xref: /freebsd/sys/dev/dwc/if_dwc.c (revision a0409676120c1e558d0ade943019934e0f15118d)
1 /*-
2  * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
3  * All rights reserved.
4  *
5  * This software was developed by SRI International and the University of
6  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
7  * ("CTSRD"), as part of the DARPA CRASH research programme.
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  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * Ethernet media access controller (EMAC)
33  * Chapter 17, Altera Cyclone V Device Handbook (CV-5V2 2014.07.22)
34  *
35  * EMAC is an instance of the Synopsys DesignWare 3504-0
36  * Universal 10/100/1000 Ethernet MAC (DWC_gmac).
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/bus.h>
45 #include <sys/gpio.h>
46 #include <sys/kernel.h>
47 #include <sys/lock.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/module.h>
51 #include <sys/mutex.h>
52 #include <sys/rman.h>
53 #include <sys/socket.h>
54 #include <sys/sockio.h>
55 
56 #include <net/bpf.h>
57 #include <net/if.h>
58 #include <net/ethernet.h>
59 #include <net/if_dl.h>
60 #include <net/if_media.h>
61 #include <net/if_types.h>
62 #include <net/if_var.h>
63 
64 #include <machine/bus.h>
65 
66 #include <dev/dwc/if_dwc.h>
67 #include <dev/dwc/if_dwcvar.h>
68 #include <dev/mii/mii.h>
69 #include <dev/mii/miivar.h>
70 #include <dev/ofw/ofw_bus.h>
71 #include <dev/ofw/ofw_bus_subr.h>
72 
73 #ifdef EXT_RESOURCES
74 #include <dev/extres/clk/clk.h>
75 #include <dev/extres/hwreset/hwreset.h>
76 #endif
77 
78 #include "if_dwc_if.h"
79 #include "gpio_if.h"
80 #include "miibus_if.h"
81 
82 #define	READ4(_sc, _reg) \
83 	bus_read_4((_sc)->res[0], _reg)
84 #define	WRITE4(_sc, _reg, _val) \
85 	bus_write_4((_sc)->res[0], _reg, _val)
86 
87 #define	MAC_RESET_TIMEOUT	100
88 #define	WATCHDOG_TIMEOUT_SECS	5
89 #define	STATS_HARVEST_INTERVAL	2
90 
91 #define	DWC_LOCK(sc)			mtx_lock(&(sc)->mtx)
92 #define	DWC_UNLOCK(sc)			mtx_unlock(&(sc)->mtx)
93 #define	DWC_ASSERT_LOCKED(sc)		mtx_assert(&(sc)->mtx, MA_OWNED)
94 #define	DWC_ASSERT_UNLOCKED(sc)		mtx_assert(&(sc)->mtx, MA_NOTOWNED)
95 
96 /* TX descriptors - TDESC0 is almost unified */
97 #define	TDESC0_OWN		(1U << 31)
98 #define	TDESC0_IHE		(1U << 16)	/* IP Header Error */
99 #define	TDESC0_ES		(1U << 15)	/* Error Summary */
100 #define	TDESC0_JT		(1U << 14)	/* Jabber Timeout */
101 #define	TDESC0_FF		(1U << 13)	/* Frame Flushed */
102 #define	TDESC0_PCE		(1U << 12)	/* Payload Checksum Error */
103 #define	TDESC0_LOC		(1U << 11)	/* Loss of Carrier */
104 #define	TDESC0_NC		(1U << 10)	/* No Carrier */
105 #define	TDESC0_LC		(1U <<  9)	/* Late Collision */
106 #define	TDESC0_EC		(1U <<  8)	/* Excessive Collision */
107 #define	TDESC0_VF		(1U <<  7)	/* VLAN Frame */
108 #define	TDESC0_CC_MASK		0xf
109 #define	TDESC0_CC_SHIFT		3		/* Collision Count */
110 #define	TDESC0_ED		(1U <<  2)	/* Excessive Deferral */
111 #define	TDESC0_UF		(1U <<  1)	/* Underflow Error */
112 #define	TDESC0_DB		(1U <<  0)	/* Deferred Bit */
113 /* TX descriptors - TDESC0 extended format only */
114 #define	ETDESC0_IC		(1U << 30)	/* Interrupt on Completion */
115 #define	ETDESC0_LS		(1U << 29)	/* Last Segment */
116 #define	ETDESC0_FS		(1U << 28)	/* First Segment */
117 #define	ETDESC0_DC		(1U << 27)	/* Disable CRC */
118 #define	ETDESC0_DP		(1U << 26)	/* Disable Padding */
119 #define	ETDESC0_CIC_NONE	(0U << 22)	/* Checksum Insertion Control */
120 #define	ETDESC0_CIC_HDR		(1U << 22)
121 #define	ETDESC0_CIC_SEG 	(2U << 22)
122 #define	ETDESC0_CIC_FULL	(3U << 22)
123 #define	ETDESC0_TER		(1U << 21)	/* Transmit End of Ring */
124 #define	ETDESC0_TCH		(1U << 20)	/* Second Address Chained */
125 
126 /* TX descriptors - TDESC1 normal format */
127 #define	NTDESC1_IC		(1U << 31)	/* Interrupt on Completion */
128 #define	NTDESC1_LS		(1U << 30)	/* Last Segment */
129 #define	NTDESC1_FS		(1U << 29)	/* First Segment */
130 #define	NTDESC1_CIC_NONE	(0U << 27)	/* Checksum Insertion Control */
131 #define	NTDESC1_CIC_HDR		(1U << 27)
132 #define	NTDESC1_CIC_SEG 	(2U << 27)
133 #define	NTDESC1_CIC_FULL	(3U << 27)
134 #define	NTDESC1_DC		(1U << 26)	/* Disable CRC */
135 #define	NTDESC1_TER		(1U << 25)	/* Transmit End of Ring */
136 #define	NTDESC1_TCH		(1U << 24)	/* Second Address Chained */
137 /* TX descriptors - TDESC1 extended format */
138 #define	ETDESC1_DP		(1U << 23)	/* Disable Padding */
139 #define	ETDESC1_TBS2_MASK	0x7ff
140 #define	ETDESC1_TBS2_SHIFT	11		/* Receive Buffer 2 Size */
141 #define	ETDESC1_TBS1_MASK	0x7ff
142 #define	ETDESC1_TBS1_SHIFT	0		/* Receive Buffer 1 Size */
143 
144 /* RX descriptor - RDESC0 is unified */
145 #define	RDESC0_OWN		(1U << 31)
146 #define	RDESC0_AFM		(1U << 30)	/* Dest. Address Filter Fail */
147 #define	RDESC0_FL_MASK		0x3fff
148 #define	RDESC0_FL_SHIFT		16		/* Frame Length */
149 #define	RDESC0_ES		(1U << 15)	/* Error Summary */
150 #define	RDESC0_DE		(1U << 14)	/* Descriptor Error */
151 #define	RDESC0_SAF		(1U << 13)	/* Source Address Filter Fail */
152 #define	RDESC0_LE		(1U << 12)	/* Length Error */
153 #define	RDESC0_OE		(1U << 11)	/* Overflow Error */
154 #define	RDESC0_VLAN		(1U << 10)	/* VLAN Tag */
155 #define	RDESC0_FS		(1U <<  9)	/* First Descriptor */
156 #define	RDESC0_LS		(1U <<  8)	/* Last Descriptor */
157 #define	RDESC0_ICE		(1U <<  7)	/* IPC Checksum Error */
158 #define	RDESC0_LC		(1U <<  6)	/* Late Collision */
159 #define	RDESC0_FT		(1U <<  5)	/* Frame Type */
160 #define	RDESC0_RWT		(1U <<  4)	/* Receive Watchdog Timeout */
161 #define	RDESC0_RE		(1U <<  3)	/* Receive Error */
162 #define	RDESC0_DBE		(1U <<  2)	/* Dribble Bit Error */
163 #define	RDESC0_CE		(1U <<  1)	/* CRC Error */
164 #define	RDESC0_PCE		(1U <<  0)	/* Payload Checksum Error */
165 #define	RDESC0_RXMA		(1U <<  0)	/* Rx MAC Address */
166 
167 /* RX descriptors - RDESC1 normal format */
168 #define	NRDESC1_DIC		(1U << 31)	/* Disable Intr on Completion */
169 #define	NRDESC1_RER		(1U << 25)	/* Receive End of Ring */
170 #define	NRDESC1_RCH		(1U << 24)	/* Second Address Chained */
171 #define	NRDESC1_RBS2_MASK	0x7ff
172 #define	NRDESC1_RBS2_SHIFT	11		/* Receive Buffer 2 Size */
173 #define	NRDESC1_RBS1_MASK	0x7ff
174 #define	NRDESC1_RBS1_SHIFT	0		/* Receive Buffer 1 Size */
175 
176 /* RX descriptors - RDESC1 enhanced format */
177 #define	ERDESC1_DIC		(1U << 31)	/* Disable Intr on Completion */
178 #define	ERDESC1_RBS2_MASK	0x7ffff
179 #define	ERDESC1_RBS2_SHIFT	16		/* Receive Buffer 2 Size */
180 #define	ERDESC1_RER		(1U << 15)	/* Receive End of Ring */
181 #define	ERDESC1_RCH		(1U << 14)	/* Second Address Chained */
182 #define	ERDESC1_RBS1_MASK	0x7ffff
183 #define	ERDESC1_RBS1_SHIFT	0		/* Receive Buffer 1 Size */
184 
185 /*
186  * A hardware buffer descriptor.  Rx and Tx buffers have the same descriptor
187  * layout, but the bits in the fields have different meanings.
