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esp.c revision 1.34
      1 /*	$NetBSD: esp.c,v 1.34 2002/10/02 05:36:38 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997 Jason R. Thorpe.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed for the NetBSD Project
     18  *	by Jason R. Thorpe.
     19  * 4. The name of the author may not be used to endorse or promote products
     20  *    derived from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 /*
     35  * Copyright (c) 1994 Peter Galbavy
     36  * All rights reserved.
     37  *
     38  * Redistribution and use in source and binary forms, with or without
     39  * modification, are permitted provided that the following conditions
     40  * are met:
     41  * 1. Redistributions of source code must retain the above copyright
     42  *    notice, this list of conditions and the following disclaimer.
     43  * 2. Redistributions in binary form must reproduce the above copyright
     44  *    notice, this list of conditions and the following disclaimer in the
     45  *    documentation and/or other materials provided with the distribution.
     46  * 3. All advertising materials mentioning features or use of this software
     47  *    must display the following acknowledgement:
     48  *	This product includes software developed by Peter Galbavy
     49  * 4. The name of the author may not be used to endorse or promote products
     50  *    derived from this software without specific prior written permission.
     51  *
     52  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     53  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     54  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     55  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
     56  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     57  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     58  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     60  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
     61  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     62  * POSSIBILITY OF SUCH DAMAGE.
     63  */
     64 
     65 /*
     66  * Based on aic6360 by Jarle Greipsland
     67  *
     68  * Acknowledgements: Many of the algorithms used in this driver are
     69  * inspired by the work of Julian Elischer (julian (at) tfs.com) and
     70  * Charles Hannum (mycroft (at) duality.gnu.ai.mit.edu).  Thanks a million!
     71  */
     72 
     73 /*
     74  * Initial m68k mac support from Allen Briggs <briggs (at) macbsd.com>
     75  * (basically consisting of the match, a bit of the attach, and the
     76  *  "DMA" glue functions).
     77  */
     78 
     79 #include <sys/types.h>
     80 #include <sys/param.h>
     81 #include <sys/systm.h>
     82 #include <sys/kernel.h>
     83 #include <sys/errno.h>
     84 #include <sys/ioctl.h>
     85 #include <sys/device.h>
     86 #include <sys/buf.h>
     87 #include <sys/proc.h>
     88 #include <sys/user.h>
     89 #include <sys/queue.h>
     90 
     91 #include <dev/scsipi/scsi_all.h>
     92 #include <dev/scsipi/scsipi_all.h>
     93 #include <dev/scsipi/scsiconf.h>
     94 #include <dev/scsipi/scsi_message.h>
     95 
     96 #include <machine/cpu.h>
     97 #include <machine/bus.h>
     98 #include <machine/param.h>
     99 
    100 #include <dev/ic/ncr53c9xreg.h>
    101 #include <dev/ic/ncr53c9xvar.h>
    102 
    103 #include <machine/viareg.h>
    104 
    105 #include <mac68k/obio/espvar.h>
    106 #include <mac68k/obio/obiovar.h>
    107 
    108 void	espattach	__P((struct device *, struct device *, void *));
    109 int	espmatch	__P((struct device *, struct cfdata *, void *));
    110 
    111 /* Linkup to the rest of the kernel */
    112 CFATTACH_DECL(esp, sizeof(struct esp_softc),
    113     espmatch, espattach, NULL, NULL);
    114 
    115 /*
    116  * Functions and the switch for the MI code.
