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if_sq.c revision 1.45
      1 /*	$NetBSD: if_sq.c,v 1.45 2016/02/09 08:32:10 ozaki-r Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2001 Rafal K. Boni
      5  * Copyright (c) 1998, 1999, 2000 The NetBSD Foundation, Inc.
      6  * All rights reserved.
      7  *
      8  * Portions of this code are derived from software contributed to The
      9  * NetBSD Foundation by Jason R. Thorpe of the Numerical Aerospace
     10  * Simulation Facility, NASA Ames Research Center.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. The name of the author may not be used to endorse or promote products
     21  *    derived from this software without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 __KERNEL_RCSID(0, "$NetBSD: if_sq.c,v 1.45 2016/02/09 08:32:10 ozaki-r Exp $");
     37 
     38 
     39 #include <sys/param.h>
     40 #include <sys/systm.h>
     41 #include <sys/device.h>
     42 #include <sys/callout.h>
     43 #include <sys/mbuf.h>
     44 #include <sys/malloc.h>
     45 #include <sys/kernel.h>
     46 #include <sys/socket.h>
     47 #include <sys/ioctl.h>
     48 #include <sys/errno.h>
     49 #include <sys/syslog.h>
     50 
     51 #include <uvm/uvm_extern.h>
     52 
     53 #include <machine/endian.h>
     54 
     55 #include <net/if.h>
     56 #include <net/if_dl.h>
     57 #include <net/if_media.h>
     58 #include <net/if_ether.h>
     59 
     60 #include <net/bpf.h>
     61 
     62 #include <sys/bus.h>
     63 #include <machine/intr.h>
     64 #include <machine/sysconf.h>
     65 
     66 #include <dev/ic/seeq8003reg.h>
     67 
     68 #include <sgimips/hpc/sqvar.h>
     69 #include <sgimips/hpc/hpcvar.h>
     70 #include <sgimips/hpc/hpcreg.h>
     71 
     72 #include <dev/arcbios/arcbios.h>
     73 #include <dev/arcbios/arcbiosvar.h>
     74 
     75 #define static
     76 
     77 /*
     78  * Short TODO list:
     79  *	(1) Do counters for bad-RX packets.
     80  *	(2) Allow multi-segment transmits, instead of copying to a single,
     81  *	    contiguous mbuf.
     82  *	(3) Verify sq_stop() turns off enough stuff; I was still getting
     83  *	    seeq interrupts after sq_stop().
     84  *	(4) Implement EDLC modes: especially packet auto-pad and simplex
     85  *	    mode.
     86  *	(5) Should the driver filter out its own transmissions in non-EDLC
     87  *	    mode?
     88  *	(6) Multicast support -- multicast filter, address management, ...
     89  *	(7) Deal with RB0 (recv buffer overflow) on reception.  Will need
     90  *	    to figure out if RB0 is read-only as stated in one spot in the
     91  *	    HPC spec or read-write (ie, is the 'write a one to clear it')
     92  *	    the correct thing?
     93  */
     94 
     95 #if defined(SQ_DEBUG)
     96  int sq_debug = 0;
     97  #define SQ_DPRINTF(x) if (sq_debug) printf x
     98 #else
     99  #define SQ_DPRINTF(x)
    100 #endif
    101 
    102 static int	sq_match(device_t, cfdata_t, void *);
    103 static void	sq_attach(device_t, device_t, void *);
    104 static int	sq_init(struct ifnet *);
    105 static void	sq_start(struct ifnet *);
    106 static void	sq_stop(struct ifnet *, int);
    107 static void	sq_watchdog(struct ifnet *);
    108 static int	sq_ioctl(struct ifnet *, u_long, void *);
    109 
    110 static void	sq_set_filter(struct sq_softc *);
    111 static int	sq_intr(void *);
    112 static int	sq_rxintr(struct sq_softc *);
    113 static int	sq_txintr(struct sq_softc *);
    114 static void	sq_txring_hpc1(struct sq_softc *);
    115 static void	sq_txring_hpc3(struct sq_softc *);
    116 static void	sq_reset(struct sq_softc *);
    117 static int	sq_add_rxbuf(struct sq_softc *, int);
    118 static void	sq_dump_buffer(paddr_t addr, psize_t len);
    119 static void	sq_trace_dump(struct sq_softc *);
    120 
    121 CFATTACH_DECL_NEW(sq, sizeof(struct sq_softc),
    122     sq_match, sq_attach, NULL, NULL);
    123 
    124 #define ETHER_PAD_LEN (ETHER_MIN_LEN - ETHER_CRC_LEN)
    125 
    126 #define sq_seeq_read(sc, off) \
    127 	bus_space_read_1(sc->sc_regt, sc->sc_regh, (off << 2) + 3)
    128 #define sq_seeq_write(sc, off, val) \
    129 	bus_space_write_1(sc->sc_regt, sc->sc_regh, (off << 2) + 3, val)
    130 
    131 #define sq_hpc_read(sc, off) \
    132 	bus_space_read_4(sc->sc_hpct, sc->sc_hpch, off)
    133 #define sq_hpc_write(sc, off, val) \
    134 	bus_space_write_4(sc->sc_hpct, sc->sc_hpch, off, val)
    135 
    136 /* MAC address offset for non-onboard implementations */
    137 #define SQ_HPC_EEPROM_ENADDR	250
    138 
    139 #define SGI_OUI_0		0x08
    140 #define SGI_OUI_1		0x00
    141 #define SGI_OUI_2		0x69
    142 
    143 static int
    144 sq_match(device_t parent, cfdata_t cf, void *aux)
    145 {
    146 	struct hpc_attach_args *ha = aux;
    147 
    148 	if (strcmp(ha->ha_name, cf->cf_name) == 0) {
    149 		vaddr_t reset, txstat;
    150 
    151 		reset = MIPS_PHYS_TO_KSEG1(ha->ha_sh +
    152 		    ha->ha_dmaoff + ha->hpc_regs->enetr_reset);
    153 		txstat = MIPS_PHYS_TO_KSEG1(ha->ha_sh +
    154 		    ha->ha_devoff + (SEEQ_TXSTAT << 2));
    155 
    156 		if (platform.badaddr((void *)reset, sizeof(reset)))
    157 			return 0;
    158 
    159 		*(volatile uint32_t *)reset = 0x1;
    160 		delay(20);
    161 		*(volatile uint32_t *)reset = 0x0;
    162 
    163 		if (platform.badaddr((void *)txstat, sizeof(txstat)))
    164 			return 0;
    165 
    166 		if ((*(volatile uint32_t *)txstat & 0xff) == TXSTAT_OLDNEW)
    167 			return 1;
    168 	}
    169 
    170 	return 0;
    171 }
    172 
    173 static void
    174 sq_attach(device_t parent, device_t self, void *aux)
    175 {
    176 	int i, err;
    177 	const char* macaddr;
    178 	struct sq_softc *sc = device_private(self);
    179 	struct hpc_attach_args *haa = aux;
