xref: /netbsd-src/sys/arch/x68k/dev/spc.c (revision d0fed6c87ddc40a8bffa6f99e7433ddfc864dd83)
1 /*	$NetBSD: spc.c,v 1.9 1996/12/10 21:27:46 thorpej Exp $	*/
2 
3 #define	integrate	static inline
4 
5 /*
6  * Copyright (c) 1996 Masaru Oki.  All rights reserved.
7  * Copyright (c) 1994, 1995, 1996 Charles M. Hannum.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by Charles M. Hannum.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * Copyright (c) 1994 Jarle Greipsland
24  * All rights reserved.
25  *
26  * Redistribution and use in source and binary forms, with or without
27  * modification, are permitted provided that the following conditions
28  * are met:
29  * 1. Redistributions of source code must retain the above copyright
30  *    notice, this list of conditions and the following disclaimer.
31  * 2. Redistributions in binary form must reproduce the above copyright
32  *    notice, this list of conditions and the following disclaimer in the
33  *    documentation and/or other materials provided with the distribution.
34  * 3. The name of the author may not be used to endorse or promote products
35  *    derived from this software without specific prior written permission.
36  *
37  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
38  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
39  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
40  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
41  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
42  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
43  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
46  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
47  * POSSIBILITY OF SUCH DAMAGE.
48  */
49 
50 /*
51  * Acknowledgements: Many of the algorithms used in this driver are
52  * inspired by the work of Julian Elischer (julian@tfs.com) and
53  * Charles Hannum (mycroft@duality.gnu.ai.mit.edu).  Thanks a million!
54  */
55 
56 /* TODO list:
57  * 1) Get the DMA stuff working.
58  * 2) Get the iov/uio stuff working. Is this a good thing ???
59  * 3) Get the synch stuff working.
60  * 4) Rewrite it to use malloc for the acb structs instead of static alloc.?
61  */
62 
63 /*
64  * A few customizable items:
65  */
66 
67 /* Use doubleword transfers to/from SCSI chip.  Note: This requires
68  * motherboard support.  Basicly, some motherboard chipsets are able to
69  * split a 32 bit I/O operation into two 16 bit I/O operations,
70  * transparently to the processor.  This speeds up some things, notably long
71  * data transfers.
72  */
73 #define SPC_USE_DWORDS		0
74 
75 /* Synchronous data transfers? */
76 #define SPC_USE_SYNCHRONOUS	0
77 #define SPC_SYNC_REQ_ACK_OFS 	8
78 
79 /* Wide data transfers? */
80 #define	SPC_USE_WIDE		0
81 #define	SPC_MAX_WIDTH		0
82 
83 /* Max attempts made to transmit a message */
84 #define SPC_MSG_MAX_ATTEMPT	3 /* Not used now XXX */
85 
86 /* Some spin loop parameters (essentially how long to wait some places)
87  * The problem(?) is that sometimes we expect either to be able to transmit a
88  * byte or to get a new one from the SCSI bus pretty soon.  In order to avoid
89  * returning from the interrupt just to get yanked back for the next byte we
90  * may spin in the interrupt routine waiting for this byte to come.  How long?
91  * This is really (SCSI) device and processor dependent.  Tuneable, I guess.
92  */
93 #define SPC_MSGIN_SPIN		1 	/* Will spinwait upto ?ms for a new msg byte */
94 #define SPC_MSGOUT_SPIN		1
95 
96 /* Include debug functions?  At the end of this file there are a bunch of
97  * functions that will print out various information regarding queued SCSI
98  * commands, driver state and chip contents.  You can call them from the
99  * kernel debugger.  If you set SPC_DEBUG to 0 they are not included (the
100  * kernel uses less memory) but you lose the debugging facilities.
101  */
102 #define SPC_DEBUG		1
103 
104 #define	SPC_ABORT_TIMEOUT	2000	/* time to wait for abort */
105 
106 /* End of customizable parameters */
107 
108 /*
109  * MB89352 SCSI Protocol Controller (SPC) routines.
110  */
111 
112 #include <sys/types.h>
113 #include <sys/param.h>
114 #include <sys/systm.h>
115 #include <sys/kernel.h>
116 #include <sys/errno.h>
117 #include <sys/ioctl.h>
118 #include <sys/device.h>
119 #include <sys/buf.h>
120 #include <sys/proc.h>
121 #include <sys/user.h>
122 #include <sys/queue.h>
123 
124 #include <scsi/scsi_all.h>
125 #include <scsi/scsi_message.h>
126 #include <scsi/scsiconf.h>
127 
128 #include <x68k/x68k/iodevice.h>
129 #include <x68k/dev/mb89352reg.h>
130 
131 /*
132  * Definitions, most of them has turned out to be unneccesary, but here they
133  * are anyway.
