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esp.c revision 1.27
      1 /*	$NetBSD: esp.c,v 1.27 2000/12/29 21:31:44 briggs 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 struct cfattach esp_ca = {
    113 	sizeof(struct esp_softc), espmatch, espattach
    114 };
    115 
    116 /*
    117  * Functions and the switch for the MI code.
    118  */
    119 u_char	esp_read_reg __P((struct ncr53c9x_softc *, int));
    120 void	esp_write_reg __P((struct ncr53c9x_softc *, int, u_char));
    121 int	esp_dma_isintr __P((struct ncr53c9x_softc *));
    122 void	esp_dma_reset __P((struct ncr53c9x_softc *));
    123 int	esp_dma_intr __P((struct ncr53c9x_softc *));
    124 int	esp_dma_setup __P((struct ncr53c9x_softc *, caddr_t *,
    125 	    size_t *, int, size_t *));
    126 void	esp_dma_go __P((struct ncr53c9x_softc *));
    127 void	esp_dma_stop __P((struct ncr53c9x_softc *));
    128 int	esp_dma_isactive __P((struct ncr53c9x_softc *));
    129 void	esp_quick_write_reg __P((struct ncr53c9x_softc *, int, u_char));
    130 int	esp_quick_dma_intr __P((struct ncr53c9x_softc *));
    131 int	esp_quick_dma_setup __P((struct ncr53c9x_softc *, caddr_t *,
    132 	    size_t *, int, size_t *));
    133 void	esp_quick_dma_go __P((struct ncr53c9x_softc *));
    134 
    135 void	esp_intr __P((void *sc));
    136 void	esp_dualbus_intr __P((void *sc));
    137 static struct esp_softc		*esp0 = NULL, *esp1 = NULL;
    138 
    139 static __inline__ int esp_dafb_have_dreq __P((struct esp_softc *esc));
    140 static __inline__ int esp_iosb_have_dreq __P((struct esp_softc *esc));
    141 int (*esp_have_dreq) __P((struct esp_softc *esc));
    142 
    143 struct ncr53c9x_glue esp_glue = {
    144 	esp_read_reg,
    145 	esp_write_reg,
    146 	esp_dma_isintr,
    147 	esp_dma_reset,
    148 	esp_dma_intr,
    149 	esp_dma_setup,
    150 	esp_dma_go,
    151 	esp_dma_stop,
    152 	esp_dma_isactive,
    153 	NULL,			/* gl_clear_latched_intr */
    154 };
    155 
    156 int
    157 espmatch(parent, cf, aux)
    158 	struct device *parent;
    159 	struct cfdata *cf;
    160 	void *aux;
    161 {
    162 	int	found = 0;
    163 
    164 	if ((cf->cf_unit == 0) && mac68k_machine.scsi96) {
    165 		found = 1;
    166 	}
    167 	if ((cf->cf_unit == 1) && mac68k_machine.scsi96_2) {
    168 		found = 1;
    169 	}
    170 
    171 	return found;
    172 }
    173 
    174 /*
    175  * Attach this instance, and then all the sub-devices
    176  */
    177 void
    178 espattach(parent, self, aux)
    179 	struct device *parent, *self;
    180 	void *aux;
    181 {
    182 	struct obio_attach_args *oa = (struct obio_attach_args *)aux;
    183 	extern vaddr_t		SCSIBase;
    184 	struct esp_softc	*esc = (void *)self;
    185 	struct ncr53c9x_softc	*sc = &esc->sc_ncr53c9x;
    186 	int			quick = 0;
    187 	unsigned long		reg_offset;
    188 
    189 	reg_offset = SCSIBase - IOBase;
    190 	esc->sc_tag = oa->oa_tag;
    191 	/*
    192 	 * For Wombat, Primus and Optimus motherboards, DREQ is
    193 	 * visible on bit 0 of the IOSB's emulated VIA2 vIFR (and
    194 	 * the scsi registers are offset 0x1000 bytes from IOBase).
