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hd64570.c revision 1.5
      1 /*	$NetBSD: hd64570.c,v 1.5 1999/03/16 21:29:23 erh Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998 Vixie Enterprises
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  *
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of Vixie Enterprises nor the names
     17  *    of its contributors may be used to endorse or promote products derived
     18  *    from this software without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY VIXIE ENTERPRISES AND
     21  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
     22  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     24  * DISCLAIMED.  IN NO EVENT SHALL VIXIE ENTERPRISES OR
     25  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
     28  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     29  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  *
     34  * This software has been written for Vixie Enterprises by Michael Graff
     35  * <explorer (at) flame.org>.  To learn more about Vixie Enterprises, see
     36  * ``http://www.vix.com''.
     37  */
     38 
     39 /*
     40  * TODO:
     41  *
     42  *	o  teach the receive logic about errors, and about long frames that
     43  *         span more than one input buffer.  (Right now, receive/transmit is
     44  *	   limited to one descriptor's buffer space, which is MTU + 4 bytes.
     45  *	   This is currently 1504, which is large enough to hold the HDLC
     46  *	   header and the packet itself.  Packets which are too long are
     47  *	   silently dropped on transmit and silently dropped on receive.
     48  *	o  write code to handle the msci interrupts, needed only for CD
     49  *	   and CTS changes.
     50  *	o  consider switching back to a "queue tx with DMA active" model which
     51  *	   should help sustain outgoing traffic
     52  *	o  through clever use of bus_dma*() functions, it should be possible
     53  *	   to map the mbuf's data area directly into a descriptor transmit
     54  *	   buffer, removing the need to allocate extra memory.  If, however,
     55  *	   we run out of descriptors for this, we will need to then allocate
     56  *	   one large mbuf, copy the fragmented chain into it, and put it onto
     57  *	   a single descriptor.
     58  *	o  use bus_dmamap_sync() with the right offset and lengths, rather
     59  *	   than cheating and always sync'ing the whole region.
     60  */
     61 
     62 #include "bpfilter.h"
     63 
     64 #include <sys/param.h>
     65 #include <sys/systm.h>
     66 #include <sys/device.h>
     67 #include <sys/mbuf.h>
     68 #include <sys/socket.h>
     69 #include <sys/sockio.h>
     70 #include <sys/kernel.h>
     71 
     72 #include <net/if.h>
     73 #include <net/if_types.h>
     74 #include <net/netisr.h>
     75 
     76 #include <netinet/in.h>
     77 #include <netinet/in_systm.h>
     78 #include <netinet/in_var.h>
     79 #include <netinet/ip.h>
     80 
     81 #if NBPFILTER > 0
     82 #include <net/bpf.h>
     83 #endif
     84 
     85 #include <machine/cpu.h>
     86 #include <machine/bus.h>
     87 #include <machine/intr.h>
     88 
     89 #include <dev/pci/pcivar.h>
     90 #include <dev/pci/pcireg.h>
     91 #include <dev/pci/pcidevs.h>
     92 
     93 #include <dev/ic/hd64570reg.h>
     94 #include <dev/ic/hd64570var.h>
     95 
     96 #define SCA_DEBUG_RX		0x0001
     97 #define SCA_DEBUG_TX		0x0002
     98 #define SCA_DEBUG_CISCO		0x0004
     99 #define SCA_DEBUG_DMA		0x0008
    100 #define SCA_DEBUG_RXPKT		0x0010
    101 #define SCA_DEBUG_TXPKT		0x0020
    102 #define SCA_DEBUG_INTR		0x0040
    103 
    104 #if 0
    105 #define SCA_DEBUG_LEVEL	( SCA_DEBUG_TX )
    106 #else
    107 #define SCA_DEBUG_LEVEL 0
    108 #endif
    109 
    110 u_int32_t sca_debug = SCA_DEBUG_LEVEL;
    111 
    112 #if SCA_DEBUG_LEVEL > 0
    113 #define SCA_DPRINTF(l, x) do { \
    114 	if ((l) & sca_debug) \
    115 		printf x;\
    116 	} while (0)
    117 #else
    118 #define SCA_DPRINTF(l, x)
    119 #endif
    120 
    121 #define SCA_MTU		1500	/* hard coded */
    122 
    123 /*
    124  * buffers per tx and rx channels, per port, and the size of each.
    125  * Don't use these constants directly, as they are really only hints.
    126  * Use the calculated values stored in struct sca_softc instead.
    127  *
    128  * Each must be at least 2, receive would be better at around 20 or so.
    129  *
    130  * XXX Due to a damned near impossible to track down bug, transmit buffers
    131  * MUST be 2, no more, no less.
    132  */
    133 #ifndef SCA_NtxBUFS
    134 #define SCA_NtxBUFS	2
    135 #endif
    136 #ifndef SCA_NrxBUFS
    137 #define SCA_NrxBUFS	20
    138 #endif
    139 #ifndef SCA_BSIZE
    140 #define SCA_BSIZE	(SCA_MTU + 4)	/* room for HDLC as well */
    141 #endif
    142 
    143 #if 0
    144 #define SCA_USE_FASTQ		/* use a split queue, one for fast traffic */
    145 #endif
    146 
    147 static inline void sca_write_1(struct sca_softc *, u_int, u_int8_t);
    148 static inline void sca_write_2(struct sca_softc *, u_int, u_int16_t);
    149 static inline u_int8_t sca_read_1(struct sca_softc *, u_int);
    150 static inline u_int16_t sca_read_2(struct sca_softc *, u_int);
    151 
    152 static inline void msci_write_1(sca_port_t *, u_int, u_int8_t);
    153 static inline u_int8_t msci_read_1(sca_port_t *, u_int);
    154 
    155 static inline void dmac_write_1(sca_port_t *, u_int, u_int8_t);
    156 static inline void dmac_write_2(sca_port_t *, u_int, u_int16_t);
    157 static inline u_int8_t dmac_read_1(sca_port_t *, u_int);
    158 static inline u_int16_t dmac_read_2(sca_port_t *, u_int);
    159 
    160 static	int sca_alloc_dma(struct sca_softc *);
    161 static	void sca_setup_dma_memory(struct sca_softc *);
    162 static	void sca_msci_init(struct sca_softc *, sca_port_t *);
    163 static	void sca_dmac_init(struct sca_softc *, sca_port_t *);
    164 static void sca_dmac_rxinit(sca_port_t *);
    165 
    166 static	int sca_dmac_intr(sca_port_t *, u_int8_t);
    167 static	int sca_msci_intr(struct sca_softc *, u_int8_t);
    168 
    169 static	void sca_get_packets(sca_port_t *);
    170 static	void sca_frame_process(sca_port_t *, sca_desc_t *, u_int8_t *);
    171 static	int sca_frame_avail(sca_port_t *, int *);
    172 static	void sca_frame_skip(sca_port_t *, int);
    173 
    174 static	void sca_port_starttx(sca_port_t *);
    175 
    176 static	void sca_port_up(sca_port_t *);
    177 static	void sca_port_down(sca_port_t *);
    178 
    179 static	int sca_output __P((struct ifnet *, struct mbuf *, struct sockaddr *,
    180 			    struct rtentry *));
    181 static	int sca_ioctl __P((struct ifnet *, u_long, caddr_t));
    182 static	void sca_start __P((struct ifnet *));
    183 static	void sca_watchdog __P((struct ifnet *));
    184 
    185 static struct mbuf *sca_mbuf_alloc(caddr_t, u_int);
    186 
    187 #if SCA_DEBUG_LEVEL > 0
    188 static	void sca_frame_print(sca_port_t *, sca_desc_t *, u_int8_t *);
    189 #endif
    190 
    191 static inline void
    192 sca_write_1(struct sca_softc *sc, u_int reg, u_int8_t val)
    193 {
    194 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, SCADDR(reg), val);
    195 }
    196 
    197 static inline void
    198 sca_write_2(struct sca_softc *sc, u_int reg, u_int16_t val)
    199 {
    200 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, SCADDR(reg), val);
    201 }
    202 
    203 static inline u_int8_t
    204 sca_read_1(struct sca_softc *sc, u_int reg)
    205 {
    206 	return bus_space_read_1(sc->sc_iot, sc->sc_ioh, SCADDR(reg));
    207 }
    208 
    209 static inline u_int16_t
    210 sca_read_2(struct sca_softc *sc, u_int reg)
    211 {
    212 	return bus_space_read_2(sc->sc_iot, sc->sc_ioh, SCADDR(reg));
    213 }
    214 
    215 static inline void
    216 msci_write_1(sca_port_t *scp, u_int reg, u_int8_t val)
    217 {
    218 	sca_write_1(scp->sca, scp->msci_off + reg, val);
    219 }
    220 
    221 static inline u_int8_t
    222 msci_read_1(sca_port_t *scp, u_int reg)
    223 {
    224 	return sca_read_1(scp->sca, scp->msci_off + reg);
    225 }
    226 
    227 static inline void
    228 dmac_write_1(sca_port_t *scp, u_int reg, u_int8_t val)
    229 {
    230 	sca_write_1(scp->sca, scp->dmac_off + reg, val);
    231 }
    232 
    233 static inline void
    234 dmac_write_2(sca_port_t *scp, u_int reg, u_int16_t val)
    235 {
    236 	sca_write_2(scp->sca, scp->dmac_off + reg, val);
    237 }
    238 
    239 static inline u_int8_t
    240 dmac_read_1(sca_port_t *scp, u_int reg)
    241 {
    242 	return sca_read_1(scp->sca, scp->dmac_off + reg);
    243 }
    244 
    245 static inline u_int16_t
    246 dmac_read_2(sca_port_t *scp, u_int reg)
    247 {
    248 	return sca_read_2(scp->sca, scp->dmac_off + reg);
    249 }
    250 
    251 int
    252 sca_init(struct sca_softc *sc, u_int nports)
    253 {
    254 	/*
    255 	 * Do a little sanity check:  check number of ports.
