xref: /netbsd-src/sys/arch/mac68k/dev/sbc.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: sbc.c,v 1.48 2005/12/24 23:24:00 perry 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 1.48 2005/12/24 23:24:00 perry 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(struct ncr5380_softc *);
100 static	int	sbc_ready(struct ncr5380_softc *);
101 static	int	sbc_wait_dreq(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(struct ncr5380_softc *sc)
116 {
117 	int timo = sbc_wait_busy_timo;
118 	for (;;) {
119 		if (SCI_BUSY(sc)) {
120 			timo = 0;	/* return 0 */
121 			break;
122 		}
123 		if (--timo < 0)
124 			break;	/* return -1 */
125 		delay(2);
126 	}
127 	return (timo);
128 }
129 
130 static inline int
131 sbc_ready(struct ncr5380_softc *sc)
132 {
133 	int timo = sbc_ready_timo;
134 
135 	for (;;) {
136 		if ((*sc->sci_csr & (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH))
137 		    == (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH)) {
138 			timo = 0;
139 			break;
140 		}
141 		if (((*sc->sci_csr & SCI_CSR_PHASE_MATCH) == 0)
142 		    || (SCI_BUSY(sc) == 0)) {
143 			timo = -1;
144 			break;
145 		}
146 		if (--timo < 0)
147 			break;	/* return -1 */
148 		delay(2);
149 	}
150 	return (timo);
151 }
152 
153 static inline int
154 sbc_wait_dreq(struct ncr5380_softc *sc)
155 {
156 	int timo = sbc_wait_dreq_timo;
157 
158 	for (;;) {
159 		if ((*sc->sci_csr & (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH))
160 		    == (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH)) {
161 			timo = 0;
162 			break;
163 		}
164 		if (--timo < 0)
165 			break;	/* return -1 */
166 		delay(2);
167 	}
168 	return (timo);
169 }
170 
171 void
172 sbc_irq_intr(void *p)
173 {
174 	struct ncr5380_softc *ncr_sc = p;
175 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
176 	int claimed = 0;
177 
178 	/* How we ever arrive here without IRQ set is a mystery... */
179 	if (*ncr_sc->sci_csr & SCI_CSR_INT) {
180 #ifdef SBC_DEBUG
181 		if (sbc_debug & SBC_DB_INTR)
182 			decode_5380_intr(ncr_sc);
183 #endif
184 		if (!cold)
185 			claimed = ncr5380_intr(ncr_sc);
186 		if (!claimed) {
187 			if (((*ncr_sc->sci_csr & ~SCI_CSR_PHASE_MATCH) == SCI_CSR_INT)
188 			    && ((*ncr_sc->sci_bus_csr & ~SCI_BUS_RST) == 0)) {
189 				SCI_CLR_INTR(ncr_sc);	/* RST interrupt */
190 				if (sc->sc_clrintr)
191 					(*sc->sc_clrintr)(ncr_sc);
192 			}
193 #ifdef SBC_DEBUG
194 			else {
195 				printf("%s: spurious intr\n",
196 				    ncr_sc->sc_dev.dv_xname);
197 				SBC_BREAK;
198 			}
199 #endif
200 		}
201 	}
202 }
203 
204 #ifdef SBC_DEBUG
205 void
206 decode_5380_intr(struct ncr5380_softc *ncr_sc)
207 {
208 	u_int8_t csr = *ncr_sc->sci_csr;
209 	u_int8_t bus_csr = *ncr_sc->sci_bus_csr;
210 
211 	if (((csr & ~(SCI_CSR_PHASE_MATCH | SCI_CSR_ATN)) == SCI_CSR_INT) &&
212 	    ((bus_csr & ~(SCI_BUS_MSG | SCI_BUS_CD | SCI_BUS_IO | SCI_BUS_DBP)) == SCI_BUS_SEL)) {
213 		if (csr & SCI_BUS_IO)
214 			printf("%s: reselect\n", ncr_sc->sc_dev.dv_xname);
215 		else
216 			printf("%s: select\n", ncr_sc->sc_dev.dv_xname);
217 	} else if (((csr & ~SCI_CSR_ACK) == (SCI_CSR_DONE | SCI_CSR_INT)) &&
218 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_SEL)) == SCI_BUS_BSY))
219 		printf("%s: DMA eop\n", ncr_sc->sc_dev.dv_xname);
220 	else if (((csr & ~SCI_CSR_PHASE_MATCH) == SCI_CSR_INT) &&
221 	    ((bus_csr & ~SCI_BUS_RST) == 0))
