xref: /netbsd-src/sys/arch/mac68k/dev/sbc.c (revision 21e37cc72a480a47828990a439cde7ac9ffaf0c6)
1 /*	$NetBSD: sbc.c,v 1.44 2003/07/15 02:43:18 lukem 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/cdefs.h>
48 __KERNEL_RCSID(0, "$NetBSD: sbc.c,v 1.44 2003/07/15 02:43:18 lukem Exp $");
49 
50 #include "opt_ddb.h"
51 
52 #include <sys/types.h>
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/kernel.h>
56 #include <sys/errno.h>
57 #include <sys/device.h>
58 #include <sys/buf.h>
59 #include <sys/proc.h>
60 #include <sys/user.h>
61 
62 #include <dev/scsipi/scsi_all.h>
63 #include <dev/scsipi/scsipi_all.h>
64 #include <dev/scsipi/scsipi_debug.h>
65 #include <dev/scsipi/scsiconf.h>
66 
67 #include <dev/ic/ncr5380reg.h>
68 #include <dev/ic/ncr5380var.h>
69 
70 #include <machine/cpu.h>
71 #include <machine/viareg.h>
72 
73 #include <mac68k/dev/sbcreg.h>
74 #include <mac68k/dev/sbcvar.h>
75 
76 /* SBC_DEBUG --  relies on DDB */
77 #ifdef SBC_DEBUG
78 # define	SBC_DB_INTR	0x01
79 # define	SBC_DB_DMA	0x02
80 # define	SBC_DB_REG	0x04
81 # define	SBC_DB_BREAK	0x08
82 # ifndef DDB
83 #  define	Debugger()	printf("Debug: sbc.c:%d\n", __LINE__)
84 # endif
85 # define	SBC_BREAK \
86 		do { if (sbc_debug & SBC_DB_BREAK) Debugger(); } while (0)
87 #else
88 # define	SBC_BREAK
89 #endif
90 
91 
92 int	sbc_debug = 0 /* | SBC_DB_INTR | SBC_DB_DMA */;
93 int	sbc_link_flags = 0 /* | SDEV_DB2 */;
94 int	sbc_options = 0 /* | SBC_PDMA */;
95 
96 extern label_t	*nofault;
97 extern caddr_t	m68k_fault_addr;
98 
99 static	int	sbc_wait_busy __P((struct ncr5380_softc *));
100 static	int	sbc_ready __P((struct ncr5380_softc *));
101 static	int	sbc_wait_dreq __P((struct ncr5380_softc *));
102 
103 
104 /***
105  * General support for Mac-specific SCSI logic.
106  ***/
107 
108 /* These are used in the following inline functions. */
109 int sbc_wait_busy_timo = 1000 * 5000;	/* X2 = 10 S. */
110 int sbc_ready_timo = 1000 * 5000;	/* X2 = 10 S. */
111 int sbc_wait_dreq_timo = 1000 * 5000;	/* X2 = 10 S. */
112 
113 /* Return zero on success. */
114 static __inline__ int
115 sbc_wait_busy(sc)
116 	struct ncr5380_softc *sc;
117 {
118 	int timo = sbc_wait_busy_timo;
119 	for (;;) {
120 		if (SCI_BUSY(sc)) {
121 			timo = 0;	/* return 0 */
122 			break;
123 		}
124 		if (--timo < 0)
125 			break;	/* return -1 */
126 		delay(2);
127 	}
128 	return (timo);
129 }
130 
131 static __inline__ int
132 sbc_ready(sc)
133 	struct ncr5380_softc *sc;
134 {
135 	int timo = sbc_ready_timo;
136 
137 	for (;;) {
138 		if ((*sc->sci_csr & (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH))
139 		    == (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH)) {
140 			timo = 0;
141 			break;
142 		}
143 		if (((*sc->sci_csr & SCI_CSR_PHASE_MATCH) == 0)
144 		    || (SCI_BUSY(sc) == 0)) {
145 			timo = -1;
146 			break;
147 		}
148 		if (--timo < 0)
149 			break;	/* return -1 */
150 		delay(2);
151 	}
152 	return (timo);
153 }
154 
155 static __inline__ int
156 sbc_wait_dreq(sc)
157 	struct ncr5380_softc *sc;