    180 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
    181 
    182 	sc->sc_dev = self;
    183 	sc->sc_hpct = haa->ha_st;
    184 	sc->hpc_regs = haa->hpc_regs;      /* HPC register definitions */
    185 
    186 	if ((err = bus_space_subregion(haa->ha_st, haa->ha_sh,
    187 	    haa->ha_dmaoff, sc->hpc_regs->enet_regs_size,
    188 	    &sc->sc_hpch)) != 0) {
    189 		printf(": unable to map HPC DMA registers, error = %d\n", err);
    190 		goto fail_0;
    191 	}
    192 
    193 	sc->sc_regt = haa->ha_st;
    194 	if ((err = bus_space_subregion(haa->ha_st, haa->ha_sh,
    195 	    haa->ha_devoff, sc->hpc_regs->enet_devregs_size,
    196 	    &sc->sc_regh)) != 0) {
    197 		printf(": unable to map Seeq registers, error = %d\n", err);
    198 		goto fail_0;
    199 	}
    200 
    201 	sc->sc_dmat = haa->ha_dmat;
    202 
    203 	if ((err = bus_dmamem_alloc(sc->sc_dmat, sizeof(struct sq_control),
    204 	    PAGE_SIZE, PAGE_SIZE, &sc->sc_cdseg, 1, &sc->sc_ncdseg,
    205 	    BUS_DMA_NOWAIT)) != 0) {
    206 		printf(": unable to allocate control data, error = %d\n", err);
    207 		goto fail_0;
    208 	}
    209 
    210 	if ((err = bus_dmamem_map(sc->sc_dmat, &sc->sc_cdseg, sc->sc_ncdseg,
    211 	    sizeof(struct sq_control), (void **)&sc->sc_control,
    212 	    BUS_DMA_NOWAIT | BUS_DMA_COHERENT)) != 0) {
    213 		printf(": unable to map control data, error = %d\n", err);
    214 		goto fail_1;
    215 	}
    216 
    217 	if ((err = bus_dmamap_create(sc->sc_dmat,
    218 	    sizeof(struct sq_control), 1, sizeof(struct sq_control), PAGE_SIZE,
    219 	    BUS_DMA_NOWAIT, &sc->sc_cdmap)) != 0) {
    220 		printf(": unable to create DMA map for control data, error "
    221 		    "= %d\n", err);
    222 		goto fail_2;
    223 	}
    224 
    225 	if ((err = bus_dmamap_load(sc->sc_dmat, sc->sc_cdmap,
    226 	    sc->sc_control, sizeof(struct sq_control), NULL,
    227 	    BUS_DMA_NOWAIT)) != 0) {
    228 		printf(": unable to load DMA map for control data, error "
    229 		    "= %d\n", err);
    230 		goto fail_3;
    231 	}
    232 
    233 	memset(sc->sc_control, 0, sizeof(struct sq_control));
    234 
    235 	/* Create transmit buffer DMA maps */
    236 	for (i = 0; i < SQ_NTXDESC; i++) {
    237 		if ((err = bus_dmamap_create(sc->sc_dmat,
    238 		    MCLBYTES, 1, MCLBYTES, 0,
    239 		    BUS_DMA_NOWAIT, &sc->sc_txmap[i])) != 0) {
    240 			printf(": unable to create tx DMA map %d, error = %d\n",
    241 			    i, err);
    242 			goto fail_4;
    243 		}
    244 	}
    245 
    246 	/* Create receive buffer DMA maps */
    247 	for (i = 0; i < SQ_NRXDESC; i++) {
    248 		if ((err = bus_dmamap_create(sc->sc_dmat,
    249 		    MCLBYTES, 1, MCLBYTES, 0,
    250 		    BUS_DMA_NOWAIT, &sc->sc_rxmap[i])) != 0) {
    251 			printf(": unable to create rx DMA map %d, error = %d\n",
    252 			    i, err);
    253 			goto fail_5;
    254 		}
    255 	}
    256 
    257 	/* Pre-allocate the receive buffers.  */
    258 	for (i = 0; i < SQ_NRXDESC; i++) {
    259 		if ((err = sq_add_rxbuf(sc, i)) != 0) {
    260 			printf(": unable to allocate or map rx buffer %d\n,"
    261 			    " error = %d\n", i, err);
    262 			goto fail_6;
    263 		}
    264 	}
    265 
    266 	memcpy(sc->sc_enaddr, &haa->hpc_eeprom[SQ_HPC_EEPROM_ENADDR],
    267 	    ETHER_ADDR_LEN);
    268 
    269 	/*
    270 	 * If our mac address is bogus, obtain it from ARCBIOS. This will
    271 	 * be true of the onboard HPC3 on IP22, since there is no eeprom,
    272 	 * but rather the DS1386 RTC's battery-backed ram is used.
    273 	 */
    274 	if (sc->sc_enaddr[0] != SGI_OUI_0 ||
    275 	    sc->sc_enaddr[1] != SGI_OUI_1 ||
    276 	    sc->sc_enaddr[2] != SGI_OUI_2) {
    277 		macaddr = arcbios_GetEnvironmentVariable("eaddr");
    278 		if (macaddr == NULL) {
    279 			printf(": unable to get MAC address!\n");
    280 			goto fail_6;
    281 		}
    282 		ether_aton_r(sc->sc_enaddr, sizeof(sc->sc_enaddr), macaddr);
    283 	}
    284 
    285 	evcnt_attach_dynamic(&sc->sq_intrcnt, EVCNT_TYPE_INTR, NULL,
    286 	    device_xname(self), "intr");
    287 
    288 	if ((cpu_intr_establish(haa->ha_irq, IPL_NET, sq_intr, sc)) == NULL) {
    289 		printf(": unable to establish interrupt!\n");
    290 		goto fail_6;
    291 	}
    292 
    293 	/* Reset the chip to a known state. */
    294 	sq_reset(sc);
    295 
    296 	/*
    297 	 * Determine if we're an 8003 or 80c03 by setting the first
    298 	 * MAC address register to non-zero, and then reading it back.
    299 	 * If it's zero, we have an 80c03, because we will have read
    300 	 * the TxCollLSB register.
    301 	 */
    302 	sq_seeq_write(sc, SEEQ_TXCOLLS0, 0xa5);
    303 	if (sq_seeq_read(sc, SEEQ_TXCOLLS0) == 0)
    304 		sc->sc_type = SQ_TYPE_80C03;
    305 	else
    306 		sc->sc_type = SQ_TYPE_8003;
    307 	sq_seeq_write(sc, SEEQ_TXCOLLS0, 0x00);
    308 
    309 	printf(": SGI Seeq %s\n",
    310 	    sc->sc_type == SQ_TYPE_80C03 ? "80c03" : "8003");
    311 
    312 	printf("%s: Ethernet address %s\n",
    313 	    device_xname(self), ether_sprintf(sc->sc_enaddr));
    314 
    315 	strcpy(ifp->if_xname, device_xname(self));
    316 	ifp->if_softc = sc;
    317 	ifp->if_mtu = ETHERMTU;
    318 	ifp->if_init = sq_init;
    319 	ifp->if_stop = sq_stop;
    320 	ifp->if_start = sq_start;
    321 	ifp->if_ioctl = sq_ioctl;
    322 	ifp->if_watchdog = sq_watchdog;
    323 	ifp->if_flags = IFF_BROADCAST | IFF_NOTRAILERS | IFF_MULTICAST;
    324 	IFQ_SET_READY(&ifp->if_snd);
    325 
    326 	if_attach(ifp);
    327 	ether_ifattach(ifp, sc->sc_enaddr);
    328 
    329 	memset(&sc->sq_trace, 0, sizeof(sc->sq_trace));
    330 	/* Done! */
    331 	return;
    332 
    333 	/*
    334 	 * Free any resources we've allocated during the failed attach
    335 	 * attempt.  Do this in reverse order and fall through.