222 		printf("%s: bus reset\n", ncr_sc->sc_dev.dv_xname);
223 	else if (((csr & ~(SCI_CSR_DREQ | SCI_CSR_ATN | SCI_CSR_ACK)) == (SCI_CSR_PERR | SCI_CSR_INT | SCI_CSR_PHASE_MATCH)) &&
224 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_SEL)) == SCI_BUS_BSY))
225 		printf("%s: parity error\n", ncr_sc->sc_dev.dv_xname);
226 	else if (((csr & ~SCI_CSR_ATN) == SCI_CSR_INT) &&
227 	    ((bus_csr & (SCI_BUS_RST | SCI_BUS_BSY | SCI_BUS_REQ | SCI_BUS_SEL)) == (SCI_BUS_BSY | SCI_BUS_REQ)))
228 		printf("%s: phase mismatch\n", ncr_sc->sc_dev.dv_xname);
229 	else if (((csr & ~SCI_CSR_PHASE_MATCH) == (SCI_CSR_INT | SCI_CSR_DISC)) &&
230 	    (bus_csr == 0))
231 		printf("%s: disconnect\n", ncr_sc->sc_dev.dv_xname);
232 	else
233 		printf("%s: unknown intr: csr=%x, bus_csr=%x\n",
234 		    ncr_sc->sc_dev.dv_xname, csr, bus_csr);
235 }
236 #endif
237 
238 
239 /***
240  * The following code implements polled PDMA.
241  ***/
242 
243 int
244 sbc_pdma_in(struct ncr5380_softc *ncr_sc, int phase, int datalen, u_char *data)
245 {
246 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
247 	volatile u_int32_t *long_data = (u_int32_t *)sc->sc_drq_addr;
248 	volatile u_int8_t *byte_data = (u_int8_t *)sc->sc_nodrq_addr;
249 	int resid, s;
250 
251 	if (datalen < ncr_sc->sc_min_dma_len ||
252 	    (sc->sc_options & SBC_PDMA) == 0)
253 		return ncr5380_pio_in(ncr_sc, phase, datalen, data);
254 
255 	s = splbio();
256 	if (sbc_wait_busy(ncr_sc)) {
257 		splx(s);
258 		return 0;
259 	}
260 
261 	*ncr_sc->sci_mode |= SCI_MODE_DMA;
262 	*ncr_sc->sci_irecv = 0;
263 
264 #define R4	*((u_int32_t *)data)++ = *long_data
265 #define R1	*((u_int8_t *)data)++ = *byte_data
266 	for (resid = datalen; resid >= 128; resid -= 128) {
267 		if (sbc_ready(ncr_sc))
268 			goto interrupt;
269 		R4; R4; R4; R4; R4; R4; R4; R4;
270 		R4; R4; R4; R4; R4; R4; R4; R4;
271 		R4; R4; R4; R4; R4; R4; R4; R4;
272 		R4; R4; R4; R4; R4; R4; R4; R4;		/* 128 */
273 	}
274 	while (resid) {
275 		if (sbc_ready(ncr_sc))
276 			goto interrupt;
277 		R1;
278 		resid--;
279 	}
280 #undef R4
281 #undef R1
282 
283 interrupt:
284 	SCI_CLR_INTR(ncr_sc);
285 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
286 	*ncr_sc->sci_icmd = 0;
287 	splx(s);
288 	return (datalen - resid);
289 }
290 
291 int
292 sbc_pdma_out(struct ncr5380_softc *ncr_sc, int phase, int datalen, u_char *data)
293 {
294 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
295 	volatile u_int32_t *long_data = (u_int32_t *)sc->sc_drq_addr;
296 	volatile u_int8_t *byte_data = (u_int8_t *)sc->sc_nodrq_addr;
297 	label_t faultbuf;
298 	int resid, s;
299 	u_int8_t icmd;
300 
301 #if 1
302 	/* Work around lame gcc initialization bug */
303 	(void)&data;
304 #endif
305 
306 	if (datalen < ncr_sc->sc_min_dma_len ||
307 	    (sc->sc_options & SBC_PDMA) == 0)
308 		return ncr5380_pio_out(ncr_sc, phase, datalen, data);
309 
310 	s = splbio();
311 	if (sbc_wait_busy(ncr_sc)) {
312 		splx(s);
313 		return 0;
314 	}
315 
316 	icmd = *(ncr_sc->sci_icmd) & SCI_ICMD_RMASK;
317 	*ncr_sc->sci_icmd = icmd | SCI_ICMD_DATA;
318 	*ncr_sc->sci_mode |= SCI_MODE_DMA;
319 	*ncr_sc->sci_dma_send = 0;
320 
321 	/*
322 	 * Setup for a possible bus error caused by SCSI controller
323 	 * switching out of DATA OUT before we're done with the
324 	 * current transfer.  (See comment before sbc_drq_intr().)