    117  */
    118 u_char	esp_read_reg __P((struct ncr53c9x_softc *, int));
    119 void	esp_write_reg __P((struct ncr53c9x_softc *, int, u_char));
    120 int	esp_dma_isintr __P((struct ncr53c9x_softc *));
    121 void	esp_dma_reset __P((struct ncr53c9x_softc *));
    122 int	esp_dma_intr __P((struct ncr53c9x_softc *));
    123 int	esp_dma_setup __P((struct ncr53c9x_softc *, caddr_t *,
    124 	    size_t *, int, size_t *));
    125 void	esp_dma_go __P((struct ncr53c9x_softc *));
    126 void	esp_dma_stop __P((struct ncr53c9x_softc *));
    127 int	esp_dma_isactive __P((struct ncr53c9x_softc *));
    128 void	esp_quick_write_reg __P((struct ncr53c9x_softc *, int, u_char));
    129 int	esp_quick_dma_intr __P((struct ncr53c9x_softc *));
    130 int	esp_quick_dma_setup __P((struct ncr53c9x_softc *, caddr_t *,
    131 	    size_t *, int, size_t *));
    132 void	esp_quick_dma_go __P((struct ncr53c9x_softc *));
    133 
    134 void	esp_intr __P((void *sc));
    135 void	esp_dualbus_intr __P((void *sc));
    136 static struct esp_softc		*esp0 = NULL, *esp1 = NULL;
    137 
    138 static __inline__ int esp_dafb_have_dreq __P((struct esp_softc *esc));
    139 static __inline__ int esp_iosb_have_dreq __P((struct esp_softc *esc));
    140 int (*esp_have_dreq) __P((struct esp_softc *esc));
    141 
    142 struct ncr53c9x_glue esp_glue = {
    143 	esp_read_reg,
    144 	esp_write_reg,
    145 	esp_dma_isintr,
    146 	esp_dma_reset,
    147 	esp_dma_intr,
    148 	esp_dma_setup,
    149 	esp_dma_go,
    150 	esp_dma_stop,
    151 	esp_dma_isactive,
    152 	NULL,			/* gl_clear_latched_intr */
    153 };
    154 
    155 int
    156 espmatch(parent, cf, aux)
    157 	struct device *parent;
    158 	struct cfdata *cf;
    159 	void *aux;
    160 {
    161 	int	found = 0;
    162 
    163 	if ((cf->cf_unit == 0) && mac68k_machine.scsi96) {
    164 		found = 1;
    165 	}
    166 	if ((cf->cf_unit == 1) && mac68k_machine.scsi96_2) {
    167 		found = 1;
    168 	}
    169 
    170 	return found;
    171 }
    172 
    173 /*
    174  * Attach this instance, and then all the sub-devices
    175  */
    176 void
    177 espattach(parent, self, aux)
    178 	struct device *parent, *self;
    179 	void *aux;
    180 {
    181 	struct obio_attach_args *oa = (struct obio_attach_args *)aux;
    182 	extern vaddr_t		SCSIBase;
    183 	struct esp_softc	*esc = (void *)self;
    184 	struct ncr53c9x_softc	*sc = &esc->sc_ncr53c9x;
    185 	int			quick = 0;
    186 	unsigned long		reg_offset;
    187 
    188 	reg_offset = SCSIBase - IOBase;
    189 	esc->sc_tag = oa->oa_tag;
    190 	/*
    191 	 * For Wombat, Primus and Optimus motherboards, DREQ is
    192 	 * visible on bit 0 of the IOSB's emulated VIA2 vIFR (and
    193 	 * the scsi registers are offset 0x1000 bytes from IOBase).
    194 	 *
    195 	 * For the Q700/900/950 it's at f9800024 for bus 0 and
    196 	 * f9800028 for bus 1 (900/950).  For these machines, that is also
    197 	 * a (12-bit) configuration register for DAFB's control of the
    198 	 * pseudo-DMA timing.  The default value is 0x1d1.
    199 	 */
    200 	esp_have_dreq = esp_dafb_have_dreq;
    201 	if (sc->sc_dev.dv_unit == 0) {
    202 		if (reg_offset == 0x10000) {
    203 			quick = 1;
    204 			esp_have_dreq = esp_iosb_have_dreq;
    205 		} else if (reg_offset == 0x18000) {
    206 			quick = 0;
    207 		} else {
    208 			if (bus_space_map(esc->sc_tag, 0xf9800024,
    209 					  4, 0, &esc->sc_bsh)) {
    210 				printf("failed to map 4 at 0xf9800024.\n");
    211 			} else {
    212 				quick = 1;
    213 				bus_space_write_4(esc->sc_tag,
    214 						  esc->sc_bsh, 0, 0x1d1);
    215 			}
    216 		}
    217 	} else {
    218 		if (bus_space_map(esc->sc_tag, 0xf9800028,
    219 				  4, 0, &esc->sc_bsh)) {
    220 			printf("failed to map 4 at 0xf9800028.\n");
    221 		} else {
    222 			quick = 1;
    223 			bus_space_write_4(esc->sc_tag, esc->sc_bsh, 0, 0x1d1);
    224 		}
    225 	}
    226 	if (quick) {
    227 		esp_glue.gl_write_reg = esp_quick_write_reg;
    228 		esp_glue.gl_dma_intr = esp_quick_dma_intr;
    229 		esp_glue.gl_dma_setup = esp_quick_dma_setup;
    230 		esp_glue.gl_dma_go = esp_quick_dma_go;
    231 	}
    232 
    233 	/*
    234 	 * Set up the glue for MI code early; we use some of it here.