    336 	 */
    337  fail_6:
    338 	for (i = 0; i < SQ_NRXDESC; i++) {
    339 		if (sc->sc_rxmbuf[i] != NULL) {
    340 			bus_dmamap_unload(sc->sc_dmat, sc->sc_rxmap[i]);
    341 			m_freem(sc->sc_rxmbuf[i]);
    342 		}
    343 	}
    344  fail_5:
    345 	for (i = 0; i < SQ_NRXDESC; i++) {
    346 		if (sc->sc_rxmap[i] != NULL)
    347 			bus_dmamap_destroy(sc->sc_dmat, sc->sc_rxmap[i]);
    348 	}
    349  fail_4:
    350 	for (i = 0; i < SQ_NTXDESC; i++) {
    351 		if (sc->sc_txmap[i] !=  NULL)
    352 			bus_dmamap_destroy(sc->sc_dmat, sc->sc_txmap[i]);
    353 	}
    354 	bus_dmamap_unload(sc->sc_dmat, sc->sc_cdmap);
    355  fail_3:
    356 	bus_dmamap_destroy(sc->sc_dmat, sc->sc_cdmap);
    357  fail_2:
    358 	bus_dmamem_unmap(sc->sc_dmat,
    359 	    (void *)sc->sc_control, sizeof(struct sq_control));
    360  fail_1:
    361 	bus_dmamem_free(sc->sc_dmat, &sc->sc_cdseg, sc->sc_ncdseg);
    362  fail_0:
    363 	return;
    364 }
    365 
    366 /* Set up data to get the interface up and running. */
    367 int
    368 sq_init(struct ifnet *ifp)
    369 {
    370 	int i;
    371 	struct sq_softc *sc = ifp->if_softc;
    372 
    373 	/* Cancel any in-progress I/O */
    374 	sq_stop(ifp, 0);
    375 
    376 	sc->sc_nextrx = 0;
    377 
    378 	sc->sc_nfreetx = SQ_NTXDESC;
    379 	sc->sc_nexttx = sc->sc_prevtx = 0;
    380 
    381 	SQ_TRACE(SQ_RESET, sc, 0, 0);
    382 
    383 	/* Set into 8003 mode, bank 0 to program ethernet address */
    384 	sq_seeq_write(sc, SEEQ_TXCMD, TXCMD_BANK0);
    385 
    386 	/* Now write the address */
    387 	for (i = 0; i < ETHER_ADDR_LEN; i++)
    388 		sq_seeq_write(sc, i, sc->sc_enaddr[i]);
    389 
    390 	sc->sc_rxcmd =
    391 	    RXCMD_IE_CRC |
    392 	    RXCMD_IE_DRIB |
    393 	    RXCMD_IE_SHORT |
    394 	    RXCMD_IE_END |
    395 	    RXCMD_IE_GOOD;
    396 
    397 	/*
    398 	 * Set the receive filter -- this will add some bits to the
    399 	 * prototype RXCMD register.  Do this before setting the
    400 	 * transmit config register, since we might need to switch
    401 	 * banks.
    402 	 */
    403 	sq_set_filter(sc);
    404 
    405 	/* Set up Seeq transmit command register */
    406 	sq_seeq_write(sc, SEEQ_TXCMD,
    407 	    TXCMD_IE_UFLOW |
    408 	    TXCMD_IE_COLL |
    409 	    TXCMD_IE_16COLL |
    410 	    TXCMD_IE_GOOD);
    411 
    412 	/* Now write the receive command register. */
    413 	sq_seeq_write(sc, SEEQ_RXCMD, sc->sc_rxcmd);
    414 
    415 	/*
    416 	 * Set up HPC ethernet PIO and DMA configurations.
    417 	 *
    418 	 * The PROM appears to do most of this for the onboard HPC3, but
    419 	 * not for the Challenge S's IOPLUS chip. We copy how the onboard
    420 	 * chip is configured and assume that it's correct for both.
    421 	 */
    422 	if (sc->hpc_regs->revision == 3) {
    423 		uint32_t dmareg, pioreg;
    424 
    425 		pioreg =
    426 		    HPC3_ENETR_PIOCFG_P1(1) |
    427 		    HPC3_ENETR_PIOCFG_P2(6) |
    428 		    HPC3_ENETR_PIOCFG_P3(1);
    429 
    430 		dmareg =
    431 		    HPC3_ENETR_DMACFG_D1(6) |
    432 		    HPC3_ENETR_DMACFG_D2(2) |
    433 		    HPC3_ENETR_DMACFG_D3(0) |
    434 		    HPC3_ENETR_DMACFG_FIX_RXDC |
    435 		    HPC3_ENETR_DMACFG_FIX_INTR |
    436 		    HPC3_ENETR_DMACFG_FIX_EOP |
    437 		    HPC3_ENETR_DMACFG_TIMEOUT;
    438 
    439 		sq_hpc_write(sc, HPC3_ENETR_PIOCFG, pioreg);
    440 		sq_hpc_write(sc, HPC3_ENETR_DMACFG, dmareg);
    441 	}
    442 
    443 	/* Pass the start of the receive ring to the HPC */
    444 	sq_hpc_write(sc, sc->hpc_regs->enetr_ndbp, SQ_CDRXADDR(sc, 0));
    445 
    446 	/* And turn on the HPC ethernet receive channel */
    447 	sq_hpc_write(sc, sc->hpc_regs->enetr_ctl,
    448 	    sc->hpc_regs->enetr_ctl_active);
    449 
    450 	/*
    451 	 * Turn off delayed receive interrupts on HPC1.
    452 	 * (see Hollywood HPC Specification 2.1.4.3)
    453 	 */
    454 	if (sc->hpc_regs->revision != 3)
    455 		sq_hpc_write(sc, HPC1_ENET_INTDELAY, HPC1_ENET_INTDELAY_OFF);
    456 
    457 	ifp->if_flags |= IFF_RUNNING;
    458 	ifp->if_flags &= ~IFF_OACTIVE;
    459 
    460 	return 0;
    461 }
    462 
    463 static void
    464 sq_set_filter(struct sq_softc *sc)
    465 {
    466 	struct ethercom *ec = &sc->sc_ethercom;
    467 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
    468 	struct ether_multi *enm;
    469 	struct ether_multistep step;
    470 
    471 	/*
    472 	 * Check for promiscuous mode.  Also implies
    473 	 * all-multicast.
    474 	 */
    475 	if (ifp->if_flags & IFF_PROMISC) {
    476 		sc->sc_rxcmd |= RXCMD_REC_ALL;
    477 		ifp->if_flags |= IFF_ALLMULTI;
    478 		return;
    479 	}
    480 
    481 	/*
    482 	 * The 8003 has no hash table.  If we have any multicast
    483 	 * addresses on the list, enable reception of all multicast
    484 	 * frames.
    485 	 *
    486 	 * XXX The 80c03 has a hash table.  We should use it.
    487 	 */
    488 
    489 	ETHER_FIRST_MULTI(step, ec, enm);
    490 
    491 	if (enm == NULL) {
    492 		sc->sc_rxcmd &= ~RXCMD_REC_MASK;
    493 		sc->sc_rxcmd |= RXCMD_REC_BROAD;
    494 
    495 		ifp->if_flags &= ~IFF_ALLMULTI;
    496 		return;
    497 	}
    498 
    499 	sc->sc_rxcmd |= RXCMD_REC_MULTI;
    500 	ifp->if_flags |= IFF_ALLMULTI;
    501 }
    502 
    503 int
    504 sq_ioctl(struct ifnet *ifp, u_long cmd, void *data)
    505 {
    506 	int s, error = 0;
    507 
    508 	SQ_TRACE(SQ_IOCTL, (struct sq_softc *)ifp->if_softc, 0, 0);
    509 
    510 	s = splnet();
    511 
    512 	error = ether_ioctl(ifp, cmd, data);
    513 	if (error == ENETRESET) {
    514 		/*
    515 		 * Multicast list has changed; set the hardware filter
    516 		 * accordingly.
