xref: /netbsd-src/sys/arch/mvme68k/dev/sbic.c (revision 5b28f239895d55856221c590945769250e289f5f)
1 /*	$NetBSD: sbic.c,v 1.37 2024/09/08 09:36:49 rillig Exp $	*/
2 
3 /*
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Van Jacobson of Lawrence Berkeley Laboratory.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *  @(#)scsi.c  7.5 (Berkeley) 5/4/91
35  */
36 
37 /*
38  * Changes Copyright (c) 1996 Steve Woodford
39  * Original Copyright (c) 1994 Christian E. Hopps
40  *
41  * This code is derived from software contributed to Berkeley by
42  * Van Jacobson of Lawrence Berkeley Laboratory.
43  *
44  * Redistribution and use in source and binary forms, with or without
45  * modification, are permitted provided that the following conditions
46  * are met:
47  * 1. Redistributions of source code must retain the above copyright
48  *    notice, this list of conditions and the following disclaimer.
49  * 2. Redistributions in binary form must reproduce the above copyright
50  *    notice, this list of conditions and the following disclaimer in the
51  *    documentation and/or other materials provided with the distribution.
52  * 3. All advertising materials mentioning features or use of this software
53  *    must display the following acknowledgement:
54  *  This product includes software developed by the University of
55  *  California, Berkeley and its contributors.
56  * 4. Neither the name of the University nor the names of its contributors
57  *    may be used to endorse or promote products derived from this software
58  *    without specific prior written permission.
59  *
60  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
61  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
62  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
63  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
64  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
65  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
66  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
67  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
68  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
69  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70  * SUCH DAMAGE.
71  *
72  *  @(#)scsi.c  7.5 (Berkeley) 5/4/91
73  */
74 
75 /*
76  * Steve Woodford (SCW), Apr, 1996
77  * MVME147S WD33C93 Scsi Bus Interface Controller driver,
78  *
79  * Basically a de-loused and tidied up version of the Amiga AMD 33C93 driver.
80  *
81  * The original driver used features which required at least a WD33C93A
82  * chip. The '147 has the original WD33C93 chip (no 'A' suffix).
83  *
84  * This version of the driver is pretty well generic, so should work with
85  * any flavour of WD33C93 chip.
86  */
87 
88 #include <sys/cdefs.h>
89 __KERNEL_RCSID(0, "$NetBSD: sbic.c,v 1.37 2024/09/08 09:36:49 rillig Exp $");
90 
91 #include "opt_ddb.h"
92 
93 #include <sys/param.h>
94 #include <sys/systm.h>
95 #include <sys/device.h>
96 #include <sys/kernel.h> /* For hz */
97 #include <sys/disklabel.h>
98 #include <sys/buf.h>
99 
100 #include <dev/scsipi/scsi_all.h>
101 #include <dev/scsipi/scsipi_all.h>
102 #include <dev/scsipi/scsiconf.h>
103 
104 #include <uvm/uvm_extern.h>
105 
106 #include <mvme68k/mvme68k/isr.h>
107 #include <mvme68k/dev/dmavar.h>
108 #include <mvme68k/dev/sbicreg.h>
109 #include <mvme68k/dev/sbicvar.h>
110 
111 
112 /*
113  * Since I can't find this in any other header files
114  */
115 #define SCSI_PHASE(reg) (reg&0x07)
116 
117 /*
118  * SCSI delays
119  * In u-seconds, primarily for state changes on the SPC.
120  */
121 #define SBIC_CMD_WAIT   50000   /* wait per step of 'immediate' cmds */
122 #define SBIC_DATA_WAIT  50000   /* wait per data in/out step */
123 #define SBIC_INIT_WAIT  50000   /* wait per step (both) during init */
124 
125 /*
126  * Convenience macro for waiting for a particular sbic event
127  */
128 #define SBIC_WAIT(regs, until, timeo) sbicwait(regs, until, timeo, __LINE__)
129 
130 int     sbicicmd            (struct sbic_softc *, void *, int, void *, int);
131 int     sbicgo              (struct sbic_softc *, struct scsipi_xfer *);
132 int     sbicdmaok           (struct sbic_softc *, struct scsipi_xfer *);
133 int     sbicwait            (sbic_regmap_p, u_char, int , int);
134 int     sbiccheckdmap       (void *, u_long, u_long);
135 u_char  sbicselectbus       (struct sbic_softc *);
136 int     sbicxfout           (sbic_regmap_p, int, void *);
137 int     sbicxfin            (sbic_regmap_p, int, void *);
138 int     sbicfromscsiperiod  (struct sbic_softc *, int);
139 int     sbictoscsiperiod    (struct sbic_softc *, int);
140 int     sbicpoll            (struct sbic_softc *);
141 int     sbicnextstate       (struct sbic_softc *, u_char, u_char);
142 int     sbicmsgin           (struct sbic_softc *);
143 int     sbicabort           (struct sbic_softc *, const char *);
144 void    sbicxfdone          (struct sbic_softc *);
145 void    sbicerror           (struct sbic_softc *, u_char);
146 void    sbicreset           (struct sbic_softc *);
147 void    sbic_scsidone       (struct sbic_acb *, int);
148 void    sbic_sched          (struct sbic_softc *);
149 void    sbic_save_ptrs      (struct sbic_softc *);
150 void    sbic_load_ptrs      (struct sbic_softc *);
151 
152 /*
153  * Synch xfer parameters, and timing conversions
154  */
155 int     sbic_min_period = SBIC_SYN_MIN_PERIOD;  /* in cycles = f(ICLK,FSn) */
156 int     sbic_max_offset = SBIC_SYN_MAX_OFFSET;  /* pure number */
157 int     sbic_cmd_wait   = SBIC_CMD_WAIT;
158 int     sbic_data_wait  = SBIC_DATA_WAIT;
159 int     sbic_init_wait  = SBIC_INIT_WAIT;
160 
161 /*
162  * was broken before.. now if you want this you get it for all drives
163  * on sbic controllers.
164  */
165 u_char  sbic_inhibit_sync[8];
166 int     sbic_enable_reselect     = 1;   /* Allow Disconnect / Reselect */
167 int     sbic_no_dma              = 0;   /* Use PIO transfers instead of DMA */
168 int     sbic_parallel_operations = 1;   /* Allow command queues */
169 
170 /*
171  * Some useful stuff for debugging purposes
172  */
173 #ifdef DEBUG
174 int     sbicdma_ops     = 0;    /* total DMA operations */
175 int     sbicdma_hits    = 0;    /* number of DMA chains that were contiguous */
176 int     sbicdma_misses  = 0;    /* number of DMA chains that were not contiguous */
177 int     sbicdma_saves   = 0;
178 
179 #define QPRINTF(a) if (sbic_debug > 1) printf a
180 
181 int     sbic_debug      = 0;    /* Debug all chip related things */
182 int     sync_debug      = 0;    /* Debug all Synchronous Scsi related things */
183 int     reselect_debug  = 0;    /* Debug all reselection related things */
184 int     data_pointer_debug = 0; /* Debug Data Pointer related things */
185 
186 void    sbictimeout(struct sbic_softc *dev);
187 
188 #else
189 #define QPRINTF(a)  /* */
190 #endif
191 
192 
193 /*
194  * default minphys routine for sbic based controllers
195  */
196 void
197 sbic_minphys(struct buf *bp)
198 {
199 	/*
200 	 * No max transfer at this level.
201 	 */
202 	minphys(bp);
203 }
204 
205 
206 /*
207  * Save DMA pointers.  Take into account partial transfer. Shut down DMA.
208  */
209 void
210 sbic_save_ptrs(struct sbic_softc *dev)
211 {
212 	sbic_regmap_p regs;
213 	struct sbic_acb *acb;
214 	int count, asr, s;
215 
216 	/*
217 	 * Only need to save pointers if DMA was active...
218 	 */
219 	if (dev->sc_cur == NULL || (dev->sc_flags & SBICF_INDMA) == 0)
220 		return;
221 
222 	regs = dev->sc_sbicp;
223 
224 	s = splbio();
225 
226 	/*
227 	 * Wait until WD chip is idle
228 	 */
229 	do {
230 		GET_SBIC_asr(regs, asr);
231 		if (asr & SBIC_ASR_DBR) {
232 			printf("%s: asr %02x canceled!\n", __func__, asr);
233 			splx(s);
234 			return;
235 		}
236 	} while(asr & (SBIC_ASR_BSY|SBIC_ASR_CIP));
237 
238 
239 	/*
240 	 * Save important state.
241 	 * must be done before dmastop
242 	 */
243 	acb            = dev->sc_nexus;
244 	acb->sc_dmacmd = dev->sc_dmacmd;
245 
246 	/*
247 	 * Fetch the residual count
248 	 */
249 	SBIC_TC_GET(regs, count);
250 
251 	/*
252 	 * Shut down DMA
253 	 */
254 	dev->sc_dmastop(dev);
255 
256 	/*
257 	 * No longer in DMA
258 	 */
259 	dev->sc_flags &= ~SBICF_INDMA;
260 
261 	/*
262 	 * Ensure the WD chip is back in polled I/O mode, with nothing to
263 	 * transfer.
264 	 */
265 	SBIC_TC_PUT(regs, 0);
266 	SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI);
267 
268 	/*
269 	 * Update current count...
270 	 */
271 	acb->sc_tcnt = count;
272 
273 	/*
274 	 * Work out how many bytes were actually transferred
275 	 */
276 	count        = dev->sc_tcnt - count;
277 	dev->sc_tcnt = acb->sc_tcnt;
278 
279 	/*
280 	 * Fixup partial xfers
281 	 */
282 	acb->sc_kv.dc_addr  += count;
283 	acb->sc_kv.dc_count -= count;
284 	acb->sc_pa.dc_addr  += count;
285 	acb->sc_pa.dc_count -= count >> 1;
286 
287 #ifdef DEBUG
288 	if (data_pointer_debug)
289 		printf("save at (%p,%x):%x\n",
290 		    dev->sc_cur->dc_addr, dev->sc_cur->dc_count,count);
291 	sbicdma_saves++;
292 #endif
293 
294 	splx(s);
295 }
296 
297 
298 /*
299  * DOES NOT RESTART DMA!!!
300  */
301 void
302 sbic_load_ptrs(struct sbic_softc *dev)
303 {
304 	struct sbic_acb *acb = dev->sc_nexus;
305 	int s;
306 
307 	if (acb->sc_kv.dc_count == 0) {
308 		/*
309 		 * No data to xfer
310 		 */
311 		return;
312 	}
313 
314 	s = splbio();
315 
316 	/*
317 	 * Reset the Scatter-Gather chain
318 	 */
319 	dev->sc_last = dev->sc_cur = &acb->sc_pa;
320 
321 	/*
322 	 * Restore the Transfer Count and DMA specific data
323 	 */
324 	dev->sc_tcnt   = acb->sc_tcnt;
325 	dev->sc_dmacmd = acb->sc_dmacmd;
326 
327 #ifdef DEBUG
328 	sbicdma_ops++;
329 #endif
330 
331 	/*
332 	 * Need to fixup new segment?
333 	 */
334 	if (dev->sc_tcnt == 0) {
335 		/*
336 		 * sc_tcnt == 0 implies end of segment
337 		 */
338 		char *vaddr, *paddr;
339 		int count;
340 
341 		/*
342 		 * do kvm to pa mappings
343 		 */
344 		vaddr = acb->sc_kv.dc_addr;
345 		paddr = acb->sc_pa.dc_addr = (char *)kvtop((void *)vaddr);
346 
347 		for (count = (PAGE_SIZE - ((int)vaddr & PGOFSET));
348 		    count < acb->sc_kv.dc_count &&
349 		    (char *)kvtop((void *)(vaddr + count + 4)) ==
350 		    paddr + count + 4;
351 		    count += PAGE_SIZE)
352 			;	/* Do nothing */
353 
354 		/*
355 		 * If it's all contiguous...