    235 	 */
    236 	sc->sc_glue = &esp_glue;
    237 
    238 	/*
    239 	 * Save the regs
    240 	 */
    241 	if (sc->sc_dev.dv_unit == 0) {
    242 		esp0 = esc;
    243 
    244 		esc->sc_reg = (volatile u_char *) SCSIBase;
    245 		via2_register_irq(VIA2_SCSIIRQ, esp_intr, esc);
    246 		esc->irq_mask = V2IF_SCSIIRQ;
    247 		if (reg_offset == 0x10000) {
    248 			/* From the Q650 developer's note */
    249 			sc->sc_freq = 16500000;
    250 		} else {
    251 			sc->sc_freq = 25000000;
    252 		}
    253 
    254 		if (esp_glue.gl_dma_go == esp_quick_dma_go) {
    255 			printf(" (quick)");
    256 		}
    257 	} else {
    258 		esp1 = esc;
    259 
    260 		esc->sc_reg = (volatile u_char *) SCSIBase + 0x402;
    261 		via2_register_irq(VIA2_SCSIIRQ, esp_dualbus_intr, NULL);
    262 		esc->irq_mask = 0;
    263 		sc->sc_freq = 25000000;
    264 
    265 		if (esp_glue.gl_dma_go == esp_quick_dma_go) {
    266 			printf(" (quick)");
    267 		}
    268 	}
    269 
    270 	printf(": address %p", esc->sc_reg);
    271 
    272 	sc->sc_id = 7;
    273 
    274 	/* gimme Mhz */
    275 	sc->sc_freq /= 1000000;
    276 
    277 	/*
    278 	 * It is necessary to try to load the 2nd config register here,
    279 	 * to find out what rev the esp chip is, else the esp_reset
    280 	 * will not set up the defaults correctly.
    281 	 */
    282 	sc->sc_cfg1 = sc->sc_id; /* | NCRCFG1_PARENB; */
    283 	sc->sc_cfg2 = NCRCFG2_SCSI2;
    284 	sc->sc_cfg3 = 0;
    285 	sc->sc_rev = NCR_VARIANT_NCR53C96;
    286 
    287 	/*
    288 	 * This is the value used to start sync negotiations
    289 	 * Note that the NCR register "SYNCTP" is programmed
    290 	 * in "clocks per byte", and has a minimum value of 4.
    291 	 * The SCSI period used in negotiation is one-fourth
    292 	 * of the time (in nanoseconds) needed to transfer one byte.
    293 	 * Since the chip's clock is given in MHz, we have the following
    294 	 * formula: 4 * period = (1000 / freq) * 4
    295 	 */
    296 	sc->sc_minsync = 1000 / sc->sc_freq;
    297 
    298 	/* We need this to fit into the TCR... */
    299 	sc->sc_maxxfer = 64 * 1024;
    300 
    301 	if (!quick) {
    302 		sc->sc_minsync = 0;	/* No synchronous xfers w/o DMA */
    303 		sc->sc_maxxfer = 8 * 1024;
    304 	}
    305 
    306 	/*
    307 	 * Configure interrupts.
    308 	 */
    309 	if (esc->irq_mask) {
    310 		via2_reg(vPCR) = 0x22;
    311 		via2_reg(vIFR) = esc->irq_mask;
    312 		via2_reg(vIER) = 0x80 | esc->irq_mask;
    313 	}
    314 
    315 	/*
    316 	 * Now try to attach all the sub-devices
    317 	 */
    318 	sc->sc_adapter.adapt_minphys = minphys;
    319 	sc->sc_adapter.adapt_request = ncr53c9x_scsipi_request;
    320 	ncr53c9x_attach(sc);
    321 }
    322 
    323 /*
    324  * Glue functions.
