_FDE | MR1_EIFC | MR1_IST);
1481 	if (mii->mii_media_active & IFM_FLOW)
1482 		sc->sc_mr1 |= MR1_EIFC;
1483 	if (mii->mii_media_active & IFM_LOOP)
1484 		sc->sc_mr1 |= MR1_ILE;
1485 	switch (IFM_SUBTYPE(mii->mii_media_active)) {
1486 	case IFM_1000_T:
1487 		sc->sc_mr1 |= (MR1_MF_1000MBS | MR1_IST);
1488 		break;
1489 
1490 	case IFM_100_TX:
1491 		sc->sc_mr1 |= (MR1_MF_100MBS | MR1_IST);
1492 		break;
1493 
1494 	case IFM_10_T:
1495 		sc->sc_mr1 |= MR1_MF_10MBS;
1496 		break;
1497 
1498 	case IFM_NONE:
1499 		break;
1500 
1501 	default:
1502 		aprint_error_dev(sc->sc_dev, "unknown sub-type %d\n",
1503 		    IFM_SUBTYPE(mii->mii_media_active));
1504 		break;
1505 	}
1506 	if (sc->sc_rmii_speed)
1507 		sc->sc_rmii_speed(device_parent(sc->sc_dev), sc->sc_instance,
1508 		    IFM_SUBTYPE(mii->mii_media_active));
1509 
1510 	EMAC_WRITE(sc, EMAC_MR1, sc->sc_mr1);
1511 
1512 	/* Enable TX and RX if already RUNNING */
1513 	if (ifp->if_flags & IFF_RUNNING)
1514 		EMAC_WRITE(sc, EMAC_MR0, MR0_TXE | MR0_RXE);
1515 }
1516 
1517 static uint32_t
1518 emac_mii_wait(struct emac_softc *sc)
1519 {
1520 	int i;
1521 	uint32_t oc;
1522 
1523 	/* wait for PHY data transfer to complete */
1524 	i = 0;
1525 	oc = EMAC_READ(sc, EMAC_STACR) & STACR_OC;
1526 	while ((oc == STACR_OC) != sc->sc_stacr_completed) {
1527 		delay(7);
1528 		if (i++ > 5) {
1529 			aprint_error_dev(sc->sc_dev, "MII timed out\n");
1530 			return -1;
1531 		}
1532 		oc = EMAC_READ(sc, EMAC_STACR) & STACR_OC;
1533 	}
1534 	return 0;
1535 }
1536 
1537 static void
1538 emac_mii_tick(void *arg)
1539 {
1540 	struct emac_softc *sc = arg;
1541 	int s;
1542 
1543 	if (!device_is_active(sc->sc_dev))
1544 		return;
1545 
1546 	s = splnet();
1547 	mii_tick(&sc->sc_mii);
1548 	splx(s);
1549 
1550 	callout_reset(&sc->sc_callout, hz, emac_mii_tick, sc);
1551 }
1552 
1553 int
1554 emac_txeob_intr(void *arg)
1555 {
1556 	struct emac_softc *sc = arg;
1557 	int handled = 0;
1558 
1559 	EMAC_EVCNT_INCR(&sc->sc_ev_txintr);
1560 	handled |= emac_txreap(sc);
1561 
1562 	/* try to get more packets going */
1563 	if_schedule_deferred_start(&sc->sc_ethercom.ec_if);
1564 
1565 	return handled;
1566 }
1567 
1568 int
1569 emac_rxeob_intr(void *arg)
1570 {
1571 	struct emac_softc *sc = arg;
1572 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1573 	struct emac_rxsoft *rxs;
1574 	struct mbuf *m;
1575 	uint32_t rxstat;
1576 	int i, len;
1577 
1578 	EMAC_EVCNT_INCR(&sc->sc_ev_rxintr);
1579 
1580 	for (i = sc->sc_rxptr; ; i = EMAC_NEXTRX(i)) {
1581 		rxs = &sc->sc_rxsoft[i];
1582 
1583 		EMAC_CDRXSYNC(sc, i,
1584 		    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
1585 
1586 		rxstat = sc->sc_rxdescs[i].md_stat_ctrl;
1587 
1588 		if (rxstat & MAL_RX_EMPTY) {
1589 			/*
1590 			 * We have processed all of the receive buffers.
1591 			 */
1592 			/* Flush current empty descriptor */
1593 			EMAC_CDRXSYNC(sc, i,
1594 			    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
1595 			break;
1596 		}
1597 
1598 		/*
1599 		 * If an error occurred, update stats, clear the status
1600 		 * word, and leave the packet buffer in place.  It will
1601 		 * simply be reused the next time the ring comes around.