158 {
159 	int timo = sbc_wait_dreq_timo;
160 
161 	for (;;) {
162 		if ((*sc->sci_csr & (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH))
163 		    == (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH)) {
164 			timo = 0;
165 			break;
166 		}
167 		if (--timo < 0)
168 			break;	/* return -1 */
169 		delay(2);
170 	}
171 	return (timo);
172 }
173 
174 void
175 sbc_irq_intr(p)
176 	void *p;
177 {
178 	struct ncr5380_softc *ncr_sc = p;
179 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
180 	int claimed = 0;
181 
182 	/* How we ever arrive here without IRQ set is a mystery... */
183 	if (*ncr_sc->sci_csr & SCI_CSR_INT) {
184 #ifdef SBC_DEBUG
185 		if (sbc_debug & SBC_DB_INTR)
186 			decode_5380_intr(ncr_sc);
187 #endif
188 		if (!cold)
189 			claimed = ncr5380_intr(ncr_sc);
190 		if (!claimed) {
191 			if (((*ncr_sc->sci_csr & ~SCI_CSR_PHASE_MATCH) == SCI_CSR_INT)
192 			    && ((*ncr_sc->sci_bus_csr & ~SCI_BUS_RST) == 0)) {
193 				SCI_CLR_INTR(ncr_sc);	/* RST interrupt */
194 				if (sc->sc_clrintr)
195 					(*sc->sc_clrintr)(ncr_sc);
196 			}
197 #ifdef SBC_DEBUG
198 			else {
199 				printf("%s: spurious intr\n",
200 				    ncr_sc->sc_dev.dv_xname);
201 				SBC_BREAK;
202 			}
203 #endif
204 		}
205 	}
206 }
207 
208 #ifdef SBC_DEBUG
209 void
210 decode_5380_intr(ncr_sc)
211 	struct ncr5380_softc *ncr_sc;
212 {
213 	u_int8_t csr = *ncr_sc->sci_csr;
214 	u_int8_t bus_csr = *ncr_sc->sci_bus_csr;
215 
216 	if (((csr & ~(SCI_CSR_PHASE_MATCH | SCI_CSR_ATN)) == SCI_CSR_INT) &&
217 	    ((bus_csr & ~(SCI_BUS_MSG | SCI_BUS_CD | SCI_BUS_IO | SCI_BUS_DBP)) == SCI_BUS_SEL)) {
218 		if (csr & SCI_BUS_IO)
219 			printf("%s: reselect\n", ncr_sc->sc_dev.dv_xname);
220 		else
221 			printf("%s: select\n", ncr_sc->sc_dev.dv_xname);
222 	} else if (((csr & ~SCI_CSR_ACK) == (SCI_CSR_DONE | SCI_CSR_INT)) &&
223 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_SEL)) == SCI_BUS_BSY))
224 		printf("%s: DMA eop\n", ncr_sc->sc_dev.dv_xname);
225 	else if (((csr & ~SCI_CSR_PHASE_MATCH) == SCI_CSR_INT) &&
226 	    ((bus_csr & ~SCI_BUS_RST) == 0))
227 		printf("%s: bus reset\n", ncr_sc->sc_dev.dv_xname);
228 	else if (((csr & ~(SCI_CSR_DREQ | SCI_CSR_ATN | SCI_CSR_ACK)) == (SCI_CSR_PERR | SCI_CSR_INT | SCI_CSR_PHASE_MATCH)) &&
229 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_SEL)) == SCI_BUS_BSY))
230 		printf("%s: parity error\n", ncr_sc->sc_dev.dv_xname);
231 	else if (((csr & ~SCI_CSR_ATN) == SCI_CSR_INT) &&
232 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_REQ | SCI_BUS_SEL)) == (SCI_BUS_BSY | SCI_BUS_REQ)))
233 		printf("%s: phase mismatch\n", ncr_sc->sc_dev.dv_xname);
234 	else if (((csr & ~SCI_CSR_PHASE_MATCH) == (SCI_CSR_INT | SCI_CSR_DISC)) &&
235 	    (bus_csr == 0))
236 		printf("%s: disconnect\n", ncr_sc->sc_dev.dv_xname);
237 	else
238 		printf("%s: unknown intr: csr=%x, bus_csr=%x\n",
239 		    ncr_sc->sc_dev.dv_xname, csr, bus_csr);
240 }
241 #endif
242 
243 
244 /***
245  * The following code implements polled PDMA.
