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esp.c revision 1.15
      1 /*	$NetBSD: esp.c,v 1.15 1998/05/02 16:45:30 scottr 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  * Copyright (c) 1995 Paul Kranenburg
     37  * All rights reserved.
     38  *
     39  * Redistribution and use in source and binary forms, with or without
     40  * modification, are permitted provided that the following conditions
     41  * are met:
     42  * 1. Redistributions of source code must retain the above copyright
     43  *    notice, this list of conditions and the following disclaimer.
     44  * 2. Redistributions in binary form must reproduce the above copyright
     45  *    notice, this list of conditions and the following disclaimer in the
     46  *    documentation and/or other materials provided with the distribution.
     47  * 3. All advertising materials mentioning features or use of this software
     48  *    must display the following acknowledgement:
     49  *	This product includes software developed by Peter Galbavy
     50  * 4. The name of the author may not be used to endorse or promote products
     51  *    derived from this software without specific prior written permission.
     52  *
     53  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     54  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     55  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     56  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
     57  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     58  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     59  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     61  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
     62  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     63  * POSSIBILITY OF SUCH DAMAGE.
     64  */
     65 
     66 /*
     67  * Based on aic6360 by Jarle Greipsland
     68  *
     69  * Acknowledgements: Many of the algorithms used in this driver are
     70  * inspired by the work of Julian Elischer (julian (at) tfs.com) and
     71  * Charles Hannum (mycroft (at) duality.gnu.ai.mit.edu).  Thanks a million!
     72  */
     73 
     74 /*
     75  * Initial m68k mac support from Allen Briggs <briggs (at) macbsd.com>
     76  * (basically consisting of the match, a bit of the attach, and the
     77  *  "DMA" glue functions).
     78  */
     79 
     80 #include <sys/types.h>
     81 #include <sys/param.h>
     82 #include <sys/systm.h>
     83 #include <sys/kernel.h>
     84 #include <sys/errno.h>
     85 #include <sys/ioctl.h>
     86 #include <sys/device.h>
     87 #include <sys/buf.h>
     88 #include <sys/proc.h>
     89 #include <sys/user.h>
     90 #include <sys/queue.h>
     91 
     92 #include <dev/scsipi/scsi_all.h>
     93 #include <dev/scsipi/scsipi_all.h>
     94 #include <dev/scsipi/scsiconf.h>
     95 #include <dev/scsipi/scsi_message.h>
     96 
     97 #include <machine/cpu.h>
     98 #include <machine/bus.h>
     99 #include <machine/param.h>
    100 
    101 #include <dev/ic/ncr53c9xreg.h>
    102 #include <dev/ic/ncr53c9xvar.h>
    103 
    104 #include <machine/viareg.h>
    105 
    106 #include <mac68k/obio/espvar.h>
    107 #include <mac68k/obio/obiovar.h>
    108 
    109 void	espattach	__P((struct device *, struct device *, void *));
    110 int	espmatch	__P((struct device *, struct cfdata *, void *));
    111 
    112 /* Linkup to the rest of the kernel */
    113 struct cfattach esp_ca = {
    114 	sizeof(struct esp_softc), espmatch, espattach
    115 };
    116 
    117 struct scsipi_adapter esp_switch = {
    118 	ncr53c9x_scsi_cmd,
    119 	minphys,		/* no max at this level; handled by DMA code */
    120 	NULL,
    121 	NULL,
    122 };
    123 
    124 struct scsipi_device esp_dev = {
    125 	NULL,			/* Use default error handler */
    126 	NULL,			/* have a queue, served by this */
    127 	NULL,			/* have no async handler */
    128 	NULL,			/* Use default 'done' routine */
    129 };
    130 
    131 /*
    132  * Functions and the switch for the MI code.