356 		 */
357 		if (count > acb->sc_kv.dc_count) {
358 			count = acb->sc_kv.dc_count;
359 #ifdef DEBUG
360 			sbicdma_hits++;
361 #endif
362 		}
363 #ifdef  DEBUG
364 		else
365 			sbicdma_misses++;
366 #endif
367 
368 		acb->sc_tcnt        = count;
369 		acb->sc_pa.dc_count = count >> 1;
370 
371 #ifdef DEBUG
372 		if (data_pointer_debug)
373 			printf("DMA recalc:kv(%p,%x)pa(%p,%lx)\n",
374 			    acb->sc_kv.dc_addr,
375                             acb->sc_kv.dc_count,
376                             acb->sc_pa.dc_addr,
377                             acb->sc_tcnt);
378 #endif
379 
380 	}
381 
382 	splx(s);
383 }
384 
385 /*
386  * used by specific sbic controller
387  *
388  * it appears that the higher level code does nothing with LUN's
389  * so I will too.  I could plug it in, however so could they
390  * in scsi_scsipi_cmd().
391  */
392 void
393 sbic_scsi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
394     void *arg)
395 {
396 	struct scsipi_xfer *xs;
397 	struct scsipi_periph *periph;
398 	struct sbic_softc *dev = device_private(chan->chan_adapter->adapt_dev);
399 	struct sbic_acb *acb;
400 	int flags, s;
401 
402 	switch (req) {
403 	case ADAPTER_REQ_RUN_XFER:
404 		xs = arg;
405 		periph = xs->xs_periph;
406 		flags = xs->xs_control;
407 
408 		if (flags & XS_CTL_DATA_UIO)
409 			panic("sbic: scsi data uio requested");
410 
411 		if (dev->sc_nexus && (flags & XS_CTL_POLL))
412 			panic("sbic_scsicmd: busy");
413 
414 		s = splbio();
415 
416 		if ((acb = dev->free_list.tqh_first) != NULL)
417 			TAILQ_REMOVE(&dev->free_list, acb, chain);
418 
419 		splx(s);
420 
421 		if (acb == NULL) {
422 #ifdef DEBUG
423 			printf("%s: unable to queue request for target %d\n",
424 			    __func__, periph->periph_target);
425 #ifdef DDB
426 			Debugger();
427 #endif
428 #endif
429 			xs->error = XS_RESOURCE_SHORTAGE;
430 			scsipi_done(xs);
431 			return;
432 		}
433 
434 		if (flags & XS_CTL_DATA_IN)
435 			acb->flags = ACB_ACTIVE | ACB_DATAIN;
436 		else
437 			acb->flags = ACB_ACTIVE;
438 
439 		acb->xs             = xs;
440 		acb->clen           = xs->cmdlen;
441 		acb->sc_kv.dc_addr  = xs->data;
442 		acb->sc_kv.dc_count = xs->datalen;
443 		acb->pa_addr        = xs->data ?
444 		    (char *)kvtop((void *)xs->data) : 0;
445 		memcpy(&acb->cmd, xs->cmd, xs->cmdlen);
446 
447 		if (flags & XS_CTL_POLL) {
448 			/*
449 			 * This has major side effects
450 			 * -- it locks up the machine
451 			 */
452 			int stat;
453 
454 			s = splbio();
455 
456 			dev->sc_flags |= SBICF_ICMD;
457 
458 			do {
459 				/*
460 				 * If we already had a nexus, while away
461 				 * the time until idle...
462 				 * This is likely only to happen if
463 				 * a reselection occurs between
464 				 * here and our earlier check for
465 				 * ICMD && sc_nexus(which would
466 				 * have resulted in a panic() had it been true).
467 				 */
468 				while (dev->sc_nexus)
469 					sbicpoll(dev);
470 
471 				/*
472 				 * Fix up the new nexus
473 				 */
474 				dev->sc_nexus   = acb;
475 				dev->sc_xs      = xs;
476 				dev->target     = periph->periph_target;
477 				dev->lun        = periph->periph_lun;
478 
479 				stat = sbicicmd(dev, &acb->cmd, acb->clen,
480 				    acb->sc_kv.dc_addr, acb->sc_kv.dc_count);
481 
482 			} while (dev->sc_nexus != acb);
483 
484 			sbic_scsidone(acb, stat);
485 
486 			splx(s);
487 
488 			return;
489 		}
490 
491 		s = splbio();
492 		TAILQ_INSERT_TAIL(&dev->ready_list, acb, chain);
493 
494 		/*
495 		 * If nothing is active, try to start it now.
496 		 */
497 		if (dev->sc_nexus == NULL)
498 			sbic_sched(dev);
499 
500 		splx(s);
501 
502 		return;
503 
504 	case ADAPTER_REQ_GROW_RESOURCES:
505 		/* XXX Not supported. */
506 		return;
507 
508 	case ADAPTER_REQ_SET_XFER_MODE:
509 		/* XXX Not supported. */
510 		return;
511 	}
512 }
513 
514 /*
515  * attempt to start the next available command
516  */
517 void
518 sbic_sched(struct sbic_softc *dev)
519 {
520 	struct scsipi_xfer *xs;
521 	struct scsipi_periph  *periph = NULL;	/* Gag the compiler */
522 	struct sbic_acb *acb;
523 	int flags, stat;
524 
525 	/*
526 	 * XXXSCW
527 	 * I'll keep this test here, even though I can't see any obvious way
528 	 * in which sbic_sched() could be called with sc_nexus non NULL
529 	 */
530 	if (dev->sc_nexus)
531 		return;		/* a command is current active */
532 
533 	/*
534 	 * Loop through the ready list looking for work to do...
535 	 */
536 	for (acb = dev->ready_list.tqh_first; acb; acb = acb->chain.tqe_next) {
537 		int i, j;
538 
539 		periph = acb->xs->xs_periph;
540 		i = periph->periph_target;
541 		j = 1 << periph->periph_lun;
542 
543 		/*
544 		 * We've found a potential command, but is the target/lun busy?
545 		 */
546 		if ((dev->sc_tinfo[i].lubusy & j) == 0) {
547 			/*
548 			 * Nope, it's not busy, so we can use it.
549 			 */
550 			dev->sc_tinfo[i].lubusy |= j;
551 			TAILQ_REMOVE(&dev->ready_list, acb, chain);
552 			dev->sc_nexus = acb;
553 			acb->sc_pa.dc_addr = acb->pa_addr;  /* XXXX check */
554 			break;
555 		}
556 	}
557 
558 	if (acb == NULL) {
559 		QPRINTF(("sbicsched: no work\n"));
560 		return;		/* did not find an available command */
561 	}
562 
563 #ifdef DEBUG
564 	if (data_pointer_debug > 1)
565 		printf("sbic_sched(%d,%d)\n", periph->periph_target,
566 		    periph->periph_lun);
567 #endif
568 
569 	dev->sc_xs = xs = acb->xs;
570 	flags      = xs->xs_control;
571 
572 	if (flags & XS_CTL_RESET)
573 		sbicreset(dev);
574 
575 	dev->sc_stat[0] = -1;
576 	dev->target     = periph->periph_target;
577 	dev->lun        = periph->periph_lun;
578 
579 	if (flags & XS_CTL_POLL || (!sbic_parallel_operations &&
580 	    (sbicdmaok(dev, xs) == 0)) )
581 		stat = sbicicmd(dev, &acb->cmd, acb->clen,
582 		    acb->sc_kv.dc_addr, acb->sc_kv.dc_count);
583 	else if (sbicgo(dev, xs) == 0 && xs->error != XS_SELTIMEOUT)
584 	        return;
585 	else
586 		stat = dev->sc_stat[0];
587 
588 	sbic_scsidone(acb, stat);
589 }
590 
591 void
592 sbic_scsidone(struct sbic_acb *acb, int stat)
593 {
594 	struct scsipi_xfer *xs  = acb->xs;
595 	struct scsipi_periph  *periph = xs->xs_periph;
596 	struct sbic_softc *dev =
597 	    device_private(periph->periph_channel->chan_adapter->adapt_dev);
598 	int dosched = 0;
599 
600 #ifdef DIAGNOSTIC
601 	if (acb == NULL || xs == NULL) {
602 		printf("sbic_scsidone -- (%d,%d) no scsipi_xfer\n",
603 		    dev->target, dev->lun);
604 #ifdef DDB
605 		Debugger();
606 #endif
607 		return;
608 	}
609 #endif
610 
611 
612 #ifdef DEBUG
613 	if (data_pointer_debug > 1)
614 		printf("scsidone: (%d,%d)->(%d,%d)%02x\n",
615 		    periph->periph_target, periph->periph_lun,
616 		    dev->target, dev->lun, stat);
617 
618 	if (xs->xs_periph->periph_target == dev->sc_channel.chan_id)
619 		panic("target == hostid");
620 #endif
621 
622 	xs->status = stat;
623 	xs->resid = 0;		/* XXXX */
624 	if (xs->error == XS_NOERROR) {
625 		if (stat == SCSI_CHECK || stat == SCSI_BUSY)
626 			xs->error = XS_BUSY;
627 	}
628 
629 
630 	/*
631 	 * Remove the ACB from whatever queue it's on.  We have to do a bit of
632 	 * a hack to figure out which queue it's on.  Note that it is *not*
633 	 * necessary to cdr down the ready queue, but we must cdr down the
634 	 * nexus queue and see if it's there, so we can mark the unit as no
635 	 * longer busy.  This code is sickening, but it works.
636 	 */
637 	if (acb == dev->sc_nexus ) {
638 
639 		dev->sc_nexus = NULL;
640 		dev->sc_xs    = NULL;
641 
642 		dev->sc_tinfo[periph->periph_target].lubusy &=
643 		    ~(1 << periph->periph_lun);
644 
645 		if (dev->ready_list.tqh_first)
646 			dosched = 1;	/* start next command */
647 
648 	} else if (dev->ready_list.tqh_last == &acb->chain.tqe_next) {
649 
650 		TAILQ_REMOVE(&dev->ready_list, acb, chain);
651 
652 	} else {
653 
654 		struct sbic_acb *a;
655 
656 		for (a = dev->nexus_list.tqh_first; a != NULL;
657 		    a = a->chain.tqe_next) {
658 			if (a == acb) {
659 				TAILQ_REMOVE(&dev->nexus_list, acb, chain);
660 				dev->sc_tinfo[periph->periph_target].lubusy &=
661 				    ~(1 << periph->periph_lun);
662 				break;
663 			}
664 		}
665 
666 		if (a != NULL)
667 			;
668 		else if ( acb->chain.tqe_next ) {
669 			TAILQ_REMOVE(&dev->ready_list, acb, chain);
670 		} else {
671 			printf("%s: can't find matching acb\n",
672 			    device_xname(dev->sc_dev));
673 #ifdef DDB
674 			Debugger();
675 #endif
676 		}
677 	}
678 
679 	/*
680 	 * Put it on the free list.
681 	 */
682 	acb->flags = ACB_FREE;
683 	TAILQ_INSERT_HEAD(&dev->free_list, acb, chain);
684 
685 	dev->sc_tinfo[periph->periph_target].cmds++;
686 
687 	scsipi_done(xs);
688 
689 	if (dosched)
690 		sbic_sched(dev);
691 }
692 
693 int
694 sbicdmaok(struct sbic_softc *dev, struct scsipi_xfer *xs)
695 {
696 
697 	if (sbic_no_dma || xs->datalen == 0 ||
698 	    xs->datalen & 0x03 || (int)xs->data & 0x03)
699 		return 0;
700 
701 	/*
702 	 * controller supports DMA to any addresses?
703 	 */
704 	if ((dev->sc_flags & SBICF_BADDMA) == 0)
705 		return 1;
706 
707 	/*
708 	 * this address is ok for DMA?