325 	 */
326 	nofault = &faultbuf;
327 
328 	if (setjmp(nofault)) {
329 		printf("buf = 0x%lx, fault = 0x%lx\n",
330 		    (u_long)sc->sc_drq_addr, (u_long)m68k_fault_addr);
331 		panic("Unexpected bus error in sbc_pdma_out()");
332 	}
333 
334 #define W1	*byte_data = *((u_int8_t *)data)++
335 #define W4	*long_data = *((u_int32_t *)data)++
336 	for (resid = datalen; resid >= 64; resid -= 64) {
337 		if (sbc_ready(ncr_sc))
338 			goto interrupt;
339 		W1;
340 		if (sbc_ready(ncr_sc))
341 			goto interrupt;
342 		W1;
343 		if (sbc_ready(ncr_sc))
344 			goto interrupt;
345 		W1;
346 		if (sbc_ready(ncr_sc))
347 			goto interrupt;
348 		W1;
349 		if (sbc_ready(ncr_sc))
350 			goto interrupt;
351 		W4; W4; W4; W4;
352 		W4; W4; W4; W4;
353 		W4; W4; W4; W4;
354 		W4; W4; W4;
355 	}
356 	while (resid) {
357 		if (sbc_ready(ncr_sc))
358 			goto interrupt;
359 		W1;
360 		resid--;
361 	}
362 #undef  W1
363 #undef  W4
364 	if (sbc_wait_dreq(ncr_sc))
365 		printf("%s: timeout waiting for DREQ.\n",
366 		    ncr_sc->sc_dev.dv_xname);
367 
368 	*byte_data = 0;
369 	goto done;
370 
371 interrupt:
372 	if ((*ncr_sc->sci_csr & SCI_CSR_PHASE_MATCH) == 0) {
373 		*ncr_sc->sci_icmd = icmd & ~SCI_ICMD_DATA;
374 		--resid;
375 	}
376 
377 done:
378 	SCI_CLR_INTR(ncr_sc);
379 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
380 	*ncr_sc->sci_icmd = icmd;
381 	splx(s);
382 	return (datalen - resid);
383 }
384 
385 
386 /***
387  * The following code implements interrupt-driven PDMA.
388  ***/
389 
390 /*
391  * This is the meat of the PDMA transfer.
392  * When we get here, we shove data as fast as the mac can take it.
393  * We depend on several things:
394  *   * All macs after the Mac Plus that have a 5380 chip should have a general
395  *     logic IC that handshakes data for blind transfers.
396  *   * If the SCSI controller finishes sending/receiving data before we do,
397  *     the same general logic IC will generate a /BERR for us in short order.
398  *   * The fault address for said /BERR minus the base address for the
399  *     transfer will be the amount of data that was actually written.
400  *
401  * We use the nofault flag and the setjmp/longjmp in locore.s so we can
402  * detect and handle the bus error for early termination of a command.
403  * This is usually caused by a disconnecting target.
404  */
405 void
406 sbc_drq_intr(void *p)
407 {
408 	struct sbc_softc *sc = (struct sbc_softc *)p;
409 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)p;
410 	struct sci_req *sr = ncr_sc->sc_current;
411 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
412 	label_t faultbuf;
413 	volatile u_int32_t *long_drq;
414 	u_int32_t *long_data;
415 	volatile u_int8_t *drq;
416 	u_int8_t *data;
417 	int count, dcount, resid;
418 	u_int8_t tmp;
419 
420 	/* Work around lame gcc initialization bug */
421 	(void)&drq;
422 
423 	/*
424 	 * If we're not ready to xfer data, or have no more, just return.
425 	 */
426 	if ((*ncr_sc->sci_csr & SCI_CSR_DREQ) == 0 || dh->dh_len == 0)
427 		return;
428 
429 #ifdef SBC_DEBUG
430 	if (sbc_debug & SBC_DB_INTR)
431 		printf("%s: drq intr, dh_len=0x%x, dh_flags=0x%x\n",
432 		    ncr_sc->sc_dev.dv_xname, dh->dh_len, dh->dh_flags);
433 #endif
434 
435 	/*
436 	 * Setup for a possible bus error caused by SCSI controller
437 	 * switching out of DATA-IN/OUT before we're done with the
438 	 * current transfer.