188  */
189 struct dwc_hwdesc
190 {
191 	uint32_t desc0;
192 	uint32_t desc1;
193 	uint32_t addr1;		/* ptr to first buffer data */
194 	uint32_t addr2;		/* ptr to next descriptor / second buffer data*/
195 };
196 
197 
198 struct dwc_hash_maddr_ctx {
199 	struct dwc_softc *sc;
200 	uint32_t hash[8];
201 };
202 
203 /*
204  * The hardware imposes alignment restrictions on various objects involved in
205  * DMA transfers.  These values are expressed in bytes (not bits).
206  */
207 #define	DWC_DESC_RING_ALIGN	2048
208 
209 static struct resource_spec dwc_spec[] = {
210 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
211 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
212 	{ -1, 0 }
213 };
214 
215 static void dwc_txfinish_locked(struct dwc_softc *sc);
216 static void dwc_rxfinish_locked(struct dwc_softc *sc);
217 static void dwc_stop_locked(struct dwc_softc *sc);
218 static void dwc_setup_rxfilter(struct dwc_softc *sc);
219 static void dwc_setup_core(struct dwc_softc *sc);
220 static void dwc_enable_mac(struct dwc_softc *sc, bool enable);
221 static void dwc_init_dma(struct dwc_softc *sc);
222 static void dwc_stop_dma(struct dwc_softc *sc);
223 
224 static void dwc_tick(void *arg);
225 
226 /* Pause time field in the transmitted control frame */
227 static int dwc_pause_time = 0xffff;
228 TUNABLE_INT("hw.dwc.pause_time", &dwc_pause_time);
229 
230 /*
231  * MIIBUS functions
232  */
233 
234 static int
235 dwc_miibus_read_reg(device_t dev, int phy, int reg)
236 {
237 	struct dwc_softc *sc;
238 	uint16_t mii;
239 	size_t cnt;
240 	int rv = 0;
241 
242 	sc = device_get_softc(dev);
243 
244 	mii = ((phy & GMII_ADDRESS_PA_MASK) << GMII_ADDRESS_PA_SHIFT)
245 	    | ((reg & GMII_ADDRESS_GR_MASK) << GMII_ADDRESS_GR_SHIFT)
246 	    | (sc->mii_clk << GMII_ADDRESS_CR_SHIFT)
247 	    | GMII_ADDRESS_GB; /* Busy flag */
248 
249 	WRITE4(sc, GMII_ADDRESS, mii);
250 
251 	for (cnt = 0; cnt < 1000; cnt++) {
252 		if (!(READ4(sc, GMII_ADDRESS) & GMII_ADDRESS_GB)) {
253 			rv = READ4(sc, GMII_DATA);
254 			break;
255 		}
256 		DELAY(10);
257 	}
258 
259 	return rv;
260 }
261 
262 static int
263 dwc_miibus_write_reg(device_t dev, int phy, int reg, int val)
264 {
265 	struct dwc_softc *sc;
266 	uint16_t mii;
267 	size_t cnt;
268 
269 	sc = device_get_softc(dev);
270 
271 	mii = ((phy & GMII_ADDRESS_PA_MASK) << GMII_ADDRESS_PA_SHIFT)
272 	    | ((reg & GMII_ADDRESS_GR_MASK) << GMII_ADDRESS_GR_SHIFT)
273 	    | (sc->mii_clk << GMII_ADDRESS_CR_SHIFT)
274 	    | GMII_ADDRESS_GB | GMII_ADDRESS_GW;
275 
276 	WRITE4(sc, GMII_DATA, val);
277 	WRITE4(sc, GMII_ADDRESS, mii);
278 
279 	for (cnt = 0; cnt < 1000; cnt++) {
280 		if (!(READ4(sc, GMII_ADDRESS) & GMII_ADDRESS_GB)) {
281 			break;
282                 }
283 		DELAY(10);
284 	}
285 
286 	return (0);
287 }
288 
289 static void
290 dwc_miibus_statchg(device_t dev)
291 {
292 	struct dwc_softc *sc;
293 	struct mii_data *mii;
294 	uint32_t reg;
295 
296 	/*
297 	 * Called by the MII bus driver when the PHY establishes
298 	 * link to set the MAC interface registers.
299 	 */
300 
301 	sc = device_get_softc(dev);
302 
303 	DWC_ASSERT_LOCKED(sc);
304 
305 	mii = sc->mii_softc;
306 
307 	if (mii->mii_media_status & IFM_ACTIVE)
308 		sc->link_is_up = true;
309 	else
310 		sc->link_is_up = false;
311 
312 	reg = READ4(sc, MAC_CONFIGURATION);
313 	switch (IFM_SUBTYPE(mii->mii_media_active)) {
314 	case IFM_1000_T:
315 	case IFM_1000_SX:
316 		reg &= ~(CONF_FES | CONF_PS);
317 		break;
318 	case IFM_100_TX:
319 		reg |= (CONF_FES | CONF_PS);
320 		break;
321 	case IFM_10_T:
322 		reg &= ~(CONF_FES);
323 		reg |= (CONF_PS);
324 		break;
325 	case IFM_NONE:
326 		sc->link_is_up = false;
327 		return;
328 	default:
329 		sc->link_is_up = false;
330 		device_printf(dev, "Unsupported media %u\n",
331 		    IFM_SUBTYPE(mii->mii_media_active));
332 		return;
333 	}
334 	if ((IFM_OPTIONS(mii->mii_media_active) & IFM_FDX) != 0)
335 		reg |= (CONF_DM);
336 	else
337 		reg &= ~(CONF_DM);
338 	WRITE4(sc, MAC_CONFIGURATION, reg);
339 
340 	reg = FLOW_CONTROL_UP;
341 	if ((IFM_OPTIONS(mii->mii_media_active) & IFM_ETH_TXPAUSE) != 0)
342 		reg |= FLOW_CONTROL_TX;
343 	if ((IFM_OPTIONS(mii->mii_media_active) & IFM_ETH_RXPAUSE) != 0)
344 		reg |= FLOW_CONTROL_RX;
345 	if ((IFM_OPTIONS(mii->mii_media_active) & IFM_FDX) != 0)
346 		reg |= dwc_pause_time << FLOW_CONTROL_PT_SHIFT;
347 	WRITE4(sc, FLOW_CONTROL, reg);
348 
349 	IF_DWC_SET_SPEED(dev, IFM_SUBTYPE(mii->mii_media_active));
350 
351 }
352 
353 /*
354  * Media functions
355  */
356 
357 static void
358 dwc_media_status(struct ifnet * ifp, struct ifmediareq *ifmr)
359 {
360 	struct dwc_softc *sc;
361 	struct mii_data *mii;
362 
363 	sc = ifp->if_softc;
364 	mii = sc->mii_softc;
365 	DWC_LOCK(sc);
366 	mii_pollstat(mii);
367 	ifmr->ifm_active = mii->mii_media_active;
368 	ifmr->ifm_status = mii->mii_media_status;
369 	DWC_UNLOCK(sc);
370 }
371 
372 static int
373 dwc_media_change_locked(struct dwc_softc *sc)
374 {
375 
376 	return (mii_mediachg(sc->mii_softc));
377 }
378 
379 static int
380 dwc_media_change(struct ifnet * ifp)
381 {
382 	struct dwc_softc *sc;
383 	int error;
384 
385 	sc = ifp->if_softc;
386 
387 	DWC_LOCK(sc);
388 	error = dwc_media_change_locked(sc);
389 	DWC_UNLOCK(sc);
390 	return (error);
391 }
392 
393 /*
394  * Core functions
395  */
396 
397 static const uint8_t nibbletab[] = {
398 	/* 0x0 0000 -> 0000 */  0x0,
399 	/* 0x1 0001 -> 1000 */  0x8,
400 	/* 0x2 0010 -> 0100 */  0x4,
401 	/* 0x3 0011 -> 1100 */  0xc,
402 	/* 0x4 0100 -> 0010 */  0x2,
403 	/* 0x5 0101 -> 1010 */  0xa,
404 	/* 0x6 0110 -> 0110 */  0x6,
405 	/* 0x7 0111 -> 1110 */  0xe,
406 	/* 0x8 1000 -> 0001 */  0x1,
407 	/* 0x9 1001 -> 1001 */  0x9,
408 	/* 0xa 1010 -> 0101 */  0x5,
409 	/* 0xb 1011 -> 1101 */  0xd,
410 	/* 0xc 1100 -> 0011 */  0x3,
411 	/* 0xd 1101 -> 1011 */  0xb,
412 	/* 0xe 1110 -> 0111 */  0x7,
413 	/* 0xf 1111 -> 1111 */  0xf, };
414 
415 static uint8_t
416 bitreverse(uint8_t x)
417 {
418 
419 	return (nibbletab[x & 0xf] << 4) | nibbletab[x >> 4];
420 }
421 
422 static u_int
423 dwc_hash_maddr(void *arg, struct sockaddr_dl *sdl, u_int cnt)
424 {
425 	struct dwc_hash_maddr_ctx *ctx = arg;
426 	uint32_t crc, hashbit, hashreg;
427 	uint8_t val;
428 
429 	crc = ether_crc32_le(LLADDR(sdl), ETHER_ADDR_LEN);
430 	/* Take lower 8 bits and reverse it */
431 	val = bitreverse(~crc & 0xff);
432 	if (ctx->sc->mactype != DWC_GMAC_EXT_DESC)
433 		val >>= 2; /* Only need lower 6 bits */
434 	hashreg = (val >> 5);
435 	hashbit = (val & 31);
436 	ctx->hash[hashreg] |= (1 << hashbit);
437 
438 	return (1);
439 }
440 
441 static void
442 dwc_setup_rxfilter(struct dwc_softc *sc)
443 {
444 	struct dwc_hash_maddr_ctx ctx;
445 	struct ifnet *ifp;
446 	uint8_t *eaddr;
447 	uint32_t ffval, hi, lo;
448 	int nhash, i;
449 
450 	DWC_ASSERT_LOCKED(sc);
451 
452 	ifp = sc->ifp;
453 	nhash = sc->mactype != DWC_GMAC_EXT_DESC ? 2 : 8;
454 
455 	/*
456 	 * Set the multicast (group) filter hash.