709 	 */
710 	if (sbiccheckdmap(xs->data, xs->datalen, dev->sc_dmamask) == 0)
711 		return 1;
712 
713 	return 0;
714 }
715 
716 int
717 sbicwait(sbic_regmap_p regs, u_char until, int timeo, int line)
718 {
719 	u_char  val;
720 
721 	if (timeo == 0)
722 		timeo = 1000000;	/* some large value.. */
723 
724 	GET_SBIC_asr(regs, val);
725 
726 	while ((val & until) == 0) {
727 
728 		if (timeo-- == 0) {
729 			int csr;
730 			GET_SBIC_csr(regs, csr);
731 			printf("sbicwait TIMEO @%d with asr=x%x csr=x%x\n",
732 			    line, val, csr);
733 #if defined(DDB) && defined(DEBUG)
734 			Debugger();
735 #endif
736 			return val;	/* Maybe I should abort */
737 			break;
738 		}
739 
740 		DELAY(1);
741 		GET_SBIC_asr(regs, val);
742 	}
743 
744 	return val;
745 }
746 
747 int
748 sbicabort(struct sbic_softc *dev, const char *where)
749 {
750 	sbic_regmap_p regs = dev->sc_sbicp;
751 	u_char csr, asr;
752 
753 	GET_SBIC_asr(regs, asr);
754 	GET_SBIC_csr(regs, csr);
755 
756 	printf ("%s: abort %s: csr = 0x%02x, asr = 0x%02x\n",
757 	    device_xname(dev->sc_dev), where, csr, asr);
758 
759 	/*
760 	 * Clean up chip itself
761 	 */
762 	if (dev->sc_flags & SBICF_SELECTED) {
763 
764 		while (asr & SBIC_ASR_DBR) {
765 			/*
766 			 * sbic is jammed w/data. need to clear it
767 			 * But we don't know what direction it needs to go
768 			 */
769 			GET_SBIC_data(regs, asr);
770 			printf("%s: abort %s: clearing data buffer 0x%02x\n",
771 			   device_xname(dev->sc_dev), where, asr);
772 			GET_SBIC_asr(regs, asr);
773 			if (asr & SBIC_ASR_DBR)
774 				/* Not the read direction, then */
775 				SET_SBIC_data(regs, asr);
776 			GET_SBIC_asr(regs, asr);
777 		}
778 
779 		WAIT_CIP(regs);
780 
781 		printf("%s: sbicabort - sending ABORT command\n",
782 		    device_xname(dev->sc_dev));
783 		SET_SBIC_cmd(regs, SBIC_CMD_ABORT);
784 		WAIT_CIP(regs);
785 
786 		GET_SBIC_asr(regs, asr);
787 
788 		if (asr & (SBIC_ASR_BSY|SBIC_ASR_LCI)) {
789 			/*
790 			 * ok, get more drastic..
791 			 */
792 			printf("%s: sbicabort - asr %x, trying to reset\n",
793 			    device_xname(dev->sc_dev), asr);
794 			sbicreset(dev);
795 			dev->sc_flags &= ~SBICF_SELECTED;
796 			return SBIC_STATE_ERROR;
797 		}
798 
799 		printf("%s: sbicabort - sending DISC command\n",
800 		    device_xname(dev->sc_dev));
801 		SET_SBIC_cmd(regs, SBIC_CMD_DISC);
802 
803 		do {
804 			SBIC_WAIT (regs, SBIC_ASR_INT, 0);
805 			GET_SBIC_asr(regs, asr);
806 			GET_SBIC_csr (regs, csr);
807 			QPRINTF(("csr: 0x%02x, asr: 0x%02x\n", csr, asr));
808 		} while ((csr != SBIC_CSR_DISC) && (csr != SBIC_CSR_DISC_1) &&
809 		    (csr != SBIC_CSR_CMD_INVALID));
810 
811 		/*
812 		 * lets just hope it worked..
813 		 */
814 		dev->sc_flags &= ~SBICF_SELECTED;
815 	}
816 
817 	return SBIC_STATE_ERROR;
818 }
819 
820 
821 /*
822  * Initialize driver-private structures
823  */
824 void
825 sbicinit(struct sbic_softc *dev)
826 {
827 	u_int i;
828 
829 	if ((dev->sc_flags & SBICF_ALIVE) == 0) {
830 
831 		struct sbic_acb *acb;
832 
833 		TAILQ_INIT(&dev->ready_list);
834 		TAILQ_INIT(&dev->nexus_list);
835 		TAILQ_INIT(&dev->free_list);
836 		callout_init(&dev->sc_timo_ch, 0);
837 
838 		dev->sc_nexus = NULL;
839 		dev->sc_xs    = NULL;
840 
841 		acb = dev->sc_acb;
842 		memset(acb, 0, sizeof(dev->sc_acb));
843 
844 		for (i = 0; i < sizeof(dev->sc_acb) / sizeof(*acb); i++) {
845 			TAILQ_INSERT_TAIL(&dev->free_list, acb, chain);
846 			acb++;
847 		}
848 
849 		memset(dev->sc_tinfo, 0, sizeof(dev->sc_tinfo));
850 
851 #ifdef DEBUG
852 		/*
853 		 * make sure timeout is really not needed
854 		 */
855 		callout_reset(&dev->sc_timo_ch, 30 * hz,
856 		    (void *)sbictimeout, dev);
857 #endif
858 
859 	} else
860 		panic("sbic: reinitializing driver!");
861 
862 	dev->sc_flags |=  SBICF_ALIVE;
863 	dev->sc_flags &= ~SBICF_SELECTED;
864 
865 	/*
866 	 * initialize inhibit array
867 	 * Never enable Sync, since it just doesn't work on mvme147 :(
868 	 */
869 	for (i = 0; i < 8; ++i)
870 		sbic_inhibit_sync[i] = 1;
871 
872 	sbicreset(dev);
873 }
874 
875 void
876 sbicreset(struct sbic_softc *dev)
877 {
878 	sbic_regmap_p regs = dev->sc_sbicp;
879 	u_int my_id, s;
880 	u_char csr;
881 
882 	s = splbio();
883 
884 	my_id = dev->sc_channel.chan_id & SBIC_ID_MASK;
885 
886 	if (dev->sc_clkfreq < 110)
887 		my_id |= SBIC_ID_FS_8_10;
888 	else if (dev->sc_clkfreq < 160)
889 		my_id |= SBIC_ID_FS_12_15;
890 	else if (dev->sc_clkfreq < 210)
891 		my_id |= SBIC_ID_FS_16_20;
892 
893 	SET_SBIC_myid(regs, my_id);
894 
895 	/*
896 	 * Reset the chip
897 	 */
898 	SET_SBIC_cmd(regs, SBIC_CMD_RESET);
899 	DELAY(25);
900 
901 	SBIC_WAIT(regs, SBIC_ASR_INT, 0);
902 	GET_SBIC_csr(regs, csr);	/* clears interrupt also */
903 	__USE(csr);
904 
905 	/*
906 	 * Set up various chip parameters
907 	 */
908 	SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI);
909 
910 	/*
911 	 * don't allow Selection (SBIC_RID_ES)
912 	 * until we can handle target mode!!
913 	 */
914 	SET_SBIC_rselid(regs, SBIC_RID_ER);
915 
916 	/*
917 	 * Asynchronous for now
918 	 */
919 	SET_SBIC_syn(regs, 0);
920 
921 	/*
922 	 * Anything else was zeroed by reset
923 	 */
924 	splx(s);
925 
926 	dev->sc_flags &= ~SBICF_SELECTED;
927 }
928 
929 void
930 sbicerror(struct sbic_softc *dev, u_char csr)
931 {
932 	struct scsipi_xfer *xs  = dev->sc_xs;
933 
934 #ifdef DIAGNOSTIC
935 	if (xs == NULL)
936 		panic("sbicerror: dev->sc_xs == NULL");
937 #endif
938 
939 	if ( xs->xs_control & XS_CTL_SILENT )
940 		return;
941 
942 	printf("%s: csr == 0x%02x\n", device_xname(dev->sc_dev), csr);
943 }
944 
945 /*
946  * select the bus, return when selected or error.
947  *
948  * Returns the current CSR following selection and optionally MSG out phase.
949  * i.e. the returned CSR *should* indicate CMD phase...
950  * If the return value is 0, some error happened.
951  */
952 u_char
953 sbicselectbus(struct sbic_softc *dev)
954 {
955 	sbic_regmap_p regs = dev->sc_sbicp;
956 	u_char target = dev->target, lun = dev->lun, asr, csr, id;
957 
958 	/*
959 	 * if we're already selected, return (XXXX panic maybe?)
960 	 */
961 	if (dev->sc_flags & SBICF_SELECTED)
962 		return 0;
963 
964 	QPRINTF(("sbicselectbus %d: ", target));
965 
966 	/*
967 	 * issue select
968 	 */
969 	SET_SBIC_selid(regs, target);
970 	SET_SBIC_timeo(regs, SBIC_TIMEOUT(250, dev->sc_clkfreq));
971 
972 	GET_SBIC_asr(regs, asr);
973 
974 	if (asr & (SBIC_ASR_INT|SBIC_ASR_BSY)) {
975 		/*
976 		 * This means we got ourselves reselected upon
977 		 */
978 		QPRINTF(("WD busy (reselect?)\n"));
979 		return 0;
980 	}
981 
982 	SET_SBIC_cmd(regs, SBIC_CMD_SEL_ATN);
983 
984 	/*
985 	 * wait for select (merged from separate function may need
986 	 * cleanup)
987 	 */
988 	WAIT_CIP(regs);
989 
990 	do {
991 
992 		asr = SBIC_WAIT(regs, SBIC_ASR_INT | SBIC_ASR_LCI, 0);
993 
994 		if (asr & SBIC_ASR_LCI) {
995 			QPRINTF(("late LCI: asr %02x\n", asr));
996 			return 0;
997 		}
998 
999 		/*
1000 		 * Clear interrupt
1001 		 */
1002 		GET_SBIC_csr (regs, csr);
1003 
1004 		QPRINTF(("%02x ", csr));
1005 
1006 		/*
1007 		 * Reselected from under our feet?
1008 		 */
1009 		if (csr == SBIC_CSR_RSLT_NI || csr == SBIC_CSR_RSLT_IFY) {
1010 			QPRINTF(("got reselected, asr %02x\n", asr));
1011 			/*
1012 			 * We need to handle this now so we don't lock up later
1013 			 */
1014 			sbicnextstate(dev, csr, asr);
1015 
1016 			return 0;
1017 		}
1018 
1019 		/*
1020 		 * Whoops!
1021 		 */
1022 		if (csr == SBIC_CSR_SLT || csr == SBIC_CSR_SLT_ATN) {
1023 			panic("sbicselectbus: target issued select!");
1024 			return 0;
1025 		}
1026 
1027 	} while (csr != (SBIC_CSR_MIS_2 | MESG_OUT_PHASE) &&
1028 	    csr != (SBIC_CSR_MIS_2 | CMD_PHASE) &&
1029 	    csr != SBIC_CSR_SEL_TIMEO);
1030 
1031 	/*
1032 	 * Anyone at home?
1033 	 */
1034 	if (csr == SBIC_CSR_SEL_TIMEO) {
1035 		dev->sc_xs->error = XS_SELTIMEOUT;
1036 		QPRINTF(("Selection Timeout\n"));
1037 		return 0;
1038 	}
1039 
1040 	QPRINTF(("Selection Complete\n"));
1041 
1042 	/*
1043 	 * Assume we're now selected
1044 	 */
1045 	GET_SBIC_selid(regs, id);
1046 	dev->target    = id;
1047 	dev->lun       = lun;
1048 	dev->sc_flags |= SBICF_SELECTED;
1049 
1050 	/*
1051 	 * Enable (or not) reselection
1052 	 * XXXSCW This is probably not necessary since we don't use use the
1053 	 * Select-and-Xfer-with-ATN command to initiate a selection...
1054 	 */
1055 	if (!sbic_enable_reselect && dev->nexus_list.tqh_first == NULL)
1056 		SET_SBIC_rselid (regs, 0);
1057 	else
1058 		SET_SBIC_rselid (regs, SBIC_RID_ER);
1059 
1060 	/*
1061 	 * We only really need to do anything when the target goes to MSG out
1062 	 * If the device ignored ATN, it's probably old and brain-dead,
1063 	 * but we'll try to support it anyhow.