246  ***/
247 
248 int
249 sbc_pdma_in(ncr_sc, phase, datalen, data)
250 	struct ncr5380_softc *ncr_sc;
251 	int phase;
252 	int datalen;
253 	u_char *data;
254 {
255 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
256 	volatile u_int32_t *long_data = (u_int32_t *)sc->sc_drq_addr;
257 	volatile u_int8_t *byte_data = (u_int8_t *)sc->sc_nodrq_addr;
258 	int resid, s;
259 
260 	if (datalen < ncr_sc->sc_min_dma_len ||
261 	    (sc->sc_options & SBC_PDMA) == 0)
262 		return ncr5380_pio_in(ncr_sc, phase, datalen, data);
263 
264 	s = splbio();
265 	if (sbc_wait_busy(ncr_sc)) {
266 		splx(s);
267 		return 0;
268 	}
269 
270 	*ncr_sc->sci_mode |= SCI_MODE_DMA;
271 	*ncr_sc->sci_irecv = 0;
272 
273 #define R4	*((u_int32_t *)data)++ = *long_data
274 #define R1	*((u_int8_t *)data)++ = *byte_data
275 	for (resid = datalen; resid >= 128; resid -= 128) {
276 		if (sbc_ready(ncr_sc))
277 			goto interrupt;
278 		R4; R4; R4; R4; R4; R4; R4; R4;
279 		R4; R4; R4; R4; R4; R4; R4; R4;
280 		R4; R4; R4; R4; R4; R4; R4; R4;
281 		R4; R4; R4; R4; R4; R4; R4; R4;		/* 128 */
282 	}
283 	while (resid) {
284 		if (sbc_ready(ncr_sc))
285 			goto interrupt;
286 		R1;
287 		resid--;
288 	}
289 #undef R4
290 #undef R1
291 
292 interrupt:
293 	SCI_CLR_INTR(ncr_sc);
294 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
295 	*ncr_sc->sci_icmd = 0;
296 	splx(s);
297 	return (datalen - resid);
298 }
299 
300 int
301 sbc_pdma_out(ncr_sc, phase, datalen, data)
302 	struct ncr5380_softc *ncr_sc;
303 	int phase;
304 	int datalen;
305 	u_char *data;
306 {
307 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
308 	volatile u_int32_t *long_data = (u_int32_t *)sc->sc_drq_addr;
309 	volatile u_int8_t *byte_data = (u_int8_t *)sc->sc_nodrq_addr;
310 	label_t faultbuf;
311 	int resid, s;
312 	u_int8_t icmd;
313 
314 #if 1
315 	/* Work around lame gcc initialization bug */
316 	(void)&data;
317 #endif
318 
319 	if (datalen < ncr_sc->sc_min_dma_len ||
320 	    (sc->sc_options & SBC_PDMA) == 0)
321 		return ncr5380_pio_out(ncr_sc, phase, datalen, data);
322 
323 	s = splbio();
324 	if (sbc_wait_busy(ncr_sc)) {
325 		splx(s);
326 		return 0;
327 	}
328 
329 	icmd = *(ncr_sc->sci_icmd) & SCI_ICMD_RMASK;
330 	*ncr_sc->sci_icmd = icmd | SCI_ICMD_DATA;
331 	*ncr_sc->sci_mode |= SCI_MODE_DMA;
332 	*ncr_sc->sci_dma_send = 0;
333 
334 	/*
335 	 * Setup for a possible bus error caused by SCSI controller
336 	 * switching out of DATA OUT before we're done with the
337 	 * current transfer.  (See comment before sbc_drq_intr().)