    256 	 */
    257 	if (nports < 1 || nports > 2)
    258 		return 1;
    259 
    260 	/*
    261 	 * remember the details
    262 	 */
    263 	sc->sc_numports = nports;
    264 
    265 	/*
    266 	 * allocate the memory and chop it into bits.
    267 	 */
    268 	if (sca_alloc_dma(sc) != 0)
    269 		return 1;
    270 	sca_setup_dma_memory(sc);
    271 
    272 	/*
    273 	 * disable DMA and MSCI interrupts
    274 	 */
    275 	sca_write_1(sc, SCA_DMER, 0);
    276 	sca_write_1(sc, SCA_IER0, 0);
    277 	sca_write_1(sc, SCA_IER1, 0);
    278 	sca_write_1(sc, SCA_IER2, 0);
    279 
    280 	/*
    281 	 * configure interrupt system
    282 	 */
    283 	sca_write_1(sc, SCA_ITCR, 0);	/* use ivr, no int ack */
    284 	sca_write_1(sc, SCA_IVR, 0x40);
    285 	sca_write_1(sc, SCA_IMVR, 0x40);
    286 
    287 	/*
    288 	 * set wait control register to zero wait states
    289 	 */
    290 	sca_write_1(sc, SCA_PABR0, 0);
    291 	sca_write_1(sc, SCA_PABR1, 0);
    292 	sca_write_1(sc, SCA_WCRL, 0);
    293 	sca_write_1(sc, SCA_WCRM, 0);
    294 	sca_write_1(sc, SCA_WCRH, 0);
    295 
    296 	/*
    297 	 * disable DMA and reset status
    298 	 */
    299 	sca_write_1(sc, SCA_PCR, SCA_PCR_PR2);
    300 
    301 	/*
    302 	 * disable transmit DMA for all channels
    303 	 */
    304 	sca_write_1(sc, SCA_DSR0 + SCA_DMAC_OFF_0, 0);
    305 	sca_write_1(sc, SCA_DCR0 + SCA_DMAC_OFF_0, SCA_DCR_ABRT);
    306 	sca_write_1(sc, SCA_DSR1 + SCA_DMAC_OFF_0, 0);
    307 	sca_write_1(sc, SCA_DCR1 + SCA_DMAC_OFF_0, SCA_DCR_ABRT);
    308 	sca_write_1(sc, SCA_DSR0 + SCA_DMAC_OFF_1, 0);
    309 	sca_write_1(sc, SCA_DCR0 + SCA_DMAC_OFF_1, SCA_DCR_ABRT);
    310 	sca_write_1(sc, SCA_DSR1 + SCA_DMAC_OFF_1, 0);
    311 	sca_write_1(sc, SCA_DCR1 + SCA_DMAC_OFF_1, SCA_DCR_ABRT);
    312 
    313 	/*
    314 	 * enable DMA based on channel enable flags for each channel
    315 	 */
    316 	sca_write_1(sc, SCA_DMER, SCA_DMER_EN);
    317 
    318 	/*
    319 	 * Should check to see if the chip is responding, but for now
    320 	 * assume it is.
    321 	 */
    322 	return 0;
    323 }
    324 
    325 /*
    326  * initialize the port and attach it to the networking layer
    327  */
    328 void
    329 sca_port_attach(struct sca_softc *sc, u_int port)
    330 {
    331 	sca_port_t *scp = &sc->sc_ports[port];
    332 	struct ifnet *ifp;
    333 	static u_int ntwo_unit = 0;
    334 
    335 	scp->sca = sc;  /* point back to the parent */
    336 
    337 	scp->sp_port = port;
    338 
    339 	if (port == 0) {
    340 		scp->msci_off = SCA_MSCI_OFF_0;
    341 		scp->dmac_off = SCA_DMAC_OFF_0;
    342 		if(sc->parent != NULL)
    343 			ntwo_unit=sc->parent->dv_unit * 2 + 0;
    344 		else
    345 			ntwo_unit = 0;	/* XXX */
    346 	} else {
    347 		scp->msci_off = SCA_MSCI_OFF_1;
    348 		scp->dmac_off = SCA_DMAC_OFF_1;
    349 		if(sc->parent != NULL)
    350 			ntwo_unit=sc->parent->dv_unit * 2 + 1;
    351 		else
    352 			ntwo_unit = 1;	/* XXX */
    353 	}
    354 
    355 	sca_msci_init(sc, scp);
    356 	sca_dmac_init(sc, scp);
    357 
    358 	/*
    359 	 * attach to the network layer
    360 	 */
    361 	ifp = &scp->sp_if;
    362 	sprintf(ifp->if_xname, "ntwo%d", ntwo_unit);
    363 	ifp->if_softc = scp;
    364 	ifp->if_mtu = SCA_MTU;
    365 	ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
    366 	ifp->if_type = IFT_OTHER;  /* Should be HDLC, but... */
    367 	ifp->if_hdrlen = HDLC_HDRLEN;
    368 	ifp->if_ioctl = sca_ioctl;
    369 	ifp->if_output = sca_output;
    370 	ifp->if_watchdog = sca_watchdog;
    371 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
    372 	scp->linkq.ifq_maxlen = 5; /* if we exceed this we are hosed already */
    373 #ifdef SCA_USE_FASTQ
    374 	scp->fastq.ifq_maxlen = IFQ_MAXLEN;
    375 #endif
    376 	if_attach(ifp);
    377 
    378 #if NBPFILTER > 0
    379 	bpfattach(&scp->sp_bpf, ifp, DLT_HDLC, HDLC_HDRLEN);
    380 #endif
    381 
    382 	if (sc->parent == NULL)
    383 		printf("%s: port %d\n", ifp->if_xname, port);
    384 	else
    385 		printf("%s at %s port %d\n",
    386 		       ifp->if_xname, sc->parent->dv_xname, port);
    387 
    388 	/*
    389 	 * reset the last seen times on the cisco keepalive protocol
    390 	 */
    391 	scp->cka_lasttx = time.tv_usec;
    392 	scp->cka_lastrx = 0;
    393 }
    394 
    395 /*
    396  * initialize the port's MSCI
    397  */
    398 static void
    399 sca_msci_init(struct sca_softc *sc, sca_port_t *scp)
    400 {
    401 	msci_write_1(scp, SCA_CMD0, SCA_CMD_RESET);
    402 	msci_write_1(scp, SCA_MD00,
    403 		     (  SCA_MD0_CRC_1
    404 		      | SCA_MD0_CRC_CCITT
    405 		      | SCA_MD0_CRC_ENABLE
    406 		      | SCA_MD0_MODE_HDLC));
    407 	msci_write_1(scp, SCA_MD10, SCA_MD1_NOADDRCHK);
    408 	msci_write_1(scp, SCA_MD20,
    409 		     (SCA_MD2_DUPLEX | SCA_MD2_NRZ));
    410 
    411 	/*
    412 	 * reset the port (and lower RTS)
    413 	 */
    414 	msci_write_1(scp, SCA_CMD0, SCA_CMD_RXRESET);
    415 	msci_write_1(scp, SCA_CTL0,
    416 		     (SCA_CTL_IDLPAT | SCA_CTL_UDRNC | SCA_CTL_RTS));
    417 	msci_write_1(scp, SCA_CMD0, SCA_CMD_TXRESET);
    418 
    419 	/*
    420 	 * select the RX clock as the TX clock, and set for external
    421 	 * clock source.