457 	 */
458 	if ((ifp->if_flags & IFF_ALLMULTI) != 0) {
459 		ffval = (FRAME_FILTER_PM);
460 		for (i = 0; i < nhash; i++)
461 			ctx.hash[i] = ~0;
462 	} else {
463 		ffval = (FRAME_FILTER_HMC);
464 		for (i = 0; i < nhash; i++)
465 			ctx.hash[i] = 0;
466 		ctx.sc = sc;
467 		if_foreach_llmaddr(ifp, dwc_hash_maddr, &ctx);
468 	}
469 
470 	/*
471 	 * Set the individual address filter hash.
472 	 */
473 	if (ifp->if_flags & IFF_PROMISC)
474 		ffval |= (FRAME_FILTER_PR);
475 
476 	/*
477 	 * Set the primary address.
478 	 */
479 	eaddr = IF_LLADDR(ifp);
480 	lo = eaddr[0] | (eaddr[1] << 8) | (eaddr[2] << 16) |
481 	    (eaddr[3] << 24);
482 	hi = eaddr[4] | (eaddr[5] << 8);
483 	WRITE4(sc, MAC_ADDRESS_LOW(0), lo);
484 	WRITE4(sc, MAC_ADDRESS_HIGH(0), hi);
485 	WRITE4(sc, MAC_FRAME_FILTER, ffval);
486 	if (sc->mactype != DWC_GMAC_EXT_DESC) {
487 		WRITE4(sc, GMAC_MAC_HTLOW, ctx.hash[0]);
488 		WRITE4(sc, GMAC_MAC_HTHIGH, ctx.hash[1]);
489 	} else {
490 		for (i = 0; i < nhash; i++)
491 			WRITE4(sc, HASH_TABLE_REG(i), ctx.hash[i]);
492 	}
493 }
494 
495 static void
496 dwc_setup_core(struct dwc_softc *sc)
497 {
498 	uint32_t reg;
499 
500 	DWC_ASSERT_LOCKED(sc);
501 
502 	/* Enable core */
503 	reg = READ4(sc, MAC_CONFIGURATION);
504 	reg |= (CONF_JD | CONF_ACS | CONF_BE);
505 	WRITE4(sc, MAC_CONFIGURATION, reg);
506 }
507 
508 static void
509 dwc_enable_mac(struct dwc_softc *sc, bool enable)
510 {
511 	uint32_t reg;
512 
513 	DWC_ASSERT_LOCKED(sc);
514 	reg = READ4(sc, MAC_CONFIGURATION);
515 	if (enable)
516 		reg |= CONF_TE | CONF_RE;
517 	else
518 		reg &= ~(CONF_TE | CONF_RE);
519 	WRITE4(sc, MAC_CONFIGURATION, reg);
520 }
521 
522 static void
523 dwc_get_hwaddr(struct dwc_softc *sc, uint8_t *hwaddr)
524 {
525 	uint32_t hi, lo, rnd;
526 
527 	/*
528 	 * Try to recover a MAC address from the running hardware. If there's
529 	 * something non-zero there, assume the bootloader did the right thing
530 	 * and just use it.
531 	 *
532 	 * Otherwise, set the address to a convenient locally assigned address,
533 	 * 'bsd' + random 24 low-order bits.  'b' is 0x62, which has the locally
534 	 * assigned bit set, and the broadcast/multicast bit clear.
535 	 */
536 	lo = READ4(sc, MAC_ADDRESS_LOW(0));
537 	hi = READ4(sc, MAC_ADDRESS_HIGH(0)) & 0xffff;
538 	if ((lo != 0xffffffff) || (hi != 0xffff)) {
539 		hwaddr[0] = (lo >>  0) & 0xff;
540 		hwaddr[1] = (lo >>  8) & 0xff;
541 		hwaddr[2] = (lo >> 16) & 0xff;
542 		hwaddr[3] = (lo >> 24) & 0xff;
543 		hwaddr[4] = (hi >>  0) & 0xff;
544 		hwaddr[5] = (hi >>  8) & 0xff;
545 	} else {
546 		rnd = arc4random() & 0x00ffffff;
547 		hwaddr[0] = 'b';
548 		hwaddr[1] = 's';
549 		hwaddr[2] = 'd';
550 		hwaddr[3] = rnd >> 16;
551 		hwaddr[4] = rnd >>  8;
552 		hwaddr[5] = rnd >>  0;
553 	}
554 }
555 
556 /*
557  * DMA functions
558  */
559 
560 static void
561 dwc_init_dma(struct dwc_softc *sc)
562 {
563 	uint32_t reg;
564 
565 	DWC_ASSERT_LOCKED(sc);
566 
567 	/* Initializa DMA and enable transmitters */
568 	reg = READ4(sc, OPERATION_MODE);
569 	reg |= (MODE_TSF | MODE_OSF | MODE_FUF);
570 	reg &= ~(MODE_RSF);
571 	reg |= (MODE_RTC_LEV32 << MODE_RTC_SHIFT);
572 	WRITE4(sc, OPERATION_MODE, reg);
573 
574 	WRITE4(sc, INTERRUPT_ENABLE, INT_EN_DEFAULT);
575 
576 	/* Start DMA */
577 	reg = READ4(sc, OPERATION_MODE);
578 	reg |= (MODE_ST | MODE_SR);
579 	WRITE4(sc, OPERATION_MODE, reg);
580 }
581 
582 static void
583 dwc_stop_dma(struct dwc_softc *sc)
584 {
585 	uint32_t reg;
586 
587 	DWC_ASSERT_LOCKED(sc);
588 
589 	/* Stop DMA TX */
590 	reg = READ4(sc, OPERATION_MODE);
591 	reg &= ~(MODE_ST);
592 	WRITE4(sc, OPERATION_MODE, reg);
593 
594 	/* Flush TX */
595 	reg = READ4(sc, OPERATION_MODE);
596 	reg |= (MODE_FTF);
597 	WRITE4(sc, OPERATION_MODE, reg);
598 
599 	/* Stop DMA RX */
600 	reg = READ4(sc, OPERATION_MODE);
601 	reg &= ~(MODE_SR);
602 	WRITE4(sc, OPERATION_MODE, reg);
603 }
604 
605 static inline uint32_t
606 next_rxidx(struct dwc_softc *sc, uint32_t curidx)
607 {
608 
609 	return ((curidx + 1) % RX_DESC_COUNT);
610 }
611 
612 static inline uint32_t
613 next_txidx(struct dwc_softc *sc, uint32_t curidx)
614 {
615 
616 	return ((curidx + 1) % TX_DESC_COUNT);
617 }
618 
619 static void
620 dwc_get1paddr(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
621 {
622 
623 	if (error != 0)
624 		return;
625 	*(bus_addr_t *)arg = segs[0].ds_addr;
626 }
627 
628 inline static void
629 dwc_setup_txdesc(struct dwc_softc *sc, int idx, bus_addr_t paddr,
630   uint32_t len, uint32_t flags, bool first, bool last)
631 {
632 	uint32_t desc0, desc1;
633 
634 	/* Addr/len 0 means we're clearing the descriptor after xmit done. */
635 	if (paddr == 0 || len == 0) {
636 		desc0 = 0;
637 		desc1 = 0;
638 		--sc->tx_desccount;
639 	} else {
640 		if (sc->mactype != DWC_GMAC_EXT_DESC) {
641 			desc0 = 0;
642 			desc1 = NTDESC1_TCH | len | flags;
643 			if (first)
644 				desc1 |=  NTDESC1_FS;
645 			if (last)
646 				desc1 |= NTDESC1_LS | NTDESC1_IC;
647 		} else {
648 			desc0 = ETDESC0_TCH | flags;
649 			if (first)
650 				desc0 |= ETDESC0_FS;
651 			if (last)
652 				desc0 |= ETDESC0_LS | ETDESC0_IC;
653 			desc1 = len;
654 		}
655 		++sc->tx_desccount;
656 	}
657 
658 	sc->txdesc_ring[idx].addr1 = (uint32_t)(paddr);
659 	sc->txdesc_ring[idx].desc0 = desc0;
660 	sc->txdesc_ring[idx].desc1 = desc1;
661 }
662 
663 inline static void
664 dwc_set_owner(struct dwc_softc *sc, int idx)
665 {
666 	wmb();
667 	sc->txdesc_ring[idx].desc0 |= TDESC0_OWN;
668 	wmb();
669 }
670 
671 static int
672 dwc_setup_txbuf(struct dwc_softc *sc, int idx, struct mbuf **mp)
673 {
674 	struct bus_dma_segment segs[TX_MAP_MAX_SEGS];
675 	int error, nsegs;
676 	struct mbuf * m;
677 	uint32_t flags = 0;
678 	int i;
679 	int first, last;
680 
681 	error = bus_dmamap_load_mbuf_sg(sc->txbuf_tag, sc->txbuf_map[idx].map,
682 	    *mp, segs, &nsegs, 0);
683 	if (error == EFBIG) {
684 		/*
685 		 * The map may be partially mapped from the first call.