338 	 */
339 	nofault = &faultbuf;
340 
341 	if (setjmp(nofault)) {
342 		printf("buf = 0x%lx, fault = 0x%lx\n",
343 		    (u_long)sc->sc_drq_addr, (u_long)m68k_fault_addr);
344 		panic("Unexpected bus error in sbc_pdma_out()");
345 	}
346 
347 #define W1	*byte_data = *((u_int8_t *)data)++
348 #define W4	*long_data = *((u_int32_t *)data)++
349 	for (resid = datalen; resid >= 64; resid -= 64) {
350 		if (sbc_ready(ncr_sc))
351 			goto interrupt;
352 		W1;
353 		if (sbc_ready(ncr_sc))
354 			goto interrupt;
355 		W1;
356 		if (sbc_ready(ncr_sc))
357 			goto interrupt;
358 		W1;
359 		if (sbc_ready(ncr_sc))
360 			goto interrupt;
361 		W1;
362 		if (sbc_ready(ncr_sc))
363 			goto interrupt;
364 		W4; W4; W4; W4;
365 		W4; W4; W4; W4;
366 		W4; W4; W4; W4;
367 		W4; W4; W4;
368 	}
369 	while (resid) {
370 		if (sbc_ready(ncr_sc))
371 			goto interrupt;
372 		W1;
373 		resid--;
374 	}
375 #undef  W1
376 #undef  W4
377 	if (sbc_wait_dreq(ncr_sc))
378 		printf("%s: timeout waiting for DREQ.\n",
379 		    ncr_sc->sc_dev.dv_xname);
380 
381 	*byte_data = 0;
382 	goto done;
383 
384 interrupt:
385 	if ((*ncr_sc->sci_csr & SCI_CSR_PHASE_MATCH) == 0) {
386 		*ncr_sc->sci_icmd = icmd & ~SCI_ICMD_DATA;
387 		--resid;
388 	}
389 
390 done:
391 	SCI_CLR_INTR(ncr_sc);
392 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
393 	*ncr_sc->sci_icmd = icmd;
394 	splx(s);
395 	return (datalen - resid);
396 }
397 
398 
399 /***
400  * The following code implements interrupt-driven PDMA.
401  ***/
402 
403 /*
404  * This is the meat of the PDMA transfer.
405  * When we get here, we shove data as fast as the mac can take it.
406  * We depend on several things:
407  *   * All macs after the Mac Plus that have a 5380 chip should have a general
408  *     logic IC that handshakes data for blind transfers.
409  *   * If the SCSI controller finishes sending/receiving data before we do,
410  *     the same general logic IC will generate a /BERR for us in short order.
411  *   * The fault address for said /BERR minus the base address for the
412  *     transfer will be the amount of data that was actually written.
413  *
414  * We use the nofault flag and the setjmp/longjmp in locore.s so we can
415  * detect and handle the bus error for early termination of a command.
416  * This is usually caused by a disconnecting target.
417  */
418 void
419 sbc_drq_intr(p)
420 	void *p;
421 {
422 	struct sbc_softc *sc = (struct sbc_softc *)p;
423 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)p;
424 	struct sci_req *sr = ncr_sc->sc_current;
425 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
426 	label_t faultbuf;
427 	volatile u_int32_t *long_drq;
428 	u_int32_t *long_data;
429 	volatile u_int8_t *drq;
430 	u_int8_t *data;
431 	int count, dcount, resid;
432 	u_int8_t tmp;
433 
434 	/* Work around lame gcc initialization bug */
435 	(void)&drq;
436 
437 	/*
438 	 * If we're not ready to xfer data, or have no more, just return.
439 	 */
440 	if ((*ncr_sc->sci_csr & SCI_CSR_DREQ) == 0 || dh->dh_len == 0)
441 		return;
442 
443 #ifdef SBC_DEBUG
444 	if (sbc_debug & SBC_DB_INTR)
445 		printf("%s: drq intr, dh_len=0x%x, dh_flags=0x%x\n",
446 		    ncr_sc->sc_dev.dv_xname, dh->dh_len, dh->dh_flags);
447 #endif
448 
449 	/*
450 	 * Setup for a possible bus error caused by SCSI controller
451 	 * switching out of DATA-IN/OUT before we're done with the
452 	 * current transfer.