    422 	 */
    423 	msci_write_1(scp, SCA_RXS0, 0);
    424 	msci_write_1(scp, SCA_TXS0, 0);
    425 
    426 	/*
    427 	 * XXX don't pay attention to CTS or CD changes right now.  I can't
    428 	 * simulate one, and the transmitter will try to transmit even if
    429 	 * CD isn't there anyway, so nothing bad SHOULD happen.
    430 	 */
    431 	msci_write_1(scp, SCA_IE00, 0);
    432 	msci_write_1(scp, SCA_IE10, 0); /* 0x0c == CD and CTS changes only */
    433 	msci_write_1(scp, SCA_IE20, 0);
    434 	msci_write_1(scp, SCA_FIE0, 0);
    435 
    436 	msci_write_1(scp, SCA_SA00, 0);
    437 	msci_write_1(scp, SCA_SA10, 0);
    438 
    439 	msci_write_1(scp, SCA_IDL0, 0x7e);
    440 
    441 	msci_write_1(scp, SCA_RRC0, 0x0e);
    442 	msci_write_1(scp, SCA_TRC00, 0x10);
    443 	msci_write_1(scp, SCA_TRC10, 0x1f);
    444 }
    445 
    446 /*
    447  * Take the memory for the port and construct two circular linked lists of
    448  * descriptors (one tx, one rx) and set the pointers in these descriptors
    449  * to point to the buffer space for this port.
    450  */
    451 static void
    452 sca_dmac_init(struct sca_softc *sc, sca_port_t *scp)
    453 {
    454 	sca_desc_t *desc;
    455 	u_int32_t desc_p;
    456 	u_int32_t buf_p;
    457 	int i;
    458 
    459 	bus_dmamap_sync(sc->sc_dmat, sc->sc_dmam,
    460 			0, sc->sc_allocsize, BUS_DMASYNC_PREWRITE);
    461 
    462 	desc = scp->txdesc;
    463 	desc_p = scp->txdesc_p;
    464 	buf_p = scp->txbuf_p;
    465 	scp->txcur = 0;
    466 	scp->txinuse = 0;
    467 
    468 	for (i = 0 ; i < SCA_NtxBUFS ; i++) {
    469 		/*
    470 		 * desc_p points to the physcial address of the NEXT desc
    471 		 */
    472 		desc_p += sizeof(sca_desc_t);
    473 
    474 		desc->cp = desc_p & 0x0000ffff;
    475 		desc->bp = buf_p & 0x0000ffff;
    476 		desc->bpb = (buf_p & 0x00ff0000) >> 16;
    477 		desc->len = SCA_BSIZE;
    478 		desc->stat = 0;
    479 
    480 		desc++;  /* point to the next descriptor */
    481 		buf_p += SCA_BSIZE;
    482 	}
    483 
    484 	/*
    485 	 * "heal" the circular list by making the last entry point to the
    486 	 * first.
    487 	 */
    488 	desc--;
    489 	desc->cp = scp->txdesc_p & 0x0000ffff;
    490 
    491 	/*
    492 	 * Now, initialize the transmit DMA logic
    493 	 *
    494 	 * CPB == chain pointer base address
    495 	 */
    496 	dmac_write_1(scp, SCA_DSR1, 0);
    497 	dmac_write_1(scp, SCA_DCR1, SCA_DCR_ABRT);
    498 	dmac_write_1(scp, SCA_DMR1, SCA_DMR_TMOD | SCA_DMR_NF);
    499 	dmac_write_1(scp, SCA_DIR1,
    500 		     (SCA_DIR_EOT | SCA_DIR_BOF | SCA_DIR_COF));
    501 	dmac_write_1(scp, SCA_CPB1,
    502 		     (u_int8_t)((scp->txdesc_p & 0x00ff0000) >> 16));
    503 
    504 	/*
    505 	 * now, do the same thing for receive descriptors
    506 	 */
    507 	desc = scp->rxdesc;
    508 	desc_p = scp->rxdesc_p;
    509 	buf_p = scp->rxbuf_p;
    510 	scp->rxstart = 0;
    511 	scp->rxend = SCA_NrxBUFS - 1;
    512 
    513 	for (i = 0 ; i < SCA_NrxBUFS ; i++) {
    514 		/*
    515 		 * desc_p points to the physcial address of the NEXT desc
    516 		 */
    517 		desc_p += sizeof(sca_desc_t);
    518 
    519 		desc->cp = desc_p & 0x0000ffff;
    520 		desc->bp = buf_p & 0x0000ffff;
    521 		desc->bpb = (buf_p & 0x00ff0000) >> 16;
    522 		desc->len = SCA_BSIZE;
    523 		desc->stat = 0x00;
    524 
    525 		desc++;  /* point to the next descriptor */
    526 		buf_p += SCA_BSIZE;
    527 	}
    528 
    529 	/*
    530 	 * "heal" the circular list by making the last entry point to the
    531 	 * first.
    532 	 */
    533 	desc--;
    534 	desc->cp = scp->rxdesc_p & 0x0000ffff;
    535 
    536 	sca_dmac_rxinit(scp);
    537 
    538 	bus_dmamap_sync(sc->sc_dmat, sc->sc_dmam,
    539 			0, sc->sc_allocsize, BUS_DMASYNC_POSTWRITE);
    540 }
    541 
    542 /*
    543  * reset and reinitialize the receive DMA logic
    544  */
    545 static void
    546 sca_dmac_rxinit(sca_port_t *scp)
    547 {
    548 	/*
    549 	 * ... and the receive DMA logic ...
    550 	 */
    551 	dmac_write_1(scp, SCA_DSR0, 0);  /* disable DMA */
    552 	dmac_write_1(scp, SCA_DCR0, SCA_DCR_ABRT);
    553 
    554 	dmac_write_1(scp, SCA_DMR0, SCA_DMR_TMOD | SCA_DMR_NF);
    555 	dmac_write_2(scp, SCA_BFLL0, SCA_BSIZE);
    556 
    557 	/*
    558 	 * CPB == chain pointer base
    559 	 * CDA == current descriptor address
    560 	 * EDA == error descriptor address (overwrite position)
    561 	 */
    562 	dmac_write_1(scp, SCA_CPB0,
    563 		     (u_int8_t)((scp->rxdesc_p & 0x00ff0000) >> 16));
    564 	dmac_write_2(scp, SCA_CDAL0,
    565 		     (u_int16_t)(scp->rxdesc_p & 0xffff));
    566 	dmac_write_2(scp, SCA_EDAL0,
    567 		     (u_int16_t)(scp->rxdesc_p
    568 				 + sizeof(sca_desc_t) * SCA_NrxBUFS));
    569 
    570 	/*
    571 	 * enable receiver DMA
    572 	 */
    573 	dmac_write_1(scp, SCA_DIR0,
    574 		     (SCA_DIR_EOT | SCA_DIR_EOM | SCA_DIR_BOF | SCA_DIR_COF));
    575 	dmac_write_1(scp, SCA_DSR0, SCA_DSR_DE);
    576 }
    577 
    578 static int
    579 sca_alloc_dma(struct sca_softc *sc)
    580 {
    581 	u_int	allocsize;
    582 	int	err;
    583 	int	rsegs;
    584 	u_int	bpp;
    585 
    586 	SCA_DPRINTF(SCA_DEBUG_DMA,
    587 		    ("sizeof sca_desc_t: %d bytes\n", sizeof (sca_desc_t)));
    588 
    589 	bpp = sc->sc_numports * (SCA_NtxBUFS + SCA_NrxBUFS);
    590 
    591 	allocsize = bpp * (SCA_BSIZE + sizeof (sca_desc_t));
    592 
    593 	/*
    594 	 * sanity checks:
    595 	 *
    596 	 * Check the total size of the data buffers, and so on.  The total
    597 	 * DMAable space needs to fit within a single 16M region, and the
    598 	 * descriptors need to fit within a 64K region.
    599 	 */
    600 	if (allocsize > 16 * 1024 * 1024)
    601 		return 1;
    602 	if (bpp * sizeof (sca_desc_t) > 64 * 1024)
    603 		return 1;
    604 
    605 	sc->sc_allocsize = allocsize;
    606 
    607 	/*
    608 	 * Allocate one huge chunk of memory.