1064 	 * If it doesn't support message out, it definitely doesn't
1065 	 * support synchronous transfers, so no point in even asking...
1066 	 */
1067 	if (csr == (SBIC_CSR_MIS_2 | MESG_OUT_PHASE)) {
1068 		/*
1069 		 * Send identify message (SCSI-2 requires an identify msg)
1070 		 */
1071 		if (sbic_inhibit_sync[id] &&
1072 		    dev->sc_sync[id].state == SYNC_START) {
1073 			/*
1074 			 * Handle drives that don't want to be asked
1075 			 * whether to go sync at all.
1076 			 */
1077 			dev->sc_sync[id].offset = 0;
1078 			dev->sc_sync[id].period = sbic_min_period;
1079 			dev->sc_sync[id].state  = SYNC_DONE;
1080 		}
1081 
1082 		/*
1083 		 * Do we need to negotiate Synchronous Xfers for this target?
1084 		 */
1085 		if (dev->sc_sync[id].state != SYNC_START) {
1086 			/*
1087 			 * Nope, we've already negotiated.
1088 			 * Now see if we should allow the target to
1089 			 * disconnect/reselect...
1090 			 */
1091 			if (dev->sc_xs->xs_control & XS_CTL_POLL ||
1092 			    dev->sc_flags & SBICF_ICMD ||
1093 			    !sbic_enable_reselect)
1094 				SEND_BYTE (regs, MSG_IDENTIFY | lun);
1095 			else
1096 				SEND_BYTE (regs, MSG_IDENTIFY_DR | lun);
1097 
1098 		} else {
1099 			/*
1100 			 * try to initiate a sync transfer.
1101 			 * So compose the sync message we're going
1102 			 * to send to the target
1103 			 */
1104 #ifdef DEBUG
1105 			if (sync_debug)
1106 				printf("\nSending sync request "
1107 				    "to target %d ... ", id);
1108 #endif
1109 			/*
1110 			 * setup scsi message sync message request
1111 			 */
1112 			dev->sc_msg[0] = MSG_IDENTIFY | lun;
1113 			dev->sc_msg[1] = MSG_EXT_MESSAGE;
1114 			dev->sc_msg[2] = 3;
1115 			dev->sc_msg[3] = MSG_SYNC_REQ;
1116 			dev->sc_msg[4] = sbictoscsiperiod(dev, sbic_min_period);
1117 			dev->sc_msg[5] = sbic_max_offset;
1118 
1119 			sbicxfout(regs, 6, dev->sc_msg);
1120 
1121 			dev->sc_sync[id].state = SYNC_SENT;
1122 #ifdef DEBUG
1123 			if (sync_debug)
1124 				printf ("sent\n");
1125 #endif
1126 		}
1127 
1128 		/*
1129 		 * There's one interrupt still to come: the change to
1130 		 * CMD phase...
1131 		 */
1132 		SBIC_WAIT(regs, SBIC_ASR_INT , 0);
1133 		GET_SBIC_csr(regs, csr);
1134 	}
1135 
1136 	/*
1137 	 * set sync or async
1138 	 */
1139 	if (dev->sc_sync[target].state == SYNC_DONE) {
1140 #ifdef  DEBUG
1141         if (sync_debug)
1142 		printf("select(%d): sync reg = 0x%02x\n", target,
1143 		    SBIC_SYN(dev->sc_sync[target].offset,
1144 		    dev->sc_sync[target].period));
1145 #endif
1146 		SET_SBIC_syn(regs, SBIC_SYN(dev->sc_sync[target].offset,
1147 		    dev->sc_sync[target].period));
1148 	} else {
1149 #ifdef  DEBUG
1150 		if (sync_debug)
1151 			printf("select(%d): sync reg = 0x%02x\n", target,
1152 			    SBIC_SYN(0,sbic_min_period));
1153 #endif
1154 		SET_SBIC_syn(regs, SBIC_SYN(0, sbic_min_period));
1155 	}
1156 
1157 	return csr;
1158 }
1159 
1160 /*
1161  * Information Transfer *to* a Scsi Target.
1162  *
1163  * Note: Don't expect there to be an interrupt immediately after all
1164  * the data is transferred out. The WD spec sheet says that the Transfer-
1165  * Info command for non-MSG_IN phases only completes when the target
1166  * next asserts 'REQ'. That is, when the SCSI bus changes to a new state.
1167  *
1168  * This can have a nasty effect on commands which take a relatively long
1169  * time to complete, for example a START/STOP unit command may remain in
1170  * CMD phase until the disk has spun up. Only then will the target change
1171  * to STATUS phase. This is really only a problem for immediate commands
1172  * since we don't allow disconnection for them (yet).
1173  */
1174 int
1175 sbicxfout(sbic_regmap_p regs, int len, void *bp)
1176 {
1177 	int wait = sbic_data_wait;
1178 	u_char  asr, *buf = bp;
1179 
1180 	QPRINTF(("sbicxfout {%d} %02x %02x %02x %02x %02x "
1181 	    "%02x %02x %02x %02x %02x\n", len, buf[0], buf[1], buf[2],
1182 	    buf[3], buf[4], buf[5], buf[6], buf[7], buf[8], buf[9]));
1183 
1184 	/*
1185 	 * sigh.. WD-PROTO strikes again.. sending the command in one go
1186 	 * causes the chip to lock up if talking to certain (misbehaving?)
1187 	 * targets. Anyway, this procedure should work for all targets, but
1188 	 * it's slightly slower due to the overhead
1189 	 */
1190 	WAIT_CIP (regs);
1191 
1192 	SBIC_TC_PUT (regs, 0);
1193 	SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI);
1194 	SBIC_TC_PUT (regs, (unsigned)len);
1195 	SET_SBIC_cmd (regs, SBIC_CMD_XFER_INFO);
1196 
1197 	/*
1198 	 * Loop for each byte transferred
1199 	 */
1200 	do {
1201 
1202 		GET_SBIC_asr(regs, asr);
1203 
1204 		if (asr & SBIC_ASR_DBR) {
1205 			if (len) {
1206 				SET_SBIC_data (regs, *buf);
1207 				buf++;
1208 				len--;
1209 			} else {
1210 				SET_SBIC_data (regs, 0);
1211 			}
1212 			wait = sbic_data_wait;
1213 		}
1214 
1215 	} while (len && (asr & SBIC_ASR_INT) == 0 && wait-- > 0);
1216 
1217 #ifdef  DEBUG
1218 	QPRINTF(("sbicxfout done: %d bytes remaining (wait:%d)\n", len, wait));
1219 #endif
1220 
1221 	/*
1222 	 * Normally, an interrupt will be pending when this routing returns.
1223 	 */
1224 	return len;
1225 }
1226 
1227 /*
1228  * Information Transfer *from* a Scsi Target
1229  * returns # bytes left to read
1230  */
1231 int
1232 sbicxfin(sbic_regmap_p regs, int len, void *bp)
1233 {
1234 	int wait = sbic_data_wait;
1235 	u_char *buf = bp;
1236 	u_char asr;
1237 #ifdef  DEBUG
1238 	u_char *obp = bp;
1239 #endif
1240 
1241 	WAIT_CIP(regs);
1242 
1243 	SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI);
1244 	SBIC_TC_PUT(regs, (unsigned int)len);
1245 	SET_SBIC_cmd (regs, SBIC_CMD_XFER_INFO);
1246 
1247 	/*
1248 	 * Loop for each byte transferred
1249 	 */
1250 	do {
1251 
1252 		GET_SBIC_asr(regs, asr);
1253 
1254 		if (asr & SBIC_ASR_DBR) {
1255 			if (len) {
1256 				GET_SBIC_data (regs, *buf);
1257 				buf++;
1258 				len--;
1259 			} else {
1260 				u_char foo;
1261 				GET_SBIC_data (regs, foo);
1262 				__USE(foo);
1263 			}
1264 			wait = sbic_data_wait;
1265 		}
1266 
1267 	} while ((asr & SBIC_ASR_INT) == 0 && wait-- > 0);
1268 
1269 	QPRINTF(("sbicxfin {%d} %02x %02x %02x %02x %02x %02x "
1270 	    "%02x %02x %02x %02x\n", len, obp[0], obp[1], obp[2],
1271 	    obp[3], obp[4], obp[5], obp[6], obp[7], obp[8], obp[9]));
1272 
1273 	SBIC_TC_PUT (regs, 0);
1274 
1275 	/*
1276 	 * this leaves with one csr to be read
1277 	 */
1278 	return len;
1279 }
1280 
1281 /*
1282  * SCSI 'immediate' command:  issue a command to some SCSI device
1283  * and get back an 'immediate' response (i.e., do programmed xfer
1284  * to get the response data).  'cbuf' is a buffer containing a scsi
1285  * command of length clen bytes.  'buf' is a buffer of length 'len'
1286  * bytes for data.  The transfer direction is determined by the device
1287  * (i.e., by the scsi bus data xfer phase).  If 'len' is zero, the
1288  * command must supply no data.
1289  *
1290  * Note that although this routine looks like it can handle disconnect/
1291  * reselect, the fact is that it can't. There is still some work to be
1292  * done to clean this lot up.
1293  */
1294 int
1295 sbicicmd(struct sbic_softc *dev, void *cbuf, int clen, void *buf, int len)
1296 {
1297 	sbic_regmap_p regs = dev->sc_sbicp;
1298 	struct sbic_acb *acb = dev->sc_nexus;
1299 	u_char csr, asr;
1300 	int still_busy = SBIC_STATE_RUNNING;
1301 
1302 	/*
1303 	 * Make sure pointers are OK
1304 	 */
1305 	dev->sc_last = dev->sc_cur = &acb->sc_pa;
1306 	dev->sc_tcnt = acb->sc_tcnt = 0;
1307 
1308 	acb->sc_dmacmd      = 0;
1309 	acb->sc_pa.dc_count = 0; /* No DMA */
1310 	acb->sc_kv.dc_addr  = buf;
1311 	acb->sc_kv.dc_count = len;
1312 
1313 #ifdef  DEBUG
1314 	if (data_pointer_debug > 1)
1315 		printf("sbicicmd(%d,%d):%d\n",
1316 		    dev->target, dev->lun, acb->sc_kv.dc_count);
1317 #endif
1318 
1319 	/*
1320 	 * set the sbic into non-DMA mode
1321 	 */
1322 	SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI);
1323 
1324 	dev->sc_stat[0] = 0xff;
1325 	dev->sc_msg[0]  = 0xff;
1326 
1327 	/*
1328 	 * We're stealing the SCSI bus
1329 	 */
1330 	dev->sc_flags |= SBICF_ICMD;
1331 
1332 	do {
1333 		GET_SBIC_asr(regs, asr);
1334 
1335 		/*
1336 		 * select the SCSI bus (it's an error if bus isn't free)
1337 		 */
1338 		if ((dev->sc_flags & SBICF_SELECTED) == 0 &&
1339 		    still_busy != SBIC_STATE_DISCONNECT) {
1340 			if ((csr = sbicselectbus(dev)) == 0) {
1341 				dev->sc_flags &= ~SBICF_ICMD;
1342 				return -1;
1343 			}
1344 		} else if ((asr & (SBIC_ASR_BSY | SBIC_ASR_INT)) ==
1345 		    SBIC_ASR_INT)
1346 			GET_SBIC_csr(regs, csr);
1347 		else
1348 			csr = 0;
1349 
1350 		if (csr) {
1351 
1352 			QPRINTF((">ASR:0x%02x CSR:0x%02x< ", asr, csr));
1353 
1354 			switch (csr) {
1355 
1356 			case SBIC_CSR_S_XFERRED:
1357 			case SBIC_CSR_DISC:
1358 			case SBIC_CSR_DISC_1:
1359 			    {
1360 				u_char  phase;
1361 
1362 				dev->sc_flags &= ~SBICF_SELECTED;
1363 				GET_SBIC_cmd_phase(regs, phase);
1364 
1365 				if (phase == 0x60) {
1366 					GET_SBIC_tlun(regs, dev->sc_stat[0]);
1367 					still_busy = SBIC_STATE_DONE; /* done */
1368 				} else {
1369 #ifdef DEBUG
1370 					if (reselect_debug > 1)
1371 						printf("sbicicmd: "
1372 						    "handling disconnect\n");
1373 #endif
1374 					still_busy = SBIC_STATE_DISCONNECT;
1375 				}
1376 				break;
1377 			    }
1378 
1379 			case SBIC_CSR_XFERRED | CMD_PHASE:
1380 			case SBIC_CSR_MIS     | CMD_PHASE:
1381 			case SBIC_CSR_MIS_1   | CMD_PHASE:
1382 			case SBIC_CSR_MIS_2   | CMD_PHASE:
1383 
1384 				if (sbicxfout(regs, clen, cbuf))
1385 					still_busy = sbicabort(dev,
1386 					    "icmd sending cmd");
1387 		                break;
1388 
1389 			case SBIC_CSR_XFERRED | STATUS_PHASE:
1390 			case SBIC_CSR_MIS     | STATUS_PHASE:
1391 			case SBIC_CSR_MIS_1   | STATUS_PHASE:
1392 			case SBIC_CSR_MIS_2   | STATUS_PHASE:
1393 
1394 				/*
1395 				 * The sbic does the status/cmd-complete
1396 				 * reading ok, so do this with its
1397 				 * hi-level commands.