    195 	 *
    196 	 * For the Q700/900/950 it's at f9800024 for bus 0 and
    197 	 * f9800028 for bus 1 (900/950).  For these machines, that is also
    198 	 * a (12-bit) configuration register for DAFB's control of the
    199 	 * pseudo-DMA timing.  The default value is 0x1d1.
    200 	 */
    201 	esp_have_dreq = esp_dafb_have_dreq;
    202 	if (sc->sc_dev.dv_unit == 0) {
    203 		if (reg_offset == 0x10000) {
    204 			quick = 1;
    205 			esp_have_dreq = esp_iosb_have_dreq;
    206 		} else if (reg_offset == 0x18000) {
    207 			quick = 0;
    208 		} else {
    209 			if (bus_space_map(esc->sc_tag, 0xf9800024,
    210 					  4, 0, &esc->sc_bsh)) {
    211 				printf("failed to map 4 at 0xf9800024.\n");
    212 			} else {
    213 				quick = 1;
    214 				bus_space_write_4(esc->sc_tag,
    215 						  esc->sc_bsh, 0, 0x1d1);
    216 			}
    217 		}
    218 	} else {
    219 		if (bus_space_map(esc->sc_tag, 0xf9800028,
    220 				  4, 0, &esc->sc_bsh)) {
    221 			printf("failed to map 4 at 0xf9800028.\n");
    222 		} else {
    223 			quick = 1;
    224 			bus_space_write_4(esc->sc_tag, esc->sc_bsh, 0, 0x1d1);
    225 		}
    226 	}
    227 	if (quick) {
    228 		esp_glue.gl_write_reg = esp_quick_write_reg;
    229 		esp_glue.gl_dma_intr = esp_quick_dma_intr;
    230 		esp_glue.gl_dma_setup = esp_quick_dma_setup;
    231 		esp_glue.gl_dma_go = esp_quick_dma_go;
    232 	}
    233 
    234 	/*
    235 	 * Set up the glue for MI code early; we use some of it here.
    236 	 */
    237 	sc->sc_glue = &esp_glue;
    238 
    239 	/*
    240 	 * Save the regs
    241 	 */
    242 	if (sc->sc_dev.dv_unit == 0) {
    243 		esp0 = esc;
    244 
    245 		esc->sc_reg = (volatile u_char *) SCSIBase;
    246 		via2_register_irq(VIA2_SCSIIRQ, esp_intr, esc);
    247 		esc->irq_mask = V2IF_SCSIIRQ;
    248 		if (reg_offset == 0x10000) {
    249 			/* From the Q650 developer's note */
    250 			sc->sc_freq = 16500000;
    251 		} else {
    252 			sc->sc_freq = 25000000;
    253 		}
    254 
    255 		if (esp_glue.gl_dma_go == esp_quick_dma_go) {
    256 			printf(" (quick)");
    257 		}
    258 	} else {
    259 		esp1 = esc;
    260 
    261 		esc->sc_reg = (volatile u_char *) SCSIBase + 0x402;
    262 		via2_register_irq(VIA2_SCSIIRQ, esp_dualbus_intr, NULL);
    263 		esc->irq_mask = 0;
    264 		sc->sc_freq = 25000000;
    265 
    266 		if (esp_glue.gl_dma_go == esp_quick_dma_go) {
    267 			printf(" (quick)");
    268 		}
    269 	}
    270 
    271 	printf(": address %p", esc->sc_reg);
    272 
    273 	sc->sc_id = 7;
    274 
    275 	/* gimme Mhz */
    276 	sc->sc_freq /= 1000000;
    277 
    278 	/*
    279 	 * It is necessary to try to load the 2nd config register here,
    280 	 * to find out what rev the esp chip is, else the esp_reset
    281 	 * will not set up the defaults correctly.