    517 		 */
    518 		if (ifp->if_flags & IFF_RUNNING)
    519 			error = sq_init(ifp);
    520 		else
    521 			error = 0;
    522 	}
    523 
    524 	splx(s);
    525 	return error;
    526 }
    527 
    528 void
    529 sq_start(struct ifnet *ifp)
    530 {
    531 	struct sq_softc *sc = ifp->if_softc;
    532 	uint32_t status;
    533 	struct mbuf *m0, *m;
    534 	bus_dmamap_t dmamap;
    535 	int err, totlen, nexttx, firsttx, lasttx = -1, ofree, seg;
    536 
    537 	if ((ifp->if_flags & (IFF_RUNNING|IFF_OACTIVE)) != IFF_RUNNING)
    538 		return;
    539 
    540 	/*
    541 	 * Remember the previous number of free descriptors and
    542 	 * the first descriptor we'll use.
    543 	 */
    544 	ofree = sc->sc_nfreetx;
    545 	firsttx = sc->sc_nexttx;
    546 
    547 	/*
    548 	 * Loop through the send queue, setting up transmit descriptors
    549 	 * until we drain the queue, or use up all available transmit
    550 	 * descriptors.
    551 	 */
    552 	while (sc->sc_nfreetx != 0) {
    553 		/*
    554 		 * Grab a packet off the queue.
    555 		 */
    556 		IFQ_POLL(&ifp->if_snd, m0);
    557 		if (m0 == NULL)
    558 			break;
    559 		m = NULL;
    560 
    561 		dmamap = sc->sc_txmap[sc->sc_nexttx];
    562 
    563 		/*
    564 		 * Load the DMA map.  If this fails, the packet either
    565 		 * didn't fit in the alloted number of segments, or we were
    566 		 * short on resources.  In this case, we'll copy and try
    567 		 * again.
    568 		 * Also copy it if we need to pad, so that we are sure there
    569 		 * is room for the pad buffer.
    570 		 * XXX the right way of doing this is to use a static buffer
    571 		 * for padding and adding it to the transmit descriptor (see
    572 		 * sys/dev/pci/if_tl.c for example). We can't do this here yet
    573 		 * because we can't send packets with more than one fragment.
    574 		 */
    575 		if (m0->m_pkthdr.len < ETHER_PAD_LEN ||
    576 		    bus_dmamap_load_mbuf(sc->sc_dmat, dmamap, m0,
    577 		    BUS_DMA_NOWAIT) != 0) {
    578 			MGETHDR(m, M_DONTWAIT, MT_DATA);
    579 			if (m == NULL) {
    580 				printf("%s: unable to allocate Tx mbuf\n",
    581 				    device_xname(sc->sc_dev));
    582 				break;
    583 			}
    584 			if (m0->m_pkthdr.len > MHLEN) {
    585 				MCLGET(m, M_DONTWAIT);
    586 				if ((m->m_flags & M_EXT) == 0) {
    587 					printf("%s: unable to allocate Tx "
    588 					    "cluster\n",
    589 					    device_xname(sc->sc_dev));
    590 					m_freem(m);
    591 					break;
    592 				}
    593 			}
    594 
    595 			m_copydata(m0, 0, m0->m_pkthdr.len, mtod(m, void *));
    596 			if (m0->m_pkthdr.len < ETHER_PAD_LEN) {
    597 				memset(mtod(m, char *) + m0->m_pkthdr.len, 0,
    598 				    ETHER_PAD_LEN - m0->m_pkthdr.len);
    599 				m->m_pkthdr.len = m->m_len = ETHER_PAD_LEN;
    600 			} else
    601 				m->m_pkthdr.len = m->m_len = m0->m_pkthdr.len;
    602 
    603 			if ((err = bus_dmamap_load_mbuf(sc->sc_dmat, dmamap,
    604 			    m, BUS_DMA_NOWAIT)) != 0) {
    605 				printf("%s: unable to load Tx buffer, "
    606 				    "error = %d\n",
    607 				    device_xname(sc->sc_dev), err);
    608 				break;
    609 			}
    610 		}
    611 
    612 		/*
    613 		 * Ensure we have enough descriptors free to describe
    614 		 * the packet.
    615 		 */
    616 		if (dmamap->dm_nsegs > sc->sc_nfreetx) {
    617 			/*
    618 			 * Not enough free descriptors to transmit this
    619 			 * packet.  We haven't committed to anything yet,
    620 			 * so just unload the DMA map, put the packet
    621 			 * back on the queue, and punt.  Notify the upper
    622 			 * layer that there are no more slots left.
    623 			 *
    624 			 * XXX We could allocate an mbuf and copy, but
    625 			 * XXX it is worth it?
    626 			 */
    627 			ifp->if_flags |= IFF_OACTIVE;
    628 			bus_dmamap_unload(sc->sc_dmat, dmamap);
    629 			if (m != NULL)
    630 				m_freem(m);
    631 			break;
    632 		}
    633 
    634 		IFQ_DEQUEUE(&ifp->if_snd, m0);
    635 		/*
    636 		 * Pass the packet to any BPF listeners.
    637 		 */
    638 		bpf_mtap(ifp, m0);
    639 		if (m != NULL) {
    640 			m_freem(m0);
    641 			m0 = m;
    642 		}
    643 
    644 		/*
    645 		 * WE ARE NOW COMMITTED TO TRANSMITTING THE PACKET.
    646 		 */
    647 
    648 		SQ_TRACE(SQ_ENQUEUE, sc, sc->sc_nexttx, 0);
    649 
    650 		/* Sync the DMA map. */
    651 		bus_dmamap_sync(sc->sc_dmat, dmamap, 0, dmamap->dm_mapsize,
    652 		    BUS_DMASYNC_PREWRITE);
    653 
    654 		/*
    655 		 * Initialize the transmit descriptors.
    656 		 */
    657 		for (nexttx = sc->sc_nexttx, seg = 0, totlen = 0;
    658 		     seg < dmamap->dm_nsegs;
    659 		     seg++, nexttx = SQ_NEXTTX(nexttx)) {
    660 			if (sc->hpc_regs->revision == 3) {
    661 				sc->sc_txdesc[nexttx].hpc3_hdd_bufptr =
    662 				    dmamap->dm_segs[seg].ds_addr;
    663 				sc->sc_txdesc[nexttx].hpc3_hdd_ctl =
    664 				    dmamap->dm_segs[seg].ds_len;
    665 			} else {
    666 				sc->sc_txdesc[nexttx].hpc1_hdd_bufptr =
    667 				    dmamap->dm_segs[seg].ds_addr;
    668 				sc->sc_txdesc[nexttx].hpc1_hdd_ctl =
    669 				    dmamap->dm_segs[seg].ds_len;
    670 			}
    671 			sc->sc_txdesc[nexttx].hdd_descptr =
    672 			    SQ_CDTXADDR(sc, SQ_NEXTTX(nexttx));
    673 			lasttx = nexttx;
    674 			totlen += dmamap->dm_segs[seg].ds_len;
    675 		}
    676 
    677 		/* Last descriptor gets end-of-packet */
    678 		KASSERT(lasttx != -1);
    679 		if (sc->hpc_regs->revision == 3)
    680 			sc->sc_txdesc[lasttx].hpc3_hdd_ctl |=
    681 			    HPC3_HDD_CTL_EOPACKET;
    682 		else
    683 			sc->sc_txdesc[lasttx].hpc1_hdd_ctl |=
    684 			    HPC1_HDD_CTL_EOPACKET;
    685 
    686 		SQ_DPRINTF(("%s: transmit %d-%d, len %d\n",
    687 		    device_xname(sc->sc_dev), sc->sc_nexttx, lasttx, totlen));
    688 
    689 		if (ifp->if_flags & IFF_DEBUG) {
    690 			printf("     transmit chain:\n");
    691 			for (seg = sc->sc_nexttx;; seg = SQ_NEXTTX(seg)) {
    692 				printf("     descriptor %d:\n", seg);
    693 				printf("       hdd_bufptr:      0x%08x\n",
    694 				    (sc->hpc_regs->revision == 3) ?