    133  */
    134 u_char	esp_read_reg __P((struct ncr53c9x_softc *, int));
    135 void	esp_write_reg __P((struct ncr53c9x_softc *, int, u_char));
    136 int	esp_dma_isintr __P((struct ncr53c9x_softc *));
    137 void	esp_dma_reset __P((struct ncr53c9x_softc *));
    138 int	esp_dma_intr __P((struct ncr53c9x_softc *));
    139 int	esp_dma_setup __P((struct ncr53c9x_softc *, caddr_t *,
    140 	    size_t *, int, size_t *));
    141 void	esp_dma_go __P((struct ncr53c9x_softc *));
    142 void	esp_dma_stop __P((struct ncr53c9x_softc *));
    143 int	esp_dma_isactive __P((struct ncr53c9x_softc *));
    144 void	esp_quick_write_reg __P((struct ncr53c9x_softc *, int, u_char));
    145 int	esp_quick_dma_intr __P((struct ncr53c9x_softc *));
    146 int	esp_quick_dma_setup __P((struct ncr53c9x_softc *, caddr_t *,
    147 	    size_t *, int, size_t *));
    148 void	esp_quick_dma_go __P((struct ncr53c9x_softc *));
    149 
    150 static __inline__ int esp_dafb_have_dreq __P((struct esp_softc *esc));
    151 static __inline__ int esp_iosb_have_dreq __P((struct esp_softc *esc));
    152 int (*esp_have_dreq) __P((struct esp_softc *esc));
    153 
    154 struct ncr53c9x_glue esp_glue = {
    155 	esp_read_reg,
    156 	esp_write_reg,
    157 	esp_dma_isintr,
    158 	esp_dma_reset,
    159 	esp_dma_intr,
    160 	esp_dma_setup,
    161 	esp_dma_go,
    162 	esp_dma_stop,
    163 	esp_dma_isactive,
    164 	NULL,			/* gl_clear_latched_intr */
    165 };
    166 
    167 int
    168 espmatch(parent, cf, aux)
    169 	struct device *parent;
    170 	struct cfdata *cf;
    171 	void *aux;
    172 {
    173 	int	found = 0;
    174 
    175 	if ((cf->cf_unit == 0) && mac68k_machine.scsi96) {
    176 		found = 1;
    177 	}
    178 	if ((cf->cf_unit == 1) && mac68k_machine.scsi96_2) {
    179 		found = 1;
    180 	}
    181 
    182 	return found;
    183 }
    184 
    185 /*
    186  * Attach this instance, and then all the sub-devices
    187  */
    188 void
    189 espattach(parent, self, aux)
    190 	struct device *parent, *self;
    191 	void *aux;
    192 {
    193 	struct obio_attach_args *oa = (struct obio_attach_args *)aux;
    194 	extern vm_offset_t	SCSIBase;
    195 	struct esp_softc	*esc = (void *)self;
    196 	struct ncr53c9x_softc	*sc = &esc->sc_ncr53c9x;
    197 	int			quick = 0;
    198 	unsigned long		reg_offset;
    199 
    200 	reg_offset = SCSIBase - IOBase;
    201 	esc->sc_tag = oa->oa_tag;
    202 	/*
    203 	 * For Wombat, Primus and Optimus motherboards, DREQ is
    204 	 * visible on bit 0 of the IOSB's emulated VIA2 vIFR (and
    205 	 * the scsi registers are offset 0x1000 bytes from IOBase).
    206 	 *
    207 	 * For the Q700/900/950 it's at f9800024 for bus 0 and
    208 	 * f9800028 for bus 1 (900/950).  For these machines, that is also
    209 	 * a (12-bit) configuration register for DAFB's control of the
    210 	 * pseudo-DMA timing.  The default value is 0x1d1.