    282 	 */
    283 	sc->sc_cfg1 = sc->sc_id; /* | NCRCFG1_PARENB; */
    284 	sc->sc_cfg2 = NCRCFG2_SCSI2;
    285 	sc->sc_cfg3 = 0;
    286 	sc->sc_rev = NCR_VARIANT_NCR53C96;
    287 
    288 	/*
    289 	 * This is the value used to start sync negotiations
    290 	 * Note that the NCR register "SYNCTP" is programmed
    291 	 * in "clocks per byte", and has a minimum value of 4.
    292 	 * The SCSI period used in negotiation is one-fourth
    293 	 * of the time (in nanoseconds) needed to transfer one byte.
    294 	 * Since the chip's clock is given in MHz, we have the following
    295 	 * formula: 4 * period = (1000 / freq) * 4
    296 	 */
    297 	sc->sc_minsync = 1000 / sc->sc_freq;
    298 
    299 	/* We need this to fit into the TCR... */
    300 	sc->sc_maxxfer = 64 * 1024;
    301 
    302 	if (!quick) {
    303 		sc->sc_minsync = 0;	/* No synchronous xfers w/o DMA */
    304 		sc->sc_maxxfer = 8 * 1024;
    305 	}
    306 
    307 	/*
    308 	 * Configure interrupts.
    309 	 */
    310 	if (esc->irq_mask) {
    311 		via2_reg(vPCR) = 0x22;
    312 		via2_reg(vIFR) = esc->irq_mask;
    313 		via2_reg(vIER) = 0x80 | esc->irq_mask;
    314 	}
    315 
    316 	/*
    317 	 * Now try to attach all the sub-devices
    318 	 */
    319 	ncr53c9x_attach(sc, NULL, NULL);
    320 }
    321 
    322 /*
    323  * Glue functions.
    324  */
    325 
    326 u_char
    327 esp_read_reg(sc, reg)
    328 	struct ncr53c9x_softc *sc;
    329 	int reg;
    330 {
    331 	struct esp_softc *esc = (struct esp_softc *)sc;
    332 
    333 	return esc->sc_reg[reg * 16];
    334 }
    335 
    336 void
    337 esp_write_reg(sc, reg, val)
    338 	struct ncr53c9x_softc *sc;
    339 	int reg;
    340 	u_char val;
    341 {
    342 	struct esp_softc *esc = (struct esp_softc *)sc;
    343 	u_char	v = val;
    344 
    345 	if (reg == NCR_CMD && v == (NCRCMD_TRANS|NCRCMD_DMA)) {
    346 		v = NCRCMD_TRANS;
    347 	}
    348 	esc->sc_reg[reg * 16] = v;
    349 }
    350 
    351 void
    352 esp_dma_stop(sc)
    353 	struct ncr53c9x_softc *sc;
    354 {
    355 }
    356 
    357 int
    358 esp_dma_isactive(sc)
    359 	struct ncr53c9x_softc *sc;
    360 {
    361 	struct esp_softc *esc = (struct esp_softc *)sc;
    362 
    363 	return esc->sc_active;
    364 }
    365 
    366 int
    367 esp_dma_isintr(sc)
    368 	struct ncr53c9x_softc *sc;
    369 {
    370 	struct esp_softc *esc = (struct esp_softc *)sc;
    371 
    372 	return esc->sc_reg[NCR_STAT * 16] & 0x80;
    373 }
    374 
    375 void
    376 esp_dma_reset(sc)
    377 	struct ncr53c9x_softc *sc;
    378 {
    379 	struct esp_softc *esc = (struct esp_softc *)sc;
    380 
    381 	esc->sc_active = 0;
    382 	esc->sc_tc = 0;
    383 }
    384 
    385 int
    386 esp_dma_intr(sc)
    387 	struct ncr53c9x_softc *sc;
    388 {
    389 	struct esp_softc *esc = (struct esp_softc *)sc;
    390 	volatile u_char *cmdreg, *intrreg, *statreg, *fiforeg;
    391 	u_char	*p;
    392 	u_int	espphase, espstat, espintr;