    609 	 */
    610 	if (bus_dmamem_alloc(sc->sc_dmat,
    611 			     allocsize,
    612 			     SCA_DMA_ALIGNMENT,
    613 			     SCA_DMA_BOUNDRY,
    614 			     &sc->sc_seg, 1, &rsegs, BUS_DMA_NOWAIT) != 0) {
    615 		printf("Could not allocate DMA memory\n");
    616 		return 1;
    617 	}
    618 	SCA_DPRINTF(SCA_DEBUG_DMA,
    619 		    ("DMA memory allocated:  %d bytes\n", allocsize));
    620 
    621 	if (bus_dmamem_map(sc->sc_dmat, &sc->sc_seg, 1, allocsize,
    622 			   &sc->sc_dma_addr, BUS_DMA_NOWAIT) != 0) {
    623 		printf("Could not map DMA memory into kernel space\n");
    624 		return 1;
    625 	}
    626 	SCA_DPRINTF(SCA_DEBUG_DMA, ("DMA memory mapped\n"));
    627 
    628 	if (bus_dmamap_create(sc->sc_dmat, allocsize, 2,
    629 			      allocsize, SCA_DMA_BOUNDRY,
    630 			      BUS_DMA_NOWAIT, &sc->sc_dmam) != 0) {
    631 		printf("Could not create DMA map\n");
    632 		return 1;
    633 	}
    634 	SCA_DPRINTF(SCA_DEBUG_DMA, ("DMA map created\n"));
    635 
    636 	err = bus_dmamap_load(sc->sc_dmat, sc->sc_dmam, sc->sc_dma_addr,
    637 			      allocsize, NULL, BUS_DMA_NOWAIT);
    638 	if (err != 0) {
    639 		printf("Could not load DMA segment:  %d\n", err);
    640 		return 1;
    641 	}
    642 	SCA_DPRINTF(SCA_DEBUG_DMA, ("DMA map loaded\n"));
    643 
    644 	return 0;
    645 }
    646 
    647 /*
    648  * Take the memory allocated with sca_alloc_dma() and divide it among the
    649  * two ports.
    650  */
    651 static void
    652 sca_setup_dma_memory(struct sca_softc *sc)
    653 {
    654 	sca_port_t *scp0, *scp1;
    655 	u_int8_t  *vaddr0;
    656 	u_int32_t paddr0;
    657 	u_long addroff;
    658 
    659 	/*
    660 	 * remember the physical address to 24 bits only, since the upper
    661 	 * 8 bits is programed into the device at a different layer.
    662 	 */
    663 	paddr0 = (sc->sc_dmam->dm_segs[0].ds_addr & 0x00ffffff);
    664 	vaddr0 = sc->sc_dma_addr;
    665 
    666 	/*
    667 	 * if we have only one port it gets the full range.  If we have
    668 	 * two we need to do a little magic to divide things up.
    669 	 *
    670 	 * The descriptors will all end up in the front of the area, while
    671 	 * the remainder of the buffer is used for transmit and receive
    672 	 * data.
    673 	 *
    674 	 * -------------------- start of memory
    675 	 *    tx desc port 0
    676 	 *    rx desc port 0
    677 	 *    tx desc port 1
    678 	 *    rx desc port 1
    679 	 *    tx buffer port 0
    680 	 *    rx buffer port 0
    681 	 *    tx buffer port 1
    682 	 *    rx buffer port 1
    683 	 * -------------------- end of memory
    684 	 */
    685 	scp0 = &sc->sc_ports[0];
    686 	scp1 = &sc->sc_ports[1];
    687 
    688 	scp0->txdesc_p = paddr0;
    689 	scp0->txdesc = (sca_desc_t *)vaddr0;
    690 	addroff = sizeof(sca_desc_t) * SCA_NtxBUFS;
    691 
    692 	/*
    693 	 * point to the range following the tx descriptors, and
    694 	 * set the rx descriptors there.
    695 	 */
    696 	scp0->rxdesc_p = paddr0 + addroff;
    697 	scp0->rxdesc = (sca_desc_t *)(vaddr0 + addroff);
    698 	addroff += sizeof(sca_desc_t) * SCA_NrxBUFS;
    699 
    700 	if (sc->sc_numports == 2) {
    701 		scp1->txdesc_p = paddr0 + addroff;
    702 		scp1->txdesc = (sca_desc_t *)(vaddr0 + addroff);
    703 		addroff += sizeof(sca_desc_t) * SCA_NtxBUFS;
    704 
    705 		scp1->rxdesc_p = paddr0 + addroff;
    706 		scp1->rxdesc = (sca_desc_t *)(vaddr0 + addroff);
    707 		addroff += sizeof(sca_desc_t) * SCA_NrxBUFS;
    708 	}
    709 
    710 	/*
    711 	 * point to the memory following the descriptors, and set the
    712 	 * transmit buffer there.
    713 	 */
    714 	scp0->txbuf_p = paddr0 + addroff;
    715 	scp0->txbuf = vaddr0 + addroff;
    716 	addroff += SCA_BSIZE * SCA_NtxBUFS;
    717 
    718 	/*
    719 	 * lastly, skip over the transmit buffer and set up pointers into
    720 	 * the receive buffer.
    721 	 */
    722 	scp0->rxbuf_p = paddr0 + addroff;
    723 	scp0->rxbuf = vaddr0 + addroff;
    724 	addroff += SCA_BSIZE * SCA_NrxBUFS;
    725 
    726 	if (sc->sc_numports == 2) {
    727 		scp1->txbuf_p = paddr0 + addroff;
    728 		scp1->txbuf = vaddr0 + addroff;
    729 		addroff += SCA_BSIZE * SCA_NtxBUFS;
    730 
    731 		scp1->rxbuf_p = paddr0 + addroff;
    732 		scp1->rxbuf = vaddr0 + addroff;
    733 		addroff += SCA_BSIZE * SCA_NrxBUFS;
    734 	}
    735 
    736 	/*
    737 	 * as a consistancy check, addroff should be equal to the allocation
    738 	 * size.
    739 	 */
    740 	if (sc->sc_allocsize != addroff)
    741 		printf("ERROR:  sc_allocsize != addroff: %lu != %lu\n",
    742 		       sc->sc_allocsize, addroff);
    743 }
    744 
    745 /*
    746  * Queue the packet for our start routine to transmit
    747  */
    748 static int
    749 sca_output(ifp, m, dst, rt0)
    750      struct ifnet *ifp;
    751      struct mbuf *m;
    752      struct sockaddr *dst;
    753      struct rtentry *rt0;
    754 {
    755 	int error;
    756 	int s;
    757 	u_int16_t protocol;
    758 	hdlc_header_t *hdlc;
    759 	struct ifqueue *ifq;
    760 #ifdef SCA_USE_FASTQ
    761 	struct ip *ip;
    762 	sca_port_t *scp = ifp->if_softc;
    763 	int highpri;
    764 #endif
    765 
    766 	error = 0;
    767 	ifp->if_lastchange = time;
    768 
    769 	if ((ifp->if_flags & IFF_UP) != IFF_UP) {
    770 		error = ENETDOWN;
    771 		goto bad;
    772 	}
    773 
    774 #ifdef SCA_USE_FASTQ
    775 	highpri = 0;
    776 #endif
    777 
    778 	/*
    779 	 * determine address family, and priority for this packet
    780 	 */
    781 	switch (dst->sa_family) {
    782 	case AF_INET:
    783 		protocol = HDLC_PROTOCOL_IP;
    784 
    785 #ifdef SCA_USE_FASTQ
    786 		ip = mtod(m, struct ip *);
    787 		if ((ip->ip_tos & IPTOS_LOWDELAY) == IPTOS_LOWDELAY)
    788 			highpri = 1;
    789 #endif
    790 		break;
    791 
    792 	default:
    793 		printf("%s: address family %d unsupported\n",
    794 		       ifp->if_xname, dst->sa_family);
    795 		error = EAFNOSUPPORT;
    796 		goto bad;
    797 	}
    798 
    799 	if (M_LEADINGSPACE(m) < HDLC_HDRLEN) {
    800 		m = m_prepend(m, HDLC_HDRLEN, M_DONTWAIT);
    801 		if (m == NULL) {
    802 			error = ENOBUFS;
    803 			goto bad;
    804 		}
    805 		m->m_len = 0;
    806 	} else {
    807 		m->m_data -= HDLC_HDRLEN;
    808 	}
    809 
    810 	hdlc = mtod(m, hdlc_header_t *);
    811 	if ((m->m_flags & (M_BCAST | M_MCAST)) != 0)
    812 		hdlc->addr = CISCO_MULTICAST;
    813 	else
    814 		hdlc->addr = CISCO_UNICAST;
    815 	hdlc->control = 0;
    816 	hdlc->protocol = htons(protocol);
    817 	m->m_len += HDLC_HDRLEN;
    818 
    819 	/*
    820 	 * queue the packet.  If interactive, use the fast queue.