    325  */
    326 
    327 u_char
    328 esp_read_reg(sc, reg)
    329 	struct ncr53c9x_softc *sc;
    330 	int reg;
    331 {
    332 	struct esp_softc *esc = (struct esp_softc *)sc;
    333 
    334 	return esc->sc_reg[reg * 16];
    335 }
    336 
    337 void
    338 esp_write_reg(sc, reg, val)
    339 	struct ncr53c9x_softc *sc;
    340 	int reg;
    341 	u_char val;
    342 {
    343 	struct esp_softc *esc = (struct esp_softc *)sc;
    344 	u_char	v = val;
    345 
    346 	if (reg == NCR_CMD && v == (NCRCMD_TRANS|NCRCMD_DMA)) {
    347 		v = NCRCMD_TRANS;
    348 	}
    349 	esc->sc_reg[reg * 16] = v;
    350 }
    351 
    352 void
    353 esp_dma_stop(sc)
    354 	struct ncr53c9x_softc *sc;
    355 {
    356 }
    357 
    358 int
    359 esp_dma_isactive(sc)
    360 	struct ncr53c9x_softc *sc;
    361 {
    362 	struct esp_softc *esc = (struct esp_softc *)sc;
    363 
    364 	return esc->sc_active;
    365 }
    366 
    367 int
    368 esp_dma_isintr(sc)
    369 	struct ncr53c9x_softc *sc;
    370 {
    371 	struct esp_softc *esc = (struct esp_softc *)sc;
    372 
    373 	return esc->sc_reg[NCR_STAT * 16] & 0x80;
    374 }
    375 
    376 void
    377 esp_dma_reset(sc)
    378 	struct ncr53c9x_softc *sc;
    379 {
    380 	struct esp_softc *esc = (struct esp_softc *)sc;
    381 
    382 	esc->sc_active = 0;
    383 	esc->sc_tc = 0;
    384 }
    385 
    386 int
    387 esp_dma_intr(sc)
    388 	struct ncr53c9x_softc *sc;
    389 {
    390 	struct esp_softc *esc = (struct esp_softc *)sc;
    391 	volatile u_char *cmdreg, *intrreg, *statreg, *fiforeg;
    392 	u_char	*p;
    393 	u_int	espphase, espstat, espintr;
    394 	int	cnt, s;
    395 
    396 	if (esc->sc_active == 0) {
    397 		printf("dma_intr--inactive DMA\n");
    398 		return -1;
    399 	}
    400 
    401 	if ((sc->sc_espintr & NCRINTR_BS) == 0) {
    402 		esc->sc_active = 0;
    403 		return 0;
    404 	}
    405 
    406 	cnt = *esc->sc_dmalen;
    407 	if (*esc->sc_dmalen == 0) {
    408 		printf("data interrupt, but no count left.");
    409 	}
    410 
    411 	p = *esc->sc_dmaaddr;
    412 	espphase = sc->sc_phase;
    413 	espstat = (u_int) sc->sc_espstat;
    414 	espintr = (u_int) sc->sc_espintr;
    415 	cmdreg = esc->sc_reg + NCR_CMD * 16;
    416 	fiforeg = esc->sc_reg + NCR_FIFO * 16;
    417 	statreg = esc->sc_reg + NCR_STAT * 16;
    418 	intrreg = esc->sc_reg + NCR_INTR * 16;
    419 	do {
    420 		if (esc->sc_datain) {
    421 			*p++ = *fiforeg;
    422 			cnt--;
    423 			if (espphase == DATA_IN_PHASE) {
    424 				*cmdreg = NCRCMD_TRANS;
    425 			} else {
    426 				esc->sc_active = 0;
    427 			}
    428 	 	} else {
    429 			if (   (espphase == DATA_OUT_PHASE)
    430 			    || (espphase == MESSAGE_OUT_PHASE)) {
    431 				*fiforeg = *p++;
    432 				cnt--;
    433 				*cmdreg = NCRCMD_TRANS;
    434 			} else {
    435 				esc->sc_active = 0;
    436 			}
    437 		}
    438 
    439 		if (esc->sc_active) {
    440 			while (!(*statreg & 0x80));
    441 			s = splhigh();
    442 			espstat = *statreg;
    443 			espintr = *intrreg;
    444 			espphase = (espintr & NCRINTR_DIS)
    445 				    ? /* Disconnected */ BUSFREE_PHASE
    446 				    : espstat & PHASE_MASK;
    447 			splx(s);
    448 		}
    449 	} while (esc->sc_active && (espintr & NCRINTR_BS));