1398 				 */
1399 #ifdef DEBUG
1400 				if (sbic_debug)
1401 					printf("SBICICMD status phase "
1402 					    "(bsy=%d)\n", still_busy);
1403 #endif
1404 				SET_SBIC_cmd_phase(regs, 0x46);
1405 				SET_SBIC_cmd(regs, SBIC_CMD_SEL_ATN_XFER);
1406 				break;
1407 
1408 			default:
1409 				still_busy = sbicnextstate(dev, csr, asr);
1410 				break;
1411 			}
1412 
1413 			/*
1414 			 * make sure the last command was taken,
1415 			 * ie. we're not hunting after an ignored command..
1416 			 */
1417 			GET_SBIC_asr(regs, asr);
1418 
1419 			/*
1420 			 * tapes may take a loooong time..
1421 			 */
1422 			while (asr & SBIC_ASR_BSY) {
1423 
1424 				if (asr & SBIC_ASR_DBR) {
1425 					int i;
1426 
1427 					printf("sbicicmd: "
1428 					    "Waiting while sbic is jammed, "
1429 					    "CSR:%02x,ASR:%02x\n", csr, asr);
1430 #ifdef DDB
1431 					Debugger();
1432 #endif
1433 					/*
1434 					 * SBIC is jammed
1435 					 * DUNNO which direction
1436 					 * Try old direction
1437 					 */
1438 					GET_SBIC_data(regs, i);
1439 					GET_SBIC_asr(regs, asr);
1440 
1441 					if (asr & SBIC_ASR_DBR)
1442 						/* Wants us to write */
1443 						SET_SBIC_data(regs, i);
1444 				}
1445 
1446 				GET_SBIC_asr(regs, asr);
1447 			}
1448 		}
1449 
1450 		/*
1451 		 * wait for last command to complete
1452 		 */
1453 		if (asr & SBIC_ASR_LCI) {
1454 			printf("sbicicmd: last command ignored\n");
1455 		} else if (still_busy >= SBIC_STATE_RUNNING) /* Bsy */
1456 			SBIC_WAIT(regs, SBIC_ASR_INT, sbic_cmd_wait);
1457 
1458 		/*
1459 		 * do it again
1460 		 */
1461 	} while (still_busy >= SBIC_STATE_RUNNING && dev->sc_stat[0] == 0xff);
1462 
1463 	/*
1464 	 * Sometimes we need to do an extra read of the CSR
1465 	 */
1466 	GET_SBIC_csr(regs, csr);
1467 
1468 #ifdef DEBUG
1469 	if (data_pointer_debug > 1)
1470 		printf("sbicicmd done(%d,%d):%d =%d=\n", dev->target, dev->lun,
1471 		    acb->sc_kv.dc_count, dev->sc_stat[0]);
1472 #endif
1473 
1474 	dev->sc_flags &= ~SBICF_ICMD;
1475 
1476 	return dev->sc_stat[0];
1477 }
1478 
1479 /*
1480  * Finish SCSI xfer command:  After the completion interrupt from
1481  * a read/write operation, sequence through the final phases in
1482  * programmed i/o.  This routine is a lot like sbicicmd except we
1483  * skip (and don't allow) the select, cmd out and data in/out phases.
1484  */
1485 void
1486 sbicxfdone(struct sbic_softc *dev)
1487 {
1488 	sbic_regmap_p regs = dev->sc_sbicp;
1489 	u_char phase, csr;
1490 	int s;
1491 
1492 	QPRINTF(("{"));
1493 	s = splbio();
1494 
1495 	/*
1496 	 * have the sbic complete on its own
1497 	 */
1498 	SBIC_TC_PUT(regs, 0);
1499 	SET_SBIC_cmd_phase(regs, 0x46);
1500 	SET_SBIC_cmd(regs, SBIC_CMD_SEL_ATN_XFER);
1501 
1502 	do {
1503 
1504 		SBIC_WAIT(regs, SBIC_ASR_INT, 0);
1505 		GET_SBIC_csr(regs, csr);
1506 		QPRINTF(("%02x:", csr));
1507 
1508 	} while ((csr != SBIC_CSR_DISC) && (csr != SBIC_CSR_DISC_1) &&
1509 	    (csr != SBIC_CSR_S_XFERRED));
1510 
1511 	dev->sc_flags &= ~SBICF_SELECTED;
1512 
1513 	GET_SBIC_cmd_phase (regs, phase);
1514 	QPRINTF(("}%02x", phase));
1515 
1516 	if (phase == 0x60)
1517 		GET_SBIC_tlun(regs, dev->sc_stat[0]);
1518 	else
1519 		sbicerror(dev, csr);
1520 
1521 	QPRINTF(("=STS:%02x=\n", dev->sc_stat[0]));
1522 
1523 	splx(s);
1524 }
1525 
1526 /*
1527  * No DMA chains
1528  */
1529 int
1530 sbicgo(struct sbic_softc *dev, struct scsipi_xfer *xs)
1531 {
1532 	struct sbic_acb *acb = dev->sc_nexus;
1533 	sbic_regmap_p regs = dev->sc_sbicp;
1534 	int i, dmaflags, count, usedma;
1535 	u_char csr, asr, *addr;
1536 
1537 	dev->target = xs->xs_periph->periph_target;
1538 	dev->lun    = xs->xs_periph->periph_lun;
1539 
1540 	usedma = sbicdmaok(dev, xs);
1541 
1542 #ifdef DEBUG
1543 	if (data_pointer_debug > 1)
1544 		printf("sbicgo(%d,%d): usedma=%d\n",
1545 		    dev->target, dev->lun, usedma);
1546 #endif
1547 
1548 	/*
1549 	 * select the SCSI bus (it's an error if bus isn't free)
1550 	 */
1551 	if ((csr = sbicselectbus(dev)) == 0)
1552 	        return 0;	/* Not done: needs to be rescheduled */
1553 
1554 	dev->sc_stat[0] = 0xff;
1555 
1556 	/*
1557 	 * Calculate DMA chains now
1558 	 */
1559 	if (acb->flags & ACB_DATAIN)
1560 		dmaflags = DMAGO_READ;
1561 	else
1562 		dmaflags = 0;
1563 
1564 	addr  = acb->sc_kv.dc_addr;
1565 	count = acb->sc_kv.dc_count;
1566 
1567 	if (count && ((char *)kvtop((void *)addr) != acb->sc_pa.dc_addr)) {
1568 		printf("sbic: DMA buffer mapping changed %p->%x\n",
1569 		    acb->sc_pa.dc_addr, kvtop((void *)addr));
1570 #ifdef DDB
1571 		Debugger();
1572 #endif
1573 	}
1574 
1575 #ifdef DEBUG
1576 	++sbicdma_ops;		/* count total DMA operations */
1577 #endif
1578 
1579 	/*
1580 	 * Allocate the DMA chain
1581 	 * Mark end of segment...
1582 	 */
1583 	acb->sc_tcnt        = dev->sc_tcnt = 0;
1584 	acb->sc_pa.dc_count = 0;
1585 
1586 	sbic_load_ptrs(dev);
1587 
1588 	/*
1589 	 * Enable interrupts but don't do any DMA
1590 	 * enintr() also enables interrupts for the sbic
1591 	 */
1592 	dev->sc_enintr(dev);
1593 
1594 	if (usedma) {
1595 		dev->sc_tcnt = dev->sc_dmago(dev, acb->sc_pa.dc_addr,
1596 		    acb->sc_pa.dc_count, dmaflags);
1597 #ifdef DEBUG
1598 		dev->sc_dmatimo = dev->sc_tcnt ? 1 : 0;
1599 #endif
1600 	} else
1601 		dev->sc_dmacmd = 0; /* Don't use DMA */
1602 
1603 	acb->sc_dmacmd = dev->sc_dmacmd;
1604 
1605 #ifdef DEBUG
1606 	if (data_pointer_debug > 1) {
1607 		printf("sbicgo dmago:%d(%p:%lx) dmacmd=0x%02x\n", dev->target,
1608 		    dev->sc_cur->dc_addr,
1609 		    dev->sc_tcnt,
1610 		    dev->sc_dmacmd);
1611 	}
1612 #endif
1613 
1614 	/*
1615 	 * Lets cycle a while then let the interrupt handler take over.
1616 	 */
1617 	GET_SBIC_asr(regs, asr);
1618 
1619 	do {
1620 
1621 		QPRINTF(("go "));
1622 
1623 		/*
1624 		 * Handle the new phase
1625 		 */
1626 		i = sbicnextstate(dev, csr, asr);
1627 #if 0
1628 		WAIT_CIP(regs);
1629 #endif
1630 		if (i == SBIC_STATE_RUNNING) {
1631 			GET_SBIC_asr(regs, asr);
1632 
1633 			if (asr & SBIC_ASR_LCI)
1634 				printf("sbicgo: LCI asr:%02x csr:%02x\n",
1635 				    asr, csr);
1636 
1637 			if (asr & SBIC_ASR_INT)
1638 				GET_SBIC_csr(regs, csr);
1639 		}
1640 
1641 	} while (i == SBIC_STATE_RUNNING && asr & (SBIC_ASR_INT|SBIC_ASR_LCI));
1642 
1643 	if (i == SBIC_STATE_DONE) {
1644 		if (dev->sc_stat[0] == 0xff)
1645 #if 0
1646 			printf("sbicgo: done & stat = 0xff\n");
1647 #else
1648 			;
1649 #endif
1650 		else
1651 			return 1;	/* Did we really finish that fast? */
1652 	}
1653 
1654 	return 0;
1655 }
1656 
1657 
1658 int
1659 sbicintr(struct sbic_softc *dev)
1660 {
1661 	sbic_regmap_p regs = dev->sc_sbicp;
1662 	u_char asr, csr;
1663 	int i;
1664 
1665 	/*
1666 	 * pending interrupt?
1667 	 */
1668 	GET_SBIC_asr (regs, asr);
1669 	if ((asr & SBIC_ASR_INT) == 0)
1670 		return 0;
1671 
1672 	GET_SBIC_csr(regs, csr);
1673 
1674 	do {
1675 
1676 		QPRINTF(("intr[0x%x]", csr));
1677 
1678 		i = sbicnextstate(dev, csr, asr);
1679 #if 0
1680 		WAIT_CIP(regs);
1681 #endif
1682 		if (i == SBIC_STATE_RUNNING) {
1683 			GET_SBIC_asr(regs, asr);
1684 
1685 			if (asr & SBIC_ASR_LCI)
1686 				printf("sbicgo: LCI asr:%02x csr:%02x\n", asr, csr);
1687 
1688 			if (asr & SBIC_ASR_INT)
1689 				GET_SBIC_csr(regs, csr);
1690 		}
1691 
1692 	} while (i == SBIC_STATE_RUNNING && asr & (SBIC_ASR_INT|SBIC_ASR_LCI));
1693 
1694 	QPRINTF(("intr done. state=%d, asr=0x%02x\n", i, asr));
1695 
1696 	return 1;
1697 }
1698 
1699 /*
1700  * Run commands and wait for disconnect.
