xref: /netbsd-src/sys/arch/mac68k/dev/sbc.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: sbc.c,v 1.33 1997/12/06 18:53:30 scottr Exp $	*/
2 
3 /*
4  * Copyright (C) 1996 Scott Reynolds.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * This file contains only the machine-dependent parts of the mac68k
31  * NCR 5380 SCSI driver.  (Autoconfig stuff and PDMA functions.)
32  * The machine-independent parts are in ncr5380sbc.c
33  *
34  * Supported hardware includes:
35  * Macintosh II family 5380-based controller
36  *
37  * Credits, history:
38  *
39  * Scott Reynolds wrote this module, based on work by Allen Briggs
40  * (mac68k), Gordon W. Ross and David Jones (sun3), and Leo Weppelman
41  * (atari).  Thanks to Allen for supplying crucial interpretation of the
42  * NetBSD/mac68k 1.1 'ncrscsi' driver.  Also, Allen, Gordon, and Jason
43  * Thorpe all helped to refine this code, and were considerable sources
44  * of moral support.
45  */
46 
47 #include <sys/types.h>
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/errno.h>
52 #include <sys/device.h>
53 #include <sys/buf.h>
54 #include <sys/proc.h>
55 #include <sys/user.h>
56 
57 #include <dev/scsipi/scsi_all.h>
58 #include <dev/scsipi/scsipi_all.h>
59 #include <dev/scsipi/scsipi_debug.h>
60 #include <dev/scsipi/scsiconf.h>
61 
62 #include <dev/ic/ncr5380reg.h>
63 #include <dev/ic/ncr5380var.h>
64 
65 #include <machine/cpu.h>
66 #include <machine/viareg.h>
67 
68 #include <mac68k/dev/sbcreg.h>
69 #include <mac68k/dev/sbcvar.h>
70 
71 int	sbc_debug = 0 /* | SBC_DB_INTR | SBC_DB_DMA */;
72 int	sbc_link_flags = 0 /* | SDEV_DB2 */;
73 int	sbc_options = 0 /* | SBC_PDMA */;
74 
75 static	void	sbc_minphys __P((struct buf *bp));
76 
77 struct scsipi_adapter	sbc_ops = {
78 	ncr5380_scsi_cmd,		/* scsi_cmd()		*/
79 	sbc_minphys,			/* scsi_minphys()	*/
80 	NULL,				/* open_target_lu()	*/
81 	NULL,				/* close_target_lu()	*/
82 };
83 
84 /* This is copied from julian's bt driver */
85 /* "so we have a default dev struct for our link struct." */
86 struct scsipi_device sbc_dev = {
87 	NULL,		/* Use default error handler.	    */
88 	NULL,		/* Use default start handler.		*/
89 	NULL,		/* Use default async handler.	    */
90 	NULL,		/* Use default "done" routine.	    */
91 };
92 
93 struct cfdriver sbc_cd = {
94 	NULL, "sbc", DV_DULL
95 };
96 
97 extern label_t	*nofault;
98 extern caddr_t	m68k_fault_addr;
99 
100 static	int	sbc_wait_busy __P((struct ncr5380_softc *));
101 static	int	sbc_ready __P((struct ncr5380_softc *));
102 static	int	sbc_wait_dreq __P((struct ncr5380_softc *));
103 
104 static void
105 sbc_minphys(struct buf *bp)
106 {
107 	if (bp->b_bcount > MAX_DMA_LEN)
108 		bp->b_bcount = MAX_DMA_LEN;
109 	return (minphys(bp));
110 }
111 
112 
113 /***
114  * General support for Mac-specific SCSI logic.