439 	 */
440 	nofault = &faultbuf;
441 
442 	if (setjmp(nofault)) {
443 		nofault = (label_t *)0;
444 		if ((dh->dh_flags & SBC_DH_DONE) == 0) {
445 			count = ((  (u_long)m68k_fault_addr
446 				  - (u_long)sc->sc_drq_addr));
447 
448 			if ((count < 0) || (count > dh->dh_len)) {
449 				printf("%s: complete=0x%x (pending 0x%x)\n",
450 				    ncr_sc->sc_dev.dv_xname, count, dh->dh_len);
451 				panic("something is wrong");
452 			}
453 
454 			dh->dh_addr += count;
455 			dh->dh_len -= count;
456 		} else
457 			count = 0;
458 
459 #ifdef SBC_DEBUG
460 		if (sbc_debug & SBC_DB_INTR)
461 			printf("%s: drq /berr, complete=0x%x (pending 0x%x)\n",
462 			   ncr_sc->sc_dev.dv_xname, count, dh->dh_len);
463 #endif
464 		m68k_fault_addr = 0;
465 
466 		return;
467 	}
468 
469 	if (dh->dh_flags & SBC_DH_OUT) { /* Data Out */
470 		dcount = 0;
471 
472 		/*
473 		 * Get the source address aligned.
474 		 */
475 		resid =
476 		    count = min(dh->dh_len, 4 - (((int)dh->dh_addr) & 0x3));
477 		if (count && count < 4) {
478 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
479 			data = (u_int8_t *)dh->dh_addr;
480 
481 #define W1		*drq++ = *data++
482 			while (count) {
483 				W1; count--;
484 			}
485 #undef W1
486 			dh->dh_addr += resid;
487 			dh->dh_len -= resid;
488 		}
489 
490 		/*
491 		 * Start the transfer.
492 		 */
493 		while (dh->dh_len) {
494 			dcount = count = min(dh->dh_len, MAX_DMA_LEN);
495 			long_drq = (volatile u_int32_t *)sc->sc_drq_addr;
496 			long_data = (u_int32_t *)dh->dh_addr;
497 
498 #define W4		*long_drq++ = *long_data++
499 			while (count >= 64) {
500 				W4; W4; W4; W4; W4; W4; W4; W4;
501 				W4; W4; W4; W4; W4; W4; W4; W4; /*  64 */
502 				count -= 64;
503 			}
504 			while (count >= 4) {
505 				W4; count -= 4;
506 			}
507 #undef W4
508 			data = (u_int8_t *)long_data;
509 			drq = (volatile u_int8_t *)long_drq;
510 
511 #define W1		*drq++ = *data++
512 			while (count) {
513 				W1; count--;
514 			}
515 #undef W1
516 			dh->dh_len -= dcount;
517 			dh->dh_addr += dcount;
518 		}
519 		dh->dh_flags |= SBC_DH_DONE;
520 
521 		/*
522 		 * XXX -- Read a byte from the SBC to trigger a /BERR.
523 		 * This seems to be necessary for us to notice that
524 		 * the target has disconnected.  Ick.  06 jun 1996 (sr)
525 		 */
526 		if (dcount >= MAX_DMA_LEN)
527 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
528 		tmp = *drq;
529 	} else {	/* Data In */
530 		/*
531 		 * Get the dest address aligned.
532 		 */
533 		resid =
534 		    count = min(dh->dh_len, 4 - (((int)dh->dh_addr) & 0x3));
535 		if (count && count < 4) {
536 			data = (u_int8_t *)dh->dh_addr;
537 			drq = (volatile u_int8_t *)sc->sc_drq_addr;
538 
539 #define R1		*data++ = *drq++
540 			while (count) {
541 				R1; count--;
542 			}
543 #undef R1
544 			dh->dh_addr += resid;
545 			dh->dh_len -= resid;
546 		}
547 
548 		/*
549 		 * Start the transfer.