453 	 */
454 	nofault = &faultbuf;
455 
456 	if (setjmp(nofault)) {
457 		nofault = (label_t *)0;
458 		if ((dh->dh_flags & SBC_DH_DONE) == 0) {
459 			count = ((  (u_long)m68k_fault_addr
460 				  - (u_long)sc->sc_drq_addr));
461 
462 			if ((count < 0) || (count > dh->dh_len)) {
463 				printf("%s: complete=0x%x (pending 0x%x)\n",
464 				    ncr_sc->sc_dev.dv_xname, count, dh->dh_len);
465 				panic("something is wrong");
466 			}
467 
468 			dh->dh_addr += count;
469 			dh->dh_len -= count;
470 		} else
471 			count = 0;
472 
473 #ifdef SBC_DEBUG
474 		if (sbc_debug & SBC_DB_INTR)
475 			printf("%s: drq /berr, complete=0x%x (pending 0x%x)\n",
476 			   ncr_sc->sc_dev.dv_xname, count, dh->dh_len);
477 #endif
478 		m68k_fault_addr = 0;
479 
480 		return;
481 	}
482 
483 	if (dh->dh_flags & SBC_DH_OUT) { /* Data Out */
484 		dcount = 0;
485 
486 		/*
487 		 * Get the source address aligned.
488 		 */
489 		resid =
490 		    count = min(dh->dh_len, 4 - (((int)dh->dh_addr) & 0x3));
491 		if (count && count < 4) {
492 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
493 			data = (u_int8_t *)dh->dh_addr;
494 
495 #define W1		*drq++ = *data++
496 			while (count) {
497 				W1; count--;
498 			}
499 #undef W1
500 			dh->dh_addr += resid;
501 			dh->dh_len -= resid;
502 		}
503 
504 		/*
505 		 * Start the transfer.
506 		 */
507 		while (dh->dh_len) {
508 			dcount = count = min(dh->dh_len, MAX_DMA_LEN);
509 			long_drq = (volatile u_int32_t *)sc->sc_drq_addr;
510 			long_data = (u_int32_t *)dh->dh_addr;
511 
512 #define W4		*long_drq++ = *long_data++
513 			while (count >= 64) {
514 				W4; W4; W4; W4; W4; W4; W4; W4;
515 				W4; W4; W4; W4; W4; W4; W4; W4; /*  64 */
516 				count -= 64;
517 			}
518 			while (count >= 4) {
519 				W4; count -= 4;
520 			}
521 #undef W4
522 			data = (u_int8_t *)long_data;
523 			drq = (u_int8_t *)long_drq;
524 
525 #define W1		*drq++ = *data++
526 			while (count) {
527 				W1; count--;
528 			}
529 #undef W1
530 			dh->dh_len -= dcount;
531 			dh->dh_addr += dcount;
532 		}
533 		dh->dh_flags |= SBC_DH_DONE;
534 
535 		/*
536 		 * XXX -- Read a byte from the SBC to trigger a /BERR.
537 		 * This seems to be necessary for us to notice that
538 		 * the target has disconnected.  Ick.  06 jun 1996 (sr)
539 		 */
540 		if (dcount >= MAX_DMA_LEN)
541 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
542 		tmp = *drq;
543 	} else {	/* Data In */
544 		/*
545 		 * Get the dest address aligned.
546 		 */
547 		resid =
548 		    count = min(dh->dh_len, 4 - (((int)dh->dh_addr) & 0x3));
549 		if (count && count < 4) {
550 			data = (u_int8_t *)dh->dh_addr;
551 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
552 
553 #define R1		*data++ = *drq++
554 			while (count) {
555 				R1; count--;
556 			}
557 #undef R1
558 			dh->dh_addr += resid;
559 			dh->dh_len -= resid;
560 		}
561 
562 		/*
563 		 * Start the transfer.
564 		 */
565 		while (dh->dh_len) {
566 			dcount = count = min(dh->dh_len, MAX_DMA_LEN);
567 			long_data = (u_int32_t *)dh->dh_addr;
568 			long_drq = (volatile u_int32_t *)sc->sc_drq_addr;
569 
570 #define R4		*long_data++ = *long_drq++
571 			while (count >= 64) {
572 				R4; R4; R4; R4; R4; R4; R4; R4;
573 				R4; R4; R4; R4; R4; R4; R4; R4;	/* 64 */
574 				count -= 64;
575 			}
576 			while (count >= 4) {
577 				R4; count -= 4;
578 			}
579 #undef R4
580 			data = (u_int8_t *)long_data;
581 			drq = (volatile u_int8_t *)long_drq;
582 
583 #define R1		*data++ = *drq++
584 			while (count) {
585 				R1; count--;
586 			}
587 #undef R1
588 			dh->dh_len -= dcount;
589 			dh->dh_addr += dcount;
590 		}
591 		dh->dh_flags |= SBC_DH_DONE;
592 	}
593 
594 	/*
595 	 * OK.  No bus error occurred above.  Clear the nofault flag
596 	 * so we no longer short-circuit bus errors.