    211 	 */
    212 	esp_have_dreq = esp_dafb_have_dreq;
    213 	if (sc->sc_dev.dv_unit == 0) {
    214 		if (reg_offset == 0x10000) {
    215 			quick = 1;
    216 			esp_have_dreq = esp_iosb_have_dreq;
    217 		} else if (reg_offset == 0x18000) {
    218 			quick = 0;
    219 		} else {
    220 			if (bus_space_map(esc->sc_tag, 0xf9800024,
    221 					  4, 0, &esc->sc_bsh)) {
    222 				printf("failed to map 4 at 0xf9800024.\n");
    223 			} else {
    224 				quick = 1;
    225 				bus_space_write_4(esc->sc_tag,
    226 						  esc->sc_bsh, 0, 0x1d1);
    227 			}
    228 		}
    229 	} else {
    230 		if (bus_space_map(esc->sc_tag, 0xf9800028,
    231 				  4, 0, &esc->sc_bsh)) {
    232 			printf("failed to map 4 at 0xf9800028.\n");
    233 		} else {
    234 			quick = 1;
    235 			bus_space_write_4(esc->sc_tag, esc->sc_bsh, 0, 0x1d1);
    236 		}
    237 	}
    238 	if (quick) {
    239 		esp_glue.gl_write_reg = esp_quick_write_reg;
    240 		esp_glue.gl_dma_intr = esp_quick_dma_intr;
    241 		esp_glue.gl_dma_setup = esp_quick_dma_setup;
    242 		esp_glue.gl_dma_go = esp_quick_dma_go;
    243 	}
    244 
    245 	/*
    246 	 * Set up the glue for MI code early; we use some of it here.
    247 	 */
    248 	sc->sc_glue = &esp_glue;
    249 
    250 	/*
    251 	 * Save the regs
    252 	 */
    253 	if (sc->sc_dev.dv_unit == 0) {
    254 
    255 		esc->sc_reg = (volatile u_char *) SCSIBase;
    256 		via2_register_irq(VIA2_SCSIIRQ,
    257 		    (void (*)(void *))ncr53c9x_intr, esc);
    258 		esc->irq_mask = V2IF_SCSIIRQ;
    259 		if (reg_offset == 0x10000) {
    260 			sc->sc_freq = 16500000;
    261 		} else {
    262 			sc->sc_freq = 25000000;
    263 		}
    264 
    265 		if (esp_glue.gl_dma_go == esp_quick_dma_go) {
    266 			printf(" (quick)");
    267 		}
    268 	} else {
    269 		esc->sc_reg = (volatile u_char *) SCSIBase + 0x402;
    270 		via2_register_irq(VIA2_SCSIDRQ,
    271 		    (void (*)(void *))ncr53c9x_intr, esc);
    272 		esc->irq_mask = V2IF_SCSIDRQ; /* V2IF_T1? */
    273 		sc->sc_freq = 25000000;
    274 
    275 		if (esp_glue.gl_dma_go == esp_quick_dma_go) {
    276 			printf(" (quick)");
    277 		}
    278 	}
    279 
    280 	printf(": address %p", esc->sc_reg);
    281 
    282 	sc->sc_id = 7;
    283 
    284 	/* gimme Mhz */
    285 	sc->sc_freq /= 1000000;
    286 
    287 	/*
    288 	 * It is necessary to try to load the 2nd config register here,
    289 	 * to find out what rev the esp chip is, else the esp_reset
    290 	 * will not set up the defaults correctly.
    291 	 */
    292 	sc->sc_cfg1 = sc->sc_id; /* | NCRCFG1_PARENB; */
    293 	sc->sc_cfg2 = NCRCFG2_SCSI2;
    294 	sc->sc_cfg3 = 0;
    295 	sc->sc_rev = NCR_VARIANT_NCR53C96;
    296 
    297 	/*
    298 	 * This is the value used to start sync negotiations
    299 	 * Note that the NCR register "SYNCTP" is programmed
    300 	 * in "clocks per byte", and has a minimum value of 4.
    301 	 * The SCSI period used in negotiation is one-fourth
    302 	 * of the time (in nanoseconds) needed to transfer one byte.