134  */
135 
136 #define IOBASE		sc->sc_iobase
137 #define BDID		(IOBASE->scsi_bdid)
138 #define SCTL		(IOBASE->scsi_sctl)
139 #define SCMD		(IOBASE->scsi_scmd)
140 #define TMOD		(IOBASE->scsi_tmod)
141 #define INTS		(IOBASE->scsi_ints)
142 #define PSNS		(IOBASE->scsi_psns)
143 #define SSTS		(IOBASE->scsi_ssts)
144 #define SERR		(IOBASE->scsi_serr)
145 #define PCTL		(IOBASE->scsi_pctl)
146 #define MBC		(IOBASE->scsi_mbc)
147 #define DREG		(IOBASE->scsi_dreg)
148 #define TEMP		(IOBASE->scsi_temp)
149 #define TCH		(IOBASE->scsi_tch)
150 #define TCM		(IOBASE->scsi_tcm)
151 #define TCL		(IOBASE->scsi_tcl)
152 #define EXBF		(IOBASE->scsi_exbf)
153 
154 /* PSNS */
155 #define REQI		0x80
156 #define ACKI		0x40
157 #define ATNI		0x20
158 #define SELI		0x10
159 #define BSYI		0x08
160 #define MSGI		0x04
161 #define CDI		0x02
162 #define IOI		0x01
163 
164 /* Important! The 3 most significant bits of this register, in initiator mode,
165  * represents the "expected" SCSI bus phase and can be used to trigger phase
166  * mismatch and phase change interrupts.  But more important:  If there is a
167  * phase mismatch the chip will not transfer any data!  This is actually a nice
168  * feature as it gives us a bit more control over what is happening when we are
169  * bursting data (in) through the FIFOs and the phase suddenly changes from
170  * DATA IN to STATUS or MESSAGE IN.  The transfer will stop and wait for the
171  * proper phase to be set in this register instead of dumping the bits into the
172  * FIFOs.
173  */
174 #if 0
175 #define REQO		0x80
176 #define ACKO		0x40
177 #define ATNO		0x20
178 #define SELO		0x10
179 #define BSYO		0x08
180 #endif
181 /* PCTL */
182 #define MSGO		0x04
183 #define CDO		0x02
184 #define IOO		0x01
185 
186 /* Information transfer phases */
187 #define PH_DATAOUT	(0)
188 #define PH_DATAIN	(IOI)
189 #define PH_CMD		(CDI)
190 #define PH_STAT		(CDI | IOI)
191 #define PH_MSGOUT	(MSGI | CDI)
192 #define PH_MSGIN	(MSGI | CDI | IOI)
193 
194 #define PH_MASK		(MSGI | CDI | IOI)
195 
196 #define	PH_INVALID	0xff
197 
198 /* SCSI selection/reselection ID (both target *and* initiator) */
199 #define SELID7		0x80
200 #define SELID6		0x40
201 #define SELID5		0x20
202 #define SELID4		0x10
203 #define SELID3		0x08
204 #define SELID2		0x04
205 #define SELID1		0x02
206 #define SELID0		0x01
207 
208 #ifndef DDB
209 #define	Debugger() panic("should call debugger here (spc.c)")
210 #endif /* ! DDB */
211 
212 /*
213  * ACB. Holds additional information for each SCSI command Comments: We
214  * need a separate scsi command block because we may need to overwrite it
215  * with a request sense command.  Basicly, we refrain from fiddling with
216  * the scsi_xfer struct (except do the expected updating of return values).
217  * We'll generally update: xs->{flags,resid,error,sense,status} and
218  * occasionally xs->retries.
219  */
220 struct spc_acb {
221 	struct scsi_generic scsi_cmd;
222 	int scsi_cmd_length;
223 	u_char *data_addr;		/* Saved data pointer */
224 	int data_length;		/* Residue */
225 
226 	u_char target_stat;		/* SCSI status byte */
227 
228 /*	struct spc_dma_seg dma[SPC_NSEG];*/ /* Physical addresses+len */
229 
230 	TAILQ_ENTRY(spc_acb) chain;
231 	struct scsi_xfer *xs;	/* SCSI xfer ctrl block from above */
232 	int flags;
233 #define ACB_ALLOC	0x01
234 #define	ACB_NEXUS	0x02
235 #define ACB_SENSE	0x04
236 #define	ACB_ABORT	0x40
237 #define	ACB_RESET	0x80
238 	int timeout;
239 };
240 
241 /*
242  * Some info about each (possible) target on the SCSI bus.  This should
243  * probably have been a "per target+lunit" structure, but we'll leave it at
244  * this for now.
