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esp.c revision 1.50
      1 /*	$NetBSD: esp.c,v 1.50 2008/04/13 04:55:52 tsutsui 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/cdefs.h>
     80 __KERNEL_RCSID(0, "$NetBSD: esp.c,v 1.50 2008/04/13 04:55:52 tsutsui Exp $");
     81 
     82 #include <sys/types.h>
     83 #include <sys/param.h>
     84 #include <sys/systm.h>
     85 #include <sys/kernel.h>
     86 #include <sys/errno.h>
     87 #include <sys/ioctl.h>
     88 #include <sys/device.h>
     89 #include <sys/buf.h>
     90 #include <sys/proc.h>
     91 #include <sys/user.h>
     92 #include <sys/queue.h>
     93 
     94 #include <dev/scsipi/scsi_all.h>
     95 #include <dev/scsipi/scsipi_all.h>
     96 #include <dev/scsipi/scsiconf.h>
     97 #include <dev/scsipi/scsi_message.h>
     98 
     99 #include <machine/cpu.h>
    100 #include <machine/bus.h>
    101 #include <machine/param.h>
    102 
    103 #include <dev/ic/ncr53c9xreg.h>
    104 #include <dev/ic/ncr53c9xvar.h>
    105 
    106 #include <machine/viareg.h>
    107 
    108 #include <mac68k/obio/espvar.h>
    109 #include <mac68k/obio/obiovar.h>
    110 
    111 int	espmatch(device_t, cfdata_t, void *);
    112 void	espattach(device_t, device_t, void *);
    113 
    114 /* Linkup to the rest of the kernel */
    115 CFATTACH_DECL_NEW(esp, sizeof(struct esp_softc),
    116     espmatch, espattach, NULL, NULL);
    117 
    118 /*
    119  * Functions and the switch for the MI code.
    120  */
    121 uint8_t	esp_read_reg(struct ncr53c9x_softc *, int);
    122 void	esp_write_reg(struct ncr53c9x_softc *, int, uint8_t);
    123 int	esp_dma_isintr(struct ncr53c9x_softc *);
    124 void	esp_dma_reset(struct ncr53c9x_softc *);
    125 int	esp_dma_intr(struct ncr53c9x_softc *);
    126 int	esp_dma_setup(struct ncr53c9x_softc *, uint8_t **, size_t *, int,
    127 	    size_t *);
    128 void	esp_dma_go(struct ncr53c9x_softc *);
    129 void	esp_dma_stop(struct ncr53c9x_softc *);
    130 int	esp_dma_isactive(struct ncr53c9x_softc *);
    131 void	esp_quick_write_reg(struct ncr53c9x_softc *, int, u_char);
    132 int	esp_quick_dma_intr(struct ncr53c9x_softc *);
    133 int	esp_quick_dma_setup(struct ncr53c9x_softc *, uint8_t **, size_t *, int,
    134 	     size_t *);
    135 void	esp_quick_dma_go(struct ncr53c9x_softc *);
    136 
    137 void	esp_intr(void *);
    138 void	esp_dualbus_intr(void *);
    139 static struct esp_softc		*esp0, *esp1;
    140 
    141 static inline int esp_dafb_have_dreq(struct esp_softc *);
    142 static inline int esp_iosb_have_dreq(struct esp_softc *);
    143 int (*esp_have_dreq)(struct esp_softc *);
    144 
    145 struct ncr53c9x_glue esp_glue = {
    146 	esp_read_reg,
    147 	esp_write_reg,
    148 	esp_dma_isintr,
    149 	esp_dma_reset,
    150 	esp_dma_intr,
    151 	esp_dma_setup,
    152 	esp_dma_go,
    153 	esp_dma_stop,
    154 	esp_dma_isactive,
    155 	NULL,			/* gl_clear_latched_intr */
    156 };
    157 
    158 int
    159 espmatch(device_t parent, cfdata_t cf, void *aux)
    160 {
    161 	struct obio_attach_args *oa = aux;
    162 
    163 	if (oa->oa_addr == 0 && mac68k_machine.scsi96) {
    164 		return 1;
    165 	}
    166 	if (oa->oa_addr == 1 && mac68k_machine.scsi96_2) {
    167 		return 1;
    168 	}
    169 	return 0;
    170 }
    171 
    172 /*