    821 	 */
    822 	s = splnet();
    823 #ifdef SCA_USE_FASTQ
    824 	ifq = (highpri == 1 ? &scp->fastq : &ifp->if_snd);
    825 #else
    826 	ifq = &ifp->if_snd;
    827 #endif
    828 	if (IF_QFULL(ifq)) {
    829 		IF_DROP(ifq);
    830 		ifp->if_oerrors++;
    831 		ifp->if_collisions++;
    832 		error = ENOBUFS;
    833 		splx(s);
    834 		goto bad;
    835 	}
    836 	ifp->if_obytes += m->m_pkthdr.len;
    837 	IF_ENQUEUE(ifq, m);
    838 
    839 	ifp->if_lastchange = time;
    840 
    841 	if (m->m_flags & M_MCAST)
    842 		ifp->if_omcasts++;
    843 
    844 	sca_start(ifp);
    845 	splx(s);
    846 
    847 	return (error);
    848 
    849  bad:
    850 	if (m)
    851 		m_freem(m);
    852 	return (error);
    853 }
    854 
    855 static int
    856 sca_ioctl(ifp, cmd, addr)
    857      struct ifnet *ifp;
    858      u_long cmd;
    859      caddr_t addr;
    860 {
    861 	struct ifreq *ifr;
    862 	struct ifaddr *ifa;
    863 	int error;
    864 	int s;
    865 
    866 	s = splnet();
    867 
    868 	ifr = (struct ifreq *)addr;
    869 	ifa = (struct ifaddr *)addr;
    870 	error = 0;
    871 
    872 	switch (cmd) {
    873 	case SIOCSIFADDR:
    874 		if (ifa->ifa_addr->sa_family == AF_INET)
    875 			sca_port_up(ifp->if_softc);
    876 		else
    877 			error = EAFNOSUPPORT;
    878 		break;
    879 
    880 	case SIOCSIFDSTADDR:
    881 		if (ifa->ifa_addr->sa_family != AF_INET)
    882 			error = EAFNOSUPPORT;
    883 		break;
    884 
    885 	case SIOCADDMULTI:
    886 	case SIOCDELMULTI:
    887 		if (ifr == 0) {
    888 			error = EAFNOSUPPORT;		/* XXX */
    889 			break;
    890 		}
    891 		switch (ifr->ifr_addr.sa_family) {
    892 
    893 #ifdef INET
    894 		case AF_INET:
    895 			break;
    896 #endif
    897 
    898 		default:
    899 			error = EAFNOSUPPORT;
    900 			break;
    901 		}
    902 		break;
    903 
    904 	case SIOCSIFFLAGS:
    905 		if (ifr->ifr_flags & IFF_UP)
    906 			sca_port_up(ifp->if_softc);
    907 		else
    908 			sca_port_down(ifp->if_softc);
    909 
    910 		break;
    911 
    912 	default:
    913 		error = EINVAL;
    914 	}
    915 
    916 	splx(s);
    917 	return error;
    918 }
    919 
    920 /*
    921  * start packet transmission on the interface
    922  *
    923  * MUST BE CALLED AT splnet()
    924  */
    925 static void
    926 sca_start(ifp)
    927 	struct ifnet *ifp;
    928 {
    929 	sca_port_t *scp = ifp->if_softc;
    930 	struct sca_softc *sc = scp->sca;
    931 	struct mbuf *m, *mb_head;
    932 	sca_desc_t *desc;
    933 	u_int8_t *buf;
    934 	u_int32_t buf_p;
    935 	int trigger_xmit;
    936 
    937 	/*
    938 	 * can't queue when we are full or transmitter is busy
    939 	 */
    940 	if ((scp->txinuse >= (SCA_NtxBUFS - 1))
    941 	    || ((ifp->if_flags & IFF_OACTIVE) == IFF_OACTIVE))
    942 		return;
    943 
    944 	bus_dmamap_sync(sc->sc_dmat, sc->sc_dmam,
    945 			0, sc->sc_allocsize,
    946 			BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
    947 
    948 	trigger_xmit = 0;
    949 
    950  txloop:
    951 	IF_DEQUEUE(&scp->linkq, mb_head);
    952 	if (mb_head == NULL)
    953 #ifdef SCA_USE_FASTQ
    954 		IF_DEQUEUE(&scp->fastq, mb_head);
    955 	if (mb_head == NULL)
    956 #endif
    957 		IF_DEQUEUE(&ifp->if_snd, mb_head);
    958 	if (mb_head == NULL)
    959 		goto start_xmit;
    960 
    961 	desc = &scp->txdesc[scp->txcur];
    962 	if (scp->txinuse != 0) {
    963 		/* Kill EOT interrupts on the previous packet. */
    964 		desc->stat &= ~SCA_DESC_EOT;
    965 		desc = &scp->txdesc[scp->txcur+1];
    966 	}
    967 	buf = scp->txbuf + SCA_BSIZE * scp->txcur;
    968 	buf_p = scp->txbuf_p + SCA_BSIZE * scp->txcur;
    969 
    970 	desc->bp = (u_int16_t)(buf_p & 0x0000ffff);
    971 	desc->bpb = (u_int8_t)((buf_p & 0x00ff0000) >> 16);
    972 	desc->stat = SCA_DESC_EOT | SCA_DESC_EOM;  /* end of frame and xfer */
    973 	desc->len = 0;
    974 
    975 	/*
    976 	 * Run through the chain, copying data into the descriptor as we
    977 	 * go.  If it won't fit in one transmission block, drop the packet.
    978 	 * No, this isn't nice, but most of the time it _will_ fit.
    979 	 */
    980 	for (m = mb_head ; m != NULL ; m = m->m_next) {
    981 		if (m->m_len != 0) {
    982 			desc->len += m->m_len;
    983 			if (desc->len > SCA_BSIZE) {
    984 				m_freem(mb_head);
    985 				goto txloop;
    986 			}
    987 			bcopy(mtod(m, u_int8_t *), buf, m->m_len);
    988 			buf += m->m_len;
    989 		}
    990 	}
    991 
    992 	ifp->if_opackets++;
    993 
    994 #if NBPFILTER > 0
    995 	/*
    996 	 * Pass packet to bpf if there is a listener.
    997 	 */
    998 	if (scp->sp_bpf)
    999 		bpf_mtap(scp->sp_bpf, mb_head);
   1000 #endif
   1001 
   1002 	m_freem(mb_head);
   1003 
   1004 	if (scp->txinuse != 0) {
   1005 		scp->txcur++;
   1006 		if (scp->txcur == SCA_NtxBUFS)
   1007 			scp->txcur = 0;
   1008 	}
   1009 	scp->txinuse++;
   1010 	trigger_xmit = 1;
   1011 
   1012 	SCA_DPRINTF(SCA_DEBUG_TX,
   1013 		    ("TX: inuse %d index %d\n", scp->txinuse, scp->txcur));
   1014 
   1015 	if (scp->txinuse < (SCA_NtxBUFS - 1))
   1016 		goto txloop;
   1017 
   1018  start_xmit:
   1019 	bus_dmamap_sync(sc->sc_dmat, sc->sc_dmam,
   1020 			0, sc->sc_allocsize,
   1021 			BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
   1022 
   1023 	if (trigger_xmit != 0)
   1024 		sca_port_starttx(scp);
   1025 }
   1026 
   1027 static void
   1028 sca_watchdog(ifp)
   1029 	struct ifnet *ifp;
   1030 {
   1031 }
   1032 
   1033 int
   1034 sca_hardintr(struct sca_softc *sc)
   1035 {
   1036 	u_int8_t isr0, isr1, isr2;
   1037 	int	ret;
   1038 
   1039 	ret = 0;  /* non-zero means we processed at least one interrupt */
   1040 
   1041 	while (1) {
   1042 		/*
   1043 		 * read SCA interrupts
   1044 		 */
   1045 		isr0 = sca_read_1(sc, SCA_ISR0);
   1046 		isr1 = sca_read_1(sc, SCA_ISR1);
   1047 		isr2 = sca_read_1(sc, SCA_ISR2);
   1048 
   1049 		if (isr0 == 0 && isr1 == 0 && isr2 == 0)
   1050 			break;
   1051 
   1052 		SCA_DPRINTF(SCA_DEBUG_INTR,
   1053 			    ("isr0 = %02x, isr1 = %02x, isr2 = %02x\n",
   1054 			     isr0, isr1, isr2));
   1055 
   1056 		/*
   1057 		 * check DMA interrupt
   1058 		 */
   1059 		if (isr1 & 0x0f)
   1060 			ret += sca_dmac_intr(&sc->sc_ports[0],
   1061 					     isr1 & 0x0f);
   1062 		if (isr1 & 0xf0)
   1063 			ret += sca_dmac_intr(&sc->sc_ports[1],
   1064 					     (isr1 & 0xf0) >> 4);
   1065 
   1066 		if (isr0)
   1067 			ret += sca_msci_intr(sc, isr0);
   1068 
   1069 #if 0 /* We don't GET timer interrupts, we have them disabled (msci IE20) */
   1070 		if (isr2)
   1071 			ret += sca_timer_intr(sc, isr2);
   1072 #endif
   1073 	}
   1074 
   1075 	return (ret);
   1076 }
   1077 
   1078 static int
   1079 sca_dmac_intr(sca_port_t *scp, u_int8_t isr)
   1080 {
   1081 	u_int8_t	 dsr;
   1082 	int		 ret;
   1083 
   1084 	ret = 0;
   1085 
   1086 	/*
   1087 	 * Check transmit channel
   1088 	 */
   1089 	if (isr & 0x0c) {
   1090 		SCA_DPRINTF(SCA_DEBUG_INTR,
   1091 			    ("TX INTERRUPT port %d\n", scp->sp_port));
   1092 
   1093 		dsr = 1;
   1094 		while (dsr != 0) {
   1095 			ret++;
   1096 			/*
   1097 			 * reset interrupt
   1098 			 */
   1099 			dsr = dmac_read_1(scp, SCA_DSR1);
   1100 			dmac_write_1(scp, SCA_DSR1,
   1101 				     dsr | SCA_DSR_DEWD);
   1102 
   1103 			/*
   1104 			 * filter out the bits we don't care about
   1105 			 */
   1106 			dsr &= ( SCA_DSR_COF | SCA_DSR_BOF | SCA_DSR_EOT);
   1107 			if (dsr == 0)
   1108 				break;
   1109 
   1110 			/*
   1111 			 * check for counter overflow
   1112 			 */
   1113 			if (dsr & SCA_DSR_COF) {
   1114 				printf("%s: TXDMA counter overflow\n",
   1115 				       scp->sp_if.if_xname);
   1116 
   1117 				scp->sp_if.if_flags &= ~IFF_OACTIVE;
   1118 				scp->txcur = 0;
   1119 				scp->txinuse = 0;
   1120 			}
   1121 
   1122 			/*
   1123 			 * check for buffer overflow
   1124 			 */
   1125 			if (dsr & SCA_DSR_BOF) {
   1126 				printf("%s: TXDMA buffer overflow, cda 0x%04x, eda 0x%04x, cpb 0x%02x\n",
   1127 				       scp->sp_if.if_xname,
   1128 				       dmac_read_2(scp, SCA_CDAL1),
   1129 				       dmac_read_2(scp, SCA_EDAL1),
   1130 				       dmac_read_1(scp, SCA_CPB1));
   1131 
   1132 				/*
   1133 				 * Yikes.  Arrange for a full
   1134 				 * transmitter restart.