1701  * This is only ever called when a command is in progress, when we
1702  * want to busy wait for it to finish.
1703  */
1704 int
1705 sbicpoll(struct sbic_softc *dev)
1706 {
1707 	sbic_regmap_p regs = dev->sc_sbicp;
1708 	u_char asr, csr = SBIC_CSR_RESET;	/* XXX: Quell un-init warning */
1709 	int i;
1710 
1711 	/*
1712 	 * Wait for the next interrupt
1713 	 */
1714 	SBIC_WAIT(regs, SBIC_ASR_INT, sbic_cmd_wait);
1715 
1716 	do {
1717 		GET_SBIC_asr (regs, asr);
1718 
1719 		if (asr & SBIC_ASR_INT)
1720 			GET_SBIC_csr(regs, csr);
1721 
1722 		QPRINTF(("poll[0x%x]", csr));
1723 
1724 		/*
1725 		 * Handle it
1726 		 */
1727 		i = sbicnextstate(dev, csr, asr);
1728 
1729 		WAIT_CIP(regs);
1730 		GET_SBIC_asr(regs, asr);
1731 
1732 		/*
1733 		 * tapes may take a loooong time..
1734 		 */
1735 		while (asr & SBIC_ASR_BSY) {
1736 			u_char z = 0;
1737 
1738 			if (asr & SBIC_ASR_DBR) {
1739 				printf("sbipoll: Waiting while sbic is jammed,"
1740 			    " CSR:%02x,ASR:%02x\n", csr, asr);
1741 #ifdef DDB
1742 				Debugger();
1743 #endif
1744 				/*
1745 				 * SBIC is jammed
1746 				 * DUNNO which direction
1747 				 * Try old direction
1748 				 */
1749 				GET_SBIC_data(regs, z);
1750 				GET_SBIC_asr(regs, asr);
1751 
1752 				if (asr & SBIC_ASR_DBR) /* Wants us to write */
1753 					SET_SBIC_data(regs, z);
1754 			}
1755 
1756 			GET_SBIC_asr(regs, asr);
1757 		}
1758 
1759 		if (asr & SBIC_ASR_LCI)
1760 			printf("sbicpoll: LCI asr:%02x csr:%02x\n", asr,csr);
1761 		else if (i == SBIC_STATE_RUNNING) /* BSY */
1762 			SBIC_WAIT(regs, SBIC_ASR_INT, sbic_cmd_wait);
1763 
1764 	} while (i == SBIC_STATE_RUNNING);
1765 
1766 	return 1;
1767 }
1768 
1769 /*
1770  * Handle a single msgin
1771  */
1772 int
1773 sbicmsgin(struct sbic_softc *dev)
1774 {
1775 	sbic_regmap_p regs = dev->sc_sbicp;
1776 	int recvlen = 1;
1777 	u_char asr, csr, *tmpaddr, *msgaddr;
1778 
1779 	tmpaddr = msgaddr = dev->sc_msg;
1780 
1781 	tmpaddr[0] = 0xff;
1782 	tmpaddr[1] = 0xff;
1783 
1784 	GET_SBIC_asr(regs, asr);
1785 
1786 #ifdef DEBUG
1787 	if (reselect_debug > 1)
1788 		printf("sbicmsgin asr=%02x\n", asr);
1789 #endif
1790 
1791 	GET_SBIC_selid (regs, csr);
1792 	SET_SBIC_selid (regs, csr | SBIC_SID_FROM_SCSI);
1793 
1794 	SBIC_TC_PUT(regs, 0);
1795 	SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI);
1796 
1797 	do {
1798 		while (recvlen--) {
1799 
1800 			/*
1801 			 * Fetch the next byte of the message
1802 			 */
1803 			RECV_BYTE(regs, *tmpaddr);
1804 
1805 			/*
1806 			 * get the command completion interrupt, or we
1807 			 * can't send a new command (LCI)
1808 			 */
1809 			SBIC_WAIT(regs, SBIC_ASR_INT, 0);
1810 			GET_SBIC_csr(regs, csr);
1811 
1812 #ifdef DEBUG
1813 			if (reselect_debug > 1)
1814 				printf("sbicmsgin: got %02x csr %02x\n",
1815 				    *tmpaddr, csr);
1816 #endif
1817 
1818 			tmpaddr++;
1819 
1820 			if (recvlen) {
1821 				/*
1822 				 * Clear ACK, and wait for the interrupt
1823 				 * for the next byte
1824 				 */
1825 				SET_SBIC_cmd(regs, SBIC_CMD_CLR_ACK);
1826 				SBIC_WAIT(regs, SBIC_ASR_INT, 0);
1827 				GET_SBIC_csr(regs, csr);
1828 			}
1829 		}
1830 
1831 		if (msgaddr[0] == 0xff) {
1832 			printf("sbicmsgin: sbic swallowed our message\n");
1833 			break;
1834 		}
1835 
1836 #ifdef DEBUG
1837 		if (sync_debug) {
1838 			GET_SBIC_asr(regs, asr);
1839 			printf("msgin done csr 0x%x asr 0x%x msg 0x%x\n",
1840 			    csr, asr, msgaddr[0]);
1841 		}
1842 #endif
1843 		/*
1844 		 * test whether this is a reply to our sync
1845 		 * request
1846 		 */
1847 		if (MSG_ISIDENTIFY(msgaddr[0])) {
1848 
1849 			/*
1850 			 * Got IFFY msg -- ack it
1851 			 */
1852 			QPRINTF(("IFFY"));
1853 
1854 		} else if (msgaddr[0] == MSG_REJECT &&
1855 		    dev->sc_sync[dev->target].state == SYNC_SENT) {
1856 
1857 			/*
1858 			 * Target probably rejected our Sync negotiation.
1859 			 */
1860 			QPRINTF(("REJECT of SYN"));
1861 
1862 #ifdef DEBUG
1863 			if (sync_debug)
1864 				printf("target %d rejected sync, going async\n",
1865 				    dev->target);
1866 #endif
1867 
1868 			dev->sc_sync[dev->target].period = sbic_min_period;
1869 			dev->sc_sync[dev->target].offset = 0;
1870 			dev->sc_sync[dev->target].state  = SYNC_DONE;
1871 			SET_SBIC_syn(regs,
1872 			    SBIC_SYN(dev->sc_sync[dev->target].offset,
1873 			    dev->sc_sync[dev->target].period));
1874 
1875 		} else if (msgaddr[0] == MSG_REJECT) {
1876 
1877 			/*
1878 			 * we'll never REJECt a REJECT message..
1879 			 */
1880 			QPRINTF(("REJECT"));
1881 
1882 		} else if (msgaddr[0] == MSG_SAVE_DATA_PTR) {
1883 
1884 			/*
1885 			 * don't reject this either.
1886 			 */
1887 			QPRINTF(("MSG_SAVE_DATA_PTR"));
1888 
1889 		} else if (msgaddr[0] == MSG_RESTORE_PTR) {
1890 
1891 			/*
1892 			 * don't reject this either.
1893 			 */
1894 			QPRINTF(("MSG_RESTORE_PTR"));
1895 
1896 		} else if (msgaddr[0] == MSG_DISCONNECT) {
1897 
1898 			/*
1899 			 * Target is disconnecting...
1900 			 */
1901 			QPRINTF(("DISCONNECT"));
1902 
1903 #ifdef DEBUG
1904 			if (reselect_debug > 1 && msgaddr[0] == MSG_DISCONNECT)
1905 				printf("sbicmsgin: got disconnect msg %s\n",
1906 				    (dev->sc_flags & SBICF_ICMD) ?
1907 				    "rejecting" : "");
1908 #endif
1909 
1910 			if (dev->sc_flags & SBICF_ICMD) {
1911 				/*
1912 				 * We're in immediate mode. Prevent disconnects.
1913 				 * prepare to reject the message, NACK
1914 				 */
1915 				SET_SBIC_cmd(regs, SBIC_CMD_SET_ATN);
1916 				WAIT_CIP(regs);
1917 			}
1918 
1919 		} else if (msgaddr[0] == MSG_CMD_COMPLETE) {
1920 
1921 			/*
1922 			 * !! KLUDGE ALERT !! quite a few drives don't seem to
1923 			 * really like the current way of sending the
1924 			 * sync-handshake together with the ident-message, and
1925 			 * they react by sending command-complete and
1926 			 * disconnecting right after returning the valid sync
1927 			 * handshake. So, all I can do is reselect the drive,
1928 			 * and hope it won't disconnect again. I don't think
1929 			 * this is valid behavior, but I can't help fixing a
1930 			 * problem that apparently exists.
1931 			 *
1932 			 * Note: we should not get here on `normal' command
1933 			 * completion, as that condition is handled by the
1934 			 * high-level sel&xfer resume command used to walk
1935 			 * thru status/cc-phase.
1936 			 */
1937 			QPRINTF(("CMD_COMPLETE"));
1938 
1939 #ifdef DEBUG
1940 			if (sync_debug)
1941 				printf("GOT MSG %d! target %d acting weird.."
1942 				    " waiting for disconnect...\n",
1943 				    msgaddr[0], dev->target);
1944 #endif
1945 
1946 			/*
1947 			 * Check to see if sbic is handling this
1948 			 */
1949 			GET_SBIC_asr(regs, asr);
1950 
1951 			/*
1952 			 * XXXSCW: I'm not convinced of this,
1953 			 * we haven't negated ACK yet...
1954 			 */
1955 			if (asr & SBIC_ASR_BSY)
1956 				return SBIC_STATE_RUNNING;
1957 
1958 			/*
1959 			 * Let's try this: Assume it works and set status to 00
1960 			 */
1961 			dev->sc_stat[0] = 0;
1962 
1963 		} else if (msgaddr[0] == MSG_EXT_MESSAGE &&
1964 		    tmpaddr == &(msgaddr[1])) {
1965 
1966 			/*
1967 			 * Target is sending us an extended message.
1968 			 * We'll assume it's the response to our Sync.
1969 			 * negotiation.
1970 			 */
1971 			QPRINTF(("ExtMSG\n"));
1972 
1973 			/*
1974 			 * Read in whole extended message.
1975 			 * First, negate ACK to accept
1976 			 * the MSG_EXT_MESSAGE byte...
1977 			 */
1978 			SET_SBIC_cmd(regs, SBIC_CMD_CLR_ACK);
1979 
1980 			/*
1981 			 * Wait for the interrupt for the next byte (length)
1982 			 */
1983 			SBIC_WAIT(regs, SBIC_ASR_INT, 0);
1984 			GET_SBIC_csr(regs, csr);
1985 
1986 #ifdef  DEBUG
1987 			QPRINTF(("CLR ACK csr %02x\n", csr));
1988 #endif
1989 
1990 			/*
1991 			 * Read the length byte
1992 			 */
1993 			RECV_BYTE(regs, *tmpaddr);
1994 
1995 			/*
1996 			 * Wait for command completion IRQ
1997 			 */
1998 			SBIC_WAIT(regs, SBIC_ASR_INT, 0);
1999 			GET_SBIC_csr(regs, csr);
2000 
2001 			/*
2002 			 * Reload the loop counter
2003 			 */
2004 			recvlen = *tmpaddr++;
2005 
2006 			QPRINTF(("Recving ext msg, csr %02x len %02x\n",
2007 			    csr, recvlen));
2008 
2009 		} else if (msgaddr[0] == MSG_EXT_MESSAGE &&
2010 		    msgaddr[1] == 3 &&
2011 		    msgaddr[2] == MSG_SYNC_REQ ) {
2012 
2013 			/*
2014 			 * We've received the complete Extended Message Sync.
2015 			 * Request...