    173  * Attach this instance, and then all the sub-devices
    174  */
    175 void
    176 espattach(device_t parent, device_t self, void *aux)
    177 {
    178 	struct esp_softc	*esc = device_private(self);
    179 	struct ncr53c9x_softc	*sc = &esc->sc_ncr53c9x;
    180 	struct obio_attach_args *oa = aux;
    181 	int			quick = 0;
    182 	unsigned long		reg_offset;
    183 	extern vaddr_t		SCSIBase;
    184 
    185 	sc->sc_dev = self;
    186 
    187 	reg_offset = SCSIBase - IOBase;
    188 	esc->sc_tag = oa->oa_tag;
    189 
    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 (oa->oa_addr == 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 				aprint_error(": failed to map 4"
    211 				    " 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 			aprint_error(": 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 (oa->oa_addr == 0) {
    243 		esp0 = esc;
    244 
    245 		esc->sc_reg = (volatile uint8_t *)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 			aprint_normal(" (quick)");
    257 		}
    258 	} else {
    259 		esp1 = esc;
    260 
    261 		esc->sc_reg = (volatile uint8_t *)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 	aprint_normal(": 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         switch (current_mac_model->machineid) {
    303         case MACH_MACQ630:
    304 		/* XXX on LC630 64k xfer causes timeout error */
    305 		sc->sc_maxxfer = 63 * 1024;
    306 		break;
    307 	}
    308 
    309 	if (!quick) {
    310 		sc->sc_minsync = 0;	/* No synchronous xfers w/o DMA */
    311 		sc->sc_maxxfer = 8 * 1024;
    312 	}
    313 
    314 	/*
    315 	 * Configure interrupts.
    316 	 */
    317 	if (esc->irq_mask) {
    318 		via2_reg(vPCR) = 0x22;
    319 		via2_reg(vIFR) = esc->irq_mask;
    320 		via2_reg(vIER) = 0x80 | esc->irq_mask;
    321 	}
    322 
    323 	/*
    324 	 * Now try to attach all the sub-devices
    325 	 */
    326 	sc->sc_adapter.adapt_minphys = minphys;
    327 	sc->sc_adapter.adapt_request = ncr53c9x_scsipi_request;
    328 	ncr53c9x_attach(sc);
    329 }
    330 
    331 /*
    332  * Glue functions.
    333  */
    334 
    335 uint8_t
    336 esp_read_reg(struct ncr53c9x_softc *sc, int reg)
    337 {
    338 	struct esp_softc *esc = (struct esp_softc *)sc;
    339 
    340 	return esc->sc_reg[reg * 16];
    341 }
    342 
    343 void
    344 esp_write_reg(struct ncr53c9x_softc *sc, int reg, uint8_t val)
    345 {
    346 	struct esp_softc *esc = (struct esp_softc *)sc;
    347 	uint8_t	v = val;
    348 
    349 	if (reg == NCR_CMD && v == (NCRCMD_TRANS|NCRCMD_DMA)) {
    350 		v = NCRCMD_TRANS;
    351 	}
    352 	esc->sc_reg[reg * 16] = v;
    353 }
    354 
    355 void
    356 esp_dma_stop(struct ncr53c9x_softc *sc)
    357 {
    358 }
    359 
    360 int
    361 esp_dma_isactive(struct ncr53c9x_softc *sc)
    362 {
    363 	struct esp_softc *esc = (struct esp_softc *)sc;
    364 
    365 	return esc->sc_active;
    366 }
    367 
    368 int
    369 esp_dma_isintr(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(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(struct ncr53c9x_softc *sc)
    387 {
    388 	struct esp_softc *esc = (struct esp_softc *)sc;
    389 	volatile u_char *cmdreg, *intrreg, *statreg, *fiforeg;
    390 	uint8_t	*p;
    391 	u_int	espphase, espstat, espintr;
    392 	int	cnt, s;
    393 