    695 				    sc->sc_txdesc[seg].hpc3_hdd_bufptr :
    696 				    sc->sc_txdesc[seg].hpc1_hdd_bufptr);
    697 				printf("       hdd_ctl: 0x%08x\n",
    698 				    (sc->hpc_regs->revision == 3) ?
    699 				    sc->sc_txdesc[seg].hpc3_hdd_ctl:
    700 				    sc->sc_txdesc[seg].hpc1_hdd_ctl);
    701 				printf("       hdd_descptr:      0x%08x\n",
    702 				    sc->sc_txdesc[seg].hdd_descptr);
    703 
    704 				if (seg == lasttx)
    705 					break;
    706 			}
    707 		}
    708 
    709 		/* Sync the descriptors we're using. */
    710 		SQ_CDTXSYNC(sc, sc->sc_nexttx, dmamap->dm_nsegs,
    711 		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
    712 
    713 		/* Store a pointer to the packet so we can free it later */
    714 		sc->sc_txmbuf[sc->sc_nexttx] = m0;
    715 
    716 		/* Advance the tx pointer. */
    717 		sc->sc_nfreetx -= dmamap->dm_nsegs;
    718 		sc->sc_nexttx = nexttx;
    719 	}
    720 
    721 	/* All transmit descriptors used up, let upper layers know */
    722 	if (sc->sc_nfreetx == 0)
    723 		ifp->if_flags |= IFF_OACTIVE;
    724 
    725 	if (sc->sc_nfreetx != ofree) {
    726 		SQ_DPRINTF(("%s: %d packets enqueued, first %d, INTR on %d\n",
    727 		    device_xname(sc->sc_dev), lasttx - firsttx + 1,
    728 		    firsttx, lasttx));
    729 
    730 		/*
    731 		 * Cause a transmit interrupt to happen on the
    732 		 * last packet we enqueued, mark it as the last
    733 		 * descriptor.
    734 		 *
    735 		 * HPC1_HDD_CTL_INTR will generate an interrupt on
    736 		 * HPC1. HPC3 requires HPC3_HDD_CTL_EOPACKET in
    737 		 * addition to HPC3_HDD_CTL_INTR to interrupt.
    738 		 */
    739 		KASSERT(lasttx != -1);
    740 		if (sc->hpc_regs->revision == 3) {
    741 			sc->sc_txdesc[lasttx].hpc3_hdd_ctl |=
    742 			    HPC3_HDD_CTL_INTR | HPC3_HDD_CTL_EOCHAIN;
    743 		} else {
    744 			sc->sc_txdesc[lasttx].hpc1_hdd_ctl |= HPC1_HDD_CTL_INTR;
    745 			sc->sc_txdesc[lasttx].hpc1_hdd_bufptr |=
    746 			    HPC1_HDD_CTL_EOCHAIN;
    747 		}
    748 
    749 		SQ_CDTXSYNC(sc, lasttx, 1,
    750 		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
    751 
    752 		/*
    753 		 * There is a potential race condition here if the HPC
    754 		 * DMA channel is active and we try and either update
    755 		 * the 'next descriptor' pointer in the HPC PIO space
    756 		 * or the 'next descriptor' pointer in a previous desc-
    757 		 * riptor.
    758 		 *
    759 		 * To avoid this, if the channel is active, we rely on
    760 		 * the transmit interrupt routine noticing that there
    761 		 * are more packets to send and restarting the HPC DMA
    762 		 * engine, rather than mucking with the DMA state here.
    763 		 */
    764 		status = sq_hpc_read(sc, sc->hpc_regs->enetx_ctl);
    765 
    766 		if ((status & sc->hpc_regs->enetx_ctl_active) != 0) {
    767 			SQ_TRACE(SQ_ADD_TO_DMA, sc, firsttx, status);
    768 
    769 			/*
    770 			 * NB: hpc3_hdd_ctl == hpc1_hdd_bufptr, and
    771 			 * HPC1_HDD_CTL_EOCHAIN == HPC3_HDD_CTL_EOCHAIN
    772 			 */
    773 			sc->sc_txdesc[SQ_PREVTX(firsttx)].hpc3_hdd_ctl &=
    774 			    ~HPC3_HDD_CTL_EOCHAIN;
    775 
    776 			if (sc->hpc_regs->revision != 3)
    777 				sc->sc_txdesc[SQ_PREVTX(firsttx)].hpc1_hdd_ctl
    778 				    &= ~HPC1_HDD_CTL_INTR;
    779 
    780 			SQ_CDTXSYNC(sc, SQ_PREVTX(firsttx),  1,
    781 			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
    782 		} else if (sc->hpc_regs->revision == 3) {
    783 			SQ_TRACE(SQ_START_DMA, sc, firsttx, status);
    784 
    785 			sq_hpc_write(sc, HPC3_ENETX_NDBP, SQ_CDTXADDR(sc,
    786 			    firsttx));
    787 
    788 			/* Kick DMA channel into life */
    789 			sq_hpc_write(sc, HPC3_ENETX_CTL, HPC3_ENETX_CTL_ACTIVE);
    790 		} else {
    791 			/*
    792 			 * In the HPC1 case where transmit DMA is
    793 			 * inactive, we can either kick off if
    794 			 * the ring was previously empty, or call
    795 			 * our transmit interrupt handler to
    796 			 * figure out if the ring stopped short
    797 			 * and restart at the right place.