115  ***/
116 
117 /* These are used in the following inline functions. */
118 int sbc_wait_busy_timo = 1000 * 5000;	/* X2 = 10 S. */
119 int sbc_ready_timo = 1000 * 5000;	/* X2 = 10 S. */
120 int sbc_wait_dreq_timo = 1000 * 5000;	/* X2 = 10 S. */
121 
122 /* Return zero on success. */
123 static __inline__ int
124 sbc_wait_busy(sc)
125 	struct ncr5380_softc *sc;
126 {
127 	int timo = sbc_wait_busy_timo;
128 	for (;;) {
129 		if (SCI_BUSY(sc)) {
130 			timo = 0;	/* return 0 */
131 			break;
132 		}
133 		if (--timo < 0)
134 			break;	/* return -1 */
135 		delay(2);
136 	}
137 	return (timo);
138 }
139 
140 static __inline__ int
141 sbc_ready(sc)
142 	struct ncr5380_softc *sc;
143 {
144 	int timo = sbc_ready_timo;
145 
146 	for (;;) {
147 		if ((*sc->sci_csr & (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH))
148 		    == (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH)) {
149 			timo = 0;
150 			break;
151 		}
152 		if (((*sc->sci_csr & SCI_CSR_PHASE_MATCH) == 0)
153 		    || (SCI_BUSY(sc) == 0)) {
154 			timo = -1;
155 			break;
156 		}
157 		if (--timo < 0)
158 			break;	/* return -1 */
159 		delay(2);
160 	}
161 	return (timo);
162 }
163 
164 static __inline__ int
165 sbc_wait_dreq(sc)
166 	struct ncr5380_softc *sc;
167 {
168 	int timo = sbc_wait_dreq_timo;
169 
170 	for (;;) {
171 		if ((*sc->sci_csr & (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH))
172 		    == (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH)) {
173 			timo = 0;
174 			break;
175 		}
176 		if (--timo < 0)
177 			break;	/* return -1 */
178 		delay(2);
179 	}
180 	return (timo);
181 }
182 
183 void
184 sbc_irq_intr(p)
185 	void *p;
186 {
187 	struct ncr5380_softc *ncr_sc = p;
188 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
189 	int claimed = 0;
190 	extern int cold;
191 
192 	/* How we ever arrive here without IRQ set is a mystery... */
193 	if (*ncr_sc->sci_csr & SCI_CSR_INT) {
194 #ifdef SBC_DEBUG
195 		if (sbc_debug & SBC_DB_INTR)
196 			decode_5380_intr(ncr_sc);
197 #endif
198 		if (!cold)
199 			claimed = ncr5380_intr(ncr_sc);
200 		if (!claimed) {
201 			if (((*ncr_sc->sci_csr & ~SCI_CSR_PHASE_MATCH) == SCI_CSR_INT)
202 			    && ((*ncr_sc->sci_bus_csr & ~SCI_BUS_RST) == 0)) {
203 				SCI_CLR_INTR(ncr_sc);	/* RST interrupt */
204 				if (sc->sc_clrintr)
205 					(*sc->sc_clrintr)(ncr_sc);
206 			}
207 #ifdef SBC_DEBUG
208 			else {
209 				printf("%s: spurious intr\n",
210 				    ncr_sc->sc_dev.dv_xname);
211 				SBC_BREAK;
212 			}
213 #endif
214 		}
215 	}
216 }
217 
218 #ifdef SBC_DEBUG
219 void
220 decode_5380_intr(ncr_sc)
221 	struct ncr5380_softc *ncr_sc;
222 {
223 	u_int8_t csr = *ncr_sc->sci_csr;
224 	u_int8_t bus_csr = *ncr_sc->sci_bus_csr;
225 
226 	if (((csr & ~(SCI_CSR_PHASE_MATCH | SCI_CSR_ATN)) == SCI_CSR_INT) &&
227 	    ((bus_csr & ~(SCI_BUS_MSG | SCI_BUS_CD | SCI_BUS_IO | SCI_BUS_DBP)) == SCI_BUS_SEL)) {
228 		if (csr & SCI_BUS_IO)
229 			printf("%s: reselect\n", ncr_sc->sc_dev.dv_xname);
230 		else
231 			printf("%s: select\n", ncr_sc->sc_dev.dv_xname);
232 	} else if (((csr & ~SCI_CSR_ACK) == (SCI_CSR_DONE | SCI_CSR_INT)) &&
233 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_SEL)) == SCI_BUS_BSY))
234 		printf("%s: dma eop\n", ncr_sc->sc_dev.dv_xname);
235 	else if (((csr & ~SCI_CSR_PHASE_MATCH) == SCI_CSR_INT) &&
236 	    ((bus_csr & ~SCI_BUS_RST) == 0))
237 		printf("%s: bus reset\n", ncr_sc->sc_dev.dv_xname);
238 	else if (((csr & ~(SCI_CSR_DREQ | SCI_CSR_ATN | SCI_CSR_ACK)) == (SCI_CSR_PERR | SCI_CSR_INT | SCI_CSR_PHASE_MATCH)) &&
239 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_SEL)) == SCI_BUS_BSY))
240 		printf("%s: parity error\n", ncr_sc->sc_dev.dv_xname);
241 	else if (((csr & ~SCI_CSR_ATN) == SCI_CSR_INT) &&
242 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_REQ | SCI_BUS_SEL)) == (SCI_BUS_BSY | SCI_BUS_REQ)))
243 		printf("%s: phase mismatch\n", ncr_sc->sc_dev.dv_xname);
244 	else if (((csr & ~SCI_CSR_PHASE_MATCH) == (SCI_CSR_INT | SCI_CSR_DISC)) &&
245 	    (bus_csr == 0))
246 		printf("%s: disconnect\n", ncr_sc->sc_dev.dv_xname);
247 	else
248 		printf("%s: unknown intr: csr=%x, bus_csr=%x\n",
249 		    ncr_sc->sc_dev.dv_xname, csr, bus_csr);
250 }
251 #endif
252 
253 
254 /***
255  * The following code implements polled PDMA.