    450 	sc->sc_phase = espphase;
    451 	sc->sc_espstat = (u_char) espstat;
    452 	sc->sc_espintr = (u_char) espintr;
    453 	*esc->sc_dmaaddr = p;
    454 	*esc->sc_dmalen = cnt;
    455 
    456 	if (*esc->sc_dmalen == 0) {
    457 		esc->sc_tc = NCRSTAT_TC;
    458 	}
    459 	sc->sc_espstat |= esc->sc_tc;
    460 	return 0;
    461 }
    462 
    463 int
    464 esp_dma_setup(sc, addr, len, datain, dmasize)
    465 	struct ncr53c9x_softc *sc;
    466 	caddr_t *addr;
    467 	size_t *len;
    468 	int datain;
    469 	size_t *dmasize;
    470 {
    471 	struct esp_softc *esc = (struct esp_softc *)sc;
    472 
    473 	esc->sc_dmaaddr = addr;
    474 	esc->sc_dmalen = len;
    475 	esc->sc_datain = datain;
    476 	esc->sc_dmasize = *dmasize;
    477 	esc->sc_tc = 0;
    478 
    479 	return 0;
    480 }
    481 
    482 void
    483 esp_dma_go(sc)
    484 	struct ncr53c9x_softc *sc;
    485 {
    486 	struct esp_softc *esc = (struct esp_softc *)sc;
    487 
    488 	if (esc->sc_datain == 0) {
    489 		esc->sc_reg[NCR_FIFO * 16] = **esc->sc_dmaaddr;
    490 		(*esc->sc_dmalen)--;
    491 		(*esc->sc_dmaaddr)++;
    492 	}
    493 	esc->sc_active = 1;
    494 }
    495 
    496 void
    497 esp_quick_write_reg(sc, reg, val)
    498 	struct ncr53c9x_softc *sc;
    499 	int reg;
    500 	u_char val;
    501 {
    502 	struct esp_softc *esc = (struct esp_softc *)sc;
    503 
    504 	esc->sc_reg[reg * 16] = val;
    505 }
    506 
    507 #if DEBUG
    508 int mac68k_esp_debug=0;
    509 #endif
    510 
    511 int
    512 esp_quick_dma_intr(sc)
    513 	struct ncr53c9x_softc *sc;
    514 {
    515 	struct esp_softc *esc = (struct esp_softc *)sc;
    516 	int trans=0, resid=0;
    517 
    518 	if (esc->sc_active == 0)
    519 		panic("dma_intr--inactive DMA");
    520 
    521 	esc->sc_active = 0;
    522 
    523 	if (esc->sc_dmasize == 0) {
    524 		int	res;
    525 
    526 		res = NCR_READ_REG(sc, NCR_TCL);
    527 		res += NCR_READ_REG(sc, NCR_TCM) << 8;
    528 		/* This can happen in the case of a TRPAD operation */
    529 		/* Pretend that it was complete */
    530 		sc->sc_espstat |= NCRSTAT_TC;
    531 #if DEBUG
    532 		if (mac68k_esp_debug) {
    533 			printf("dmaintr: DMA xfer of zero xferred %d\n",
    534 			    65536 - res);
    535 		}
    536 #endif
    537 		return 0;
    538 	}
    539 
    540 	if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
    541 		if (esc->sc_datain == 0) {
    542 			resid = NCR_READ_REG(sc, NCR_FFLAG) & 0x1f;
    543 #if DEBUG
    544 			if (mac68k_esp_debug) {
    545 				printf("Write FIFO residual %d bytes\n", resid);
    546 			}
    547 #endif
    548 		}
    549 		resid += NCR_READ_REG(sc, NCR_TCL);
    550 		resid += NCR_READ_REG(sc, NCR_TCM) << 8;
    551 		if (resid == 0)
    552 			resid = 65536;
    553 	}
    554 
    555 	trans = esc->sc_dmasize - resid;
    556 	if (trans < 0) {
    557 		printf("dmaintr: trans < 0????");
    558 		trans = *esc->sc_dmalen;
    559 	}
    560 
    561 	NCR_DMA(("dmaintr: trans %d, resid %d.\n", trans, resid));
    562 #if DEBUG
    563 	if (mac68k_esp_debug) {
    564 		printf("eqd_intr: trans %d, resid %d.\n", trans, resid);
    565 	}
    566 #endif
    567 	*esc->sc_dmaaddr += trans;
    568 	*esc->sc_dmalen -= trans;
    569 