    798 			 */
    799 			if (ofree == SQ_NTXDESC) {
    800 				SQ_TRACE(SQ_START_DMA, sc, firsttx, status);
    801 
    802 				sq_hpc_write(sc, HPC1_ENETX_NDBP,
    803 				    SQ_CDTXADDR(sc, firsttx));
    804 				sq_hpc_write(sc, HPC1_ENETX_CFXBP,
    805 				    SQ_CDTXADDR(sc, firsttx));
    806 				sq_hpc_write(sc, HPC1_ENETX_CBP,
    807 				    SQ_CDTXADDR(sc, firsttx));
    808 
    809 				/* Kick DMA channel into life */
    810 				sq_hpc_write(sc, HPC1_ENETX_CTL,
    811 				    HPC1_ENETX_CTL_ACTIVE);
    812 			} else
    813 				sq_txring_hpc1(sc);
    814 		}
    815 
    816 		/* Set a watchdog timer in case the chip flakes out. */
    817 		ifp->if_timer = 5;
    818 	}
    819 }
    820 
    821 void
    822 sq_stop(struct ifnet *ifp, int disable)
    823 {
    824 	int i;
    825 	struct sq_softc *sc = ifp->if_softc;
    826 
    827 	for (i = 0; i < SQ_NTXDESC; i++) {
    828 		if (sc->sc_txmbuf[i] != NULL) {
    829 			bus_dmamap_unload(sc->sc_dmat, sc->sc_txmap[i]);
    830 			m_freem(sc->sc_txmbuf[i]);
    831 			sc->sc_txmbuf[i] = NULL;
    832 		}
    833 	}
    834 
    835 	/* Clear Seeq transmit/receive command registers */
    836 	sq_seeq_write(sc, SEEQ_TXCMD, 0);
    837 	sq_seeq_write(sc, SEEQ_RXCMD, 0);
    838 
    839 	sq_reset(sc);
    840 
    841 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
    842 	ifp->if_timer = 0;
    843 }
    844 
    845 /* Device timeout/watchdog routine. */
    846 void
    847 sq_watchdog(struct ifnet *ifp)
    848 {
    849 	uint32_t status;
    850 	struct sq_softc *sc = ifp->if_softc;
    851 
    852 	status = sq_hpc_read(sc, sc->hpc_regs->enetx_ctl);
    853 	log(LOG_ERR, "%s: device timeout (prev %d, next %d, free %d, "
    854 	    "status %08x)\n", device_xname(sc->sc_dev), sc->sc_prevtx,
    855 	    sc->sc_nexttx, sc->sc_nfreetx, status);
    856 
    857 	sq_trace_dump(sc);
    858 
    859 	memset(&sc->sq_trace, 0, sizeof(sc->sq_trace));
    860 	sc->sq_trace_idx = 0;
    861 
    862 	++ifp->if_oerrors;
    863 
    864 	sq_init(ifp);
    865 }
    866 
    867 static void
    868 sq_trace_dump(struct sq_softc *sc)
    869 {
    870 	int i;
    871 	const char *act;
    872 
    873 	for (i = 0; i < sc->sq_trace_idx; i++) {
    874 		switch (sc->sq_trace[i].action) {
    875 		case SQ_RESET:		act = "SQ_RESET";		break;
    876 		case SQ_ADD_TO_DMA:	act = "SQ_ADD_TO_DMA";		break;
    877 		case SQ_START_DMA:	act = "SQ_START_DMA";		break;
    878 		case SQ_DONE_DMA:	act = "SQ_DONE_DMA";		break;
    879 		case SQ_RESTART_DMA:	act = "SQ_RESTART_DMA";		break;
    880 		case SQ_TXINTR_ENTER:	act = "SQ_TXINTR_ENTER";	break;
    881 		case SQ_TXINTR_EXIT:	act = "SQ_TXINTR_EXIT";		break;
    882 		case SQ_TXINTR_BUSY:	act = "SQ_TXINTR_BUSY";		break;
    883 		case SQ_IOCTL:		act = "SQ_IOCTL";		break;
    884 		case SQ_ENQUEUE:	act = "SQ_ENQUEUE";		break;
    885 		default:		act = "UNKNOWN";
    886 		}
    887 
    888 		printf("%s: [%03d] action %-16s buf %03d free %03d "
    889 		    "status %08x line %d\n", device_xname(sc->sc_dev), i, act,
    890 		    sc->sq_trace[i].bufno, sc->sq_trace[i].freebuf,
    891 		    sc->sq_trace[i].status, sc->sq_trace[i].line);
    892 	}
    893 }
    894 
    895 static int
    896 sq_intr(void *arg)
    897 {
    898 	struct sq_softc *sc = arg;
    899 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
    900 	int handled = 0;
    901 	uint32_t stat;
    902 
    903 	stat = sq_hpc_read(sc, sc->hpc_regs->enetr_reset);
    904 
    905 	if ((stat & 2) == 0)
    906 		SQ_DPRINTF(("%s: Unexpected interrupt!\n",
    907 		    device_xname(sc->sc_dev)));
    908 	else
    909 		sq_hpc_write(sc, sc->hpc_regs->enetr_reset, (stat | 2));
    910 
    911 	/*
    912 	 * If the interface isn't running, the interrupt couldn't
    913 	 * possibly have come from us.
    914 	 */
    915 	if ((ifp->if_flags & IFF_RUNNING) == 0)
    916 		return 0;
    917 
    918 	sc->sq_intrcnt.ev_count++;
    919 
    920 	/* Always check for received packets */
    921 	if (sq_rxintr(sc) != 0)
    922 		handled++;
    923 
    924 	/* Only handle transmit interrupts if we actually sent something */
    925 	if (sc->sc_nfreetx < SQ_NTXDESC) {
    926 		sq_txintr(sc);
    927 		handled++;
    928 	}
    929 
    930 	if (handled)
    931 		rnd_add_uint32(&sc->rnd_source, stat);
    932 	return handled;
    933 }
    934 
    935 static int
    936 sq_rxintr(struct sq_softc *sc)
    937 {
    938 	int count = 0;
    939 	struct mbuf* m;
    940 	int i, framelen;
    941 	uint8_t pktstat;
    942 	uint32_t status;
    943 	uint32_t ctl_reg;
    944 	int new_end, orig_end;
    945 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
    946 
    947 	for (i = sc->sc_nextrx;; i = SQ_NEXTRX(i)) {
    948 		SQ_CDRXSYNC(sc, i,
    949 		    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
    950 
    951 		/*
    952 		 * If this is a CPU-owned buffer, we're at the end of the list.
    953 		 */
    954 		if (sc->hpc_regs->revision == 3)
    955 			ctl_reg =
    956 			    sc->sc_rxdesc[i].hpc3_hdd_ctl & HPC3_HDD_CTL_OWN;
    957 		else
    958 			ctl_reg =
    959 			    sc->sc_rxdesc[i].hpc1_hdd_ctl & HPC1_HDD_CTL_OWN;
    960 
    961 		if (ctl_reg) {
    962 #if defined(SQ_DEBUG)
    963 			uint32_t reg;
    964 
    965 			reg = sq_hpc_read(sc, sc->hpc_regs->enetr_ctl);
    966 			SQ_DPRINTF(("%s: rxintr: done at %d (ctl %08x)\n",
    967 			    device_xname(sc->sc_dev), i, reg));
    968 #endif
    969 			break;
    970 		}
    971 
    972 		count++;
    973 
    974 		m = sc->sc_rxmbuf[i];
    975 		framelen = m->m_ext.ext_size - 3;
    976 		if (sc->hpc_regs->revision == 3)
    977 		    framelen -=
    978 			HPC3_HDD_CTL_BYTECNT(sc->sc_rxdesc[i].hpc3_hdd_ctl);
    979 		else
    980 		    framelen -=
    981 			HPC1_HDD_CTL_BYTECNT(sc->sc_rxdesc[i].hpc1_hdd_ctl);
    982 
    983 		/* Now sync the actual packet data */
    984 		bus_dmamap_sync(sc->sc_dmat, sc->sc_rxmap[i], 0,
    985 		    sc->sc_rxmap[i]->dm_mapsize, BUS_DMASYNC_POSTREAD);
    986 
    987 		pktstat = *((uint8_t *)m->m_data + framelen + 2);
    988 
    989 		if ((pktstat & RXSTAT_GOOD) == 0) {
    990 			ifp->if_ierrors++;
    991 
    992 			if (pktstat & RXSTAT_OFLOW)
    993 				printf("%s: receive FIFO overflow\n",
    994 				    device_xname(sc->sc_dev));
    995 
    996 			bus_dmamap_sync(sc->sc_dmat, sc->sc_rxmap[i], 0,
    997 			    sc->sc_rxmap[i]->dm_mapsize, BUS_DMASYNC_PREREAD);