256  ***/
257 
258 int
259 sbc_pdma_in(ncr_sc, phase, datalen, data)
260 	struct ncr5380_softc *ncr_sc;
261 	int phase;
262 	int datalen;
263 	u_char *data;
264 {
265 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
266 	volatile u_int32_t *long_data = (u_int32_t *)sc->sc_drq_addr;
267 	volatile u_int8_t *byte_data = (u_int8_t *)sc->sc_nodrq_addr;
268 	int resid, s;
269 
270 	if (datalen < ncr_sc->sc_min_dma_len ||
271 	    (sc->sc_options & SBC_PDMA) == 0)
272 		return ncr5380_pio_in(ncr_sc, phase, datalen, data);
273 
274 	s = splbio();
275 	if (sbc_wait_busy(ncr_sc)) {
276 		splx(s);
277 		return 0;
278 	}
279 
280 	*ncr_sc->sci_mode |= SCI_MODE_DMA;
281 	*ncr_sc->sci_irecv = 0;
282 
283 #define R4	*((u_int32_t *)data)++ = *long_data
284 #define R1	*((u_int8_t *)data)++ = *byte_data
285 	for (resid = datalen; resid >= 128; resid -= 128) {
286 		if (sbc_ready(ncr_sc))
287 			goto interrupt;
288 		R4; R4; R4; R4; R4; R4; R4; R4;
289 		R4; R4; R4; R4; R4; R4; R4; R4;
290 		R4; R4; R4; R4; R4; R4; R4; R4;
291 		R4; R4; R4; R4; R4; R4; R4; R4;		/* 128 */
292 	}
293 	while (resid) {
294 		if (sbc_ready(ncr_sc))
295 			goto interrupt;
296 		R1;
297 		resid--;
298 	}
299 #undef R4
300 #undef R1
301 
302 interrupt:
303 	SCI_CLR_INTR(ncr_sc);
304 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
305 	*ncr_sc->sci_icmd = 0;
306 	splx(s);
307 	return (datalen - resid);
308 }
309 
310 int
311 sbc_pdma_out(ncr_sc, phase, datalen, data)
312 	struct ncr5380_softc *ncr_sc;
313 	int phase;
314 	int datalen;
315 	u_char *data;
316 {
317 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
318 	volatile u_int32_t *long_data = (u_int32_t *)sc->sc_drq_addr;
319 	volatile u_int8_t *byte_data = (u_int8_t *)sc->sc_nodrq_addr;
320 	label_t faultbuf;
321 	int resid, s;
322 	u_int8_t icmd;
323 
324 #if 1
325 	/* Work around lame gcc initialization bug */
326 	(void)&data;
327 #endif
328 
329 	if (datalen < ncr_sc->sc_min_dma_len ||
330 	    (sc->sc_options & SBC_PDMA) == 0)
331 		return ncr5380_pio_out(ncr_sc, phase, datalen, data);
332 
333 	s = splbio();
334 	if (sbc_wait_busy(ncr_sc)) {
335 		splx(s);
336 		return 0;
337 	}
338 
339 	icmd = *(ncr_sc->sci_icmd) & SCI_ICMD_RMASK;
340 	*ncr_sc->sci_icmd = icmd | SCI_ICMD_DATA;
341 	*ncr_sc->sci_mode |= SCI_MODE_DMA;
342 	*ncr_sc->sci_dma_send = 0;
343 
344 	/*
345 	 * Setup for a possible bus error caused by SCSI controller
346 	 * switching out of DATA OUT before we're done with the
347 	 * current transfer.  (See comment before sbc_drq_intr().)