    570 	return 0;
    571 }
    572 
    573 int
    574 esp_quick_dma_setup(sc, addr, len, datain, dmasize)
    575 	struct ncr53c9x_softc *sc;
    576 	caddr_t *addr;
    577 	size_t *len;
    578 	int datain;
    579 	size_t *dmasize;
    580 {
    581 	struct esp_softc *esc = (struct esp_softc *)sc;
    582 
    583 	esc->sc_dmaaddr = addr;
    584 	esc->sc_dmalen = len;
    585 
    586 	if (*len & 1) {
    587 		esc->sc_pad = 1;
    588 	} else {
    589 		esc->sc_pad = 0;
    590 	}
    591 
    592 	esc->sc_datain = datain;
    593 	esc->sc_dmasize = *dmasize;
    594 
    595 #if DIAGNOSTIC
    596 	if (esc->sc_dmasize == 0) {
    597 		/* This can happen in the case of a TRPAD operation */
    598 	}
    599 #endif
    600 #if DEBUG
    601 	if (mac68k_esp_debug) {
    602 	printf("eqd_setup: addr %lx, len %lx, in? %d, dmasize %lx\n",
    603 	    (long) *addr, (long) *len, datain, (long) esc->sc_dmasize);
    604 	}
    605 #endif
    606 
    607 	return 0;
    608 }
    609 
    610 static __inline__ int
    611 esp_dafb_have_dreq(esc)
    612 	struct esp_softc *esc;
    613 {
    614 	return (*(volatile u_int32_t *)(esc->sc_bsh.base) & 0x200);
    615 }
    616 
    617 static __inline__ int
    618 esp_iosb_have_dreq(esc)
    619 	struct esp_softc *esc;
    620 {
    621 	return (via2_reg(vIFR) & V2IF_SCSIDRQ);
    622 }
    623 
    624 static volatile int espspl=-1;
    625 
    626 /*
    627  * Apple "DMA" is weird.
    628  *
    629  * Basically, the CPU acts like the DMA controller.  The DREQ/ off the
    630  * chip goes to a register that we've mapped at attach time (on the
    631  * IOSB or DAFB, depending on the machine).  Apple also provides some
    632  * space for which the memory controller handshakes data to/from the
    633  * NCR chip with the DACK/ line.  This space appears to be mapped over
    634  * and over, every 4 bytes, but only the lower 16 bits are valid (but
    635  * reading the upper 16 bits will handshake DACK/ just fine, so if you
    636  * read *u_int16_t++ = *u_int16_t++ in a loop, you'll get
    637  * <databyte><databyte>0xff0xff<databyte><databyte>0xff0xff...
    638  *
    639  * When you're attempting to read or write memory to this DACK/ed space,
    640  * and the NCR is not ready for some timeout period, the system will
    641  * generate a bus error.  This might be for one of several reasons:
    642  *
    643  *	1) (on write) The FIFO is full and is not draining.
    644  *	2) (on read) The FIFO is empty and is not filling.
    645  *	3) An interrupt condition has occurred.
    646  *	4) Anything else?
    647  *
    648  * So if a bus error occurs, we first turn off the nofault bus error handler,
    649  * then we check for an interrupt (which would render the first two
    650  * possibilities moot).  If there's no interrupt, check for a DREQ/.  If we
    651  * have that, then attempt to resume stuffing (or unstuffing) the FIFO.  If
    652  * neither condition holds, pause briefly and check again.
    653  *
    654  * NOTE!!!  In order to make allowances for the hardware structure of
    655  *          the mac, spl values in here are hardcoded!!!!!!!!!
    656  *          This is done to allow serial interrupts to get in during
    657  *          scsi transfers.  This is ugly.