    303 	 * Since the chip's clock is given in MHz, we have the following
    304 	 * formula: 4 * period = (1000 / freq) * 4
    305 	 */
    306 	sc->sc_minsync = 1000 / sc->sc_freq;
    307 
    308 	sc->sc_minsync = 0;	/* No synchronous xfers w/o DMA */
    309 	/* Really no limit, but since we want to fit into the TCR... */
    310 	sc->sc_maxxfer = 8 * 1024; /*64 * 1024; XXX */
    311 
    312 	/*
    313 	 * Now try to attach all the sub-devices
    314 	 */
    315 	ncr53c9x_attach(sc, &esp_switch, &esp_dev);
    316 
    317 	/*
    318 	 * Configure interrupts.
    319 	 */
    320 	via2_reg(vPCR) = 0x22;
    321 	via2_reg(vIFR) = esc->irq_mask;
    322 	via2_reg(vIER) = 0x80 | esc->irq_mask;
    323 }
    324 
    325 /*
    326  * Glue functions.
    327  */
    328 
    329 u_char
    330 esp_read_reg(sc, reg)
    331 	struct ncr53c9x_softc *sc;
    332 	int reg;
    333 {
    334 	struct esp_softc *esc = (struct esp_softc *)sc;
    335 
    336 	return esc->sc_reg[reg * 16];
    337 }
    338 
    339 void
    340 esp_write_reg(sc, reg, val)
    341 	struct ncr53c9x_softc *sc;
    342 	int reg;
    343 	u_char val;
    344 {
    345 	struct esp_softc *esc = (struct esp_softc *)sc;
    346 	u_char v = val;
    347 
    348 	if (reg == NCR_CMD && v == (NCRCMD_TRANS|NCRCMD_DMA)) {
    349 		v = NCRCMD_TRANS;
    350 	}
    351 	esc->sc_reg[reg * 16] = v;
    352 }
    353 
    354 void
    355 esp_dma_stop(sc)
    356 	struct ncr53c9x_softc *sc;
    357 {
    358 }
    359 
    360 int
    361 esp_dma_isactive(sc)
    362 	struct ncr53c9x_softc *sc;
    363 {
    364 	struct esp_softc *esc = (struct esp_softc *)sc;
    365 
    366 	return esc->sc_active;
    367 }
    368 
    369 int
    370 esp_dma_isintr(sc)
    371 	struct ncr53c9x_softc *sc;
    372 {
    373 	struct esp_softc *esc = (struct esp_softc *)sc;
    374 
    375 	return esc->sc_reg[NCR_STAT * 16] & 0x80;
    376 }
    377 
    378 void
    379 esp_dma_reset(sc)
    380 	struct ncr53c9x_softc *sc;
    381 {
    382 	struct esp_softc *esc = (struct esp_softc *)sc;
    383 
    384 	esc->sc_active = 0;
    385 	esc->sc_tc = 0;
    386 }
    387 
    388 int
    389 esp_dma_intr(sc)
    390 	struct ncr53c9x_softc *sc;
    391 {
    392 	register struct esp_softc *esc = (struct esp_softc *)sc;
    393 	register u_char	*p;
    394 	volatile u_char *cmdreg, *intrreg, *statreg, *fiforeg;
    395 	register u_int	espphase, espstat, espintr;
    396 	register int	cnt;
    397 
    398 	if (esc->sc_active == 0) {
    399 		printf("dma_intr--inactive DMA\n");
    400 		return -1;
    401 	}
    402 
    403 	if ((sc->sc_espintr & NCRINTR_BS) == 0) {
    404 		esc->sc_active = 0;
    405 		return 0;
    406 	}
    407 
    408 	cnt = *esc->sc_dmalen;
    409 	if (*esc->sc_dmalen == 0) {
    410 		printf("data interrupt, but no count left.");
    411 	}
    412 
    413 	p = *esc->sc_dmaaddr;
    414 	espphase = sc->sc_phase;
    415 	espstat = (u_int) sc->sc_espstat;
    416 	espintr = (u_int) sc->sc_espintr;
    417 	cmdreg = esc->sc_reg + NCR_CMD * 16;