   1135 				 */
   1136 				scp->sp_if.if_flags &= ~IFF_OACTIVE;
   1137 				scp->txcur = 0;
   1138 				scp->txinuse = 0;
   1139 			}
   1140 
   1141 			/*
   1142 			 * check for end of transfer, which is not
   1143 			 * an error. It means that all data queued
   1144 			 * was transmitted, and we mark ourself as
   1145 			 * not in use and stop the watchdog timer.
   1146 			 */
   1147 			if (dsr & SCA_DSR_EOT) {
   1148 				SCA_DPRINTF(SCA_DEBUG_TX,
   1149 					    ("Transmit completed.\n"));
   1150 
   1151 				scp->sp_if.if_flags &= ~IFF_OACTIVE;
   1152 				scp->txcur = 0;
   1153 				scp->txinuse = 0;
   1154 
   1155 				/*
   1156 				 * check for more packets
   1157 				 */
   1158 				sca_start(&scp->sp_if);
   1159 			}
   1160 		}
   1161 	}
   1162 	/*
   1163 	 * receive channel check
   1164 	 */
   1165 	if (isr & 0x03) {
   1166 		SCA_DPRINTF(SCA_DEBUG_INTR,
   1167 			    ("RX INTERRUPT port %d\n", mch));
   1168 
   1169 		dsr = 1;
   1170 		while (dsr != 0) {
   1171 			ret++;
   1172 
   1173 			dsr = dmac_read_1(scp, SCA_DSR0);
   1174 			dmac_write_1(scp, SCA_DSR0, dsr | SCA_DSR_DEWD);
   1175 
   1176 			/*
   1177 			 * filter out the bits we don't care about
   1178 			 */
   1179 			dsr &= (SCA_DSR_EOM | SCA_DSR_COF
   1180 				| SCA_DSR_BOF | SCA_DSR_EOT);
   1181 			if (dsr == 0)
   1182 				break;
   1183 
   1184 			/*
   1185 			 * End of frame
   1186 			 */
   1187 			if (dsr & SCA_DSR_EOM) {
   1188 				SCA_DPRINTF(SCA_DEBUG_RX, ("Got a frame!\n"));
   1189 
   1190 				sca_get_packets(scp);
   1191 			}
   1192 
   1193 			/*
   1194 			 * check for counter overflow
   1195 			 */
   1196 			if (dsr & SCA_DSR_COF) {
   1197 				printf("%s: RXDMA counter overflow\n",
   1198 				       scp->sp_if.if_xname);
   1199 
   1200 				sca_dmac_rxinit(scp);
   1201 			}
   1202 
   1203 			/*
   1204 			 * check for end of transfer, which means we
   1205 			 * ran out of descriptors to receive into.
   1206 			 * This means the line is much faster than
   1207 			 * we can handle.
   1208 			 */
   1209 			if (dsr & (SCA_DSR_BOF | SCA_DSR_EOT)) {
   1210 				printf("%s: RXDMA buffer overflow\n",
   1211 				       scp->sp_if.if_xname);
   1212 
   1213 				sca_dmac_rxinit(scp);
   1214 			}
   1215 		}
   1216 	}
   1217 
   1218 	return ret;
   1219 }
   1220 
   1221 static int
   1222 sca_msci_intr(struct sca_softc *sc, u_int8_t isr)
   1223 {
   1224 	printf("Got msci interrupt XXX\n");
   1225 
   1226 	return 0;
   1227 }
   1228 
   1229 static void
   1230 sca_get_packets(sca_port_t *scp)
   1231 {
   1232 	int		 descidx;
   1233 	sca_desc_t	*desc;
   1234 	u_int8_t	*buf;
   1235 
   1236 	bus_dmamap_sync(scp->sca->sc_dmat, scp->sca->sc_dmam,
   1237 			0, scp->sca->sc_allocsize,
   1238 			BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
   1239 
   1240 	/*
   1241 	 * Loop while there are packets to receive.  After each is processed,
   1242 	 * call sca_frame_skip() to update the DMA registers to the new
   1243 	 * state.
   1244 	 */
   1245 	while (sca_frame_avail(scp, &descidx)) {
   1246 		desc = &scp->rxdesc[descidx];
   1247 		buf = scp->rxbuf + SCA_BSIZE * descidx;
   1248 
   1249 		sca_frame_process(scp, desc, buf);
   1250 #if SCA_DEBUG_LEVEL > 0
   1251 		if (sca_debug & SCA_DEBUG_RXPKT)
   1252 			sca_frame_print(scp, desc, buf);
   1253 #endif
   1254 		sca_frame_skip(scp, descidx);
   1255 	}
   1256 
   1257 	bus_dmamap_sync(scp->sca->sc_dmat, scp->sca->sc_dmam,
   1258 			0, scp->sca->sc_allocsize,
   1259 			BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
   1260 }
   1261 
   1262 /*
   1263  * Starting with the first descriptor we wanted to read into, up to but
   1264  * not including the current SCA read descriptor, look for a packet.
   1265  */
   1266 static int
   1267 sca_frame_avail(sca_port_t *scp, int *descindx)
   1268 {
   1269 	u_int16_t	 cda;
   1270 	int		 cdaidx;
   1271 	u_int32_t	 desc_p;	/* physical address (lower 16 bits) */
   1272 	sca_desc_t	*desc;
   1273 	u_int8_t	 rxstat;
   1274 
   1275 	/*
   1276 	 * Read the current descriptor from the SCA.
   1277 	 */
   1278 	cda = dmac_read_2(scp, SCA_CDAL0);
   1279 
   1280 	/*
   1281 	 * calculate the index of the current descriptor
   1282 	 */
   1283 	desc_p = cda - (u_int16_t)(scp->rxdesc_p & 0x0000ffff);
   1284 	cdaidx = desc_p / sizeof(sca_desc_t);
   1285 
   1286 	if (cdaidx >= SCA_NrxBUFS)
   1287 		return 0;
   1288 
   1289 	for (;;) {
   1290 		/*
   1291 		 * if the SCA is reading into the first descriptor, we somehow
   1292 		 * got this interrupt incorrectly.  Just return that there are
   1293 		 * no packets ready.