    393 	int	cnt, s;
    394 
    395 	if (esc->sc_active == 0) {
    396 		printf("dma_intr--inactive DMA\n");
    397 		return -1;
    398 	}
    399 
    400 	if ((sc->sc_espintr & NCRINTR_BS) == 0) {
    401 		esc->sc_active = 0;
    402 		return 0;
    403 	}
    404 
    405 	cnt = esc->sc_dmasize;
    406 	if (esc->sc_dmasize == 0) {
    407 		printf("data interrupt, but no count left.");
    408 	}
    409 
    410 	p = *esc->sc_dmaaddr;
    411 	espphase = sc->sc_phase;
    412 	espstat = (u_int) sc->sc_espstat;
    413 	espintr = (u_int) sc->sc_espintr;
    414 	cmdreg = esc->sc_reg + NCR_CMD * 16;
    415 	fiforeg = esc->sc_reg + NCR_FIFO * 16;
    416 	statreg = esc->sc_reg + NCR_STAT * 16;
    417 	intrreg = esc->sc_reg + NCR_INTR * 16;
    418 	do {
    419 		if (esc->sc_datain) {
    420 			*p++ = *fiforeg;
    421 			cnt--;
    422 			if (espphase == DATA_IN_PHASE) {
    423 				*cmdreg = NCRCMD_TRANS;
    424 			} else {
    425 				esc->sc_active = 0;
    426 			}
    427 	 	} else {
    428 			if (   (espphase == DATA_OUT_PHASE)
    429 			    || (espphase == MESSAGE_OUT_PHASE)) {
    430 				*fiforeg = *p++;
    431 				cnt--;
    432 				*cmdreg = NCRCMD_TRANS;
    433 			} else {
    434 				esc->sc_active = 0;
    435 			}
    436 		}
    437 
    438 		if (esc->sc_active) {
    439 			while (!(*statreg & 0x80));
    440 			s = splhigh();
    441 			espstat = *statreg;
    442 			espintr = *intrreg;
    443 			espphase = (espintr & NCRINTR_DIS)
    444 				    ? /* Disconnected */ BUSFREE_PHASE
    445 				    : espstat & PHASE_MASK;
    446 			splx(s);
    447 		}
    448 	} while (esc->sc_active && (espintr & NCRINTR_BS));
    449 	sc->sc_phase = espphase;
    450 	sc->sc_espstat = (u_char) espstat;
    451 	sc->sc_espintr = (u_char) espintr;
    452 	*esc->sc_dmaaddr = p;
    453 	esc->sc_dmasize = cnt;
    454 
    455 	if (esc->sc_dmasize == 0) {
    456 		esc->sc_tc = NCRSTAT_TC;
    457 	}
    458 	sc->sc_espstat |= esc->sc_tc;
    459 	return 0;
    460 }
    461 
    462 int
    463 esp_dma_setup(sc, addr, len, datain, dmasize)
    464 	struct ncr53c9x_softc *sc;
    465 	caddr_t *addr;
    466 	size_t *len;
    467 	int datain;
    468 	size_t *dmasize;
    469 {
    470 	struct esp_softc *esc = (struct esp_softc *)sc;
    471 
    472 	esc->sc_dmaaddr = addr;
    473 	esc->sc_dmalen = len;
    474 	esc->sc_datain = datain;
    475 	esc->sc_dmasize = *dmasize;
    476 	esc->sc_tc = 0;
    477 
    478 	return 0;
    479 }
    480 
    481 void
    482 esp_dma_go(sc)
    483 	struct ncr53c9x_softc *sc;
    484 {
    485 	struct esp_softc *esc = (struct esp_softc *)sc;
    486 
    487 	if (esc->sc_datain == 0) {
    488 		esc->sc_reg[NCR_FIFO * 16] = **esc->sc_dmaaddr;
    489 		(*esc->sc_dmalen)--;
    490 		(*esc->sc_dmaaddr)++;
    491 	}
    492 	esc->sc_active = 1;
    493 }
    494 
    495 void
    496 esp_quick_write_reg(sc, reg, val)
    497 	struct ncr53c9x_softc *sc;
    498 	int reg;
    499 	u_char val;