    418 	fiforeg = esc->sc_reg + NCR_FIFO * 16;
    419 	statreg = esc->sc_reg + NCR_STAT * 16;
    420 	intrreg = esc->sc_reg + NCR_INTR * 16;
    421 	do {
    422 		if (esc->sc_datain) {
    423 			*p++ = *fiforeg;
    424 			cnt--;
    425 			if (espphase == DATA_IN_PHASE) {
    426 				*cmdreg = NCRCMD_TRANS;
    427 			} else {
    428 				esc->sc_active = 0;
    429 			}
    430 	 	} else {
    431 			if (   (espphase == DATA_OUT_PHASE)
    432 			    || (espphase == MESSAGE_OUT_PHASE)) {
    433 				*fiforeg = *p++;
    434 				cnt--;
    435 				*cmdreg = NCRCMD_TRANS;
    436 			} else {
    437 				esc->sc_active = 0;
    438 			}
    439 		}
    440 
    441 		if (esc->sc_active) {
    442 			while (!(*statreg & 0x80));
    443 			espstat = *statreg;
    444 			espintr = *intrreg;
    445 			espphase = (espintr & NCRINTR_DIS)
    446 				    ? /* Disconnected */ BUSFREE_PHASE
    447 				    : espstat & PHASE_MASK;
    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 	u_char v = val;
    504 
    505 	esc->sc_reg[reg * 16] = v;
    506 }
    507 
    508 int
    509 esp_quick_dma_intr(sc)
    510 	struct ncr53c9x_softc *sc;
    511 {
    512 	struct esp_softc *esc = (struct esp_softc *)sc;
    513 	int trans=0, resid=0;
    514 
    515 	if (esc->sc_active == 0)
    516 		panic("dma_intr--inactive DMA\n");
    517 
    518 	esc->sc_active = 0;
    519 
    520 	if (esc->sc_dmasize == 0) {
    521 		int	res;
    522 
    523 		res = 65536;
    524 		res -= NCR_READ_REG(sc, NCR_TCL);
    525 		res -= NCR_READ_REG(sc, NCR_TCM) << 8;
    526 		printf("dmaintr: discarded %d b (last transfer was %d b).\n",
    527 			res, esc->sc_prevdmasize);
    528 		return 0;
    529 	}
    530 
    531 	if (esc->sc_datain &&
    532 	    (resid = (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF)) != 0) {
    533 		printf("dmaintr: empty FIFO of %d\n", resid);
    534 		DELAY(1);
    535 	}
    536 
    537 	if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
    538 		resid += NCR_READ_REG(sc, NCR_TCL);
    539 		resid += NCR_READ_REG(sc, NCR_TCM) << 8;
    540 
    541 		if (resid == 0)
    542 			resid = 65536;
    543 	}
    544 
    545 	trans = esc->sc_dmasize - resid;
    546 	if (trans < 0) {
    547 		printf("dmaintr: trans < 0????");
    548 		trans = esc->sc_dmasize;
    549 	}
    550 
    551 	NCR_DMA(("dmaintr: trans %d, resid %d.\n", trans, resid));
    552 	*esc->sc_dmaaddr += trans;
    553 	*esc->sc_dmalen -= trans;
    554 
    555 	return 0;
    556 }
    557 
    558 int
    559 esp_quick_dma_setup(sc, addr, len, datain, dmasize)
    560 	struct ncr53c9x_softc *sc;
    561 	caddr_t *addr;
    562 	size_t *len;
    563 	int datain;
    564 	size_t *dmasize;
    565 {
    566 	struct esp_softc *esc = (struct esp_softc *)sc;
    567 
    568 	esc->sc_dmaaddr = addr;
    569 	esc->sc_dmalen = len;
    570 
    571 	esc->sc_pdmaddr = (u_int16_t *) *addr;
    572 	esc->sc_pdmalen = *len;
    573 	if (esc->sc_pdmalen & 1) {
    574 		esc->sc_pdmalen--;
    575 		esc->sc_pad = 1;
    576 	} else {
    577 		esc->sc_pad = 0;