245  */
246 struct spc_tinfo {
247 	int	cmds;		/* #commands processed */
248 	int	dconns;		/* #disconnects */
249 	int	touts;		/* #timeouts */
250 	int	perrs;		/* #parity errors */
251 	int	senses;		/* #request sense commands sent */
252 	ushort	lubusy;		/* What local units/subr. are busy? */
253 	u_char  flags;
254 #define DO_SYNC		0x01	/* (Re)Negotiate synchronous options */
255 #define	DO_WIDE		0x02	/* (Re)Negotiate wide options */
256 	u_char  period;		/* Period suggestion */
257 	u_char  offset;		/* Offset suggestion */
258 	u_char	width;		/* Width suggestion */
259 } tinfo_t;
260 
261 struct spc_softc {
262 	struct device sc_dev;
263 	volatile struct mb89352 *sc_iobase;
264 
265 	struct scsi_link sc_link;	/* prototype for subdevs */
266 
267 	TAILQ_HEAD(, spc_acb) free_list, ready_list, nexus_list;
268 	struct spc_acb *sc_nexus;	/* current command */
269 	struct spc_acb sc_acb[8];
270 	struct spc_tinfo sc_tinfo[8];
271 
272 	/* Data about the current nexus (updated for every cmd switch) */
273 	u_char	*sc_dp;		/* Current data pointer */
274 	size_t	sc_dleft;	/* Data bytes left to transfer */
275 	u_char	*sc_cp;		/* Current command pointer */
276 	size_t	sc_cleft;	/* Command bytes left to transfer */
277 
278 	/* Adapter state */
279 	u_char	 sc_phase;	/* Current bus phase */
280 	u_char	 sc_prevphase;	/* Previous bus phase */
281 	u_char	 sc_state;	/* State applicable to the adapter */
282 #define	SPC_INIT	0
283 #define SPC_IDLE	1
284 #define SPC_SELECTING	2	/* SCSI command is arbiting  */
285 #define SPC_RESELECTED	3	/* Has been reselected */
286 #define SPC_CONNECTED	4	/* Actively using the SCSI bus */
287 #define	SPC_DISCONNECT	5	/* MSG_DISCONNECT received */
288 #define	SPC_CMDCOMPLETE	6	/* MSG_CMDCOMPLETE received */
289 #define SPC_CLEANING	7
290 	u_char	 sc_flags;
291 #define SPC_DROP_MSGIN	0x01	/* Discard all msgs (parity err detected) */
292 #define	SPC_ABORTING	0x02	/* Bailing out */
293 #define SPC_DOINGDMA	0x04	/* The FIFO data path is active! */
294 	u_char	sc_selid;	/* Reselection ID */
295 
296 	/* Message stuff */
297 	u_char	sc_msgpriq;	/* Messages we want to send */
298 	u_char	sc_msgoutq;	/* Messages sent during last MESSAGE OUT */
299 	u_char	sc_lastmsg;	/* Message last transmitted */
300 	u_char	sc_currmsg;	/* Message currently ready to transmit */
301 #define SEND_DEV_RESET		0x01
302 #define SEND_PARITY_ERROR	0x02
303 #define SEND_INIT_DET_ERR	0x04
304 #define SEND_REJECT		0x08
305 #define SEND_IDENTIFY  		0x10
306 #define SEND_ABORT		0x20
307 #define SEND_SDTR		0x40
308 #define	SEND_WDTR		0x80
309 #define SPC_MAX_MSG_LEN 8
310 	u_char  sc_omess[SPC_MAX_MSG_LEN];
311 	u_char	*sc_omp;		/* Outgoing message pointer */
312 	u_char	sc_imess[SPC_MAX_MSG_LEN];
313 	u_char	*sc_imp;		/* Incoming message pointer */
314 
315 	/* Hardware stuff */
316 	int	sc_initiator;		/* Our scsi id */
317 	int	sc_freq;		/* Clock frequency in MHz */
318 	int	sc_minsync;		/* Minimum sync period / 4 */
319 	int	sc_maxsync;		/* Maximum sync period / 4 */
320 };
321 
322 #if SPC_DEBUG
323 #define SPC_SHOWACBS	0x01
324 #define SPC_SHOWINTS	0x02
325 #define SPC_SHOWCMDS	0x04
326 #define SPC_SHOWMISC	0x08
327 #define SPC_SHOWTRACE	0x10
328 #define SPC_SHOWSTART	0x20
329 #define SPC_DOBREAK	0x40
330 int spc_debug = 0x00; /* SPC_SHOWSTART|SPC_SHOWMISC|SPC_SHOWTRACE; */
331 #define	SPC_PRINT(b, s)	do {if ((spc_debug & (b)) != 0) printf s;} while (0)
332 #define	SPC_BREAK()	do {if ((spc_debug & SPC_DOBREAK) != 0) Debugger();} while (0)
333 #define	SPC_ASSERT(x)	do {if (x) {} else {printf("%s at line %d: assertion failed\n", sc->sc_dev.dv_xname, __LINE__); Debugger();}} while (0)
334 #else
335 #define	SPC_PRINT(b, s)
336 #define	SPC_BREAK()
337 #define	SPC_ASSERT(x)
338 #endif
339 
340 #define SPC_ACBS(s)	SPC_PRINT(SPC_SHOWACBS, s)
341 #define SPC_INTS(s)	SPC_PRINT(SPC_SHOWINTS, s)