686 		 * Make sure to reset it.
687 		 */
688 		bus_dmamap_unload(sc->txbuf_tag, sc->txbuf_map[idx].map);
689 		if ((m = m_defrag(*mp, M_NOWAIT)) == NULL)
690 			return (ENOMEM);
691 		*mp = m;
692 		error = bus_dmamap_load_mbuf_sg(sc->txbuf_tag, sc->txbuf_map[idx].map,
693 		    *mp, segs, &nsegs, 0);
694 	}
695 	if (error != 0)
696 		return (ENOMEM);
697 
698 	if (sc->tx_desccount + nsegs > TX_DESC_COUNT) {
699 		bus_dmamap_unload(sc->txbuf_tag, sc->txbuf_map[idx].map);
700 		return (ENOMEM);
701 	}
702 
703 	m = *mp;
704 
705 	if ((m->m_pkthdr.csum_flags & CSUM_IP) != 0) {
706 		if ((m->m_pkthdr.csum_flags & (CSUM_TCP|CSUM_UDP)) != 0) {
707 			if (sc->mactype != DWC_GMAC_EXT_DESC)
708 				flags = NTDESC1_CIC_FULL;
709 			else
710 				flags = ETDESC0_CIC_FULL;
711 		} else {
712 			if (sc->mactype != DWC_GMAC_EXT_DESC)
713 				flags = NTDESC1_CIC_HDR;
714 			else
715 				flags = ETDESC0_CIC_HDR;
716 		}
717 	}
718 
719 	bus_dmamap_sync(sc->txbuf_tag, sc->txbuf_map[idx].map,
720 	    BUS_DMASYNC_PREWRITE);
721 
722 	sc->txbuf_map[idx].mbuf = m;
723 
724 	first = sc->tx_desc_head;
725 	for (i = 0; i < nsegs; i++) {
726 		dwc_setup_txdesc(sc, sc->tx_desc_head,
727 		    segs[i].ds_addr, segs[i].ds_len,
728 		    (i == 0) ? flags : 0, /* only first desc needs flags */
729 		    (i == 0),
730 		    (i == nsegs - 1));
731 		if (i > 0)
732 			dwc_set_owner(sc, sc->tx_desc_head);
733 		last = sc->tx_desc_head;
734 		sc->tx_desc_head = next_txidx(sc, sc->tx_desc_head);
735 	}
736 
737 	sc->txbuf_map[idx].last_desc_idx = last;
738 
739 	dwc_set_owner(sc, first);
740 
741 	return (0);
742 }
743 
744 inline static uint32_t
745 dwc_setup_rxdesc(struct dwc_softc *sc, int idx, bus_addr_t paddr)
746 {
747 	uint32_t nidx;
748 
749 	sc->rxdesc_ring[idx].addr1 = (uint32_t)paddr;
750 	nidx = next_rxidx(sc, idx);
751 	sc->rxdesc_ring[idx].addr2 = sc->rxdesc_ring_paddr +
752 	    (nidx * sizeof(struct dwc_hwdesc));
753 	if (sc->mactype != DWC_GMAC_EXT_DESC)
754 		sc->rxdesc_ring[idx].desc1 = NRDESC1_RCH |
755 		    MIN(MCLBYTES, NRDESC1_RBS1_MASK);
756 	else
757 		sc->rxdesc_ring[idx].desc1 = ERDESC1_RCH |
758 		    MIN(MCLBYTES, ERDESC1_RBS1_MASK);
759 
760 	wmb();
761 	sc->rxdesc_ring[idx].desc0 = RDESC0_OWN;
762 	wmb();
763 	return (nidx);
764 }
765 
766 static int
767 dwc_setup_rxbuf(struct dwc_softc *sc, int idx, struct mbuf *m)
768 {
769 	struct bus_dma_segment seg;
770 	int error, nsegs;
771 
772 	m_adj(m, ETHER_ALIGN);
773 
774 	error = bus_dmamap_load_mbuf_sg(sc->rxbuf_tag, sc->rxbuf_map[idx].map,
775 	    m, &seg, &nsegs, 0);
776 	if (error != 0)
777 		return (error);
778 
779 	KASSERT(nsegs == 1, ("%s: %d segments returned!", __func__, nsegs));
780 
781 	bus_dmamap_sync(sc->rxbuf_tag, sc->rxbuf_map[idx].map,
782 	    BUS_DMASYNC_PREREAD);
783 
784 	sc->rxbuf_map[idx].mbuf = m;
785 	dwc_setup_rxdesc(sc, idx, seg.ds_addr);
786 
787 	return (0);
788 }
789 
790 static struct mbuf *
791 dwc_alloc_mbufcl(struct dwc_softc *sc)
792 {
793 	struct mbuf *m;
794 
795 	m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
796 	if (m != NULL)
797 		m->m_pkthdr.len = m->m_len = m->m_ext.ext_size;
798 
799 	return (m);
800 }
801 
802 static struct mbuf *
803 dwc_rxfinish_one(struct dwc_softc *sc, struct dwc_hwdesc *desc,
804     struct dwc_bufmap *map)
805 {
806 	struct ifnet *ifp;
807 	struct mbuf *m, *m0;
808 	int len;
809 	uint32_t rdesc0;
810 
811 	m = map->mbuf;
812 	ifp = sc->ifp;
813 	rdesc0 = desc ->desc0;
814 	/* Validate descriptor. */
815 	if (rdesc0 & RDESC0_ES) {
816 		/*
817 		 * Errored packet. Statistic counters are updated
818 		 * globally, so do nothing
819 		 */
820 		return (NULL);
821 	}
822 
823 	if ((rdesc0 & (RDESC0_FS | RDESC0_LS)) !=
824 		    (RDESC0_FS | RDESC0_LS)) {
825 		/*
826 		 * Something very wrong happens. The whole packet should be
827 		 * recevied in one descriptr. Report problem.