    658  */
    659 void
    660 esp_quick_dma_go(sc)
    661 	struct ncr53c9x_softc *sc;
    662 {
    663 	struct esp_softc *esc = (struct esp_softc *)sc;
    664 	extern long mac68k_a2_fromfault;
    665 	extern int *nofault;
    666 	label_t faultbuf;
    667 	u_int16_t volatile *pdma;
    668 	u_int16_t *addr;
    669 	int		len, res;
    670 	u_short		cnt32, cnt2;
    671 	u_char volatile *statreg;
    672 
    673 	esc->sc_active = 1;
    674 
    675 	espspl = splhigh();
    676 
    677 	addr = (u_int16_t *) *esc->sc_dmaaddr;
    678 	len  = esc->sc_dmasize;
    679 
    680 restart_dmago:
    681 #if DEBUG
    682 	if (mac68k_esp_debug) {
    683 		printf("eqdg: a %lx, l %lx, in? %d ... ",
    684 		    (long) addr, (long) len, esc->sc_datain);
    685 	}
    686 #endif
    687 	nofault = (int *) &faultbuf;
    688 	if (setjmp((label_t *) nofault)) {
    689 		int	i=0;
    690 
    691 		nofault = (int *) 0;
    692 #if DEBUG
    693 		if (mac68k_esp_debug) {
    694 			printf("be\n");
    695 		}
    696 #endif
    697 		/*
    698 		 * Bus error...
    699 		 * So, we first check for an interrupt.  If we have
    700 		 * one, go handle it.  Next we check for DREQ/.  If
    701 		 * we have it, then we restart the transfer.  If
    702 		 * neither, then loop until we get one or the other.
    703 		 */
    704 		statreg = esc->sc_reg + NCR_STAT * 16;
    705 		for (;;) {
    706 			spl2();		/* Give serial a chance... */
    707 			splhigh();	/* That's enough... */
    708 
    709 			if (*statreg & 0x80) {
    710 				goto gotintr;
    711 			}
    712 
    713 			if (esp_have_dreq(esc)) {
    714 				/*
    715 				 * Get the remaining length from the address
    716 				 * differential.
    717 				 */
    718 				addr = (u_int16_t *) mac68k_a2_fromfault;
    719 				len = esc->sc_dmasize -
    720 				    ((long) addr - (long) *esc->sc_dmaaddr);
    721 
    722 				if (esc->sc_datain == 0) {
    723 					/*
    724 					 * Let the FIFO drain before we read
    725 					 * the transfer count.
    726 					 * Do we need to do this?
    727 					 * Can we do this?
    728 					 */
    729 					while (NCR_READ_REG(sc, NCR_FFLAG)
    730 					    & 0x1f);
    731 					/*
    732 					 * Get the length from the transfer
    733 					 * counters.
    734 					 */
    735 					res = NCR_READ_REG(sc, NCR_TCL);
    736 					res += NCR_READ_REG(sc, NCR_TCM) << 8;
    737 					/*
    738 					 * If they don't agree,
    739 					 * adjust accordingly.
    740 					 */
    741 					while (res > len) {
    742 						len+=2; addr--;
    743 					}
    744 					if (res != len) {
    745 						panic("esp_quick_dma_go: res %d != len %d",
    746 							res, len);
    747 					}
    748 				}
    749 				break;
    750 			}
    751 
    752 			DELAY(1);
    753 			if (i++ > 1000000)
    754 				panic("esp_dma_go: Bus error, but no condition!  Argh!");
    755 		}
    756 		goto restart_dmago;
    757 	}
    758 
    759 	len &= ~1;
    760 
    761 	statreg = esc->sc_reg + NCR_STAT * 16;
    762 	pdma = (u_int16_t *) (esc->sc_reg + 0x100);
    763 
    764 	/*
    765 	 * These loops are unrolled into assembly for two reasons:
    766 	 * 1) We can make sure that they are as efficient as possible, and
    767 	 * 2) (more importantly) we need the address that we are reading
    768 	 *    from or writing to to be in a2.