   1294 		 */
   1295 		if (cdaidx == scp->rxstart)
   1296 			return 0;
   1297 
   1298 		/*
   1299 		 * We might have a valid descriptor.  Set up a pointer
   1300 		 * to the kva address for it so we can more easily examine
   1301 		 * the contents.
   1302 		 */
   1303 		desc = &scp->rxdesc[scp->rxstart];
   1304 
   1305 		rxstat = desc->stat;
   1306 
   1307 		/*
   1308 		 * check for errors
   1309 		 */
   1310 		if (rxstat & SCA_DESC_ERRORS)
   1311 			goto nextpkt;
   1312 
   1313 		/*
   1314 		 * full packet?  Good.
   1315 		 */
   1316 		if (rxstat & SCA_DESC_EOM) {
   1317 			*descindx = scp->rxstart;
   1318 			return 1;
   1319 		}
   1320 
   1321 		/*
   1322 		 * increment the rxstart address, since this frame is
   1323 		 * somehow damaged.  Skip over it in later calls.
   1324 		 * XXX This breaks multidescriptor receives, so each
   1325 		 * frame HAS to fit within one descriptor's buffer
   1326 		 * space now...
   1327 		 */
   1328 	nextpkt:
   1329 		scp->rxstart++;
   1330 		if (scp->rxstart == SCA_NrxBUFS)
   1331 			scp->rxstart = 0;
   1332 	}
   1333 
   1334 	return 0;
   1335 }
   1336 
   1337 /*
   1338  * Pass the packet up to the kernel if it is a packet we want to pay
   1339  * attention to.
   1340  *
   1341  * MUST BE CALLED AT splnet()
   1342  */
   1343 static void
   1344 sca_frame_process(sca_port_t *scp, sca_desc_t *desc, u_int8_t *p)
   1345 {
   1346 	hdlc_header_t	*hdlc;
   1347 	cisco_pkt_t	*cisco, *ncisco;
   1348 	u_int16_t	 len;
   1349 	struct mbuf	*m;
   1350 	u_int8_t	*nbuf;
   1351 	u_int32_t	 t = (time.tv_sec - boottime.tv_sec) * 1000;
   1352 	struct ifqueue *ifq;
   1353 
   1354 	len = desc->len;
   1355 
   1356 	/*
   1357 	 * skip packets that are too short
   1358 	 */
   1359 	if (len < sizeof(hdlc_header_t))
   1360 		return;
   1361 
   1362 #if NBPFILTER > 0
   1363 	if (scp->sp_bpf)
   1364 		bpf_tap(scp->sp_bpf, p, len);
   1365 #endif
   1366 
   1367 	/*
   1368 	 * read and then strip off the HDLC information
   1369 	 */
   1370 	hdlc = (hdlc_header_t *)p;
   1371 
   1372 	scp->sp_if.if_ipackets++;
   1373 	scp->sp_if.if_lastchange = time;
   1374 
   1375 	switch (ntohs(hdlc->protocol)) {
   1376 	case HDLC_PROTOCOL_IP:
   1377 		SCA_DPRINTF(SCA_DEBUG_RX, ("Received IP packet\n"));
   1378 
   1379 		m = sca_mbuf_alloc(p, len);
   1380 		if (m == NULL) {
   1381 			scp->sp_if.if_iqdrops++;
   1382 			return;
   1383 		}
   1384 		m->m_pkthdr.rcvif = &scp->sp_if;
   1385 
   1386 		if (IF_QFULL(&ipintrq)) {
   1387 			IF_DROP(&ipintrq);
   1388 			scp->sp_if.if_ierrors++;
   1389 			scp->sp_if.if_iqdrops++;
   1390 			m_freem(m);
   1391 		} else {
   1392 			/*
   1393 			 * strip off the HDLC header and hand off to IP stack
   1394 			 */
   1395 			m->m_pkthdr.len -= HDLC_HDRLEN;
   1396 			m->m_data += HDLC_HDRLEN;
   1397 			m->m_len -= HDLC_HDRLEN;
   1398 			IF_ENQUEUE(&ipintrq, m);
   1399 			schednetisr(NETISR_IP);
   1400 		}
   1401 
   1402 		break;
   1403 
   1404 	case CISCO_KEEPALIVE:
   1405 		SCA_DPRINTF(SCA_DEBUG_CISCO,
   1406 			    ("Received CISCO keepalive packet\n"));
   1407 
   1408 		if (len < CISCO_PKT_LEN) {
   1409 			SCA_DPRINTF(SCA_DEBUG_CISCO,
   1410 				    ("short CISCO packet %d, wanted %d\n",
   1411 				     len, CISCO_PKT_LEN));
   1412 			return;
   1413 		}
   1414 
   1415 		/*
   1416 		 * allocate an mbuf and copy the important bits of data
   1417 		 * into it.
   1418 		 */
   1419 		m = sca_mbuf_alloc(p, HDLC_HDRLEN + CISCO_PKT_LEN);
   1420 		if (m == NULL)
   1421 			return;
   1422 
   1423 		nbuf = mtod(m, u_int8_t *);
   1424 		ncisco = (cisco_pkt_t *)(nbuf + HDLC_HDRLEN);
   1425 		m->m_pkthdr.rcvif = &scp->sp_if;
   1426 
   1427 		cisco = (cisco_pkt_t *)(p + HDLC_HDRLEN);
   1428 
   1429 		switch (ntohl(cisco->type)) {
   1430 		case CISCO_ADDR_REQ:
   1431 			printf("Got CISCO addr_req, ignoring\n");
   1432 			m_freem(m);
   1433 			break;
   1434 
   1435 		case CISCO_ADDR_REPLY:
   1436 			printf("Got CISCO addr_reply, ignoring\n");
   1437 			m_freem(m);
   1438 			break;
   1439 
   1440 		case CISCO_KEEPALIVE_REQ:
   1441 			SCA_DPRINTF(SCA_DEBUG_CISCO,
   1442 				    ("Received KA, mseq %d,"
   1443 				     " yseq %d, rel 0x%04x, t0"
   1444 				     " %04x, t1 %04x\n",
   1445 				     ntohl(cisco->par1), ntohl(cisco->par2),
   1446 				     ntohs(cisco->rel), ntohs(cisco->time0),
   1447 				     ntohs(cisco->time1)));
   1448 
   1449 			scp->cka_lastrx = ntohl(cisco->par1);
   1450 			scp->cka_lasttx++;
   1451 
   1452 			/*
   1453 			 * schedule the transmit right here.
   1454 			 */
   1455 			ncisco->par2 = cisco->par1;
   1456 			ncisco->par1 = htonl(scp->cka_lasttx);
   1457 			ncisco->time0 = htons((u_int16_t)(t >> 16));
   1458 			ncisco->time1 = htons((u_int16_t)(t & 0x0000ffff));
   1459 
   1460 			ifq = &scp->linkq;
   1461 			if (IF_QFULL(ifq)) {
   1462 				IF_DROP(ifq);
   1463 				m_freem(m);
   1464 				return;
   1465 			}
   1466 			IF_ENQUEUE(ifq, m);
   1467 
   1468 			sca_start(&scp->sp_if);
   1469 
   1470 			break;
   1471 
   1472 		default:
   1473 			m_freem(m);
   1474 			SCA_DPRINTF(SCA_DEBUG_CISCO,
   1475 				    ("Unknown CISCO keepalive protocol 0x%04x\n",
   1476 				     ntohl(cisco->type)));
   1477 			return;
   1478 		}
   1479 
   1480 		break;
   1481 
   1482 	default:
   1483 		SCA_DPRINTF(SCA_DEBUG_RX,
   1484 			    ("Unknown/unexpected ethertype 0x%04x\n",
   1485 			     ntohs(hdlc->protocol)));
   1486 	}
   1487 }
   1488 
   1489 #if SCA_DEBUG_LEVEL > 0
   1490 /*
   1491  * do a hex dump of the packet received into descriptor "desc" with
   1492  * data buffer "p"
   1493  */
   1494 static void
   1495 sca_frame_print(sca_port_t *scp, sca_desc_t *desc, u_int8_t *p)
   1496 {
   1497 	int i;
   1498 	int nothing_yet = 1;
   1499 
   1500 	printf("descriptor va %p: cp 0x%x bpb 0x%0x bp 0x%0x stat 0x%0x len %d\n",
   1501 	       desc, desc->cp, desc->bpb, desc->bp, desc->stat, desc->len);
   1502 
   1503 	for (i = 0 ; i < desc->len ; i++) {
   1504 		if (nothing_yet == 1 && *p == 0) {
   1505 			p++;
   1506 			continue;
   1507 		}
   1508 		nothing_yet = 0;
   1509 		if (i % 16 == 0)
   1510 			printf("\n");
   1511 		printf("%02x ", *p++);
   1512 	}
   1513 
   1514 	if (i % 16 != 1)
   1515 		printf("\n");
   1516 }
   1517 #endif
   1518 
   1519 /*
   1520  * skip all frames before the descriptor index "indx" -- we do this by
   1521  * moving the rxstart pointer to the index following this one, and
   1522  * setting the end descriptor to this index.