348 	 */
349 	nofault = &faultbuf;
350 
351 	if (setjmp(nofault)) {
352 		printf("buf = 0x%lx, fault = 0x%lx\n",
353 		    (u_long)sc->sc_drq_addr, (u_long)m68k_fault_addr);
354 		panic("Unexpected bus error in sbc_pdma_out()");
355 	}
356 
357 #define W1	*byte_data = *((u_int8_t *)data)++
358 #define W4	*long_data = *((u_int32_t *)data)++
359 	for (resid = datalen; resid >= 64; resid -= 64) {
360 		if (sbc_ready(ncr_sc))
361 			goto interrupt;
362 		W1;
363 		if (sbc_ready(ncr_sc))
364 			goto interrupt;
365 		W1;
366 		if (sbc_ready(ncr_sc))
367 			goto interrupt;
368 		W1;
369 		if (sbc_ready(ncr_sc))
370 			goto interrupt;
371 		W1;
372 		if (sbc_ready(ncr_sc))
373 			goto interrupt;
374 		W4; W4; W4; W4;
375 		W4; W4; W4; W4;
376 		W4; W4; W4; W4;
377 		W4; W4; W4;
378 	}
379 	while (resid) {
380 		if (sbc_ready(ncr_sc))
381 			goto interrupt;
382 		W1;
383 		resid--;
384 	}
385 #undef  W1
386 #undef  W4
387 	if (sbc_wait_dreq(ncr_sc))
388 		printf("%s: timeout waiting for DREQ.\n",
389 		    ncr_sc->sc_dev.dv_xname);
390 
391 	*byte_data = 0;
392 	goto done;
393 
394 interrupt:
395 	if ((*ncr_sc->sci_csr & SCI_CSR_PHASE_MATCH) == 0) {
396 		*ncr_sc->sci_icmd = icmd & ~SCI_ICMD_DATA;
397 		--resid;
398 	}
399 
400 done:
401 	SCI_CLR_INTR(ncr_sc);
402 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
403 	*ncr_sc->sci_icmd = icmd;
404 	splx(s);
405 	return (datalen - resid);
406 }
407 
408 
409 /***
410  * The following code implements interrupt-driven PDMA.
411  ***/
412 
413 /*
414  * This is the meat of the PDMA transfer.
415  * When we get here, we shove data as fast as the mac can take it.
416  * We depend on several things:
417  *   * All macs after the Mac Plus that have a 5380 chip should have a general
418  *     logic IC that handshakes data for blind transfers.
419  *   * If the SCSI controller finishes sending/receiving data before we do,
420  *     the same general logic IC will generate a /BERR for us in short order.
421  *   * The fault address for said /BERR minus the base address for the
422  *     transfer will be the amount of data that was actually written.
423  *
424  * We use the nofault flag and the setjmp/longjmp in locore.s so we can
425  * detect and handle the bus error for early termination of a command.
426  * This is usually caused by a disconnecting target.
427  */
428 void
429 sbc_drq_intr(p)
430 	void *p;
431 {
432 	struct sbc_softc *sc = (struct sbc_softc *)p;
433 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)p;
434 	struct sci_req *sr = ncr_sc->sc_current;
435 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
436 	label_t faultbuf;
437 	volatile u_int32_t *long_drq;
438 	u_int32_t *long_data;
439 	volatile u_int8_t *drq;
440 	u_int8_t *data;
441 	int count, dcount, resid;
442 	u_int8_t tmp;
443 
444 	/* Work around lame gcc initialization bug */
445 	(void)&drq;
446 
447 	/*
448 	 * If we're not ready to xfer data, or have no more, just return.
449 	 */
450 	if ((*ncr_sc->sci_csr & SCI_CSR_DREQ) == 0 || dh->dh_len == 0)
451 		return;
452 
453 #ifdef SBC_DEBUG
454 	if (sbc_debug & SBC_DB_INTR)
455 		printf("%s: drq intr, dh_len=0x%x, dh_flags=0x%x\n",
456 		    ncr_sc->sc_dev.dv_xname, dh->dh_len, dh->dh_flags);
457 #endif
458 
459 	/*
460 	 * Setup for a possible bus error caused by SCSI controller
461 	 * switching out of DATA-IN/OUT before we're done with the
462 	 * current transfer.