    394 	if (esc->sc_active == 0) {
    395 		printf("dma_intr--inactive DMA\n");
    396 		return -1;
    397 	}
    398 
    399 	if ((sc->sc_espintr & NCRINTR_BS) == 0) {
    400 		esc->sc_active = 0;
    401 		return 0;
    402 	}
    403 
    404 	cnt = *esc->sc_dmalen;
    405 	if (*esc->sc_dmalen == 0) {
    406 		printf("data interrupt, but no count left.");
    407 	}
    408 
    409 	p = *esc->sc_dmaaddr;
    410 	espphase = sc->sc_phase;
    411 	espstat = (u_int)sc->sc_espstat;
    412 	espintr = (u_int)sc->sc_espintr;
    413 	cmdreg = esc->sc_reg + NCR_CMD * 16;
    414 	fiforeg = esc->sc_reg + NCR_FIFO * 16;
    415 	statreg = esc->sc_reg + NCR_STAT * 16;
    416 	intrreg = esc->sc_reg + NCR_INTR * 16;
    417 	do {
    418 		if (esc->sc_datain) {
    419 			*p++ = *fiforeg;
    420 			cnt--;
    421 			if (espphase == DATA_IN_PHASE) {
    422 				*cmdreg = NCRCMD_TRANS;
    423 			} else {
    424 				esc->sc_active = 0;
    425 			}
    426 	 	} else {
    427 			if (   (espphase == DATA_OUT_PHASE)
    428 			    || (espphase == MESSAGE_OUT_PHASE)) {
    429 				*fiforeg = *p++;
    430 				cnt--;
    431 				*cmdreg = NCRCMD_TRANS;
    432 			} else {
    433 				esc->sc_active = 0;
    434 			}
    435 		}
    436 
    437 		if (esc->sc_active) {
    438 			while (!(*statreg & 0x80));
    439 			s = splhigh();
    440 			espstat = *statreg;
    441 			espintr = *intrreg;
    442 			espphase = (espintr & NCRINTR_DIS)
    443 				    ? /* Disconnected */ BUSFREE_PHASE
    444 				    : espstat & PHASE_MASK;
    445 			splx(s);
    446 		}
    447 	} while (esc->sc_active && (espintr & NCRINTR_BS));
    448 	sc->sc_phase = espphase;
    449 	sc->sc_espstat = (u_char)espstat;
    450 	sc->sc_espintr = (u_char)espintr;
    451 	*esc->sc_dmaaddr = p;
    452 	*esc->sc_dmalen = cnt;
    453 
    454 	if (*esc->sc_dmalen == 0) {
    455 		esc->sc_tc = NCRSTAT_TC;
    456 	}
    457 	sc->sc_espstat |= esc->sc_tc;
    458 	return 0;
    459 }
    460 
    461 int
    462 esp_dma_setup(struct ncr53c9x_softc *sc, uint8_t **addr, size_t *len,
    463     int datain, size_t *dmasize)
    464 {
    465 	struct esp_softc *esc = (struct esp_softc *)sc;
    466 
    467 	esc->sc_dmaaddr = addr;
    468 	esc->sc_dmalen = len;
    469 	esc->sc_datain = datain;
    470 	esc->sc_dmasize = *dmasize;
    471 	esc->sc_tc = 0;
    472 
    473 	return 0;
    474 }
    475 
    476 void
    477 esp_dma_go(struct ncr53c9x_softc *sc)
    478 {
    479 	struct esp_softc *esc = (struct esp_softc *)sc;
    480 
    481 	if (esc->sc_datain == 0) {
    482 		esc->sc_reg[NCR_FIFO * 16] = **esc->sc_dmaaddr;
    483 		(*esc->sc_dmalen)--;
    484 		(*esc->sc_dmaaddr)++;
    485 	}
    486 	esc->sc_active = 1;
    487 }
    488 
    489 void
    490 esp_quick_write_reg(struct ncr53c9x_softc *sc, int reg, u_char val)
    491 {
    492 	struct esp_softc *esc = (struct esp_softc *)sc;
    493 
    494 	esc->sc_reg[reg * 16] = val;
    495 }
    496 
    497 #if DEBUG
    498 int mac68k_esp_debug=0;
    499 #endif
    500 
    501 int
    502 esp_quick_dma_intr(struct ncr53c9x_softc *sc)
    503 {
    504 	struct esp_softc *esc = (struct esp_softc *)sc;
    505 	int trans=0, resid=0;
    506 
    507 	if (esc->sc_active == 0)
    508 		panic("dma_intr--inactive DMA");
    509 
    510 	esc->sc_active = 0;
    511 
    512 	if (esc->sc_dmasize == 0) {