1602 		 */
1603 		if (rxstat & (EMAC_RXS_OE | EMAC_RXS_BP | EMAC_RXS_SE |
1604 		    EMAC_RXS_AE | EMAC_RXS_BFCS | EMAC_RXS_PTL | EMAC_RXS_ORE |
1605 		    EMAC_RXS_IRE)) {
1606 #define	PRINTERR(bit, str)					\
1607 			if (rxstat & (bit))			\
1608 				aprint_error_ifnet(ifp,		\
1609 				    "receive error: %s\n", str)
1610 			ifp->if_ierrors++;
1611 			PRINTERR(EMAC_RXS_OE, "overrun error");
1612 			PRINTERR(EMAC_RXS_BP, "bad packet");
1613 			PRINTERR(EMAC_RXS_RP, "runt packet");
1614 			PRINTERR(EMAC_RXS_SE, "short event");
1615 			PRINTERR(EMAC_RXS_AE, "alignment error");
1616 			PRINTERR(EMAC_RXS_BFCS, "bad FCS");
1617 			PRINTERR(EMAC_RXS_PTL, "packet too long");
1618 			PRINTERR(EMAC_RXS_ORE, "out of range error");
1619 			PRINTERR(EMAC_RXS_IRE, "in range error");
1620 #undef PRINTERR
1621 			EMAC_INIT_RXDESC(sc, i);
1622 			continue;
1623 		}
1624 
1625 		bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1626 		    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
1627 
1628 		/*
1629 		 * No errors; receive the packet.  Note, the 405GP emac
1630 		 * includes the CRC with every packet.
1631 		 */
1632 		len = sc->sc_rxdescs[i].md_data_len - ETHER_CRC_LEN;
1633 
1634 		/*
1635 		 * If the packet is small enough to fit in a
1636 		 * single header mbuf, allocate one and copy
1637 		 * the data into it.  This greatly reduces
1638 		 * memory consumption when we receive lots
1639 		 * of small packets.
1640 		 *
1641 		 * Otherwise, we add a new buffer to the receive
1642 		 * chain.  If this fails, we drop the packet and
1643 		 * recycle the old buffer.
1644 		 */
1645 		if (emac_copy_small != 0 && len <= MHLEN) {
1646 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1647 			if (m == NULL)
1648 				goto dropit;
1649 			memcpy(mtod(m, void *),
1650 			    mtod(rxs->rxs_mbuf, void *), len);
1651 			EMAC_INIT_RXDESC(sc, i);
1652 			bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1653 			    rxs->rxs_dmamap->dm_mapsize,
1654 			    BUS_DMASYNC_PREREAD);
1655 		} else {
1656 			m = rxs->rxs_mbuf;
1657 			if (emac_add_rxbuf(sc, i) != 0) {
1658  dropit:
1659 				ifp->if_ierrors++;
1660 				EMAC_INIT_RXDESC(sc, i);
1661 				bus_dmamap_sync(sc->sc_dmat,
1662 				    rxs->rxs_dmamap, 0,
1663 				    rxs->rxs_dmamap->dm_mapsize,
1664 				    BUS_DMASYNC_PREREAD);
1665 				continue;
1666 			}
1667 		}
1668 
1669 		m_set_rcvif(m, ifp);
1670 		m->m_pkthdr.len = m->m_len = len;
1671 
1672 		/* Pass it on. */
1673 		if_percpuq_enqueue(ifp->if_percpuq, m);
1674 	}
1675 
1676 	/* Update the receive pointer. */
1677 	sc->sc_rxptr = i;
1678 
1679 	return 1;
1680 }
1681 
1682 int
1683 emac_txde_intr(void *arg)
1684 {
1685 	struct emac_softc *sc = arg;
1686 
1687 	EMAC_EVCNT_INCR(&sc->sc_ev_txde);
1688 	aprint_error_dev(sc->sc_dev, "emac_txde_intr\n");
1689 	return 1;
1690 }
1691 
1692 int
1693 emac_rxde_intr(void *arg)
1694 {
1695 	struct emac_softc *sc = arg;
1696 	int i;
1697 
1698 	EMAC_EVCNT_INCR(&sc->sc_ev_rxde);
1699 	aprint_error_dev(sc->sc_dev, "emac_rxde_intr\n");
1700 	/*
1701 	 * XXX!
1702 	 * This is a bit drastic; we just drop all descriptors that aren't
1703 	 * "clean".  We should probably send any that are up the stack.
1704 	 */
1705 	for (i = 0; i < EMAC_NRXDESC; i++) {
1706 		EMAC_CDRXSYNC(sc, i,
1707 		    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
1708 
1709 		if (sc->sc_rxdescs[i].md_data_len != MCLBYTES)
1710 			EMAC_INIT_RXDESC(sc, i);
1711 	}
1712 
1713 	return 1;
1714 }
1715