463 	 */
464 	nofault = &faultbuf;
465 
466 	if (setjmp(nofault)) {
467 		nofault = (label_t *)0;
468 		if ((dh->dh_flags & SBC_DH_DONE) == 0) {
469 			count = ((  (u_long)m68k_fault_addr
470 				  - (u_long)sc->sc_drq_addr));
471 
472 			if ((count < 0) || (count > dh->dh_len)) {
473 				printf("%s: complete=0x%x (pending 0x%x)\n",
474 				    ncr_sc->sc_dev.dv_xname, count, dh->dh_len);
475 				panic("something is wrong");
476 			}
477 
478 			dh->dh_addr += count;
479 			dh->dh_len -= count;
480 		} else
481 			count = 0;
482 
483 #ifdef SBC_DEBUG
484 		if (sbc_debug & SBC_DB_INTR)
485 			printf("%s: drq /berr, complete=0x%x (pending 0x%x)\n",
486 			   ncr_sc->sc_dev.dv_xname, count, dh->dh_len);
487 #endif
488 		m68k_fault_addr = 0;
489 
490 		return;
491 	}
492 
493 	if (dh->dh_flags & SBC_DH_OUT) { /* Data Out */
494 		dcount = 0;
495 
496 		/*
497 		 * Get the source address aligned.
498 		 */
499 		resid =
500 		    count = min(dh->dh_len, 4 - (((int)dh->dh_addr) & 0x3));
501 		if (count && count < 4) {
502 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
503 			data = (u_int8_t *)dh->dh_addr;
504 
505 #define W1		*drq++ = *data++
506 			while (count) {
507 				W1; count--;
508 			}
509 #undef W1
510 			dh->dh_addr += resid;
511 			dh->dh_len -= resid;
512 		}
513 
514 		/*
515 		 * Start the transfer.
516 		 */
517 		while (dh->dh_len) {
518 			dcount = count = min(dh->dh_len, MAX_DMA_LEN);
519 			long_drq = (volatile u_int32_t *)sc->sc_drq_addr;
520 			long_data = (u_int32_t *)dh->dh_addr;
521 
522 #define W4		*long_drq++ = *long_data++
523 			while (count >= 64) {
524 				W4; W4; W4; W4; W4; W4; W4; W4;
525 				W4; W4; W4; W4; W4; W4; W4; W4; /*  64 */
526 				count -= 64;
527 			}
528 			while (count >= 4) {
529 				W4; count -= 4;
530 			}
531 #undef W4
532 			data = (u_int8_t *)long_data;
533 			drq = (u_int8_t *)long_drq;
534 
535 #define W1		*drq++ = *data++
536 			while (count) {
537 				W1; count--;
538 			}
539 #undef W1
540 			dh->dh_len -= dcount;
541 			dh->dh_addr += dcount;
542 		}
543 		dh->dh_flags |= SBC_DH_DONE;
544 
545 		/*
546 		 * XXX -- Read a byte from the SBC to trigger a /BERR.
547 		 * This seems to be necessary for us to notice that
548 		 * the target has disconnected.  Ick.  06 jun 1996 (sr)
549 		 */
550 		if (dcount >= MAX_DMA_LEN)
551 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
552 		tmp = *drq;
553 	} else {	/* Data In */
554 		/*
555 		 * Get the dest address aligned.
556 		 */
557 		resid =
558 		    count = min(dh->dh_len, 4 - (((int)dh->dh_addr) & 0x3));
559 		if (count && count < 4) {
560 			data = (u_int8_t *)dh->dh_addr;
561 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
562 
563 #define R1		*data++ = *drq++
564 			while (count) {
565 				R1; count--;
566 			}
567 #undef R1
568 			dh->dh_addr += resid;
569 			dh->dh_len -= resid;
570 		}
571 
572 		/*
573 		 * Start the transfer.