2016 			 */
2017 			QPRINTF(("SYN"));
2018 
2019 			/*
2020 			 * Compute the required Transfer Period for
2021 			 * the WD chip...
2022 			 */
2023 			dev->sc_sync[dev->target].period =
2024 			    sbicfromscsiperiod(dev, msgaddr[3]);
2025 			dev->sc_sync[dev->target].offset = msgaddr[4];
2026 			dev->sc_sync[dev->target].state  = SYNC_DONE;
2027 
2028 			/*
2029 			 * Put the WD chip in synchronous mode
2030 			 */
2031 			SET_SBIC_syn(regs,
2032 			    SBIC_SYN(dev->sc_sync[dev->target].offset,
2033                             dev->sc_sync[dev->target].period));
2034 #ifdef  DEBUG
2035 			if (sync_debug)
2036 				printf("msgin(%d): sync reg = 0x%02x\n",
2037 				    dev->target,
2038 				    SBIC_SYN(dev->sc_sync[dev->target].offset,
2039 				    dev->sc_sync[dev->target].period));
2040 #endif
2041 
2042 			printf("%s: target %d now synchronous, "
2043 			    "period=%dns, offset=%d.\n",
2044 			    device_xname(dev->sc_dev), dev->target,
2045 			    msgaddr[3] * 4, msgaddr[4]);
2046 
2047 		} else {
2048 
2049 			/*
2050 			 * We don't support whatever this message is...
2051 			 */
2052 #ifdef DEBUG
2053 			if (sbic_debug || sync_debug)
2054 				printf("sbicmsgin: Rejecting message 0x%02x\n",
2055 				    msgaddr[0]);
2056 #endif
2057 
2058 			/*
2059 			 * prepare to reject the message, NACK
2060 			 */
2061 			SET_SBIC_cmd(regs, SBIC_CMD_SET_ATN);
2062 			WAIT_CIP(regs);
2063 		}
2064 
2065 		/*
2066 		 * Negate ACK to complete the transfer
2067 		 */
2068 		SET_SBIC_cmd(regs, SBIC_CMD_CLR_ACK);
2069 
2070 		/*
2071 		 * Wait for the interrupt for the next byte, or phase change.
2072 		 * Only read the CSR if we have more data to transfer.
2073 		 * XXXSCW: We should really verify that we're still in
2074 		 * MSG IN phase before blindly going back around this loop,
2075 		 * but that would mean we read the CSR... <sigh>
2076 		 */
2077 		SBIC_WAIT(regs, SBIC_ASR_INT, 0);
2078 		if (recvlen > 0)
2079 			GET_SBIC_csr(regs, csr);
2080 
2081 	} while (recvlen > 0);
2082 
2083 	/*
2084 	 * Should still have one CSR to read
2085 	 */
2086 	return SBIC_STATE_RUNNING;
2087 }
2088 
2089 
2090 /*
2091  * sbicnextstate()
2092  * return:
2093  *      SBIC_STATE_DONE        == done
2094  *      SBIC_STATE_RUNNING     == working
2095  *      SBIC_STATE_DISCONNECT  == disconnected
2096  *      SBIC_STATE_ERROR       == error
2097  */
2098 int
2099 sbicnextstate(struct sbic_softc *dev, u_char csr, u_char asr)
2100 {
2101 	sbic_regmap_p   regs = dev->sc_sbicp;
2102 	struct sbic_acb *acb = dev->sc_nexus;
2103 
2104 	QPRINTF(("next[%02x,%02x]: ",asr,csr));
2105 
2106 	switch (csr) {
2107 
2108 	case SBIC_CSR_XFERRED | CMD_PHASE:
2109 	case SBIC_CSR_MIS     | CMD_PHASE:
2110 	case SBIC_CSR_MIS_1   | CMD_PHASE:
2111 	case SBIC_CSR_MIS_2   | CMD_PHASE:
2112 		if ( sbicxfout(regs, acb->clen, &acb->cmd) )
2113                 goto abort;
2114 		break;
2115 
2116 	case SBIC_CSR_XFERRED | STATUS_PHASE:
2117 	case SBIC_CSR_MIS     | STATUS_PHASE:
2118 	case SBIC_CSR_MIS_1   | STATUS_PHASE:
2119 	case SBIC_CSR_MIS_2   | STATUS_PHASE:
2120 		SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI);
2121 
2122 		/*
2123 		 * this should be the normal i/o completion case.
2124 		 * get the status & cmd complete msg then let the
2125 		 * device driver look at what happened.
2126 		 */
2127 		sbicxfdone(dev);
2128 
2129 #ifdef DEBUG
2130 		dev->sc_dmatimo = 0;
2131 		if (data_pointer_debug > 1)
2132 			printf("next dmastop: %d(%p:%lx)\n",
2133 			    dev->target,
2134 			    dev->sc_cur->dc_addr,
2135 			    dev->sc_tcnt);
2136 #endif
2137 		/*
2138 		 * Stop the DMA chip
2139 		 */
2140 		dev->sc_dmastop(dev);
2141 
2142 		dev->sc_flags &= ~(SBICF_INDMA | SBICF_DCFLUSH);
2143 
2144 		/*
2145 		 * Indicate to the upper layers that the command is done
2146 		 */
2147 		sbic_scsidone(acb, dev->sc_stat[0]);
2148 
2149 		return SBIC_STATE_DONE;
2150 
2151 	case SBIC_CSR_XFERRED | DATA_OUT_PHASE:
2152 	case SBIC_CSR_XFERRED | DATA_IN_PHASE:
2153 	case SBIC_CSR_MIS     | DATA_OUT_PHASE:
2154 	case SBIC_CSR_MIS     | DATA_IN_PHASE:
2155 	case SBIC_CSR_MIS_1   | DATA_OUT_PHASE:
2156 	case SBIC_CSR_MIS_1   | DATA_IN_PHASE:
2157 	case SBIC_CSR_MIS_2   | DATA_OUT_PHASE:
2158 	case SBIC_CSR_MIS_2   | DATA_IN_PHASE:
2159 		/*
2160 		 * Verify that we expected to transfer data...
2161 		 */
2162 		if (acb->sc_kv.dc_count <= 0) {
2163 			printf("next: DATA phase with xfer count == %d, "
2164 			    "asr:0x%02x csr:0x%02x\n",
2165 			    acb->sc_kv.dc_count, asr, csr);
2166 			goto abort;
2167 		}
2168 
2169 		/*
2170 		 * Should we transfer using PIO or DMA ?
2171 		 */
2172 		if (dev->sc_xs->xs_control & XS_CTL_POLL ||
2173 		    dev->sc_flags & SBICF_ICMD ||
2174 		    acb->sc_dmacmd == 0 ) {
2175 
2176 			/*
2177 			 * Do PIO transfer
2178 			 */
2179 			int i;
2180 
2181 #ifdef DEBUG
2182 			if (data_pointer_debug > 1)
2183 				printf("next PIO: %d(%p:%x)\n", dev->target,
2184 				    acb->sc_kv.dc_addr,
2185 				    acb->sc_kv.dc_count);
2186 #endif
2187 
2188 			if (SBIC_PHASE(csr) == DATA_IN_PHASE)
2189 				/*
2190 				 * data in
2191 				 */
2192 				i = sbicxfin(regs, acb->sc_kv.dc_count,
2193 				    acb->sc_kv.dc_addr);
2194 			else
2195 				/*
2196 				 * data out
2197 				 */
2198 				i = sbicxfout(regs, acb->sc_kv.dc_count,
2199 				    acb->sc_kv.dc_addr);
2200 
2201 			acb->sc_kv.dc_addr += (acb->sc_kv.dc_count - i);
2202 			acb->sc_kv.dc_count = i;
2203 
2204 			/*
2205 			 * Update current count...
2206 			 */
2207 			acb->sc_tcnt = dev->sc_tcnt = i;
2208 
2209 			dev->sc_flags &= ~SBICF_INDMA;
2210 
2211 		} else {
2212 
2213 			/*
2214 			 * Do DMA transfer
2215 			 * set next DMA addr and dec count
2216 			 */
2217 			sbic_save_ptrs(dev);
2218 			sbic_load_ptrs(dev);
2219 
2220 			SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI |
2221 			    SBIC_MACHINE_DMA_MODE);
2222 
2223 #ifdef DEBUG
2224 			dev->sc_dmatimo = 1;
2225 			if (data_pointer_debug > 1)
2226 				printf("next DMA: %d(%p:%lx)\n", dev->target,
2227 				    dev->sc_cur->dc_addr,
2228 				    dev->sc_tcnt);
2229 #endif
2230 			/*
2231 			 * Start the DMA chip going
2232 			 */
2233 			dev->sc_tcnt = dev->sc_dmanext(dev);
2234 
2235 			/*
2236 			 * Tell the WD chip how much to transfer
2237 			 * this time around
2238 			 */
2239 			SBIC_TC_PUT(regs, (unsigned)dev->sc_tcnt);
2240 
2241 			/*
2242 			 * Start the transfer
2243 			 */
2244 			SET_SBIC_cmd(regs, SBIC_CMD_XFER_INFO);
2245 
2246 			/*
2247 			 * Indicate that we're in DMA mode
2248 			 */
2249 			dev->sc_flags |= SBICF_INDMA;
2250 		}
2251 		break;
2252 
2253 	case SBIC_CSR_XFERRED | MESG_IN_PHASE:
2254 	case SBIC_CSR_MIS     | MESG_IN_PHASE:
2255 	case SBIC_CSR_MIS_1   | MESG_IN_PHASE:
2256 	case SBIC_CSR_MIS_2   | MESG_IN_PHASE:
2257 		sbic_save_ptrs(dev);
2258 
2259 		/*
2260 		 * Handle a single message in...
2261 		 */
2262 		return sbicmsgin(dev);
2263 
2264 	case SBIC_CSR_MSGIN_W_ACK:
2265 		/*
2266 		 * We should never see this since it's handled in 'sbicmsgin()'
2267 		 * but just for the sake of paranoia...
2268 		 */
2269 		/* Dunno what I'm ACKing */
2270 		SET_SBIC_cmd(regs, SBIC_CMD_CLR_ACK);
2271 		printf("Acking unknown msgin CSR:%02x",csr);
2272         	break;
2273 
2274 	case SBIC_CSR_XFERRED | MESG_OUT_PHASE:
2275 	case SBIC_CSR_MIS     | MESG_OUT_PHASE:
2276 	case SBIC_CSR_MIS_1   | MESG_OUT_PHASE:
2277 	case SBIC_CSR_MIS_2   | MESG_OUT_PHASE:
2278 		/*
2279 		 * We only ever handle a message out phase here for sending a
2280 		 * REJECT message.
2281 		 */
2282 		sbic_save_ptrs(dev);
2283 
2284 #ifdef DEBUG
2285 		if (sync_debug)
2286 			printf("sending REJECT msg to last msg.\n");
2287 #endif
2288 
2289 		SEND_BYTE(regs, MSG_REJECT);
2290 		WAIT_CIP(regs);
2291 		break;
2292 
2293 	case SBIC_CSR_DISC:
2294 	case SBIC_CSR_DISC_1:
2295 		/*
2296 		 * Try to schedule another target
2297 		 */
2298 		sbic_save_ptrs(dev);
2299 
2300 		dev->sc_flags &= ~SBICF_SELECTED;
2301 
2302 #ifdef DEBUG
2303 		if (reselect_debug > 1)
2304 			printf("sbicnext target %d disconnected\n",
2305 			    dev->target);
2306 #endif
2307 
2308 		TAILQ_INSERT_HEAD(&dev->nexus_list, acb, chain);
2309 
2310 		++dev->sc_tinfo[dev->target].dconns;
2311 
2312 		dev->sc_nexus = NULL;
2313 		dev->sc_xs    = NULL;
2314 
2315 		if (acb->xs->xs_control & XS_CTL_POLL ||
2316 		    dev->sc_flags & SBICF_ICMD ||
2317 		    !sbic_parallel_operations )
2318 			return SBIC_STATE_DISCONNECT;
2319 
2320 		QPRINTF(("sbicnext: calling sbic_sched\n"));
2321 
2322 		sbic_sched(dev);
2323 
2324 		QPRINTF(("sbicnext: sbic_sched returned\n"));
2325 
2326 		return SBIC_STATE_DISCONNECT;
2327 
2328 	case SBIC_CSR_RSLT_NI:
2329 	case SBIC_CSR_RSLT_IFY:
2330 	    {
2331 		/*
2332 		 * A reselection.