597 	 */
598 	nofault = (label_t *)0;
599 
600 #ifdef SBC_DEBUG
601 	if (sbc_debug & (SBC_DB_REG | SBC_DB_INTR))
602 		printf("%s: drq intr complete: csr=0x%x, bus_csr=0x%x\n",
603 		    ncr_sc->sc_dev.dv_xname, *ncr_sc->sci_csr,
604 		    *ncr_sc->sci_bus_csr);
605 #endif
606 }
607 
608 void
609 sbc_dma_alloc(ncr_sc)
610 	struct ncr5380_softc *ncr_sc;
611 {
612 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
613 	struct sci_req *sr = ncr_sc->sc_current;
614 	struct scsipi_xfer *xs = sr->sr_xs;
615 	struct sbc_pdma_handle *dh;
616 	int		i, xlen;
617 
618 #ifdef DIAGNOSTIC
619 	if (sr->sr_dma_hand != NULL)
620 		panic("sbc_dma_alloc: already have PDMA handle");
621 #endif
622 
623 	/* Polled transfers shouldn't allocate a PDMA handle. */
624 	if (sr->sr_flags & SR_IMMED)
625 		return;
626 
627 	xlen = ncr_sc->sc_datalen;
628 
629 	/* Make sure our caller checked sc_min_dma_len. */
630 	if (xlen < MIN_DMA_LEN)
631 		panic("sbc_dma_alloc: len=0x%x", xlen);
632 
633 	/*
634 	 * Find free PDMA handle.  Guaranteed to find one since we
635 	 * have as many PDMA handles as the driver has processes.
636 	 * (instances?)
637 	 */
638 	 for (i = 0; i < SCI_OPENINGS; i++) {
639 		if ((sc->sc_pdma[i].dh_flags & SBC_DH_BUSY) == 0)
640 			goto found;
641 	}
642 	panic("sbc: no free PDMA handles");
643 found:
644 	dh = &sc->sc_pdma[i];
645 	dh->dh_flags = SBC_DH_BUSY;
646 	dh->dh_addr = ncr_sc->sc_dataptr;
647 	dh->dh_len = xlen;
648 
649 	/* Copy the 'write' flag for convenience. */
650 	if (xs->xs_control & XS_CTL_DATA_OUT)
651 		dh->dh_flags |= SBC_DH_OUT;
652 
653 	sr->sr_dma_hand = dh;
654 }
655 
656 void
657 sbc_dma_free(ncr_sc)
658 	struct ncr5380_softc *ncr_sc;
659 {
660 	struct sci_req *sr = ncr_sc->sc_current;
661 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
662 
663 #ifdef DIAGNOSTIC
664 	if (sr->sr_dma_hand == NULL)
665 		panic("sbc_dma_free: no DMA handle");
666 #endif
667 
668 	if (ncr_sc->sc_state & NCR_DOINGDMA)
669 		panic("sbc_dma_free: free while in progress");
670 
671 	if (dh->dh_flags & SBC_DH_BUSY) {
672 		dh->dh_flags = 0;
673 		dh->dh_addr = NULL;
674 		dh->dh_len = 0;
675 	}
676 	sr->sr_dma_hand = NULL;
677 }
678 
679 void
680 sbc_dma_poll(ncr_sc)
681 	struct ncr5380_softc *ncr_sc;
682 {
683 	struct sci_req *sr = ncr_sc->sc_current;
684 
685 	/*
686 	 * We shouldn't arrive here; if SR_IMMED is set, then
687 	 * dma_alloc() should have refused to allocate a handle
688 	 * for the transfer.  This forces the polled PDMA code
689 	 * to handle the request...