574 		 */
575 		while (dh->dh_len) {
576 			dcount = count = min(dh->dh_len, MAX_DMA_LEN);
577 			long_data = (u_int32_t *)dh->dh_addr;
578 			long_drq = (volatile u_int32_t *)sc->sc_drq_addr;
579 
580 #define R4		*long_data++ = *long_drq++
581 			while (count >= 64) {
582 				R4; R4; R4; R4; R4; R4; R4; R4;
583 				R4; R4; R4; R4; R4; R4; R4; R4;	/* 64 */
584 				count -= 64;
585 			}
586 			while (count >= 4) {
587 				R4; count -= 4;
588 			}
589 #undef R4
590 			data = (u_int8_t *)long_data;
591 			drq = (volatile u_int8_t *)long_drq;
592 
593 #define R1		*data++ = *drq++
594 			while (count) {
595 				R1; count--;
596 			}
597 #undef R1
598 			dh->dh_len -= dcount;
599 			dh->dh_addr += dcount;
600 		}
601 		dh->dh_flags |= SBC_DH_DONE;
602 	}
603 
604 	/*
605 	 * OK.  No bus error occurred above.  Clear the nofault flag
606 	 * so we no longer short-circuit bus errors.
607 	 */
608 	nofault = (label_t *)0;
609 
610 #ifdef SBC_DEBUG
611 	if (sbc_debug & (SBC_DB_REG | SBC_DB_INTR))
612 		printf("%s: drq intr complete: csr=0x%x, bus_csr=0x%x\n",
613 		    ncr_sc->sc_dev.dv_xname, *ncr_sc->sci_csr,
614 		    *ncr_sc->sci_bus_csr);
615 #endif
616 }
617 
618 void
619 sbc_dma_alloc(ncr_sc)
620 	struct ncr5380_softc *ncr_sc;
621 {
622 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
623 	struct sci_req *sr = ncr_sc->sc_current;
624 	struct scsipi_xfer *xs = sr->sr_xs;
625 	struct sbc_pdma_handle *dh;
626 	int		i, xlen;
627 
628 #ifdef DIAGNOSTIC
629 	if (sr->sr_dma_hand != NULL)
630 		panic("sbc_dma_alloc: already have PDMA handle");
631 #endif
632 
633 	/* Polled transfers shouldn't allocate a PDMA handle. */
634 	if (sr->sr_flags & SR_IMMED)
635 		return;
636 
637 	xlen = ncr_sc->sc_datalen;
638 
639 	/* Make sure our caller checked sc_min_dma_len. */
640 	if (xlen < MIN_DMA_LEN)
641 		panic("sbc_dma_alloc: len=0x%x\n", xlen);
642 
643 	/*
644 	 * Find free PDMA handle.  Guaranteed to find one since we
645 	 * have as many PDMA handles as the driver has processes.
646 	 * (instances?)
647 	 */
648 	 for (i = 0; i < SCI_OPENINGS; i++) {
649 		if ((sc->sc_pdma[i].dh_flags & SBC_DH_BUSY) == 0)
650 			goto found;
651 	}
652 	panic("sbc: no free PDMA handles");
653 found:
654 	dh = &sc->sc_pdma[i];
655 	dh->dh_flags = SBC_DH_BUSY;
656 	dh->dh_addr = ncr_sc->sc_dataptr;
657 	dh->dh_len = xlen;
658 
659 	/* Copy the 'write' flag for convenience. */
660 	if (xs->flags & SCSI_DATA_OUT)
661 		dh->dh_flags |= SBC_DH_OUT;
662 
663 	sr->sr_dma_hand = dh;
664 }
665 
666 void
667 sbc_dma_free(ncr_sc)
668 	struct ncr5380_softc *ncr_sc;
669 {
670 	struct sci_req *sr = ncr_sc->sc_current;
671 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
672 
673 #ifdef DIAGNOSTIC
674 	if (sr->sr_dma_hand == NULL)
675 		panic("sbc_dma_free: no DMA handle");
676 #endif
677 
678 	if (ncr_sc->sc_state & NCR_DOINGDMA)
679 		panic("sbc_dma_free: free while in progress");
680 
681 	if (dh->dh_flags & SBC_DH_BUSY) {
682 		dh->dh_flags = 0;
683 		dh->dh_addr = NULL;
684 		dh->dh_len = 0;
685 	}
686 	sr->sr_dma_hand = NULL;
687 }
688 
689 void
690 sbc_dma_poll(ncr_sc)
691 	struct ncr5380_softc *ncr_sc;
692 {
693 	struct sci_req *sr = ncr_sc->sc_current;
694 
695 	/*
696 	 * We shouldn't arrive here; if SR_IMMED is set, then
697 	 * dma_alloc() should have refused to allocate a handle
698 	 * for the transfer.  This forces the polled PDMA code
699 	 * to handle the request...