2333 		 * Note that since we don't enable Advanced Features (assuming
2334 		 * the WD chip is at least the 'A' revision), we're only ever
2335 		 * likely to see the 'SBIC_CSR_RSLT_NI' status. But for the
2336 		 * hell of it, we'll handle it anyway, for all the extra code
2337 		 * it needs...
2338 		 */
2339 		u_char  newtarget, newlun;
2340 
2341 		GET_SBIC_rselid(regs, newtarget);
2342 
2343 		/*
2344 		 * check SBIC_RID_SIV?
2345 		 */
2346 		newtarget &= SBIC_RID_MASK;
2347 
2348 		if (csr == SBIC_CSR_RSLT_IFY) {
2349 
2350 			/*
2351 			 * Read Identify msg to avoid lockup
2352 			 */
2353 			GET_SBIC_data(regs, newlun);
2354 			WAIT_CIP(regs);
2355 			newlun &= SBIC_TLUN_MASK;
2356 
2357 		} else {
2358 
2359 			/*
2360 			 * Need to read Identify message the hard way, assuming
2361 			 * the target even sends us one...
2362 			 */
2363 			for (newlun = 255; newlun; --newlun) {
2364 				GET_SBIC_asr(regs, asr);
2365 				if (asr & SBIC_ASR_INT)
2366 					break;
2367 				delay(10);
2368 			}
2369 
2370 			/*
2371 			 * If we didn't get an interrupt, something's up
2372 			 */
2373 			if ((asr & SBIC_ASR_INT) == 0) {
2374 				printf("%s: Reselect without identify?"
2375 				    " asr %x\n", device_xname(dev->sc_dev), asr);
2376 				newlun = 0;	/* XXXX */
2377 			} else {
2378 				/*
2379 				 * We got an interrupt, verify that
2380 				 * it's a change to message in phase,
2381 				 * and if so read the message.
2382 				 */
2383 				GET_SBIC_csr(regs,csr);
2384 
2385 				if (csr == (SBIC_CSR_MIS   | MESG_IN_PHASE) ||
2386 				    csr == (SBIC_CSR_MIS_1 | MESG_IN_PHASE) ||
2387 				    csr == (SBIC_CSR_MIS_2 | MESG_IN_PHASE)) {
2388 					/*
2389 					 * Yup, gone to message in.
2390 					 * Fetch the target LUN
2391 					 */
2392 					sbicmsgin(dev);
2393 					newlun = dev->sc_msg[0] & 0x07;
2394 
2395 				} else {
2396 					/*
2397 					 * Whoops! Target didn't go to
2398 					 * message in phase!!
2399 					 */
2400 					printf("RSLT_NI - "
2401 					    "not MESG_IN_PHASE %x\n", csr);
2402 					newlun = 0;	/* XXXSCW */
2403 				}
2404 			}
2405 		}
2406 
2407 		/*
2408 		 * Ok, we have the identity of the reselecting target.
2409 		 */
2410 #ifdef DEBUG
2411 		if (reselect_debug > 1 ||
2412 		    (reselect_debug && csr == SBIC_CSR_RSLT_NI)) {
2413 			printf("sbicnext: reselect %s from targ %d lun %d\n",
2414 			    csr == SBIC_CSR_RSLT_NI ? "NI" : "IFY",
2415 			    newtarget, newlun);
2416 		}
2417 #endif
2418 
2419 		if (dev->sc_nexus) {
2420 			/*
2421 			 * Whoops! We've been reselected with
2422 			 * a command in progress!
2423 			 * The best we can do is to put the current command
2424 			 * back on the ready list and hope for the best.
2425 			 */
2426 #ifdef DEBUG
2427 			if (reselect_debug > 1) {
2428 				printf("%s: reselect %s with active command\n",
2429 				    device_xname(dev->sc_dev),
2430 				csr == SBIC_CSR_RSLT_NI ? "NI" : "IFY");
2431 			}
2432 #endif
2433 
2434 			TAILQ_INSERT_HEAD(&dev->ready_list, dev->sc_nexus,
2435 			    chain);
2436 
2437 			dev->sc_tinfo[dev->target].lubusy &= ~(1 << dev->lun);
2438 
2439 			dev->sc_nexus = NULL;
2440 			dev->sc_xs    = NULL;
2441 		}
2442 
2443 		/*
2444 		 * Reload sync values for this target
2445 		 */
2446 		if (dev->sc_sync[newtarget].state == SYNC_DONE)
2447 			SET_SBIC_syn(regs,
2448 			    SBIC_SYN(dev->sc_sync[newtarget].offset,
2449 			    dev->sc_sync[newtarget].period));
2450 		else
2451 			SET_SBIC_syn(regs, SBIC_SYN (0, sbic_min_period));
2452 
2453 		/*
2454 		 * Loop through the nexus list until we find the saved entry
2455 		 * for the reselecting target...
2456 		 */
2457 		for (acb = dev->nexus_list.tqh_first; acb;
2458                      acb = acb->chain.tqe_next) {
2459 
2460 			if ( acb->xs->xs_periph->periph_target == newtarget &&
2461 			     acb->xs->xs_periph->periph_lun    == newlun) {
2462 				/*
2463 				 * We've found the saved entry. Dequeue it, and
2464 				 * make it current again.
2465 				 */
2466 				TAILQ_REMOVE(&dev->nexus_list, acb, chain);
2467 
2468 				dev->sc_nexus  = acb;
2469 				dev->sc_xs     = acb->xs;
2470 				dev->sc_flags |= SBICF_SELECTED;
2471 				dev->target    = newtarget;
2472 				dev->lun       = newlun;
2473 				break;
2474 			}
2475 		}
2476 
2477 		if (acb == NULL) {
2478 			printf("%s: reselect %s targ %d not in nexus_list %p\n",
2479 			    device_xname(dev->sc_dev),
2480 			    csr == SBIC_CSR_RSLT_NI ? "NI" : "IFY", newtarget,
2481 			    &dev->nexus_list.tqh_first);
2482 			panic("bad reselect in sbic");
2483 		}
2484 
2485 		if (csr == SBIC_CSR_RSLT_IFY)
2486 			SET_SBIC_cmd(regs, SBIC_CMD_CLR_ACK);
2487 	        break;
2488 	    }
2489 	default:
2490         abort:
2491 		/*
2492 		 * Something unexpected happened -- deal with it.
2493 		 */
2494 		printf("next: aborting asr 0x%02x csr 0x%02x\n", asr, csr);
2495 
2496 #ifdef DDB
2497 		Debugger();
2498 #endif
2499 
2500 #ifdef DEBUG
2501 		dev->sc_dmatimo = 0;
2502 		if (data_pointer_debug > 1)
2503 			printf("next dmastop: %d(%p:%lx)\n", dev->target,
2504 			    dev->sc_cur->dc_addr,
2505 			    dev->sc_tcnt);
2506 #endif
2507 
2508 		dev->sc_dmastop(dev);
2509 		SET_SBIC_control(regs, SBIC_CTL_EDI | SBIC_CTL_IDI);
2510 		if (dev->sc_xs)
2511 			sbicerror(dev, csr);
2512 		sbicabort(dev, "next");
2513 
2514 		if (dev->sc_flags & SBICF_INDMA) {
2515 			dev->sc_flags &= ~(SBICF_INDMA | SBICF_DCFLUSH);
2516 
2517 #ifdef DEBUG
2518 			dev->sc_dmatimo = 0;
2519 			if (data_pointer_debug > 1)
2520 				printf("next dmastop: %d(%p:%lx)\n",
2521 				    dev->target,
2522 				    dev->sc_cur->dc_addr,
2523 				    dev->sc_tcnt);
2524 #endif
2525 			sbic_scsidone(acb, -1);
2526 		}
2527 
2528 		return SBIC_STATE_ERROR;
2529 	}
2530 
2531 	return SBIC_STATE_RUNNING;
2532 }
2533 
2534 
2535 /*
2536  * Check if DMA can not be used with specified buffer
2537  */
2538 int
2539 sbiccheckdmap(void *bp, u_long len, u_long mask)
2540 {
2541 	u_char  *buffer;
2542 	u_long  phy_buf;
2543 	u_long  phy_len;
2544 
2545 	buffer = bp;
2546 
2547 	if (len == 0)
2548 		return 1;
2549 
2550 	while (len) {
2551 
2552 		phy_buf = kvtop((void *)buffer);
2553 		phy_len = PAGE_SIZE - ((int)buffer & PGOFSET);
2554 
2555 		if (len < phy_len)
2556 			phy_len = len;
2557 
2558 		if (phy_buf & mask)
2559 			return 1;
2560 
2561 		buffer += phy_len;
2562 		len    -= phy_len;
2563 	}
2564 
2565 	return 0;
2566 }
2567 
2568 int
2569 sbictoscsiperiod(struct sbic_softc *dev, int a)
2570 {
2571 	unsigned int fs;
2572 
2573 	/*
2574 	 * cycle = DIV / (2 * CLK)
2575 	 * DIV = FS + 2
2576 	 * best we can do is 200ns at 20 MHz, 2 cycles
2577 	 */
2578 
2579 	GET_SBIC_myid(dev->sc_sbicp, fs);
2580 
2581 	fs = (fs >> 6) + 2;	/* DIV */
2582 
2583 	fs = (fs * 10000) / (dev->sc_clkfreq << 1);	/* Cycle, in ns */
2584 
2585 	if (a < 2)
2586 		a = 8;		/* map to Cycles */
2587 
2588 	return (fs * a) >> 2;	/* in 4 ns units */
2589 }
2590 
2591 int
2592 sbicfromscsiperiod(struct sbic_softc *dev, int p)
2593 {
2594 	unsigned int fs, ret;
2595 
2596 	/*
2597 	 * Just the inverse of the above
2598 	 */
2599 	GET_SBIC_myid(dev->sc_sbicp, fs);
2600 
2601 	fs = (fs >> 6) + 2;	/* DIV */
2602 
2603 	fs = (fs * 10000) / (dev->sc_clkfreq << 1);	/* Cycle, in ns */
2604 
2605 	ret = p << 2;		/* in ns units */
2606 	ret = ret / fs;		/* in Cycles */
2607 
2608 	if (ret < sbic_min_period)
2609 		return(sbic_min_period);
2610 
2611 	/*
2612 	 * verify rounding
2613 	 */
2614 	if (sbictoscsiperiod(dev, ret) < p)
2615 		ret++;
2616 
2617 	return (ret >= 8) ? 0 : ret;
2618 }
2619 
2620 #ifdef DEBUG
2621 void
2622 sbictimeout(struct sbic_softc *dev)
2623 {
2624 	int s, asr;
2625 
2626 	s = splbio();
2627 
2628 	if (dev->sc_dmatimo) {
2629 
2630 		if (dev->sc_dmatimo > 1) {
2631 
2632 			printf("%s: DMA timeout #%d\n", device_xname(dev->sc_dev),
2633                             dev->sc_dmatimo - 1);
2634 
2635 			GET_SBIC_asr(dev->sc_sbicp, asr);
2636 
2637 			if (asr & SBIC_ASR_INT) {
2638 				/*
2639 				 * We need to service a missed IRQ
2640 				 */
2641 				sbicintr(dev);
2642 			} else {
2643 				(void)sbicabort(dev, "timeout");
2644 				splx(s);
2645 				return;
2646 			}
2647 		}
2648 
2649 		dev->sc_dmatimo++;
2650 	}
2651 
2652 	splx(s);
2653 
2654 	callout_reset(&dev->sc_timo_ch, 30 * hz, (void *)sbictimeout, dev);
2655 }
2656 #endif
2657