    500 {
    501 	struct esp_softc *esc = (struct esp_softc *)sc;
    502 
    503 	esc->sc_reg[reg * 16] = val;
    504 }
    505 
    506 #if DEBUG
    507 int mac68k_esp_debug=0;
    508 #endif
    509 
    510 int
    511 esp_quick_dma_intr(sc)
    512 	struct ncr53c9x_softc *sc;
    513 {
    514 	struct esp_softc *esc = (struct esp_softc *)sc;
    515 	int trans=0, resid=0;
    516 
    517 	if (esc->sc_active == 0)
    518 		panic("dma_intr--inactive DMA\n");
    519 
    520 	esc->sc_active = 0;
    521 
    522 	if (esc->sc_dmasize == 0) {
    523 		int	res;
    524 
    525 		res = NCR_READ_REG(sc, NCR_TCL);
    526 		res += NCR_READ_REG(sc, NCR_TCM) << 8;
    527 		printf("dmaintr: DMA xfer of zero xferred %d\n", res);
    528 		return 0;
    529 	}
    530 
    531 	if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
    532 		resid += NCR_READ_REG(sc, NCR_TCL);
    533 		resid += NCR_READ_REG(sc, NCR_TCM) << 8;
    534 		if (resid == 0)
    535 			resid = 65536;
    536 	}
    537 
    538 	trans = esc->sc_dmasize - resid;
    539 	if (trans < 0) {
    540 		printf("dmaintr: trans < 0????");
    541 		trans = *esc->sc_dmalen;
    542 	}
    543 
    544 	NCR_DMA(("dmaintr: trans %d, resid %d.\n", trans, resid));
    545 #if DEBUG
    546 	if (mac68k_esp_debug) {
    547 		printf("eqd_intr: trans %d, resid %d.\n", trans, resid);
    548 	}
    549 #endif
    550 	*esc->sc_dmaaddr += trans;
    551 	*esc->sc_dmalen -= trans;
    552 
    553 	return 0;
    554 }
    555 
    556 int
    557 esp_quick_dma_setup(sc, addr, len, datain, dmasize)
    558 	struct ncr53c9x_softc *sc;
    559 	caddr_t *addr;
    560 	size_t *len;
    561 	int datain;
    562 	size_t *dmasize;
    563 {
    564 	struct esp_softc *esc = (struct esp_softc *)sc;
    565 
    566 	esc->sc_dmaaddr = addr;
    567 	esc->sc_dmalen = len;
    568 
    569 	if (*len & 1) {
    570 		esc->sc_pad = 1;
    571 	} else {
    572 		esc->sc_pad = 0;
    573 	}
    574 
    575 	esc->sc_datain = datain;
    576 	esc->sc_dmasize = *dmasize;
    577 
    578 #if DIAGNOSTIC
    579 	if (esc->sc_dmasize == 0) {
    580 		printf("esp_quick_dma_setup called with %lx, %lx, %d, %lx\n",
    581 		    (long) *addr, (long) *len, datain, (long) esc->sc_dmasize);
    582 	}
    583 #endif
    584 #if DEBUG
    585 	if (mac68k_esp_debug) {
    586 	printf("eqd_setup: addr %lx, len %lx, in? %d, dmasize %lx\n",
    587 	    (long) *addr, (long) *len, datain, (long) esc->sc_dmasize);
    588 	}
    589 #endif
    590 
    591 	return 0;
    592 }
    593 
    594 static __inline__ int
    595 esp_dafb_have_dreq(esc)
    596 	struct esp_softc *esc;
    597 {
    598 	return (*(volatile u_int32_t *)(esc->sc_bsh.base) & 0x200);
    599 }
    600 
    601 static __inline__ int
    602 esp_iosb_have_dreq(esc)
    603 	struct esp_softc *esc;
    604 {
    605 	return (via2_reg(vIFR) & V2IF_SCSIDRQ);
    606 }
    607 
    608 static volatile int espspl=-1;
    609 
    610 /*
    611  * Apple "DMA" is weird.