550 		 */
551 		while (dh->dh_len) {
552 			dcount = count = min(dh->dh_len, MAX_DMA_LEN);
553 			long_data = (u_int32_t *)dh->dh_addr;
554 			long_drq = (volatile u_int32_t *)sc->sc_drq_addr;
555 
556 #define R4		*long_data++ = *long_drq++
557 			while (count >= 64) {
558 				R4; R4; R4; R4; R4; R4; R4; R4;
559 				R4; R4; R4; R4; R4; R4; R4; R4;	/* 64 */
560 				count -= 64;
561 			}
562 			while (count >= 4) {
563 				R4; count -= 4;
564 			}
565 #undef R4
566 			data = (u_int8_t *)long_data;
567 			drq = (volatile u_int8_t *)long_drq;
568 
569 #define R1		*data++ = *drq++
570 			while (count) {
571 				R1; count--;
572 			}
573 #undef R1
574 			dh->dh_len -= dcount;
575 			dh->dh_addr += dcount;
576 		}
577 		dh->dh_flags |= SBC_DH_DONE;
578 	}
579 
580 	/*
581 	 * OK.  No bus error occurred above.  Clear the nofault flag
582 	 * so we no longer short-circuit bus errors.
583 	 */
584 	nofault = (label_t *)0;
585 
586 #ifdef SBC_DEBUG
587 	if (sbc_debug & (SBC_DB_REG | SBC_DB_INTR))
588 		printf("%s: drq intr complete: csr=0x%x, bus_csr=0x%x\n",
589 		    ncr_sc->sc_dev.dv_xname, *ncr_sc->sci_csr,
590 		    *ncr_sc->sci_bus_csr);
591 #endif
592 }
593 
594 void
595 sbc_dma_alloc(struct ncr5380_softc *ncr_sc)
596 {
597 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
598 	struct sci_req *sr = ncr_sc->sc_current;
599 	struct scsipi_xfer *xs = sr->sr_xs;
600 	struct sbc_pdma_handle *dh;
601 	int		i, xlen;
602 
603 #ifdef DIAGNOSTIC
604 	if (sr->sr_dma_hand != NULL)
605 		panic("sbc_dma_alloc: already have PDMA handle");
606 #endif
607 
608 	/* Polled transfers shouldn't allocate a PDMA handle. */
609 	if (sr->sr_flags & SR_IMMED)
610 		return;
611 
612 	xlen = ncr_sc->sc_datalen;
613 
614 	/* Make sure our caller checked sc_min_dma_len. */
615 	if (xlen < MIN_DMA_LEN)
616 		panic("sbc_dma_alloc: len=0x%x", xlen);
617 
618 	/*
619 	 * Find free PDMA handle.  Guaranteed to find one since we
620 	 * have as many PDMA handles as the driver has processes.
621 	 * (instances?)
622 	 */
623 	 for (i = 0; i < SCI_OPENINGS; i++) {
624 		if ((sc->sc_pdma[i].dh_flags & SBC_DH_BUSY) == 0)
625 			goto found;
626 	}
627 	panic("sbc: no free PDMA handles");
628 found:
629 	dh = &sc->sc_pdma[i];
630 	dh->dh_flags = SBC_DH_BUSY;
631 	dh->dh_addr = ncr_sc->sc_dataptr;
632 	dh->dh_len = xlen;
633 
634 	/* Copy the 'write' flag for convenience. */
635 	if (xs->xs_control & XS_CTL_DATA_OUT)
636 		dh->dh_flags |= SBC_DH_OUT;
637 
638 	sr->sr_dma_hand = dh;
639 }
640 
641 void
642 sbc_dma_free(struct ncr5380_softc *ncr_sc)
643 {
644 	struct sci_req *sr = ncr_sc->sc_current;
645 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
646 
647 #ifdef DIAGNOSTIC
648 	if (sr->sr_dma_hand == NULL)
649 		panic("sbc_dma_free: no DMA handle");
650 #endif
651 
652 	if (ncr_sc->sc_state & NCR_DOINGDMA)
653 		panic("sbc_dma_free: free while in progress");
654 
655 	if (dh->dh_flags & SBC_DH_BUSY) {
656 		dh->dh_flags = 0;
657 		dh->dh_addr = NULL;
658 		dh->dh_len = 0;
659 	}
660 	sr->sr_dma_hand = NULL;
661 }
662 
663 void
664 sbc_dma_poll(struct ncr5380_softc *ncr_sc)
665 {
666 	struct sci_req *sr = ncr_sc->sc_current;
667 
668 	/*
669 	 * We shouldn't arrive here; if SR_IMMED is set, then
670 	 * dma_alloc() should have refused to allocate a handle
671 	 * for the transfer.  This forces the polled PDMA code
672 	 * to handle the request...