690 	 */
691 #ifdef SBC_DEBUG
692 	if (sbc_debug & SBC_DB_DMA)
693 		printf("%s: lost DRQ interrupt?\n", ncr_sc->sc_dev.dv_xname);
694 #endif
695 	sr->sr_flags |= SR_OVERDUE;
696 }
697 
698 void
699 sbc_dma_setup(ncr_sc)
700 	struct ncr5380_softc *ncr_sc;
701 {
702 	/* Not needed; we don't have real DMA */
703 }
704 
705 void
706 sbc_dma_start(ncr_sc)
707 	struct ncr5380_softc *ncr_sc;
708 {
709 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
710 	struct sci_req *sr = ncr_sc->sc_current;
711 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
712 
713 	/*
714 	 * Match bus phase, clear pending interrupts, set DMA mode, and
715 	 * assert data bus (for writing only), then start the transfer.
716 	 */
717 	if (dh->dh_flags & SBC_DH_OUT) {
718 		*ncr_sc->sci_tcmd = PHASE_DATA_OUT;
719 		SCI_CLR_INTR(ncr_sc);
720 		if (sc->sc_clrintr)
721 			(*sc->sc_clrintr)(ncr_sc);
722 		*ncr_sc->sci_mode |= SCI_MODE_DMA;
723 		*ncr_sc->sci_icmd = SCI_ICMD_DATA;
724 		*ncr_sc->sci_dma_send = 0;
725 	} else {
726 		*ncr_sc->sci_tcmd = PHASE_DATA_IN;
727 		SCI_CLR_INTR(ncr_sc);
728 		if (sc->sc_clrintr)
729 			(*sc->sc_clrintr)(ncr_sc);
730 		*ncr_sc->sci_mode |= SCI_MODE_DMA;
731 		*ncr_sc->sci_icmd = 0;
732 		*ncr_sc->sci_irecv = 0;
733 	}
734 	ncr_sc->sc_state |= NCR_DOINGDMA;
735 
736 #ifdef SBC_DEBUG
737 	if (sbc_debug & SBC_DB_DMA)
738 		printf("%s: PDMA started, va=%p, len=0x%x\n",
739 		    ncr_sc->sc_dev.dv_xname, dh->dh_addr, dh->dh_len);
740 #endif
741 }
742 
743 void
744 sbc_dma_eop(ncr_sc)
745 	struct ncr5380_softc *ncr_sc;
746 {
747 	/* Not used; the EOP pin is wired high (GMFH, pp. 389-390) */
748 }
749 
750 void
751 sbc_dma_stop(ncr_sc)
752 	struct ncr5380_softc *ncr_sc;
753 {
754 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
755 	struct sci_req *sr = ncr_sc->sc_current;
756 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
757 	int ntrans;
758 
759 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
760 #ifdef SBC_DEBUG
761 		if (sbc_debug & SBC_DB_DMA)
762 			printf("%s: dma_stop: DMA not running\n",
763 			    ncr_sc->sc_dev.dv_xname);
764 #endif
765 		return;
766 	}
767 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
768 
769 	if ((ncr_sc->sc_state & NCR_ABORTING) == 0) {
770 		ntrans = ncr_sc->sc_datalen - dh->dh_len;
771 
772 #ifdef SBC_DEBUG
773 		if (sbc_debug & SBC_DB_DMA)
774 			printf("%s: dma_stop: ntrans=0x%x\n",
775 			    ncr_sc->sc_dev.dv_xname, ntrans);
776 #endif
777 
778 		if (ntrans > ncr_sc->sc_datalen)
779 			panic("sbc_dma_stop: excess transfer");
780 
781 		/* Adjust data pointer */
782 		ncr_sc->sc_dataptr += ntrans;
783 		ncr_sc->sc_datalen -= ntrans;
784 
785 		/* Clear any pending interrupts. */
786 		SCI_CLR_INTR(ncr_sc);
787 		if (sc->sc_clrintr)
788 			(*sc->sc_clrintr)(ncr_sc);
789 	}
790 
791 	/* Put SBIC back into PIO mode. */
792 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
793 	*ncr_sc->sci_icmd = 0;
794 
795 #ifdef SBC_DEBUG
796 	if (sbc_debug & SBC_DB_REG)
797 		printf("%s: dma_stop: csr=0x%x, bus_csr=0x%x\n",
798 		    ncr_sc->sc_dev.dv_xname, *ncr_sc->sci_csr,
799 		    *ncr_sc->sci_bus_csr);
800 #endif
801 }
802