    998 			SQ_INIT_RXDESC(sc, i);
    999 			SQ_DPRINTF(("%s: sq_rxintr: buf %d no RXSTAT_GOOD\n",
   1000 			    device_xname(sc->sc_dev), i));
   1001 			continue;
   1002 		}
   1003 
   1004 		if (sq_add_rxbuf(sc, i) != 0) {
   1005 			ifp->if_ierrors++;
   1006 			bus_dmamap_sync(sc->sc_dmat, sc->sc_rxmap[i], 0,
   1007 			    sc->sc_rxmap[i]->dm_mapsize, BUS_DMASYNC_PREREAD);
   1008 			SQ_INIT_RXDESC(sc, i);
   1009 			SQ_DPRINTF(("%s: sq_rxintr: buf %d sq_add_rxbuf() "
   1010 			    "failed\n", device_xname(sc->sc_dev), i));
   1011 			continue;
   1012 		}
   1013 
   1014 
   1015 		m->m_data += 2;
   1016 		m->m_pkthdr.rcvif = ifp;
   1017 		m->m_pkthdr.len = m->m_len = framelen;
   1018 
   1019 		ifp->if_ipackets++;
   1020 
   1021 		SQ_DPRINTF(("%s: sq_rxintr: buf %d len %d\n",
   1022 		    device_xname(sc->sc_dev), i, framelen));
   1023 
   1024 		bpf_mtap(ifp, m);
   1025 		if_percpuq_enqueue(ifp->if_percpuq, m);
   1026 	}
   1027 
   1028 
   1029 	/* If anything happened, move ring start/end pointers to new spot */
   1030 	if (i != sc->sc_nextrx) {
   1031 		/*
   1032 		 * NB: hpc3_hdd_ctl == hpc1_hdd_bufptr, and
   1033 		 * HPC1_HDD_CTL_EOCHAIN == HPC3_HDD_CTL_EOCHAIN
   1034 		 */
   1035 
   1036 		new_end = SQ_PREVRX(i);
   1037 		sc->sc_rxdesc[new_end].hpc3_hdd_ctl |= HPC3_HDD_CTL_EOCHAIN;
   1038 		SQ_CDRXSYNC(sc, new_end,
   1039 		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
   1040 
   1041 		orig_end = SQ_PREVRX(sc->sc_nextrx);
   1042 		sc->sc_rxdesc[orig_end].hpc3_hdd_ctl &= ~HPC3_HDD_CTL_EOCHAIN;
   1043 		SQ_CDRXSYNC(sc, orig_end,
   1044 		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
   1045 
   1046 		sc->sc_nextrx = i;
   1047 	}
   1048 
   1049 	status = sq_hpc_read(sc, sc->hpc_regs->enetr_ctl);
   1050 
   1051 	/* If receive channel is stopped, restart it... */
   1052 	if ((status & sc->hpc_regs->enetr_ctl_active) == 0) {
   1053 		/* Pass the start of the receive ring to the HPC */
   1054 		sq_hpc_write(sc, sc->hpc_regs->enetr_ndbp,
   1055 		    SQ_CDRXADDR(sc, sc->sc_nextrx));
   1056 
   1057 		/* And turn on the HPC ethernet receive channel */
   1058 		sq_hpc_write(sc, sc->hpc_regs->enetr_ctl,
   1059 		    sc->hpc_regs->enetr_ctl_active);
   1060 	}
   1061 
   1062 	return count;
   1063 }
   1064 
   1065 static int
   1066 sq_txintr(struct sq_softc *sc)
   1067 {
   1068 	int shift = 0;
   1069 	uint32_t status, tmp;
   1070 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
   1071 
   1072 	if (sc->hpc_regs->revision != 3)
   1073 		shift = 16;
   1074 
   1075 	status = sq_hpc_read(sc, sc->hpc_regs->enetx_ctl) >> shift;
   1076 
   1077 	SQ_TRACE(SQ_TXINTR_ENTER, sc, sc->sc_prevtx, status);
   1078 
   1079 	tmp = (sc->hpc_regs->enetx_ctl_active >> shift) | TXSTAT_GOOD;
   1080 	if ((status & tmp) == 0) {
   1081 		if (status & TXSTAT_COLL)
   1082 			ifp->if_collisions++;
   1083 
   1084 		if (status & TXSTAT_UFLOW) {
   1085 			printf("%s: transmit underflow\n",
   1086 			    device_xname(sc->sc_dev));
   1087 			ifp->if_oerrors++;
   1088 		}
   1089 
   1090 		if (status & TXSTAT_16COLL) {
   1091 			printf("%s: max collisions reached\n",
   1092 			    device_xname(sc->sc_dev));
   1093 			ifp->if_oerrors++;
   1094 			ifp->if_collisions += 16;
   1095 		}
   1096 	}
   1097 
   1098 	/* prevtx now points to next xmit packet not yet finished */
   1099 	if (sc->hpc_regs->revision == 3)
   1100 		sq_txring_hpc3(sc);
   1101 	else
   1102 		sq_txring_hpc1(sc);
   1103 
   1104 	/* If we have buffers free, let upper layers know */
   1105 	if (sc->sc_nfreetx > 0)
   1106 		ifp->if_flags &= ~IFF_OACTIVE;
   1107 
   1108 	/* If all packets have left the coop, cancel watchdog */
   1109 	if (sc->sc_nfreetx == SQ_NTXDESC)
   1110 		ifp->if_timer = 0;
   1111 
   1112 	SQ_TRACE(SQ_TXINTR_EXIT, sc, sc->sc_prevtx, status);
   1113 	sq_start(ifp);
   1114 
   1115 	return 1;
   1116 }
   1117 
   1118 /*
   1119  * Reclaim used transmit descriptors and restart the transmit DMA
   1120  * engine if necessary.
   1121  */
   1122 static void
   1123 sq_txring_hpc1(struct sq_softc *sc)
   1124 {
   1125 	/*
   1126 	 * HPC1 doesn't tag transmitted descriptors, however,
   1127 	 * the NDBP register points to the next descriptor that
   1128 	 * has not yet been processed. If DMA is not in progress,
   1129 	 * we can safely reclaim all descriptors up to NDBP, and,
   1130 	 * if necessary, restart DMA at NDBP. Otherwise, if DMA
   1131 	 * is active, we can only safely reclaim up to CBP.
   1132 	 *
   1133 	 * For now, we'll only reclaim on inactive DMA and assume
   1134 	 * that a sufficiently large ring keeps us out of trouble.
   1135 	 */
   1136 	uint32_t reclaimto, status;
   1137 	int reclaimall, i = sc->sc_prevtx;
   1138 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
   1139 
   1140 	status = sq_hpc_read(sc, HPC1_ENETX_CTL);
   1141 	if (status & HPC1_ENETX_CTL_ACTIVE) {
   1142 		SQ_TRACE(SQ_TXINTR_BUSY, sc, i, status);
   1143 		return;
   1144 	} else
   1145 		reclaimto = sq_hpc_read(sc, HPC1_ENETX_NDBP);
   1146 
   1147 	if (sc->sc_nfreetx == 0 && SQ_CDTXADDR(sc, i) == reclaimto)
   1148 		reclaimall = 1;
   1149 	else
   1150 		reclaimall = 0;
   1151 
   1152 	while (sc->sc_nfreetx < SQ_NTXDESC) {
   1153 		if (SQ_CDTXADDR(sc, i) == reclaimto && !reclaimall)
   1154 			break;
   1155 
   1156 		SQ_CDTXSYNC(sc, i, sc->sc_txmap[i]->dm_nsegs,
   1157 		    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
   1158 
   1159 		/* Sync the packet data, unload DMA map, free mbuf */
   1160 		bus_dmamap_sync(sc->sc_dmat, sc->sc_txmap[i],
   1161 		    0, sc->sc_txmap[i]->dm_mapsize, BUS_DMASYNC_POSTWRITE);
   1162 		bus_dmamap_unload(sc->sc_dmat, sc->sc_txmap[i]);
   1163 		m_freem(sc->sc_txmbuf[i]);
   1164 		sc->sc_txmbuf[i] = NULL;
   1165 
   1166 		ifp->if_opackets++;
   1167 		sc->sc_nfreetx++;
   1168 
   1169 		SQ_TRACE(SQ_DONE_DMA, sc, i, status);
   1170 
   1171 		i = SQ_NEXTTX(i);
   1172 	}
   1173 
   1174 	if (sc->sc_nfreetx < SQ_NTXDESC) {
   1175 		SQ_TRACE(SQ_RESTART_DMA, sc, i, status);
   1176 
   1177 		KASSERT(reclaimto == SQ_CDTXADDR(sc, i));
   1178 
   1179 		sq_hpc_write(sc, HPC1_ENETX_CFXBP, reclaimto);
   1180 		sq_hpc_write(sc, HPC1_ENETX_CBP, reclaimto);
   1181 
   1182 		/* Kick DMA channel into life */
   1183 		sq_hpc_write(sc, HPC1_ENETX_CTL, HPC1_ENETX_CTL_ACTIVE);
   1184 
   1185 		/*
   1186 		 * Set a watchdog timer in case the chip
   1187 		 * flakes out.