700 	 */
701 #ifdef SBC_DEBUG
702 	if (sbc_debug & SBC_DB_DMA)
703 		printf("%s: lost DRQ interrupt?\n", ncr_sc->sc_dev.dv_xname);
704 #endif
705 	sr->sr_flags |= SR_OVERDUE;
706 }
707 
708 void
709 sbc_dma_setup(ncr_sc)
710 	struct ncr5380_softc *ncr_sc;
711 {
712 	/* Not needed; we don't have real DMA */
713 }
714 
715 void
716 sbc_dma_start(ncr_sc)
717 	struct ncr5380_softc *ncr_sc;
718 {
719 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
720 	struct sci_req *sr = ncr_sc->sc_current;
721 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
722 
723 	/*
724 	 * Match bus phase, clear pending interrupts, set DMA mode, and
725 	 * assert data bus (for writing only), then start the transfer.
726 	 */
727 	if (dh->dh_flags & SBC_DH_OUT) {
728 		*ncr_sc->sci_tcmd = PHASE_DATA_OUT;
729 		SCI_CLR_INTR(ncr_sc);
730 		if (sc->sc_clrintr)
731 			(*sc->sc_clrintr)(ncr_sc);
732 		*ncr_sc->sci_mode |= SCI_MODE_DMA;
733 		*ncr_sc->sci_icmd = SCI_ICMD_DATA;
734 		*ncr_sc->sci_dma_send = 0;
735 	} else {
736 		*ncr_sc->sci_tcmd = PHASE_DATA_IN;
737 		SCI_CLR_INTR(ncr_sc);
738 		if (sc->sc_clrintr)
739 			(*sc->sc_clrintr)(ncr_sc);
740 		*ncr_sc->sci_mode |= SCI_MODE_DMA;
741 		*ncr_sc->sci_icmd = 0;
742 		*ncr_sc->sci_irecv = 0;
743 	}
744 	ncr_sc->sc_state |= NCR_DOINGDMA;
745 
746 #ifdef SBC_DEBUG
747 	if (sbc_debug & SBC_DB_DMA)
748 		printf("%s: PDMA started, va=%p, len=0x%x\n",
749 		    ncr_sc->sc_dev.dv_xname, dh->dh_addr, dh->dh_len);
750 #endif
751 }
752 
753 void
754 sbc_dma_eop(ncr_sc)
755 	struct ncr5380_softc *ncr_sc;
756 {
757 	/* Not used; the EOP pin is wired high (GMFH, pp. 389-390) */
758 }
759 
760 void
761 sbc_dma_stop(ncr_sc)
762 	struct ncr5380_softc *ncr_sc;
763 {
764 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
765 	struct sci_req *sr = ncr_sc->sc_current;
766 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
767 	int ntrans;
768 
769 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
770 #ifdef SBC_DEBUG
771 		if (sbc_debug & SBC_DB_DMA)
772 			printf("%s: dma_stop: DMA not running\n",
773 			    ncr_sc->sc_dev.dv_xname);
774 #endif
775 		return;
776 	}
777 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
778 
779 	if ((ncr_sc->sc_state & NCR_ABORTING) == 0) {
780 		ntrans = ncr_sc->sc_datalen - dh->dh_len;
781 
782 #ifdef SBC_DEBUG
783 		if (sbc_debug & SBC_DB_DMA)
784 			printf("%s: dma_stop: ntrans=0x%x\n",
785 			    ncr_sc->sc_dev.dv_xname, ntrans);
786 #endif
787 
788 		if (ntrans > ncr_sc->sc_datalen)
789 			panic("sbc_dma_stop: excess transfer\n");
790 
791 		/* Adjust data pointer */
792 		ncr_sc->sc_dataptr += ntrans;
793 		ncr_sc->sc_datalen -= ntrans;
794 
795 		/* Clear any pending interrupts. */
796 		SCI_CLR_INTR(ncr_sc);
797 		if (sc->sc_clrintr)
798 			(*sc->sc_clrintr)(ncr_sc);
799 	}
800 
801 	/* Put SBIC back into PIO mode. */
802 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
803 	*ncr_sc->sci_icmd = 0;
804 
805 #ifdef SBC_DEBUG
806 	if (sbc_debug & SBC_DB_REG)
807 		printf("%s: dma_stop: csr=0x%x, bus_csr=0x%x\n",
808 		    ncr_sc->sc_dev.dv_xname, *ncr_sc->sci_csr,
809 		    *ncr_sc->sci_bus_csr);
810 #endif
811 }
812