342 #define SPC_CMDS(s)	SPC_PRINT(SPC_SHOWCMDS, s)
343 #define SPC_MISC(s)	SPC_PRINT(SPC_SHOWMISC, s)
344 #define SPC_TRACE(s)	SPC_PRINT(SPC_SHOWTRACE, s)
345 #define SPC_START(s)	SPC_PRINT(SPC_SHOWSTART, s)
346 
347 int	spcmatch	__P((struct device *, void *, void *));
348 void	spcattach	__P((struct device *, struct device *, void *));
349 void	spc_minphys	__P((struct buf *));
350 int	spcintr		__P((int));
351 void 	spc_init	__P((struct spc_softc *));
352 void	spc_done	__P((struct spc_softc *, struct spc_acb *));
353 void	spc_dequeue	__P((struct spc_softc *, struct spc_acb *));
354 int	spc_scsi_cmd	__P((struct scsi_xfer *));
355 int	spc_poll	__P((struct spc_softc *, struct scsi_xfer *, int));
356 integrate void	spc_sched_msgout __P((struct spc_softc *, u_char));
357 integrate void	spc_setsync	__P((struct spc_softc *, struct spc_tinfo *));
358 void	spc_select	__P((struct spc_softc *, struct spc_acb *));
359 void	spc_timeout	__P((void *));
360 void	spc_sched	__P((struct spc_softc *));
361 void	spc_scsi_reset	__P((struct spc_softc *));
362 void	spc_reset	__P((struct spc_softc *));
363 #if SPC_DEBUG
364 void	spc_print_active_acb();
365 void	spc_dump_driver();
366 #endif
367 volatile void *	spc_find	__P((int));
368 
369 struct cfattach spc_ca = {
370 	sizeof(struct spc_softc), spcmatch, spcattach
371 };
372 
373 struct cfdriver spc_cd = {
374 	NULL, "spc", DV_DULL
375 };
376 
377 struct scsi_adapter spc_switch = {
378 	spc_scsi_cmd,
379 	spc_minphys,
380 	0,
381 	0,
382 };
383 
384 struct scsi_device spc_dev = {
385 	NULL,			/* Use default error handler */
386 	NULL,			/* have a queue, served by this */
387 	NULL,			/* have no async handler */
388 	NULL,			/* Use default 'done' routine */
389 };
390 
391 /*
392  * INITIALIZATION ROUTINES (probe, attach ++)
393  */
394 
395 /*
396  * returns non-zero value if a controller is found.
397  */
398 int
399 spcmatch(parent, match, aux)
400 	struct device *parent;
401 	void *match, *aux;
402 {
403 	struct cfdata *cf = match;
404 
405 	if (strcmp(aux, "spc") || spc_find(cf->cf_unit) == 0)
406 		return 0;
407 	return 1;
408 }
409 
410 /*
411  * Find the board
412  */
413 volatile void *
414 spc_find(unit)
415 	int unit;
416 {
417 	volatile void *addr;
418 
419 	if (unit > 1)
420 		return 0;
421 	switch(unit) {
422 	case 0: /* builtin */
423 		if (badaddr(IODEVbase->inscsirom) ||
424 	    	    badbaddr(&IODEVbase->io_inspc.bdid) ||
425 	    	    bcmp((void *)&IODEVbase->inscsirom[0x24], "SCSIIN", 6))
426 			return 0;
427 		addr = &IODEVbase->io_inspc;
428 		break;
429 	case 1: /* external */
430 		if (badaddr(IODEVbase->exscsirom) ||
431 	    	    badbaddr(&IODEVbase->io_exspc.bdid) ||
432 	    	    bcmp((void *)&IODEVbase->exscsirom[0x24], "SCSIEX", 6))
433 			return 0;
434 		addr = &IODEVbase->io_exspc;
435 		break;
436 	}
437 
438 	if (badaddr(addr))
439 		return 0;
440 
441 	return addr;
442 }
443 
444 /*
445  */
446 void
447 spcattach(parent, self, aux)
448 	struct device *parent, *self;
449 	void *aux;
450 {
451 	struct spc_softc *sc = (void *)self;
452 
453 	SPC_TRACE(("spcattach  "));
454 	sc->sc_state = SPC_INIT;
455 	sc->sc_iobase = spc_find(sc->sc_dev.dv_unit); /* XXX */
456 	spc_init(sc);	/* Init chip and driver */
457 
458 	/*
459 	 * Fill in the prototype scsi_link
460 	 */
461 	sc->sc_link.channel = SCSI_CHANNEL_ONLY_ONE;
462 	sc->sc_link.adapter_softc = sc;
463 	sc->sc_link.adapter_target = sc->sc_initiator;
464 	sc->sc_link.adapter = &spc_switch;
465 	sc->sc_link.device = &spc_dev;
466 	sc->sc_link.openings = 2;
467 	sc->sc_link.max_target = 7;
468 
469 	printf("\n");
470 
471 	config_found(self, &sc->sc_link, scsiprint);
472 }
473 
474 void
475 spc_reset(sc)
476 	struct spc_softc *sc;
477 {
478 	sc->sc_initiator = IODEVbase->io_sram[0x70] & 0x7; /* XXX */
479 	/*
480 	 * Disable interrupts then reset the FUJITSU chip.