   1188 		 */
   1189 		ifp->if_timer = 5;
   1190 	}
   1191 
   1192 	sc->sc_prevtx = i;
   1193 }
   1194 
   1195 /*
   1196  * Reclaim used transmit descriptors and restart the transmit DMA
   1197  * engine if necessary.
   1198  */
   1199 static void
   1200 sq_txring_hpc3(struct sq_softc *sc)
   1201 {
   1202 	/*
   1203 	 * HPC3 tags descriptors with a bit once they've been
   1204 	 * transmitted. We need only free each XMITDONE'd
   1205 	 * descriptor, and restart the DMA engine if any
   1206 	 * descriptors are left over.
   1207 	 */
   1208 	int i;
   1209 	uint32_t status = 0;
   1210 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
   1211 
   1212 	i = sc->sc_prevtx;
   1213 	while (sc->sc_nfreetx < SQ_NTXDESC) {
   1214 		/*
   1215 		 * Check status first so we don't end up with a case of
   1216 		 * the buffer not being finished while the DMA channel
   1217 		 * has gone idle.
   1218 		 */
   1219 		status = sq_hpc_read(sc, HPC3_ENETX_CTL);
   1220 
   1221 		SQ_CDTXSYNC(sc, i, sc->sc_txmap[i]->dm_nsegs,
   1222 		    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
   1223 
   1224 		/* Check for used descriptor and restart DMA chain if needed */
   1225 		if ((sc->sc_txdesc[i].hpc3_hdd_ctl &
   1226 		    HPC3_HDD_CTL_XMITDONE) == 0) {
   1227 			if ((status & HPC3_ENETX_CTL_ACTIVE) == 0) {
   1228 				SQ_TRACE(SQ_RESTART_DMA, sc, i, status);
   1229 
   1230 				sq_hpc_write(sc, HPC3_ENETX_NDBP,
   1231 				    SQ_CDTXADDR(sc, i));
   1232 
   1233 				/* Kick DMA channel into life */
   1234 				sq_hpc_write(sc, HPC3_ENETX_CTL,
   1235 				    HPC3_ENETX_CTL_ACTIVE);
   1236 
   1237 				/*
   1238 				 * Set a watchdog timer in case the chip
   1239 				 * flakes out.
   1240 				 */
   1241 				ifp->if_timer = 5;
   1242 			} else
   1243 				SQ_TRACE(SQ_TXINTR_BUSY, sc, i, status);
   1244 			break;
   1245 		}
   1246 
   1247 		/* Sync the packet data, unload DMA map, free mbuf */
   1248 		bus_dmamap_sync(sc->sc_dmat, sc->sc_txmap[i],
   1249 		    0, sc->sc_txmap[i]->dm_mapsize, BUS_DMASYNC_POSTWRITE);
   1250 		bus_dmamap_unload(sc->sc_dmat, sc->sc_txmap[i]);
   1251 		m_freem(sc->sc_txmbuf[i]);
   1252 		sc->sc_txmbuf[i] = NULL;
   1253 
   1254 		ifp->if_opackets++;
   1255 		sc->sc_nfreetx++;
   1256 
   1257 		SQ_TRACE(SQ_DONE_DMA, sc, i, status);
   1258 		i = SQ_NEXTTX(i);
   1259 	}
   1260 
   1261 	sc->sc_prevtx = i;
   1262 }
   1263 
   1264 void
   1265 sq_reset(struct sq_softc *sc)
   1266 {
   1267 
   1268 	/* Stop HPC dma channels */
   1269 	sq_hpc_write(sc, sc->hpc_regs->enetr_ctl, 0);
   1270 	sq_hpc_write(sc, sc->hpc_regs->enetx_ctl, 0);
   1271 
   1272 	sq_hpc_write(sc, sc->hpc_regs->enetr_reset, 3);
   1273 	delay(20);
   1274 	sq_hpc_write(sc, sc->hpc_regs->enetr_reset, 0);
   1275 }
   1276 
   1277 /* sq_add_rxbuf: Add a receive buffer to the indicated descriptor. */
   1278 int
   1279 sq_add_rxbuf(struct sq_softc *sc, int idx)
   1280 {
   1281 	int err;
   1282 	struct mbuf *m;
   1283 
   1284 	MGETHDR(m, M_DONTWAIT, MT_DATA);
   1285 	if (m == NULL)
   1286 		return ENOBUFS;
   1287 
   1288 	MCLGET(m, M_DONTWAIT);
   1289 	if ((m->m_flags & M_EXT) == 0) {
   1290 		m_freem(m);
   1291 		return ENOBUFS;
   1292 	}
   1293 
   1294 	if (sc->sc_rxmbuf[idx] != NULL)
   1295 		bus_dmamap_unload(sc->sc_dmat, sc->sc_rxmap[idx]);
   1296 
   1297 	sc->sc_rxmbuf[idx] = m;
   1298 
   1299 	if ((err = bus_dmamap_load(sc->sc_dmat, sc->sc_rxmap[idx],
   1300 	    m->m_ext.ext_buf, m->m_ext.ext_size, NULL, BUS_DMA_NOWAIT)) != 0) {
   1301 		printf("%s: can't load rx DMA map %d, error = %d\n",
   1302 		    device_xname(sc->sc_dev), idx, err);
   1303 		panic("sq_add_rxbuf");	/* XXX */
   1304 	}
   1305 
   1306 	bus_dmamap_sync(sc->sc_dmat, sc->sc_rxmap[idx],
   1307 	    0, sc->sc_rxmap[idx]->dm_mapsize, BUS_DMASYNC_PREREAD);
   1308 
   1309 	SQ_INIT_RXDESC(sc, idx);
   1310 
   1311 	return 0;
   1312 }
   1313 
   1314 void
   1315 sq_dump_buffer(paddr_t addr, psize_t len)
   1316 {
   1317 	u_int i;
   1318 	uint8_t *physaddr = (uint8_t *)MIPS_PHYS_TO_KSEG1(addr);
   1319 
   1320 	if (len == 0)
   1321 		return;
   1322 
   1323 	printf("%p: ", physaddr);
   1324 
   1325 	for (i = 0; i < len; i++) {
   1326 		printf("%02x ", *(physaddr + i) & 0xff);
   1327 		if ((i % 16) ==  15 && i != len - 1)
   1328 		    printf("\n%p: ", physaddr + i);
   1329 	}
   1330 
   1331 	printf("\n");
   1332 }
   1333