    578 	}
    579 
    580 	esc->sc_datain = datain;
    581 	esc->sc_prevdmasize = esc->sc_dmasize;
    582 	esc->sc_dmasize = *dmasize;
    583 
    584 	return 0;
    585 }
    586 
    587 static __inline__ int
    588 esp_dafb_have_dreq(esc)
    589 	struct esp_softc *esc;
    590 {
    591 	u_int32_t r;
    592 
    593 	r = bus_space_read_4(esc->sc_tag, esc->sc_bsh, 0);
    594 	return (r & 0x200);
    595 }
    596 
    597 static __inline__ int
    598 esp_iosb_have_dreq(esc)
    599 	struct esp_softc *esc;
    600 {
    601 	return (via2_reg(vIFR) & V2IF_SCSIDRQ);
    602 }
    603 
    604 static int espspl=-1;
    605 #define __splx(s) __asm __volatile ("movew %0,sr" : : "di" (s));
    606 #define __spl2()  __splx(PSL_S|PSL_IPL2)
    607 #define __spl4()  __splx(PSL_S|PSL_IPL4)
    608 
    609 void
    610 esp_quick_dma_go(sc)
    611 	struct ncr53c9x_softc *sc;
    612 {
    613 	struct esp_softc *esc = (struct esp_softc *)sc;
    614 	extern int *nofault;
    615 	label_t faultbuf;
    616 	u_int16_t volatile *pdma;
    617 	u_char volatile *statreg;
    618 
    619 	esc->sc_active = 1;
    620 
    621 	espspl = spl2();
    622 
    623 restart_dmago:
    624 	nofault = (int *) &faultbuf;
    625 	if (setjmp((label_t *) nofault)) {
    626 		int	i=0;
    627 
    628 		nofault = (int *) 0;
    629 		statreg = esc->sc_reg + NCR_STAT * 16;
    630 		for (;;) {
    631 			if (*statreg & 0x80) {
    632 				goto gotintr;
    633 			}
    634 
    635 			if (esp_have_dreq(esc)) {
    636 				break;
    637 			}
    638 
    639 			DELAY(1);
    640 			if (i++ > 10000)
    641 				panic("esp_dma_go: Argh!");
    642 		}
    643 		goto restart_dmago;
    644 	}
    645 
    646 	statreg = esc->sc_reg + NCR_STAT * 16;
    647 	pdma = (u_int16_t *) (esc->sc_reg + 0x100);
    648 
    649 #define WAIT while (!esp_have_dreq(esc)) if (*statreg & 0x80) goto gotintr
    650 
    651 	if (esc->sc_datain == 0) {
    652 		while (esc->sc_pdmalen) {
    653 			WAIT;
    654 			__spl4(); *pdma = *(esc->sc_pdmaddr)++; __spl2()
    655 			esc->sc_pdmalen -= 2;
    656 		}
    657 		if (esc->sc_pad) {
    658 			unsigned short	us;
    659 			unsigned char	*c;
    660 			c = (unsigned char *) esc->sc_pdmaddr;
    661 			us = *c;
    662 			WAIT;
    663 			__spl4(); *pdma = us; __spl2()
    664 		}
    665 	} else {
    666 		while (esc->sc_pdmalen) {
    667 			WAIT;
    668 			__spl4(); *(esc->sc_pdmaddr)++ = *pdma; __spl2()
    669 			esc->sc_pdmalen -= 2;
    670 		}
    671 		if (esc->sc_pad) {
    672 			unsigned short	us;
    673 			unsigned char	*c;
    674 			WAIT;
    675 			__spl4(); us = *pdma; __spl2()
    676 			c = (unsigned char *) esc->sc_pdmaddr;
    677 			*c = us & 0xff;
    678 		}
    679 	}
    680 #undef WAIT
    681 
    682 	nofault = (int *) 0;
    683 
    684 	if ((*statreg & 0x80) == 0) {
    685 		if (espspl != -1) splx(espspl); espspl = -1;
    686 		return;
    687 	}
    688 
    689 gotintr:
    690 	ncr53c9x_intr(sc);
    691 	if (espspl != -1) splx(espspl); espspl = -1;
    692 }
    693