481 	 */
482 	SCTL = SCTL_DISABLE | SCTL_CTRLRST;
483 	SCMD = 0;
484 	PCTL = 0;
485 	TEMP = 0;
486 	TCH  = 0;
487 	TCM  = 0;
488 	TCL  = 0;
489 	INTS = 0;
490 	SCTL = SCTL_DISABLE | SCTL_ABRT_ENAB | SCTL_PARITY_ENAB | SCTL_RESEL_ENAB;
491 	BDID = sc->sc_initiator;
492 	delay(400);
493 	SCTL &= ~SCTL_DISABLE;
494 }
495 
496 /*
497  * Pull the SCSI RST line for 500us.
498  */
499 void
500 spc_scsi_reset(sc)
501 	struct spc_softc *sc;
502 {
503 
504 	SCMD |= SCMD_RST;
505 	delay(500);
506 	SCMD &= ~SCMD_RST;
507 	delay(50);
508 }
509 
510 /*
511  * Initialize spc SCSI driver.
512  */
513 void
514 spc_init(sc)
515 	struct spc_softc *sc;
516 {
517 	struct spc_acb *acb;
518 	int r;
519 
520 	spc_reset(sc);
521 	spc_scsi_reset(sc);
522 	spc_reset(sc);
523 
524 	if (sc->sc_state == SPC_INIT) {
525 		/* First time through; initialize. */
526 		TAILQ_INIT(&sc->ready_list);
527 		TAILQ_INIT(&sc->nexus_list);
528 		TAILQ_INIT(&sc->free_list);
529 		sc->sc_nexus = NULL;
530 		acb = sc->sc_acb;
531 		bzero(acb, sizeof(sc->sc_acb));
532 		for (r = 0; r < sizeof(sc->sc_acb) / sizeof(*acb); r++) {
533 			TAILQ_INSERT_TAIL(&sc->free_list, acb, chain);
534 			acb++;
535 		}
536 		bzero(&sc->sc_tinfo, sizeof(sc->sc_tinfo));
537 	} else {
538 		/* Cancel any active commands. */
539 		sc->sc_state = SPC_CLEANING;
540 		if ((acb = sc->sc_nexus) != NULL) {
541 			acb->xs->error = XS_DRIVER_STUFFUP;
542 			untimeout(spc_timeout, acb);
543 			spc_done(sc, acb);
544 		}
545 		while ((acb = sc->nexus_list.tqh_first) != NULL) {
546 			acb->xs->error = XS_DRIVER_STUFFUP;
547 			untimeout(spc_timeout, acb);
548 			spc_done(sc, acb);
549 		}
550 	}
551 
552 	sc->sc_prevphase = PH_INVALID;
553 	for (r = 0; r < 8; r++) {
554 		struct spc_tinfo *ti = &sc->sc_tinfo[r];
555 
556 		ti->flags = 0;
557 #if SPC_USE_SYNCHRONOUS
558 		ti->flags |= DO_SYNC;
559 		ti->period = sc->sc_minsync;
560 		ti->offset = SPC_SYNC_REQ_ACK_OFS;
561 #else
562 		ti->period = ti->offset = 0;
563 #endif
564 #if SPC_USE_WIDE
565 		ti->flags |= DO_WIDE;
566 		ti->width = SPC_MAX_WIDTH;
567 #else
568 		ti->width = 0;
569 #endif
570 	}
571 
572 	sc->sc_state = SPC_IDLE;
573 	SCTL |= SCTL_INTR_ENAB;
574 }
575 
576 void
577 spc_free_acb(sc, acb, flags)
578 	struct spc_softc *sc;
579 	struct spc_acb *acb;
580 	int flags;
581 {
582 	int s;
583 
584 	s = splbio();
585 
586 	acb->flags = 0;
587 	TAILQ_INSERT_HEAD(&sc->free_list, acb, chain);
588 
589 	/*
590 	 * If there were none, wake anybody waiting for one to come free,
591 	 * starting with queued entries.
592 	 */
593 	if (acb->chain.tqe_next == 0)
594 		wakeup(&sc->free_list);
595 
596 	splx(s);
597 }
598 
599 struct spc_acb *
600 spc_get_acb(sc, flags)
601 	struct spc_softc *sc;
602 	int flags;
603 {
604 	struct spc_acb *acb;
605 	int s;
606 
607 	s = splbio();
608 
609 	while ((acb = sc->free_list.tqh_first) == NULL &&
610 	       (flags & SCSI_NOSLEEP) == 0)
611 		tsleep(&sc->free_list, PRIBIO, "spcacb", 0);
612 	if (acb) {
613 		TAILQ_REMOVE(&sc->free_list, acb, chain);
614 		acb->flags |= ACB_ALLOC;
615 	}
616 
617 	splx(s);
618 	return acb;
619 }
620 
621 /*
622  * DRIVER FUNCTIONS CALLABLE FROM HIGHER LEVEL DRIVERS
623  */
624 
625 /*
626  * Expected sequence:
627  * 1) Command inserted into ready list
628  * 2) Command selected for execution
629  * 3) Command won arbitration and has selected target device
630  * 4) Send message out (identify message, eventually also sync.negotiations)
631  * 5) Send command
632  * 5a) Receive disconnect message, disconnect.