    769 	 */
    770 	cnt32 = len / 32;
    771 	cnt2 = (len % 32) / 2;
    772 	if (esc->sc_datain == 0) {
    773 		/* while (cnt32--) { 16 instances of *pdma = *addr++; } */
    774 		/* while (cnt2--) { *pdma = *addr++; } */
    775 		__asm __volatile (
    776 			"	movl %1, %%a2	\n"
    777 			"	movl %2, %%a3	\n"
    778 			"	movw %3, %%d2	\n"
    779 			"	cmpw #0, %%d2	\n"
    780 			"	beq  2f		\n"
    781 			"	subql #1, %%d2	\n"
    782 			"1:	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    783 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    784 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    785 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    786 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    787 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    788 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    789 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    790 			"	movw #8704,%%sr	\n"
    791 			"	movw #9728,%%sr	\n"
    792 			"	dbra %%d2, 1b	\n"
    793 			"2:	movw %4, %%d2	\n"
    794 			"	cmpw #0, %%d2	\n"
    795 			"	beq  4f		\n"
    796 			"	subql #1, %%d2	\n"
    797 			"3:	movw %%a2@+,%%a3@ \n"
    798 			"	dbra %%d2, 3b	\n"
    799 			"4:	movl %%a2, %0"
    800 			: "=g" (addr)
    801 			: "0" (addr), "g" (pdma), "g" (cnt32), "g" (cnt2)
    802 			: "a2", "a3", "d2");
    803 		if (esc->sc_pad) {
    804 			unsigned char	*c;
    805 			c = (unsigned char *) addr;
    806 			/* Wait for DREQ */
    807 			while (!esp_have_dreq(esc)) {
    808 				if (*statreg & 0x80) {
    809 					nofault = (int *) 0;
    810 					goto gotintr;
    811 				}
    812 			}
    813 			*(unsigned char *)pdma = *c;
    814 		}
    815 	} else {
    816 		/* while (cnt32--) { 16 instances of *addr++ = *pdma; } */
    817 		/* while (cnt2--) { *addr++ = *pdma; } */
    818 		__asm __volatile (
    819 			"	movl %1, %%a2	\n"
    820 			"	movl %2, %%a3	\n"
    821 			"	movw %3, %%d2	\n"
    822 			"	cmpw #0, %%d2	\n"
    823 			"	beq  6f		\n"
    824 			"	subql #1, %%d2	\n"
    825 			"5:	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    826 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    827 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    828 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    829 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    830 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    831 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    832 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    833 			"	movw #8704,%%sr	\n"
    834 			"	movw #9728,%%sr	\n"
    835 			"	dbra %%d2, 5b	\n"
    836 			"6:	movw %4, %%d2	\n"
    837 			"	cmpw #0, %%d2	\n"
    838 			"	beq  8f		\n"
    839 			"	subql #1, %%d2	\n"
    840 			"7:	movw %%a3@,%%a2@+ \n"
    841 			"	dbra %%d2, 7b	\n"
    842 			"8:	movl %%a2, %0"
    843 			: "=g" (addr)
    844 			: "0" (addr), "g" (pdma), "g" (cnt32), "g" (cnt2)
    845 			: "a2", "a3", "d2");
    846 		if (esc->sc_pad) {
    847 			unsigned char	*c;
    848 			c = (unsigned char *) addr;
    849 			/* Wait for DREQ */
    850 			while (!esp_have_dreq(esc)) {
    851 				if (*statreg & 0x80) {
    852 					nofault = (int *) 0;
    853 					goto gotintr;
    854 				}
    855 			}
    856 			*c = *(unsigned char *)pdma;
    857 		}
    858 	}
    859 
    860 	nofault = (int *) 0;
    861 
    862 	/*
    863 	 * If we have not received an interrupt yet, we should shortly,
    864 	 * and we can't prevent it, so return and wait for it.
    865 	 */
    866 	if ((*statreg & 0x80) == 0) {
    867 #if DEBUG
    868 		if (mac68k_esp_debug) {
    869 			printf("g.\n");
    870 		}
    871 #endif
    872 		if (espspl != -1) splx(espspl); espspl = -1;
    873 		return;
    874 	}
    875 
    876 gotintr:
    877 #if DEBUG
    878 	if (mac68k_esp_debug) {
    879 		printf("g!\n");
    880 	}
    881 #endif
    882 	ncr53c9x_intr(sc);
    883 	if (espspl != -1) splx(espspl); espspl = -1;
    884 }
    885 
    886 void
    887 esp_intr(sc)
    888 	void *sc;
    889 {
    890 	struct esp_softc *esc = (struct esp_softc *)sc;
    891 
    892 	if (esc->sc_reg[NCR_STAT * 16] & 0x80) {
    893 		ncr53c9x_intr((struct ncr53c9x_softc *) esp0);
    894 	}
    895 }
    896 
    897 void
    898 esp_dualbus_intr(sc)
    899 	void *sc;
    900 {
    901 	if (esp0 && (esp0->sc_reg[NCR_STAT * 16] & 0x80)) {
    902 		ncr53c9x_intr((struct ncr53c9x_softc *) esp0);
    903 	}
    904 
    905 	if (esp1 && (esp1->sc_reg[NCR_STAT * 16] & 0x80)) {
    906 		ncr53c9x_intr((struct ncr53c9x_softc *) esp1);
    907 	}
    908 }
    909