828 		 */
829 		device_printf(sc->dev,
830 		    "%s: RX descriptor without FIRST and LAST bit set: 0x%08X",
831 		    __func__, rdesc0);
832 		return (NULL);
833 	}
834 
835 	len = (rdesc0 >> RDESC0_FL_SHIFT) & RDESC0_FL_MASK;
836 	if (len < 64) {
837 		/*
838 		 * Lenght is invalid, recycle old mbuf
839 		 * Probably impossible case
840 		 */
841 		return (NULL);
842 	}
843 
844 	/* Allocate new buffer */
845 	m0 = dwc_alloc_mbufcl(sc);
846 	if (m0 == NULL) {
847 		/* no new mbuf available, recycle old */
848 		if_inc_counter(sc->ifp, IFCOUNTER_IQDROPS, 1);
849 		return (NULL);
850 	}
851 	/* Do dmasync for newly received packet */
852 	bus_dmamap_sync(sc->rxbuf_tag, map->map, BUS_DMASYNC_POSTREAD);
853 	bus_dmamap_unload(sc->rxbuf_tag, map->map);
854 
855 	/* Received packet is valid, process it */
856 	m->m_pkthdr.rcvif = ifp;
857 	m->m_pkthdr.len = len;
858 	m->m_len = len;
859 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
860 
861 	if ((if_getcapenable(ifp) & IFCAP_RXCSUM) != 0 &&
862 	  (rdesc0 & RDESC0_FT) != 0) {
863 		m->m_pkthdr.csum_flags = CSUM_IP_CHECKED;
864 		if ((rdesc0 & RDESC0_ICE) == 0)
865 			m->m_pkthdr.csum_flags |= CSUM_IP_VALID;
866 		if ((rdesc0 & RDESC0_PCE) == 0) {
867 			m->m_pkthdr.csum_flags |=
868 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
869 			m->m_pkthdr.csum_data = 0xffff;
870 		}
871 	}
872 
873 	/* Remove trailing FCS */
874 	m_adj(m, -ETHER_CRC_LEN);
875 
876 	DWC_UNLOCK(sc);
877 	(*ifp->if_input)(ifp, m);
878 	DWC_LOCK(sc);
879 	return (m0);
880 }
881 
882 static int
883 setup_dma(struct dwc_softc *sc)
884 {
885 	struct mbuf *m;
886 	int error;
887 	int nidx;
888 	int idx;
889 
890 	/*
891 	 * Set up TX descriptor ring, descriptors, and dma maps.
892 	 */
893 	error = bus_dma_tag_create(
894 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
895 	    DWC_DESC_RING_ALIGN, 0,	/* alignment, boundary */
896 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
897 	    BUS_SPACE_MAXADDR,		/* highaddr */
898 	    NULL, NULL,			/* filter, filterarg */
899 	    TX_DESC_SIZE, 1, 		/* maxsize, nsegments */
900 	    TX_DESC_SIZE,		/* maxsegsize */
901 	    0,				/* flags */
902 	    NULL, NULL,			/* lockfunc, lockarg */
903 	    &sc->txdesc_tag);
904 	if (error != 0) {
905 		device_printf(sc->dev,
906 		    "could not create TX ring DMA tag.\n");
907 		goto out;
908 	}
909 
910 	error = bus_dmamem_alloc(sc->txdesc_tag, (void**)&sc->txdesc_ring,
911 	    BUS_DMA_COHERENT | BUS_DMA_WAITOK | BUS_DMA_ZERO,
912 	    &sc->txdesc_map);
913 	if (error != 0) {
914 		device_printf(sc->dev,
915 		    "could not allocate TX descriptor ring.\n");
916 		goto out;
917 	}
918 
919 	error = bus_dmamap_load(sc->txdesc_tag, sc->txdesc_map,
920 	    sc->txdesc_ring, TX_DESC_SIZE, dwc_get1paddr,
921 	    &sc->txdesc_ring_paddr, 0);
922 	if (error != 0) {
923 		device_printf(sc->dev,
924 		    "could not load TX descriptor ring map.\n");
925 		goto out;
926 	}
927 
928 	for (idx = 0; idx < TX_DESC_COUNT; idx++) {
929 		nidx = next_txidx(sc, idx);
930 		sc->txdesc_ring[idx].addr2 = sc->txdesc_ring_paddr +
931 		    (nidx * sizeof(struct dwc_hwdesc));
932 	}
933 
934 	error = bus_dma_tag_create(
935 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
936 	    1, 0,			/* alignment, boundary */
937 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
938 	    BUS_SPACE_MAXADDR,		/* highaddr */
939 	    NULL, NULL,			/* filter, filterarg */
940 	    MCLBYTES*TX_MAP_MAX_SEGS,	/* maxsize */
941 	    TX_MAP_MAX_SEGS,		/* nsegments */
942 	    MCLBYTES,			/* maxsegsize */
943 	    0,				/* flags */
944 	    NULL, NULL,			/* lockfunc, lockarg */
945 	    &sc->txbuf_tag);
946 	if (error != 0) {
947 		device_printf(sc->dev,
948 		    "could not create TX ring DMA tag.\n");
949 		goto out;
950 	}
951 
952 	for (idx = 0; idx < TX_MAP_COUNT; idx++) {
953 		error = bus_dmamap_create(sc->txbuf_tag, BUS_DMA_COHERENT,
954 		    &sc->txbuf_map[idx].map);
955 		if (error != 0) {
956 			device_printf(sc->dev,
957 			    "could not create TX buffer DMA map.\n");
958 			goto out;
959 		}
960 	}
961 
962 	for (idx = 0; idx < TX_DESC_COUNT; idx++)
963 		dwc_setup_txdesc(sc, idx, 0, 0, 0, false, false);
964 
965 	/*
966 	 * Set up RX descriptor ring, descriptors, dma maps, and mbufs.
967 	 */
968 	error = bus_dma_tag_create(
969 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
970 	    DWC_DESC_RING_ALIGN, 0,	/* alignment, boundary */
971 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
972 	    BUS_SPACE_MAXADDR,		/* highaddr */
973 	    NULL, NULL,			/* filter, filterarg */
974 	    RX_DESC_SIZE, 1, 		/* maxsize, nsegments */
975 	    RX_DESC_SIZE,		/* maxsegsize */
976 	    0,				/* flags */
977 	    NULL, NULL,			/* lockfunc, lockarg */
978 	    &sc->rxdesc_tag);
979 	if (error != 0) {
980 		device_printf(sc->dev,
981 		    "could not create RX ring DMA tag.\n");
982 		goto out;
983 	}
984 
985 	error = bus_dmamem_alloc(sc->rxdesc_tag, (void **)&sc->rxdesc_ring,
986 	    BUS_DMA_COHERENT | BUS_DMA_WAITOK | BUS_DMA_ZERO,
987 	    &sc->rxdesc_map);
988 	if (error != 0) {
989 		device_printf(sc->dev,
990 		    "could not allocate RX descriptor ring.\n");
991 		goto out;
992 	}
993 
994 	error = bus_dmamap_load(sc->rxdesc_tag, sc->rxdesc_map,
995 	    sc->rxdesc_ring, RX_DESC_SIZE, dwc_get1paddr,
996 	    &sc->rxdesc_ring_paddr, 0);
997 	if (error != 0) {
998 		device_printf(sc->dev,
999 		    "could not load RX descriptor ring map.\n");
1000 		goto out;
1001 	}
1002 
1003 	error = bus_dma_tag_create(
1004 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
1005 	    1, 0,			/* alignment, boundary */
1006 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
1007 	    BUS_SPACE_MAXADDR,		/* highaddr */
1008 	    NULL, NULL,			/* filter, filterarg */
1009 	    MCLBYTES, 1, 		/* maxsize, nsegments */
1010 	    MCLBYTES,			/* maxsegsize */
1011 	    0,				/* flags */
1012 	    NULL, NULL,			/* lockfunc, lockarg */
1013 	    &sc->rxbuf_tag);
1014 	if (error != 0) {
1015 		device_printf(sc->dev,
1016 		    "could not create RX buf DMA tag.\n");
1017 		goto out;
1018 	}
1019 
1020 	for (idx = 0; idx < RX_DESC_COUNT; idx++) {
1021 		error = bus_dmamap_create(sc->rxbuf_tag, BUS_DMA_COHERENT,
1022 		    &sc->rxbuf_map[idx].map);
1023 		if (error != 0) {
1024 			device_printf(sc->dev,
1025 			    "could not create RX buffer DMA map.\n");
1026 			goto out;
1027 		}
1028 		if ((m = dwc_alloc_mbufcl(sc)) == NULL) {
1029 			device_printf(sc->dev, "Could not alloc mbuf\n");
1030 			error = ENOMEM;
1031 			goto out;
1032 		}
1033 		if ((error = dwc_setup_rxbuf(sc, idx, m)) != 0) {
1034 			device_printf(sc->dev,
1035 			    "could not create new RX buffer.\n");
1036 			goto out;
1037 		}
1038 	}
1039 
1040 out:
1041 	if (error != 0)
1042 		return (ENXIO);
1043 
1044 	return (0);
1045 }
1046 
1047 /*
1048  * if_ functions
1049  */
1050 
1051 static void
1052 dwc_txstart_locked(struct dwc_softc *sc)
1053 {
1054 	struct ifnet *ifp;
1055 	struct mbuf *m;
1056 	int enqueued;
1057 
1058 	DWC_ASSERT_LOCKED(sc);
1059 
1060 	if (!sc->link_is_up)
1061 		return;
1062 
1063 	ifp = sc->ifp;
1064 
1065 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING|IFF_DRV_OACTIVE)) !=
1066 	    IFF_DRV_RUNNING)
1067 		return;
1068 
1069 	enqueued = 0;
1070 
1071 	for (;;) {
1072 		if (sc->tx_desccount > (TX_DESC_COUNT - TX_MAP_MAX_SEGS  + 1)) {
1073 			if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, 0);
1074 			break;
1075 		}
1076 
1077 		if (sc->tx_mapcount == (TX_MAP_COUNT - 1)) {
1078 			if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, 0);
1079 			break;
1080 		}
1081 
1082 		m = if_dequeue(ifp);
1083 		if (m == NULL)
1084 			break;
1085 		if (dwc_setup_txbuf(sc, sc->tx_map_head, &m) != 0) {
1086 			if_sendq_prepend(ifp, m);
1087 			if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, 0);
1088 			break;
1089 		}
1090 		if_bpfmtap(ifp, m);
1091 		sc->tx_map_head = next_txidx(sc, sc->tx_map_head);
1092 		sc->tx_mapcount++;
1093 		++enqueued;
1094 	}
1095 
1096 	if (enqueued != 0) {
1097 		WRITE4(sc, TRANSMIT_POLL_DEMAND, 0x1);
1098 		sc->tx_watchdog_count = WATCHDOG_TIMEOUT_SECS;
1099 	}
1100 }
1101 
1102 static void
1103 dwc_txstart(struct ifnet *ifp)
1104 {
1105 	struct dwc_softc *sc = ifp->if_softc;
1106 
1107 	DWC_LOCK(sc);
1108 	dwc_txstart_locked(sc);
1109 	DWC_UNLOCK(sc);
1110 }
1111 
1112 static void
1113 dwc_init_locked(struct dwc_softc *sc)
1114 {
1115 	struct ifnet *ifp = sc->ifp;
1116 
1117 	DWC_ASSERT_LOCKED(sc);
1118 
1119 	if (if_getdrvflags(ifp) & IFF_DRV_RUNNING)
1120 		return;
1121 
1122 	dwc_setup_rxfilter(sc);
1123 	dwc_setup_core(sc);
1124 	dwc_enable_mac(sc, true);
1125 	dwc_init_dma(sc);
1126 
1127 	if_setdrvflagbits(ifp, IFF_DRV_RUNNING, IFF_DRV_OACTIVE);
1128 
1129 	/*
1130 	 * Call mii_mediachg() which will call back into dwc_miibus_statchg()
1131 	 * to set up the remaining config registers based on current media.