633  * 5b) Reselected by target
634  * 5c) Receive identify message from target.
635  * 6) Send or receive data
636  * 7) Receive status
637  * 8) Receive message (command complete etc.)
638  * 9) If status == SCSI_CHECK construct a synthetic request sense SCSI cmd.
639  *    Repeat 2-8 (no disconnects please...)
640  */
641 
642 /*
643  * Start a SCSI-command
644  * This function is called by the higher level SCSI-driver to queue/run
645  * SCSI-commands.
646  */
647 int
648 spc_scsi_cmd(xs)
649 	struct scsi_xfer *xs;
650 {
651 	struct scsi_link *sc_link = xs->sc_link;
652 	struct spc_softc *sc = sc_link->adapter_softc;
653 	struct spc_acb *acb;
654 	int s, flags;
655 
656 	SPC_TRACE(("spc_scsi_cmd  "));
657 	SPC_CMDS(("[0x%x, %d]->%d ", (int)xs->cmd->opcode, xs->cmdlen,
658 	    sc_link->target));
659 
660 	flags = xs->flags;
661 	if ((acb = spc_get_acb(sc, flags)) == NULL) {
662 		xs->error = XS_DRIVER_STUFFUP;
663 		return TRY_AGAIN_LATER;
664 	}
665 
666 	/* Initialize acb */
667 	acb->xs = xs;
668 	acb->timeout = xs->timeout;
669 
670 	if (xs->flags & SCSI_RESET) {
671 		acb->flags |= ACB_RESET;
672 		acb->scsi_cmd_length = 0;
673 		acb->data_length = 0;
674 	} else {
675 		bcopy(xs->cmd, &acb->scsi_cmd, xs->cmdlen);
676 #if 1
677 		acb->scsi_cmd.bytes[0] |= sc_link->lun << 5; /* XXX? */
678 #endif
679 		acb->scsi_cmd_length = xs->cmdlen;
680 		acb->data_addr = xs->data;
681 		acb->data_length = xs->datalen;
682 	}
683 	acb->target_stat = 0;
684 
685 	s = splbio();
686 
687 	TAILQ_INSERT_TAIL(&sc->ready_list, acb, chain);
688 	/*
689 	 * $B%-%e!<$N=hM}Cf$G$J$1$l$P!"%9%1%8%e!<%j%s%03+;O$9$k(B
690 	 */
691 	if (sc->sc_state == SPC_IDLE)
692 		spc_sched(sc);
693 	/*
694 	 * $BAw?.$K@.8y$7$?$i!"$9$0$K%j%?!<%s$9$k$+D4$Y$k(B
695 	 * $B$9$0%j%?!<%s$9$k$J$i(B SUCCESSFULLY_QUEUED $B$rJV$9(B
696 	 */
697 
698 	splx(s);
699 
700 	if ((flags & SCSI_POLL) == 0)
701 		return SUCCESSFULLY_QUEUED;
702 
703 	/* Not allowed to use interrupts, use polling instead */
704 	s = splbio();
705 	if (spc_poll(sc, xs, acb->timeout)) {
706 		spc_timeout(acb);
707 		if (spc_poll(sc, xs, acb->timeout))
708 			spc_timeout(acb);
709 	}
710 	splx(s);
711 	return COMPLETE;
712 }
713 
714 /*
715  * Adjust transfer size in buffer structure
716  */
717 void
718 spc_minphys(bp)
719 	struct buf *bp;
720 {
721 
722 	SPC_TRACE(("spc_minphys  "));
723 	minphys(bp);
724 }
725 
726 /*
727  * Used when interrupt driven I/O isn't allowed, e.g. during boot.
728  */
729 int
730 spc_poll(sc, xs, count)
731 	struct spc_softc *sc;
732 	struct scsi_xfer *xs;
733 	int count;
734 {
735 
736 	SPC_TRACE(("spc_poll  "));
737 	while (count) {
738 		/*
739 		 * If we had interrupts enabled, would we
740 		 * have got an interrupt?
741 		 */
742 		if (INTS != 0)
743 			spcintr(sc->sc_dev.dv_unit);
744 		if ((xs->flags & ITSDONE) != 0)
745 			return 0;
746 		delay(1000);
747 		count--;
748 	}
749 	return 1;
750 }
751 
752 /*
753  * LOW LEVEL SCSI UTILITIES
754  */
755 
756 integrate void
757 spc_sched_msgout(sc, m)
758 	struct spc_softc *sc;
759 	u_char m;
760 {
761 	if (sc->sc_msgpriq == 0)
762 		SCMD = SCMD_SET_ATN;
763 	sc->sc_msgpriq |= m;
764 }
765 
766 /*
767  * Set synchronous transfer offset and period.