    513 		int	res;
    514 
    515 		res = NCR_READ_REG(sc, NCR_TCL);
    516 		res += NCR_READ_REG(sc, NCR_TCM) << 8;
    517 		/* This can happen in the case of a TRPAD operation */
    518 		/* Pretend that it was complete */
    519 		sc->sc_espstat |= NCRSTAT_TC;
    520 #if DEBUG
    521 		if (mac68k_esp_debug) {
    522 			printf("dmaintr: DMA xfer of zero xferred %d\n",
    523 			    65536 - res);
    524 		}
    525 #endif
    526 		return 0;
    527 	}
    528 
    529 	if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
    530 		if (esc->sc_datain == 0) {
    531 			resid = NCR_READ_REG(sc, NCR_FFLAG) & 0x1f;
    532 #if DEBUG
    533 			if (mac68k_esp_debug) {
    534 				printf("Write FIFO residual %d bytes\n", resid);
    535 			}
    536 #endif
    537 		}
    538 		resid += NCR_READ_REG(sc, NCR_TCL);
    539 		resid += NCR_READ_REG(sc, NCR_TCM) << 8;
    540 		if (resid == 0)
    541 			resid = 65536;
    542 	}
    543 
    544 	trans = esc->sc_dmasize - resid;
    545 	if (trans < 0) {
    546 		printf("dmaintr: trans < 0????");
    547 		trans = *esc->sc_dmalen;
    548 	}
    549 
    550 	NCR_DMA(("dmaintr: trans %d, resid %d.\n", trans, resid));
    551 #if DEBUG
    552 	if (mac68k_esp_debug) {
    553 		printf("eqd_intr: trans %d, resid %d.\n", trans, resid);
    554 	}
    555 #endif
    556 	*esc->sc_dmaaddr += trans;
    557 	*esc->sc_dmalen -= trans;
    558 
    559 	return 0;
    560 }
    561 
    562 int
    563 esp_quick_dma_setup(struct ncr53c9x_softc *sc, uint8_t **addr, size_t *len,
    564     int datain, 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 	if (*len & 1) {
    572 		esc->sc_pad = 1;
    573 	} else {
    574 		esc->sc_pad = 0;
    575 	}
    576 
    577 	esc->sc_datain = datain;
    578 	esc->sc_dmasize = *dmasize;
    579 
    580 #if DIAGNOSTIC
    581 	if (esc->sc_dmasize == 0) {
    582 		/* This can happen in the case of a TRPAD operation */
    583 	}
    584 #endif
    585 #if DEBUG
    586 	if (mac68k_esp_debug) {
    587 	printf("eqd_setup: addr %lx, len %lx, in? %d, dmasize %lx\n",
    588 	    (long) *addr, (long) *len, datain, (long) esc->sc_dmasize);
    589 	}
    590 #endif
    591 
    592 	return 0;
    593 }
    594 
    595 static inline int
    596 esp_dafb_have_dreq(struct esp_softc *esc)
    597 {
    598 
    599 	return *(volatile uint32_t *)(esc->sc_bsh.base) & 0x200;
    600 }
    601 
    602 static inline int
    603 esp_iosb_have_dreq(struct esp_softc *esc)
    604 {
    605 
    606 	return via2_reg(vIFR) & V2IF_SCSIDRQ;
    607 }
    608 
    609 static volatile int espspl = -1;
    610 
    611 /*
    612  * Apple "DMA" is weird.
    613  *
    614  * Basically, the CPU acts like the DMA controller.  The DREQ/ off the
    615  * chip goes to a register that we've mapped at attach time (on the
    616  * IOSB or DAFB, depending on the machine).  Apple also provides some
    617  * space for which the memory controller handshakes data to/from the
    618  * NCR chip with the DACK/ line.  This space appears to be mapped over
    619  * and over, every 4 bytes, but only the lower 16 bits are valid (but
    620  * reading the upper 16 bits will handshake DACK/ just fine, so if you
    621  * read *u_int16_t++ = *u_int16_t++ in a loop, you'll get
    622  * <databyte><databyte>0xff0xff<databyte><databyte>0xff0xff...