    612  *
    613  * Basically, the CPU acts like the DMA controller.  The DREQ/ off the
    614  * chip goes to a register that we've mapped at attach time (on the
    615  * IOSB or DAFB, depending on the machine).  Apple also provides some
    616  * space for which the memory controller handshakes data to/from the
    617  * NCR chip with the DACK/ line.  This space appears to be mapped over
    618  * and over, every 4 bytes, but only the lower 16 bits are valid (but
    619  * reading the upper 16 bits will handshake DACK/ just fine, so if you
    620  * read *u_int16_t++ = *u_int16_t++ in a loop, you'll get
    621  * <databyte><databyte>0xff0xff<databyte><databyte>0xff0xff...
    622  *
    623  * When you're attempting to read or write memory to this DACK/ed space,
    624  * and the NCR is not ready for some timeout period, the system will
    625  * generate a bus error.  This might be for one of several reasons:
    626  *
    627  *	1) (on write) The FIFO is full and is not draining.
    628  *	2) (on read) The FIFO is empty and is not filling.
    629  *	3) An interrupt condition has occurred.
    630  *	4) Anything else?
    631  *
    632  * So if a bus error occurs, we first turn off the nofault bus error handler,
    633  * then we check for an interrupt (which would render the first two
    634  * possibilities moot).  If there's no interrupt, check for a DREQ/.  If we
    635  * have that, then attempt to resume stuffing (or unstuffing) the FIFO.  If
    636  * neither condition holds, pause briefly and check again.
    637  *
    638  * NOTE!!!  In order to make allowances for the hardware structure of
    639  *          the mac, spl values in here are hardcoded!!!!!!!!!
    640  *          This is done to allow serial interrupts to get in during
    641  *          scsi transfers.  This is ugly.
    642  */
    643 void
    644 esp_quick_dma_go(sc)
    645 	struct ncr53c9x_softc *sc;
    646 {
    647 	struct esp_softc *esc = (struct esp_softc *)sc;
    648 	extern long mac68k_a2_fromfault;
    649 	extern int *nofault;
    650 	label_t faultbuf;
    651 	u_int16_t volatile *pdma;
    652 	u_int16_t *addr;
    653 	int		len, res;
    654 	u_short		cnt32, cnt2;
    655 	u_char volatile *statreg;
    656 
    657 	esc->sc_active = 1;
    658 
    659 	espspl = splhigh();
    660 
    661 	addr = (u_int16_t *) *esc->sc_dmaaddr;
    662 	len  = esc->sc_dmasize;
    663 
    664 restart_dmago:
    665 #if DEBUG
    666 	if (mac68k_esp_debug) {
    667 		printf("eqdg: a %lx, l %lx, in? %d ... ",
    668 		    (long) addr, (long) len, esc->sc_datain);
    669 	}
    670 #endif
    671 	nofault = (int *) &faultbuf;
    672 	if (setjmp((label_t *) nofault)) {
    673 		int	i=0;
    674 
    675 		nofault = (int *) 0;
    676 #if DEBUG
    677 		if (mac68k_esp_debug) {
    678 			printf("be\n");
    679 		}
    680 #endif
    681 		/*
    682 		 * Bus error...
    683 		 * So, we first check for an interrupt.  If we have
    684 		 * one, go handle it.  Next we check for DREQ/.  If
    685 		 * we have it, then we restart the transfer.  If
    686 		 * neither, then loop until we get one or the other.
    687 		 */
    688 		statreg = esc->sc_reg + NCR_STAT * 16;
    689 		for (;;) {
    690 			spl2();		/* Give serial a chance... */
    691 			splhigh();	/* That's enough... */
    692 
    693 			if (*statreg & 0x80) {
    694 				goto gotintr;
    695 			}
    696 
    697 			if (esp_have_dreq(esc)) {
    698 				/*
    699 				 * Get the length from the address
    700 				 * differential.