1132 	 */
1133 	mii_mediachg(sc->mii_softc);
1134 	callout_reset(&sc->dwc_callout, hz, dwc_tick, sc);
1135 }
1136 
1137 static void
1138 dwc_init(void *if_softc)
1139 {
1140 	struct dwc_softc *sc = if_softc;
1141 
1142 	DWC_LOCK(sc);
1143 	dwc_init_locked(sc);
1144 	DWC_UNLOCK(sc);
1145 }
1146 
1147 static void
1148 dwc_stop_locked(struct dwc_softc *sc)
1149 {
1150 	struct ifnet *ifp;
1151 
1152 	DWC_ASSERT_LOCKED(sc);
1153 
1154 	ifp = sc->ifp;
1155 	if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
1156 	sc->tx_watchdog_count = 0;
1157 	sc->stats_harvest_count = 0;
1158 
1159 	callout_stop(&sc->dwc_callout);
1160 
1161 	dwc_stop_dma(sc);
1162 	dwc_enable_mac(sc, false);
1163 }
1164 
1165 static int
1166 dwc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1167 {
1168 	struct dwc_softc *sc;
1169 	struct mii_data *mii;
1170 	struct ifreq *ifr;
1171 	int flags, mask, error;
1172 
1173 	sc = ifp->if_softc;
1174 	ifr = (struct ifreq *)data;
1175 
1176 	error = 0;
1177 	switch (cmd) {
1178 	case SIOCSIFFLAGS:
1179 		DWC_LOCK(sc);
1180 		if (if_getflags(ifp) & IFF_UP) {
1181 			if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
1182 				flags = if_getflags(ifp) ^ sc->if_flags;
1183 				if ((flags & (IFF_PROMISC|IFF_ALLMULTI)) != 0)
1184 					dwc_setup_rxfilter(sc);
1185 			} else {
1186 				if (!sc->is_detaching)
1187 					dwc_init_locked(sc);
1188 			}
1189 		} else {
1190 			if (if_getdrvflags(ifp) & IFF_DRV_RUNNING)
1191 				dwc_stop_locked(sc);
1192 		}
1193 		sc->if_flags = if_getflags(ifp);
1194 		DWC_UNLOCK(sc);
1195 		break;
1196 	case SIOCADDMULTI:
1197 	case SIOCDELMULTI:
1198 		if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
1199 			DWC_LOCK(sc);
1200 			dwc_setup_rxfilter(sc);
1201 			DWC_UNLOCK(sc);
1202 		}
1203 		break;
1204 	case SIOCSIFMEDIA:
1205 	case SIOCGIFMEDIA:
1206 		mii = sc->mii_softc;
1207 		error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, cmd);
1208 		break;
1209 	case SIOCSIFCAP:
1210 		mask = ifr->ifr_reqcap ^ if_getcapenable(ifp);
1211 		if (mask & IFCAP_VLAN_MTU) {
1212 			/* No work to do except acknowledge the change took */
1213 			if_togglecapenable(ifp, IFCAP_VLAN_MTU);
1214 		}
1215 		if (mask & IFCAP_RXCSUM)
1216 			if_togglecapenable(ifp, IFCAP_RXCSUM);
1217 		if (mask & IFCAP_TXCSUM)
1218 			if_togglecapenable(ifp, IFCAP_TXCSUM);
1219 		if ((if_getcapenable(ifp) & IFCAP_TXCSUM) != 0)
1220 			if_sethwassistbits(ifp, CSUM_IP | CSUM_UDP | CSUM_TCP, 0);
1221 		else
1222 			if_sethwassistbits(ifp, 0, CSUM_IP | CSUM_UDP | CSUM_TCP);
1223 		break;
1224 
1225 	default:
1226 		error = ether_ioctl(ifp, cmd, data);
1227 		break;
1228 	}
1229 
1230 	return (error);
1231 }
1232 
1233 /*
1234  * Interrupts functions
1235  */
1236 
1237 static void
1238 dwc_txfinish_locked(struct dwc_softc *sc)
1239 {
1240 	struct dwc_bufmap *bmap;
1241 	struct dwc_hwdesc *desc;
1242 	struct ifnet *ifp;
1243 	int idx, last_idx;
1244 	bool map_finished;
1245 
1246 	DWC_ASSERT_LOCKED(sc);
1247 
1248 	ifp = sc->ifp;
1249 	/* check if all descriptors of the map are done */
1250 	while (sc->tx_map_tail != sc->tx_map_head) {
1251 		map_finished = true;
1252 		bmap = &sc->txbuf_map[sc->tx_map_tail];
1253 		idx = sc->tx_desc_tail;
1254 		last_idx = next_txidx(sc, bmap->last_desc_idx);
1255 		while (idx != last_idx) {
1256 			desc = &sc->txdesc_ring[idx];
1257 			if ((desc->desc0 & TDESC0_OWN) != 0) {
1258 				map_finished = false;
1259 				break;
1260 			}
1261 			idx = next_txidx(sc, idx);
1262 		}
1263 
1264 		if (!map_finished)
1265 			break;
1266 		bus_dmamap_sync(sc->txbuf_tag, bmap->map,
1267 		    BUS_DMASYNC_POSTWRITE);
1268 		bus_dmamap_unload(sc->txbuf_tag, bmap->map);
1269 		m_freem(bmap->mbuf);
1270 		bmap->mbuf = NULL;
1271 		sc->tx_mapcount--;
1272 		while (sc->tx_desc_tail != last_idx) {
1273 			dwc_setup_txdesc(sc, sc->tx_desc_tail, 0, 0, 0, false, false);
1274 			sc->tx_desc_tail = next_txidx(sc, sc->tx_desc_tail);
1275 		}
1276 		sc->tx_map_tail = next_txidx(sc, sc->tx_map_tail);
1277 		if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);
1278 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1279 	}
1280 
1281 	/* If there are no buffers outstanding, muzzle the watchdog. */
1282 	if (sc->tx_desc_tail == sc->tx_desc_head) {
1283 		sc->tx_watchdog_count = 0;
1284 	}
1285 }
1286 
1287 static void
1288 dwc_rxfinish_locked(struct dwc_softc *sc)
1289 {
1290 	struct ifnet *ifp;
1291 	struct mbuf *m;
1292 	int error, idx;
1293 	struct dwc_hwdesc *desc;
1294 
1295 	DWC_ASSERT_LOCKED(sc);
1296 	ifp = sc->ifp;
1297 	for (;;) {
1298 		idx = sc->rx_idx;
1299 		desc = sc->rxdesc_ring + idx;
1300 		if ((desc->desc0 & RDESC0_OWN) != 0)
1301 			break;
1302 
1303 		m = dwc_rxfinish_one(sc, desc, sc->rxbuf_map + idx);
1304 		if (m == NULL) {
1305 			wmb();
1306 			desc->desc0 = RDESC0_OWN;
1307 			wmb();
1308 		} else {
1309 			/* We cannot create hole in RX ring */
1310 			error = dwc_setup_rxbuf(sc, idx, m);
1311 			if (error != 0)
1312 				panic("dwc_setup_rxbuf failed:  error %d\n",
1313 				    error);
1314 
1315 		}
1316 		sc->rx_idx = next_rxidx(sc, sc->rx_idx);
1317 	}
1318 }
1319 
1320 static void
1321 dwc_intr(void *arg)
1322 {
1323 	struct dwc_softc *sc;
1324 	uint32_t reg;
1325 
1326 	sc = arg;
1327 
1328 	DWC_LOCK(sc);
1329 
1330 	reg = READ4(sc, INTERRUPT_STATUS);
1331 	if (reg)
1332 		READ4(sc, SGMII_RGMII_SMII_CTRL_STATUS);
1333 
1334 	reg = READ4(sc, DMA_STATUS);
1335 	if (reg & DMA_STATUS_NIS) {
1336 		if (reg & DMA_STATUS_RI)
1337 			dwc_rxfinish_locked(sc);
1338 
1339 		if (reg & DMA_STATUS_TI) {
1340 			dwc_txfinish_locked(sc);