    623  *
    624  * When you're attempting to read or write memory to this DACK/ed space,
    625  * and the NCR is not ready for some timeout period, the system will
    626  * generate a bus error.  This might be for one of several reasons:
    627  *
    628  *	1) (on write) The FIFO is full and is not draining.
    629  *	2) (on read) The FIFO is empty and is not filling.
    630  *	3) An interrupt condition has occurred.
    631  *	4) Anything else?
    632  *
    633  * So if a bus error occurs, we first turn off the nofault bus error handler,
    634  * then we check for an interrupt (which would render the first two
    635  * possibilities moot).  If there's no interrupt, check for a DREQ/.  If we
    636  * have that, then attempt to resume stuffing (or unstuffing) the FIFO.  If
    637  * neither condition holds, pause briefly and check again.
    638  *
    639  * NOTE!!!  In order to make allowances for the hardware structure of
    640  *          the mac, spl values in here are hardcoded!!!!!!!!!
    641  *          This is done to allow serial interrupts to get in during
    642  *          scsi transfers.  This is ugly.
    643  */
    644 void
    645 esp_quick_dma_go(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 	uint16_t volatile *pdma;
    652 	uint16_t *addr;
    653 	int		len, res;
    654 	uint16_t	cnt32, cnt2;
    655 	volatile uint8_t *statreg;
    656 
    657 	esc->sc_active = 1;
    658 
    659 	espspl = splhigh();
    660 
    661 	addr = (uint16_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 = NULL;
    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 remaining length from the address
    700 				 * differential.
    701 				 */
    702 				addr = (uint16_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("%s: res %d != len %d",
    730 						    __func__, res, len);
    731 					}
    732 				}
    733 				break;
    734 			}
    735 
    736 			DELAY(1);
    737 			if (i++ > 1000000)
    738 				panic("%s: Bus error, but no condition!  Argh!",
    739 				    __func__);
    740 		}
    741 		goto restart_dmago;
    742 	}
    743 
    744 	len &= ~1;
    745 
    746 	statreg = esc->sc_reg + NCR_STAT * 16;
    747 	pdma = (volatile uint16_t *)(esc->sc_reg + 0x100);
    748 
    749 	/*
    750 	 * These loops are unrolled into assembly for two reasons:
    751 	 * 1) We can make sure that they are as efficient as possible, and
    752 	 * 2) (more importantly) we need the address that we are reading
    753 	 *    from or writing to to be in a2.
    754 	 */
    755 	cnt32 = len / 32;
    756 	cnt2 = (len % 32) / 2;
    757 	if (esc->sc_datain == 0) {
    758 		/* while (cnt32--) { 16 instances of *pdma = *addr++; } */
    759 		/* while (cnt2--) { *pdma = *addr++; } */
    760 		__asm volatile (
    761 			"	movl %1, %%a2	\n"
    762 			"	movl %2, %%a3	\n"
    763 			"	movw %3, %%d2	\n"
    764 			"	cmpw #0, %%d2	\n"
    765 			"	beq  2f		\n"
    766 			"	subql #1, %%d2	\n"
    767 			"1:	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    768 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    769 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    770 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    771 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    772 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    773 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    774 			"	movw %%a2@+,%%a3@; movw %%a2@+,%%a3@	\n"
    775 			"	movw #8704,%%sr	\n"
    776 			"	movw #9728,%%sr	\n"
    777 			"	dbra %%d2, 1b	\n"
    778 			"2:	movw %4, %%d2	\n"