768  */
769 integrate void
770 spc_setsync(sc, ti)
771 	struct spc_softc *sc;
772 	struct spc_tinfo *ti;
773 {
774 #if SPC_USE_SYNCHRONOUS
775 
776 	if (ti->offset != 0)
777 		TMOD =
778 		    ((ti->period * sc->sc_freq) / 250 - 2) << 4 | ti->offset);
779 	else
780 		TMOD = 0;
781 #endif
782 }
783 
784 /*
785  * Start a selection.  This is used by spc_sched() to select an idle target,
786  * and by spc_done() to immediately reselect a target to get sense information.
787  */
788 void
789 spc_select(sc, acb)
790 	struct spc_softc *sc;
791 	struct spc_acb *acb;
792 {
793 	struct scsi_link *sc_link = acb->xs->sc_link;
794 	int target = sc_link->target;
795 	struct spc_tinfo *ti = &sc->sc_tinfo[target];
796 
797 	spc_setsync(sc, ti);
798 
799 #if 0
800 	SCMD = SCMD_SET_ATN;
801 #endif
802 	PCTL = 0;
803 	TEMP = (1 << sc->sc_initiator) | (1 << target);
804 	/*
805 	 * BSY $B$K$h$k1~EzBT$A;~4V@_Dj(B ($B@_Dj;~4V$r2a$.$k$H(B selection timeout)
806 	 * 0 $B$K$9$k$HL58BBT$A(B (x68k $B$G$O(B Tclf == 200ns)
807 	 * T = (X * 256 + 15) * Tclf * 2 $B$J$N$G(B... 256ms $BBT$D$H$9$k$H(B
808 	 * 128000ns/200ns = X * 256 + 15
809 	 * 640 - 15 = X * 256
810 	 * X = 625 / 256
811 	 * X = 2 + 113 / 256
812 	 * $B$J$N$G(B tch $B$K(B 2, tcm $B$K(B 113 $B$rBeF~!#(B($B$$$$$N$+(B?)
813 	 */
814 	TCH = 2;
815 	TCM = 113;
816 	/* BSY $B$H(B SEL $B$,(B 0 $B$K$J$C$F$+$i%U%'!<%:3+;O$^$G$N;~4V(B */
817 	TCL = 3;
818 	SCMD = SCMD_SELECT;
819 
820 	sc->sc_state = SPC_SELECTING;
821 }
822 
823 int
824 spc_reselect(sc, message)
825 	struct spc_softc *sc;
826 	u_char message;
827 {
828 	u_char selid, target, lun;
829 	struct spc_acb *acb;
830 	struct scsi_link *sc_link;
831 	struct spc_tinfo *ti;
832 
833 	/*
834 	 * The SCSI chip made a snapshot of the data bus while the reselection
835 	 * was being negotiated.  This enables us to determine which target did
836 	 * the reselect.
837 	 */
838 	selid = sc->sc_selid & ~(1 << sc->sc_initiator);
839 	if (selid & (selid - 1)) {
840 		printf("%s: reselect with invalid selid %02x; sending DEVICE RESET\n",
841 		    sc->sc_dev.dv_xname, selid);
842 		SPC_BREAK();
843 		goto reset;
844 	}
845 
846 	/*
847 	 * Search wait queue for disconnected cmd
848 	 * The list should be short, so I haven't bothered with
849 	 * any more sophisticated structures than a simple
850 	 * singly linked list.
851 	 */
852 	target = ffs(selid) - 1;
853 	lun = message & 0x07;
854 	for (acb = sc->nexus_list.tqh_first; acb != NULL;
855 	     acb = acb->chain.tqe_next) {
856 		sc_link = acb->xs->sc_link;
857 		if (sc_link->target == target && sc_link->lun == lun)
858 			break;
859 	}
860 	if (acb == NULL) {
861 		printf("%s: reselect from target %d lun %d with no nexus; sending ABORT\n",
862 		    sc->sc_dev.dv_xname, target, lun);
863 		SPC_BREAK();
864 		goto abort;
865 	}
866 
867 	/* Make this nexus active again. */
868 	TAILQ_REMOVE(&sc->nexus_list, acb, chain);
869 	sc->sc_state = SPC_CONNECTED;
870 	sc->sc_nexus = acb;
871 	ti = &sc->sc_tinfo[target];
872 	ti->lubusy |= (1 << lun);
873 	spc_setsync(sc, ti);
874 
875 	if (acb->flags & ACB_RESET)
876 		spc_sched_msgout(sc, SEND_DEV_RESET);
877 	else if (acb->flags & ACB_ABORT)
878 		spc_sched_msgout(sc, SEND_ABORT);
879 
880 	/* Do an implicit RESTORE POINTERS. */
881 	sc->sc_dp = acb->data_addr;
882 	sc->sc_dleft = acb->data_length;
883 	sc->sc_cp = (u_char *)&acb->scsi_cmd;
884 	sc->sc_cleft = acb->scsi_cmd_length;
885 
886 	return (0);
887 
888 reset:
889 	spc_sched_msgout(sc, SEND_DEV_RESET);
890 	return (1);
891 
892 abort:
893 	spc_sched_msgout(sc, SEND_ABORT);
894 	return (1);
895 }
896 
897 /*
898  * Schedule a SCSI operation.  This has now been pulled out of the interrupt
899  * handler so that we may call it from spc_scsi_cmd and spc_done.  This may
900  * save us an unecessary interrupt just to get things going.  Should only be
901  * called when state == SPC_IDLE and at bio pl.