1341 			dwc_txstart_locked(sc);
1342 		}
1343 	}
1344 
1345 	if (reg & DMA_STATUS_AIS) {
1346 		if (reg & DMA_STATUS_FBI) {
1347 			/* Fatal bus error */
1348 			device_printf(sc->dev,
1349 			    "Ethernet DMA error, restarting controller.\n");
1350 			dwc_stop_locked(sc);
1351 			dwc_init_locked(sc);
1352 		}
1353 	}
1354 
1355 	WRITE4(sc, DMA_STATUS, reg & DMA_STATUS_INTR_MASK);
1356 	DWC_UNLOCK(sc);
1357 }
1358 
1359 /*
1360  * Stats
1361  */
1362 
1363 static void dwc_clear_stats(struct dwc_softc *sc)
1364 {
1365 	uint32_t reg;
1366 
1367 	reg = READ4(sc, MMC_CONTROL);
1368 	reg |= (MMC_CONTROL_CNTRST);
1369 	WRITE4(sc, MMC_CONTROL, reg);
1370 }
1371 
1372 static void
1373 dwc_harvest_stats(struct dwc_softc *sc)
1374 {
1375 	struct ifnet *ifp;
1376 
1377 	/* We don't need to harvest too often. */
1378 	if (++sc->stats_harvest_count < STATS_HARVEST_INTERVAL)
1379 		return;
1380 
1381 	sc->stats_harvest_count = 0;
1382 	ifp = sc->ifp;
1383 
1384 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, READ4(sc, RXFRAMECOUNT_GB));
1385 	if_inc_counter(ifp, IFCOUNTER_IMCASTS, READ4(sc, RXMULTICASTFRAMES_G));
1386 	if_inc_counter(ifp, IFCOUNTER_IERRORS,
1387 	    READ4(sc, RXOVERSIZE_G) + READ4(sc, RXUNDERSIZE_G) +
1388 	    READ4(sc, RXCRCERROR) + READ4(sc, RXALIGNMENTERROR) +
1389 	    READ4(sc, RXRUNTERROR) + READ4(sc, RXJABBERERROR) +
1390 	    READ4(sc, RXLENGTHERROR));
1391 
1392 	if_inc_counter(ifp, IFCOUNTER_OPACKETS, READ4(sc, TXFRAMECOUNT_G));
1393 	if_inc_counter(ifp, IFCOUNTER_OMCASTS, READ4(sc, TXMULTICASTFRAMES_G));
1394 	if_inc_counter(ifp, IFCOUNTER_OERRORS,
1395 	    READ4(sc, TXOVERSIZE_G) + READ4(sc, TXEXCESSDEF) +
1396 	    READ4(sc, TXCARRIERERR) + READ4(sc, TXUNDERFLOWERROR));
1397 
1398 	if_inc_counter(ifp, IFCOUNTER_COLLISIONS,
1399 	    READ4(sc, TXEXESSCOL) + READ4(sc, TXLATECOL));
1400 
1401 	dwc_clear_stats(sc);
1402 }
1403 
1404 static void
1405 dwc_tick(void *arg)
1406 {
1407 	struct dwc_softc *sc;
1408 	struct ifnet *ifp;
1409 	int link_was_up;
1410 
1411 	sc = arg;
1412 
1413 	DWC_ASSERT_LOCKED(sc);
1414 
1415 	ifp = sc->ifp;
1416 
1417 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0)
1418 	    return;
1419 
1420 	/*
1421 	 * Typical tx watchdog.  If this fires it indicates that we enqueued
1422 	 * packets for output and never got a txdone interrupt for them.  Maybe
1423 	 * it's a missed interrupt somehow, just pretend we got one.
1424 	 */
1425 	if (sc->tx_watchdog_count > 0) {
1426 		if (--sc->tx_watchdog_count == 0) {
1427 			dwc_txfinish_locked(sc);
1428 		}
1429 	}
1430 
1431 	/* Gather stats from hardware counters. */
1432 	dwc_harvest_stats(sc);
1433 
1434 	/* Check the media status. */
1435 	link_was_up = sc->link_is_up;
1436 	mii_tick(sc->mii_softc);
1437 	if (sc->link_is_up && !link_was_up)
1438 		dwc_txstart_locked(sc);
1439 
1440 	/* Schedule another check one second from now. */
1441 	callout_reset(&sc->dwc_callout, hz, dwc_tick, sc);
1442 }
1443 
1444 /*
1445  * Probe/Attach functions
1446  */
1447 
1448 #define	GPIO_ACTIVE_LOW 1
1449 
1450 static int
1451 dwc_reset(device_t dev)
1452 {
1453 	pcell_t gpio_prop[4];
1454 	pcell_t delay_prop[3];
1455 	phandle_t node, gpio_node;
1456 	device_t gpio;
1457 	uint32_t pin, flags;
1458 	uint32_t pin_value;
1459 
1460 	node = ofw_bus_get_node(dev);
1461 	if (OF_getencprop(node, "snps,reset-gpio",
1462 	    gpio_prop, sizeof(gpio_prop)) <= 0)
1463 		return (0);
1464 
1465 	if (OF_getencprop(node, "snps,reset-delays-us",
1466 	    delay_prop, sizeof(delay_prop)) <= 0) {
1467 		device_printf(dev,
1468 		    "Wrong property for snps,reset-delays-us");
1469 		return (ENXIO);
1470 	}
1471 
1472 	gpio_node = OF_node_from_xref(gpio_prop[0]);
1473 	if ((gpio = OF_device_from_xref(gpio_prop[0])) == NULL) {
1474 		device_printf(dev,
1475 		    "Can't find gpio controller for phy reset\n");
1476 		return (ENXIO);
1477 	}
1478 
1479 	if (GPIO_MAP_GPIOS(gpio, node, gpio_node,
1480 	    nitems(gpio_prop) - 1,
1481 	    gpio_prop + 1, &pin, &flags) != 0) {
1482 		device_printf(dev, "Can't map gpio for phy reset\n");
1483 		return (ENXIO);
1484 	}
1485 
1486 	pin_value = GPIO_PIN_LOW;
1487 	if (OF_hasprop(node, "snps,reset-active-low"))
1488 		pin_value = GPIO_PIN_HIGH;
1489 
1490 	GPIO_PIN_SETFLAGS(gpio, pin, GPIO_PIN_OUTPUT);
1491 	GPIO_PIN_SET(gpio, pin, pin_value);
1492 	DELAY(delay_prop[0] * 5);
1493 	GPIO_PIN_SET(gpio, pin, !pin_value);
1494 	DELAY(delay_prop[1] * 5);
1495 	GPIO_PIN_SET(gpio, pin, pin_value);
1496 	DELAY(delay_prop[2] * 5);
1497 
1498 	return (0);
1499 }
1500 
1501 #ifdef EXT_RESOURCES
1502 static int
1503 dwc_clock_init(device_t dev)
1504 {
1505 	hwreset_t rst;
1506 	clk_t clk;
1507 	int error;
1508 	int64_t freq;
1509 
1510 	/* Enable clocks */
1511 	if (clk_get_by_ofw_name(dev, 0, "stmmaceth", &clk) == 0) {
1512 		error = clk_enable(clk);
1513 		if (error != 0) {
1514 			device_printf(dev, "could not enable main clock\n");
1515 			return (error);
1516 		}
1517 		if (bootverbose) {
1518 			clk_get_freq(clk, &freq);
1519 			device_printf(dev, "MAC clock(%s) freq: %jd\n",
1520 					clk_get_name(clk), (intmax_t)freq);
1521 		}
1522 	}
1523 	else {
1524 		device_printf(dev, "could not find clock stmmaceth\n");
1525 	}
1526 
1527 	/* De-assert reset */
1528 	if (hwreset_get_by_ofw_name(dev, 0, "stmmaceth", &rst) == 0) {
1529 		error = hwreset_deassert(rst);
1530 		if (error != 0) {
1531 			device_printf(dev, "could not de-assert reset\n");
1532 			return (error);
1533 		}
1534 	}
1535 
1536 	return (0);
1537 }
1538 #endif
1539 
1540 static int
1541 dwc_probe(device_t dev)
1542 {