    779 			"	cmpw #0, %%d2	\n"
    780 			"	beq  4f		\n"
    781 			"	subql #1, %%d2	\n"
    782 			"3:	movw %%a2@+,%%a3@ \n"
    783 			"	dbra %%d2, 3b	\n"
    784 			"4:	movl %%a2, %0"
    785 			: "=g" (addr)
    786 			: "0" (addr), "g" (pdma), "g" (cnt32), "g" (cnt2)
    787 			: "a2", "a3", "d2");
    788 		if (esc->sc_pad) {
    789 			volatile uint8_t *c;
    790 			c = (volatile uint8_t *) addr;
    791 			/* Wait for DREQ */
    792 			while (!esp_have_dreq(esc)) {
    793 				if (*statreg & 0x80) {
    794 					nofault = NULL;
    795 					goto gotintr;
    796 				}
    797 			}
    798 			*(volatile int8_t *)pdma = *c;
    799 		}
    800 	} else {
    801 		/* while (cnt32--) { 16 instances of *addr++ = *pdma; } */
    802 		/* while (cnt2--) { *addr++ = *pdma; } */
    803 		__asm volatile (
    804 			"	movl %1, %%a2	\n"
    805 			"	movl %2, %%a3	\n"
    806 			"	movw %3, %%d2	\n"
    807 			"	cmpw #0, %%d2	\n"
    808 			"	beq  6f		\n"
    809 			"	subql #1, %%d2	\n"
    810 			"5:	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    811 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    812 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    813 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    814 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    815 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    816 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    817 			"	movw %%a3@,%%a2@+; movw %%a3@,%%a2@+	\n"
    818 			"	movw #8704,%%sr	\n"
    819 			"	movw #9728,%%sr	\n"
    820 			"	dbra %%d2, 5b	\n"
    821 			"6:	movw %4, %%d2	\n"
    822 			"	cmpw #0, %%d2	\n"
    823 			"	beq  8f		\n"
    824 			"	subql #1, %%d2	\n"
    825 			"7:	movw %%a3@,%%a2@+ \n"
    826 			"	dbra %%d2, 7b	\n"
    827 			"8:	movl %%a2, %0"
    828 			: "=g" (addr)
    829 			: "0" (addr), "g" (pdma), "g" (cnt32), "g" (cnt2)
    830 			: "a2", "a3", "d2");
    831 		if (esc->sc_pad) {
    832 			volatile uint8_t *c;
    833 			c = (volatile int8_t *)addr;
    834 			/* Wait for DREQ */
    835 			while (!esp_have_dreq(esc)) {
    836 				if (*statreg & 0x80) {
    837 					nofault = NULL;
    838 					goto gotintr;
    839 				}
    840 			}
    841 			*c = *(volatile uint8_t *)pdma;
    842 		}
    843 	}
    844 
    845 	nofault = NULL;
    846 
    847 	/*
    848 	 * If we have not received an interrupt yet, we should shortly,
    849 	 * and we can't prevent it, so return and wait for it.
    850 	 */
    851 	if ((*statreg & 0x80) == 0) {
    852 #if DEBUG
    853 		if (mac68k_esp_debug) {
    854 			printf("g.\n");
    855 		}
    856 #endif
    857 		if (espspl != -1)
    858 			splx(espspl);
    859 		espspl = -1;
    860 		return;
    861 	}
    862 
    863 gotintr:
    864 #if DEBUG
    865 	if (mac68k_esp_debug) {
    866 		printf("g!\n");
    867 	}
    868 #endif
    869 	ncr53c9x_intr(sc);
    870 	if (espspl != -1)
    871 		splx(espspl);
    872 	espspl = -1;
    873 }
    874 
    875 void
    876 esp_intr(void *sc)
    877 {
    878 	struct esp_softc *esc = (struct esp_softc *)sc;
    879 
    880 	if (esc->sc_reg[NCR_STAT * 16] & 0x80) {
    881 		ncr53c9x_intr((struct ncr53c9x_softc *)esp0);
    882 	}
    883 }
    884 
    885 void
    886 esp_dualbus_intr(void *sc)
    887 {
    888 	if (esp0 && (esp0->sc_reg[NCR_STAT * 16] & 0x80)) {
    889 		ncr53c9x_intr((struct ncr53c9x_softc *)esp0);
    890 	}
    891 
    892 	if (esp1 && (esp1->sc_reg[NCR_STAT * 16] & 0x80)) {
    893 		ncr53c9x_intr((struct ncr53c9x_softc *)esp1);
    894 	}
    895 }
    896