   1523  */
   1524 static void
   1525 sca_frame_skip(sca_port_t *scp, int indx)
   1526 {
   1527 	u_int32_t	desc_p;
   1528 
   1529 	scp->rxstart++;
   1530 	if (scp->rxstart == SCA_NrxBUFS)
   1531 		scp->rxstart = 0;
   1532 
   1533 	desc_p = scp->rxdesc_p * sizeof(sca_desc_t) * indx;
   1534 	dmac_write_2(scp, SCA_EDAL0,
   1535 		     (u_int16_t)(desc_p & 0x0000ffff));
   1536 }
   1537 
   1538 /*
   1539  * set a port to the "up" state
   1540  */
   1541 static void
   1542 sca_port_up(sca_port_t *scp)
   1543 {
   1544 	struct sca_softc *sc = scp->sca;
   1545 
   1546 	/*
   1547 	 * reset things
   1548 	 */
   1549 #if 0
   1550 	msci_write_1(scp, SCA_CMD0, SCA_CMD_TXRESET);
   1551 	msci_write_1(scp, SCA_CMD0, SCA_CMD_RXRESET);
   1552 #endif
   1553 	/*
   1554 	 * clear in-use flag
   1555 	 */
   1556 	scp->sp_if.if_flags &= ~IFF_OACTIVE;
   1557 
   1558 	/*
   1559 	 * raise DTR
   1560 	 */
   1561 	sc->dtr_callback(sc->dtr_aux, scp->sp_port, 1);
   1562 
   1563 	/*
   1564 	 * raise RTS
   1565 	 */
   1566 	msci_write_1(scp, SCA_CTL0,
   1567 		     msci_read_1(scp, SCA_CTL0) & ~SCA_CTL_RTS);
   1568 
   1569 	/*
   1570 	 * enable interrupts
   1571 	 */
   1572 	if (scp->sp_port == 0) {
   1573 		sca_write_1(sc, SCA_IER0, sca_read_1(sc, SCA_IER0) | 0x0f);
   1574 		sca_write_1(sc, SCA_IER1, sca_read_1(sc, SCA_IER1) | 0x0f);
   1575 	} else {
   1576 		sca_write_1(sc, SCA_IER0, sca_read_1(sc, SCA_IER0) | 0xf0);
   1577 		sca_write_1(sc, SCA_IER1, sca_read_1(sc, SCA_IER1) | 0xf0);
   1578 	}
   1579 
   1580 	/*
   1581 	 * enable transmit and receive
   1582 	 */
   1583 	msci_write_1(scp, SCA_CMD0, SCA_CMD_TXENABLE);
   1584 	msci_write_1(scp, SCA_CMD0, SCA_CMD_RXENABLE);
   1585 
   1586 	/*
   1587 	 * reset internal state
   1588 	 */
   1589 	scp->txinuse = 0;
   1590 	scp->txcur = 0;
   1591 	scp->cka_lasttx = time.tv_usec;
   1592 	scp->cka_lastrx = 0;
   1593 }
   1594 
   1595 /*
   1596  * set a port to the "down" state
   1597  */
   1598 static void
   1599 sca_port_down(sca_port_t *scp)
   1600 {
   1601 	struct sca_softc *sc = scp->sca;
   1602 
   1603 	/*
   1604 	 * lower DTR
   1605 	 */
   1606 	sc->dtr_callback(sc->dtr_aux, scp->sp_port, 0);
   1607 
   1608 	/*
   1609 	 * lower RTS
   1610 	 */
   1611 	msci_write_1(scp, SCA_CTL0,
   1612 		     msci_read_1(scp, SCA_CTL0) | SCA_CTL_RTS);
   1613 
   1614 	/*
   1615 	 * disable interrupts
   1616 	 */
   1617 	if (scp->sp_port == 0) {
   1618 		sca_write_1(sc, SCA_IER0, sca_read_1(sc, SCA_IER0) & 0xf0);
   1619 		sca_write_1(sc, SCA_IER1, sca_read_1(sc, SCA_IER1) & 0xf0);
   1620 	} else {
   1621 		sca_write_1(sc, SCA_IER0, sca_read_1(sc, SCA_IER0) & 0x0f);
   1622 		sca_write_1(sc, SCA_IER1, sca_read_1(sc, SCA_IER1) & 0x0f);
   1623 	}
   1624 
   1625 	/*
   1626 	 * disable transmit and receive
   1627 	 */
   1628 	msci_write_1(scp, SCA_CMD0, SCA_CMD_RXDISABLE);
   1629 	msci_write_1(scp, SCA_CMD0, SCA_CMD_TXDISABLE);
   1630 
   1631 	/*
   1632 	 * no, we're not in use anymore
   1633 	 */
   1634 	scp->sp_if.if_flags &= ~IFF_OACTIVE;
   1635 }
   1636 
   1637 /*
   1638  * disable all DMA and interrupts for all ports at once.
   1639  */
   1640 void
   1641 sca_shutdown(struct sca_softc *sca)
   1642 {
   1643 	/*
   1644 	 * disable DMA and interrupts
   1645 	 */
   1646 	sca_write_1(sca, SCA_DMER, 0);
   1647 	sca_write_1(sca, SCA_IER0, 0);
   1648 	sca_write_1(sca, SCA_IER1, 0);
   1649 }
   1650 
   1651 /*
   1652  * If there are packets to transmit, start the transmit DMA logic.
   1653  */
   1654 static void
   1655 sca_port_starttx(sca_port_t *scp)
   1656 {
   1657 	struct sca_softc *sc;
   1658 	u_int32_t	startdesc_p, enddesc_p;
   1659 	int enddesc;
   1660 
   1661 	sc = scp->sca;
   1662 
   1663 	if (((scp->sp_if.if_flags & IFF_OACTIVE) == IFF_OACTIVE)
   1664 	    || scp->txinuse == 0)
   1665 		return;
   1666 	scp->sp_if.if_flags |= IFF_OACTIVE;
   1667 
   1668 	/*
   1669 	 * We have something to do, since we have at least one packet
   1670 	 * waiting, and we are not already marked as active.
   1671 	 */
   1672 	enddesc = scp->txcur;
   1673 	enddesc++;
   1674 	if (enddesc == SCA_NtxBUFS)
   1675 		enddesc = 0;
   1676 
   1677 	startdesc_p = scp->txdesc_p;
   1678 	enddesc_p = scp->txdesc_p + sizeof(sca_desc_t) * enddesc;
   1679 
   1680 	dmac_write_2(scp, SCA_EDAL1, (u_int16_t)(enddesc_p & 0x0000ffff));
   1681 	dmac_write_2(scp, SCA_CDAL1,
   1682 		     (u_int16_t)(startdesc_p & 0x0000ffff));
   1683 
   1684 	/*
   1685 	 * enable the DMA
   1686 	 */
   1687 	dmac_write_1(scp, SCA_DSR1, SCA_DSR_DE);
   1688 }
   1689 
   1690 /*
   1691  * allocate an mbuf at least long enough to hold "len" bytes.
   1692  * If "p" is non-NULL, copy "len" bytes from it into the new mbuf,
   1693  * otherwise let the caller handle copying the data in.
   1694  */
   1695 static struct mbuf *
   1696 sca_mbuf_alloc(caddr_t p, u_int len)
   1697 {
   1698 	struct mbuf *m;
   1699 
   1700 	/*
   1701 	 * allocate an mbuf and copy the important bits of data
   1702 	 * into it.  If the packet won't fit in the header,
   1703 	 * allocate a cluster for it and store it there.
   1704 	 */
   1705 	MGETHDR(m, M_DONTWAIT, MT_DATA);
   1706 	if (m == NULL)
   1707 		return NULL;
   1708 	if (len > MHLEN) {
   1709 		if (len > MCLBYTES) {
   1710 			m_freem(m);
   1711 			return NULL;
   1712 		}
   1713 		MCLGET(m, M_DONTWAIT);
   1714 		if ((m->m_flags & M_EXT) == 0) {
   1715 			m_freem(m);
   1716 			return NULL;
   1717 		}
   1718 	}
   1719 	if (p != NULL)
   1720 		bcopy(p, mtod(m, caddr_t), len);
   1721 	m->m_len = len;
   1722 	m->m_pkthdr.len = len;
   1723 
   1724 	return (m);
   1725 }
   1726