1543 
1544 	if (!ofw_bus_status_okay(dev))
1545 		return (ENXIO);
1546 
1547 	if (!ofw_bus_is_compatible(dev, "snps,dwmac"))
1548 		return (ENXIO);
1549 
1550 	device_set_desc(dev, "Gigabit Ethernet Controller");
1551 	return (BUS_PROBE_DEFAULT);
1552 }
1553 
1554 static int
1555 dwc_attach(device_t dev)
1556 {
1557 	uint8_t macaddr[ETHER_ADDR_LEN];
1558 	struct dwc_softc *sc;
1559 	struct ifnet *ifp;
1560 	int error, i;
1561 	uint32_t reg;
1562 	char *phy_mode;
1563 	phandle_t node;
1564 	uint32_t txpbl, rxpbl, pbl;
1565 	bool nopblx8 = false;
1566 	bool fixed_burst = false;
1567 
1568 	sc = device_get_softc(dev);
1569 	sc->dev = dev;
1570 	sc->rx_idx = 0;
1571 	sc->tx_desccount = TX_DESC_COUNT;
1572 	sc->tx_mapcount = 0;
1573 	sc->mii_clk = IF_DWC_MII_CLK(dev);
1574 	sc->mactype = IF_DWC_MAC_TYPE(dev);
1575 
1576 	node = ofw_bus_get_node(dev);
1577 	if (OF_getprop_alloc(node, "phy-mode", (void **)&phy_mode)) {
1578 		if (strcmp(phy_mode, "rgmii") == 0)
1579 			sc->phy_mode = PHY_MODE_RGMII;
1580 		if (strcmp(phy_mode, "rmii") == 0)
1581 			sc->phy_mode = PHY_MODE_RMII;
1582 		OF_prop_free(phy_mode);
1583 	}
1584 
1585 	if (OF_getencprop(node, "snps,pbl", &pbl, sizeof(uint32_t)) <= 0)
1586 		pbl = BUS_MODE_DEFAULT_PBL;
1587 	if (OF_getencprop(node, "snps,txpbl", &txpbl, sizeof(uint32_t)) <= 0)
1588 		txpbl = pbl;
1589 	if (OF_getencprop(node, "snps,rxpbl", &rxpbl, sizeof(uint32_t)) <= 0)
1590 		rxpbl = pbl;
1591 	if (OF_hasprop(node, "snps,no-pbl-x8") == 1)
1592 		nopblx8 = true;
1593 	if (OF_hasprop(node, "snps,fixed-burst") == 1)
1594 		fixed_burst = true;
1595 
1596 	if (IF_DWC_INIT(dev) != 0)
1597 		return (ENXIO);
1598 
1599 #ifdef EXT_RESOURCES
1600 	if (dwc_clock_init(dev) != 0)
1601 		return (ENXIO);
1602 #endif
1603 
1604 	if (bus_alloc_resources(dev, dwc_spec, sc->res)) {
1605 		device_printf(dev, "could not allocate resources\n");
1606 		return (ENXIO);
1607 	}
1608 
1609 	/* Read MAC before reset */
1610 	dwc_get_hwaddr(sc, macaddr);
1611 
1612 	/* Reset the PHY if needed */
1613 	if (dwc_reset(dev) != 0) {
1614 		device_printf(dev, "Can't reset the PHY\n");
1615 		return (ENXIO);
1616 	}
1617 
1618 	/* Reset */
1619 	reg = READ4(sc, BUS_MODE);
1620 	reg |= (BUS_MODE_SWR);
1621 	WRITE4(sc, BUS_MODE, reg);
1622 
1623 	for (i = 0; i < MAC_RESET_TIMEOUT; i++) {
1624 		if ((READ4(sc, BUS_MODE) & BUS_MODE_SWR) == 0)
1625 			break;
1626 		DELAY(10);
1627 	}
1628 	if (i >= MAC_RESET_TIMEOUT) {
1629 		device_printf(sc->dev, "Can't reset DWC.\n");
1630 		return (ENXIO);
1631 	}
1632 
1633 	reg = BUS_MODE_USP;
1634 	if (!nopblx8)
1635 		reg |= BUS_MODE_EIGHTXPBL;
1636 	reg |= (txpbl << BUS_MODE_PBL_SHIFT);
1637 	reg |= (rxpbl << BUS_MODE_RPBL_SHIFT);
1638 	if (fixed_burst)
1639 		reg |= BUS_MODE_FIXEDBURST;
1640 
1641 	WRITE4(sc, BUS_MODE, reg);
1642 
1643 	/*
1644 	 * DMA must be stop while changing descriptor list addresses.
1645 	 */
1646 	reg = READ4(sc, OPERATION_MODE);
1647 	reg &= ~(MODE_ST | MODE_SR);
1648 	WRITE4(sc, OPERATION_MODE, reg);
1649 
1650 	if (setup_dma(sc))
1651 	        return (ENXIO);
1652 
1653 	/* Setup addresses */
1654 	WRITE4(sc, RX_DESCR_LIST_ADDR, sc->rxdesc_ring_paddr);
1655 	WRITE4(sc, TX_DESCR_LIST_ADDR, sc->txdesc_ring_paddr);
1656 
1657 	mtx_init(&sc->mtx, device_get_nameunit(sc->dev),
1658 	    MTX_NETWORK_LOCK, MTX_DEF);
1659 
1660 	callout_init_mtx(&sc->dwc_callout, &sc->mtx, 0);
1661 
1662 	/* Setup interrupt handler. */
1663 	error = bus_setup_intr(dev, sc->res[1], INTR_TYPE_NET | INTR_MPSAFE,
1664 	    NULL, dwc_intr, sc, &sc->intr_cookie);
1665 	if (error != 0) {
1666 		device_printf(dev, "could not setup interrupt handler.\n");
1667 		return (ENXIO);
1668 	}
1669 
1670 	/* Set up the ethernet interface. */
1671 	sc->ifp = ifp = if_alloc(IFT_ETHER);
1672 
1673 	ifp->if_softc = sc;
1674 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
1675 	if_setflags(sc->ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
1676 	if_setstartfn(ifp, dwc_txstart);
1677 	if_setioctlfn(ifp, dwc_ioctl);
1678 	if_setinitfn(ifp, dwc_init);
1679 	if_setsendqlen(ifp, TX_MAP_COUNT - 1);
1680 	if_setsendqready(sc->ifp);
1681 	if_sethwassist(sc->ifp, CSUM_IP | CSUM_UDP | CSUM_TCP);
1682 	if_setcapabilities(sc->ifp, IFCAP_VLAN_MTU | IFCAP_HWCSUM);
1683 	if_setcapenable(sc->ifp, if_getcapabilities(sc->ifp));
1684 
1685 	/* Attach the mii driver. */
1686 	error = mii_attach(dev, &sc->miibus, ifp, dwc_media_change,
1687 	    dwc_media_status, BMSR_DEFCAPMASK, MII_PHY_ANY,
1688 	    MII_OFFSET_ANY, 0);
1689 
1690 	if (error != 0) {
1691 		device_printf(dev, "PHY attach failed\n");
1692 		return (ENXIO);
1693 	}
1694 	sc->mii_softc = device_get_softc(sc->miibus);
1695 
1696 	/* All ready to run, attach the ethernet interface. */
1697 	ether_ifattach(ifp, macaddr);
1698 	sc->is_attached = true;
1699 
1700 	return (0);
1701 }
1702 
1703 static device_method_t dwc_methods[] = {
1704 	DEVMETHOD(device_probe,		dwc_probe),
1705 	DEVMETHOD(device_attach,	dwc_attach),
1706 
1707 	/* MII Interface */
1708 	DEVMETHOD(miibus_readreg,	dwc_miibus_read_reg),
1709 	DEVMETHOD(miibus_writereg,	dwc_miibus_write_reg),
1710 	DEVMETHOD(miibus_statchg,	dwc_miibus_statchg),
1711 
1712 	{ 0, 0 }
1713 };
1714 
1715 driver_t dwc_driver = {
1716 	"dwc",
1717 	dwc_methods,
1718 	sizeof(struct dwc_softc),
1719 };
1720 
1721 static devclass_t dwc_devclass;
1722 
1723 DRIVER_MODULE(dwc, simplebus, dwc_driver, dwc_devclass, 0, 0);
1724 DRIVER_MODULE(miibus, dwc, miibus_driver, miibus_devclass, 0, 0);
1725 
1726 MODULE_DEPEND(dwc, ether, 1, 1, 1);
1727 MODULE_DEPEND(dwc, miibus, 1, 1, 1);
1728