    701 				 */
    702 				addr = (u_int16_t *) mac68k_a2_fromfault;
    703 				len = esc->sc_dmasize -
    704 				    ((long) addr - (long) *esc->sc_dmaaddr);
    705 
    706 				if (esc->sc_datain == 0) {
    707 					/*
    708 					 * Let the FIFO drain before we read
    709 					 * the transfer count.
    710 					 * Do we need to do this?
    711 					 * Can we do this?
    712 					 */
    713 					while (NCR_READ_REG(sc, NCR_FFLAG)
    714 					    & 0x1f);
    715 					/*
    716 					 * Get the length from the transfer
    717 					 * counters.
    718 					 */
    719 					res = NCR_READ_REG(sc, NCR_TCL);
    720 					res += NCR_READ_REG(sc, NCR_TCM) << 8;
    721 					/*
    722 					 * If they don't agree,
    723 					 * adjust accordingly.
    724 					 */
    725 					while (res > len) {
    726 						len+=2; addr--;
    727 					}
    728 					if (res != len) {
    729 						panic("esp_quick_dma_go: res %d != len %d\n",
    730 							res, len);
    731 					}
    732 				}
    733 				break;
    734 			}
    735 
    736 			DELAY(1);
    737 			if (i++ > 1000000)
    738 				panic("esp_dma_go: Bus error, but no condition!  Argh!");
    739 		}
    740 		goto restart_dmago;
    741 	}
    742 
    743 	len &= ~1;
    744 
    745 	statreg = esc->sc_reg + NCR_STAT * 16;
    746 	pdma = (u_int16_t *) (esc->sc_reg + 0x100);
    747 
    748 	/*
    749 	 * These loops are unrolled into assembly for two reasons:
    750 	 * 1) We can make sure that they are as efficient as possible, and
    751 	 * 2) (more importantly) we need the address that we are reading
    752 	 *    from or writing to to be in a2.
    753 	 */
    754 	cnt32 = len / 32;
    755 	cnt2 = (len % 32) / 2;
    756 	if (esc->sc_datain == 0) {
    757 		/* while (cnt32--) { 16 instances of *pdma = *addr++; } */
    758 		/* while (cnt2--) { *pdma = *addr++; } */
    759 		__asm __volatile ("
    760 				movl %1, %%a2
    761 				movl %2, %%a3
    762 				movw %3, %%d2
    763 				cmpw #0, %%d2
    764 				beq  2f
    765 				subql #1, %%d2
    766 			1:	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@
    767 				movw %%a2@+,%%a3@; movw %%a2@+,%%a3@
    768 				movw %%a2@+,%%a3@; movw %%a2@+,%%a3@
    769 				movw %%a2@+,%%a3@; movw %%a2@+,%%a3@
    770 				movw %%a2@+,%%a3@; movw %%a2@+,%%a3@
    771 				movw %%a2@+,%%a3@; movw %%a2@+,%%a3@
    772 				movw %%a2@+,%%a3@; movw %%a2@+,%%a3@
    773 				movw %%a2@+,%%a3@; movw %%a2@+,%%a3@
    774 				movw #8704,%%sr
    775 				movw #9728,%%sr
    776 				dbra %%d2, 1b
    777 			2:	movw %4, %%d2
    778 				cmpw #0, %%d2
    779 				beq  4f
    780 				subql #1, %%d2
    781 			3:	movw %%a2@+,%%a3@
    782 				dbra %%d2, 3b
    783 			4:	movl %%a2, %0"
    784 			: "=g" (addr)
    785 			: "0" (addr), "g" (pdma), "g" (cnt32), "g" (cnt2)
    786 			: "a2", "a3", "d2");
    787 		if (esc->sc_pad) {
    788 			unsigned char	*c;
    789 			c = (unsigned char *) addr;
    790 			/* Wait for DREQ */