673 	 */
674 #ifdef SBC_DEBUG
675 	if (sbc_debug & SBC_DB_DMA)
676 		printf("%s: lost DRQ interrupt?\n", ncr_sc->sc_dev.dv_xname);
677 #endif
678 	sr->sr_flags |= SR_OVERDUE;
679 }
680 
681 void
682 sbc_dma_setup(struct ncr5380_softc *ncr_sc)
683 {
684 	/* Not needed; we don't have real DMA */
685 }
686 
687 void
688 sbc_dma_start(struct ncr5380_softc *ncr_sc)
689 {
690 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
691 	struct sci_req *sr = ncr_sc->sc_current;
692 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
693 
694 	/*
695 	 * Match bus phase, clear pending interrupts, set DMA mode, and
696 	 * assert data bus (for writing only), then start the transfer.
697 	 */
698 	if (dh->dh_flags & SBC_DH_OUT) {
699 		*ncr_sc->sci_tcmd = PHASE_DATA_OUT;
700 		SCI_CLR_INTR(ncr_sc);
701 		if (sc->sc_clrintr)
702 			(*sc->sc_clrintr)(ncr_sc);
703 		*ncr_sc->sci_mode |= SCI_MODE_DMA;
704 		*ncr_sc->sci_icmd = SCI_ICMD_DATA;
705 		*ncr_sc->sci_dma_send = 0;
706 	} else {
707 		*ncr_sc->sci_tcmd = PHASE_DATA_IN;
708 		SCI_CLR_INTR(ncr_sc);
709 		if (sc->sc_clrintr)
710 			(*sc->sc_clrintr)(ncr_sc);
711 		*ncr_sc->sci_mode |= SCI_MODE_DMA;
712 		*ncr_sc->sci_icmd = 0;
713 		*ncr_sc->sci_irecv = 0;
714 	}
715 	ncr_sc->sc_state |= NCR_DOINGDMA;
716 
717 #ifdef SBC_DEBUG
718 	if (sbc_debug & SBC_DB_DMA)
719 		printf("%s: PDMA started, va=%p, len=0x%x\n",
720 		    ncr_sc->sc_dev.dv_xname, dh->dh_addr, dh->dh_len);
721 #endif
722 }
723 
724 void
725 sbc_dma_eop(struct ncr5380_softc *ncr_sc)
726 {
727 	/* Not used; the EOP pin is wired high (GMFH, pp. 389-390) */
728 }
729 
730 void
731 sbc_dma_stop(struct ncr5380_softc *ncr_sc)
732 {
733 	struct sbc_softc *sc = (struct sbc_softc *)ncr_sc;
734 	struct sci_req *sr = ncr_sc->sc_current;
735 	struct sbc_pdma_handle *dh = sr->sr_dma_hand;
736 	int ntrans;
737 
738 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
739 #ifdef SBC_DEBUG
740 		if (sbc_debug & SBC_DB_DMA)
741 			printf("%s: dma_stop: DMA not running\n",
742 			    ncr_sc->sc_dev.dv_xname);
743 #endif
744 		return;
745 	}
746 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
747 
748 	if ((ncr_sc->sc_state & NCR_ABORTING) == 0) {
749 		ntrans = ncr_sc->sc_datalen - dh->dh_len;
750 
751 #ifdef SBC_DEBUG
752 		if (sbc_debug & SBC_DB_DMA)
753 			printf("%s: dma_stop: ntrans=0x%x\n",
754 			    ncr_sc->sc_dev.dv_xname, ntrans);
755 #endif
756 
757 		if (ntrans > ncr_sc->sc_datalen)
758 			panic("sbc_dma_stop: excess transfer");
759 
760 		/* Adjust data pointer */
761 		ncr_sc->sc_dataptr += ntrans;
762 		ncr_sc->sc_datalen -= ntrans;
763 
764 		/* Clear any pending interrupts. */
765 		SCI_CLR_INTR(ncr_sc);
766 		if (sc->sc_clrintr)
767 			(*sc->sc_clrintr)(ncr_sc);
768 	}
769 
770 	/* Put SBIC back into PIO mode. */
771 	*ncr_sc->sci_mode &= ~SCI_MODE_DMA;
772 	*ncr_sc->sci_icmd = 0;
773 
774 #ifdef SBC_DEBUG
775 	if (sbc_debug & SBC_DB_REG)
776 		printf("%s: dma_stop: csr=0x%x, bus_csr=0x%x\n",
777 		    ncr_sc->sc_dev.dv_xname, *ncr_sc->sci_csr,
778 		    *ncr_sc->sci_bus_csr);
779 #endif
780 }
781