    791 			while (!esp_have_dreq(esc)) {
    792 				if (*statreg & 0x80) {
    793 					nofault = (int *) 0;
    794 					goto gotintr;
    795 				}
    796 			}
    797 			*(unsigned char *)pdma = *c;
    798 		}
    799 	} else {
    800 		/* while (cnt32--) { 16 instances of *addr++ = *pdma; } */
    801 		/* while (cnt2--) { *addr++ = *pdma; } */
    802 		__asm __volatile ("
    803 				movl %1, %%a2
    804 				movl %2, %%a3
    805 				movw %3, %%d2
    806 				cmpw #0, %%d2
    807 				beq  6f
    808 				subql #1, %%d2
    809 			5:	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+
    810 				movw %%a3@,%%a2@+; movw %%a3@,%%a2@+
    811 				movw %%a3@,%%a2@+; movw %%a3@,%%a2@+
    812 				movw %%a3@,%%a2@+; movw %%a3@,%%a2@+
    813 				movw %%a3@,%%a2@+; movw %%a3@,%%a2@+
    814 				movw %%a3@,%%a2@+; movw %%a3@,%%a2@+
    815 				movw %%a3@,%%a2@+; movw %%a3@,%%a2@+
    816 				movw %%a3@,%%a2@+; movw %%a3@,%%a2@+
    817 				movw #8704,%%sr
    818 				movw #9728,%%sr
    819 				dbra %%d2, 5b
    820 			6:	movw %4, %%d2
    821 				cmpw #0, %%d2
    822 				beq  8f
    823 				subql #1, %%d2
    824 			7:	movw %%a3@,%%a2@+
    825 				dbra %%d2, 7b
    826 			8:	movl %%a2, %0"
    827 			: "=g" (addr)
    828 			: "0" (addr), "g" (pdma), "g" (cnt32), "g" (cnt2)
    829 			: "a2", "a3", "d2");
    830 		if (esc->sc_pad) {
    831 			unsigned char	*c;
    832 			c = (unsigned char *) addr;
    833 			/* Wait for DREQ */
    834 			while (!esp_have_dreq(esc)) {
    835 				if (*statreg & 0x80) {
    836 					nofault = (int *) 0;
    837 					goto gotintr;
    838 				}
    839 			}
    840 			*c = *(unsigned char *)pdma;
    841 		}
    842 	}
    843 
    844 	nofault = (int *) 0;
    845 
    846 	/*
    847 	 * If we have not received an interrupt yet, we should shortly,
    848 	 * and we can't prevent it, so return and wait for it.
    849 	 */
    850 	if ((*statreg & 0x80) == 0) {
    851 #if DEBUG
    852 		if (mac68k_esp_debug) {
    853 			printf("g.\n");
    854 		}
    855 #endif
    856 		if (espspl != -1) splx(espspl); espspl = -1;
    857 		return;
    858 	}
    859 
    860 gotintr:
    861 #if DEBUG
    862 	if (mac68k_esp_debug) {
    863 		printf("g!\n");
    864 	}
    865 #endif
    866 	ncr53c9x_intr(sc);
    867 	if (espspl != -1) splx(espspl); espspl = -1;
    868 }
    869 
    870 void
    871 esp_intr(sc)
    872 	void *sc;
    873 {
    874 	struct esp_softc *esc = (struct esp_softc *)sc;
    875 
    876 	if (esc->sc_reg[NCR_STAT * 16] & 0x80) {
    877 		ncr53c9x_intr((struct ncr53c9x_softc *) esp0);
    878 	}
    879 }
    880 
    881 void
    882 esp_dualbus_intr(sc)
    883 	void *sc;
    884 {
    885 	if (esp0 && (esp0->sc_reg[NCR_STAT * 16] & 0x80)) {
    886 		ncr53c9x_intr((struct ncr53c9x_softc *) esp0);
    887 	}
    888 
    889 	if (esp1 && (esp1->sc_reg[NCR_STAT * 16] & 0x80)) {
    890 		ncr53c9x_intr((struct ncr53c9x_softc *) esp1);
    891 	}
    892 }
    893