902  */
903 void
904 spc_sched(sc)
905 	register struct spc_softc *sc;
906 {
907 	struct spc_acb *acb;
908 	struct scsi_link *sc_link;
909 	struct spc_tinfo *ti;
910 
911 	/*
912 	 * Find first acb in ready queue that is for a target/lunit pair that
913 	 * is not busy.
914 	 */
915 	for (acb = sc->ready_list.tqh_first; acb != NULL;
916 	    acb = acb->chain.tqe_next) {
917 		sc_link = acb->xs->sc_link;
918 		ti = &sc->sc_tinfo[sc_link->target];
919 		if ((ti->lubusy & (1 << sc_link->lun)) == 0) {
920 			SPC_MISC(("selecting %d:%d  ",
921 			    sc_link->target, sc_link->lun));
922 			TAILQ_REMOVE(&sc->ready_list, acb, chain);
923 			sc->sc_nexus = acb;
924 			spc_select(sc, acb);
925 			return;
926 		} else
927 			SPC_MISC(("%d:%d busy\n",
928 			    sc_link->target, sc_link->lun));
929 	}
930 	SPC_MISC(("idle  "));
931 	/* Nothing to start; just enable reselections and wait. */
932 }
933 
934 void
935 spc_sense(sc, acb)
936 	struct spc_softc *sc;
937 	struct spc_acb *acb;
938 {
939 	struct scsi_xfer *xs = acb->xs;
940 	struct scsi_link *sc_link = xs->sc_link;
941 	struct spc_tinfo *ti = &sc->sc_tinfo[sc_link->target];
942 	struct scsi_sense *ss = (void *)&acb->scsi_cmd;
943 
944 	SPC_MISC(("requesting sense  "));
945 	/* Next, setup a request sense command block */
946 	bzero(ss, sizeof(*ss));
947 	ss->opcode = REQUEST_SENSE;
948 	ss->byte2 = sc_link->lun << 5;
949 	ss->length = sizeof(struct scsi_sense_data);
950 	acb->scsi_cmd_length = sizeof(*ss);
951 	acb->data_addr = (char *)&xs->sense;
952 	acb->data_length = sizeof(struct scsi_sense_data);
953 	acb->flags |= ACB_SENSE;
954 	ti->senses++;
955 	if (acb->flags & ACB_NEXUS)
956 		ti->lubusy &= ~(1 << sc_link->lun);
957 	if (acb == sc->sc_nexus) {
958 		spc_select(sc, acb);
959 	} else {
960 		spc_dequeue(sc, acb);
961 		TAILQ_INSERT_HEAD(&sc->ready_list, acb, chain);
962 		if (sc->sc_state == SPC_IDLE)
963 			spc_sched(sc);
964 	}
965 }
966 
967 /*
968  * POST PROCESSING OF SCSI_CMD (usually current)
969  */
970 void
971 spc_done(sc, acb)
972 	struct spc_softc *sc;
973 	struct spc_acb *acb;
974 {
975 	struct scsi_xfer *xs = acb->xs;
976 	struct scsi_link *sc_link = xs->sc_link;
977 	struct spc_tinfo *ti = &sc->sc_tinfo[sc_link->target];
978 
979 	SPC_TRACE(("spc_done  "));
980 
981 	/*
982 	 * Now, if we've come here with no error code, i.e. we've kept the
983 	 * initial XS_NOERROR, and the status code signals that we should
984 	 * check sense, we'll need to set up a request sense cmd block and
985 	 * push the command back into the ready queue *before* any other
986 	 * commands for this target/lunit, else we lose the sense info.
987 	 * We don't support chk sense conditions for the request sense cmd.
988 	 */
989 	if (xs->error == XS_NOERROR) {
990 		if (acb->flags & ACB_ABORT) {
991 			xs->error = XS_DRIVER_STUFFUP;
992 		} else if (acb->flags & ACB_SENSE) {
993 			xs->error = XS_SENSE;
994 		} else if (acb->target_stat == SCSI_CHECK) {
995 			/* First, save the return values */
996 			xs->resid = acb->data_length;
997 			xs->status = acb->target_stat;
998 			spc_sense(sc, acb);
999 			return;
1000 		} else {
1001 			xs->resid = acb->data_length;
1002 		}
1003 	}
1004 
1005 	xs->flags |= ITSDONE;
1006 
1007 #if SPC_DEBUG
1008 	if ((spc_debug & SPC_SHOWMISC) != 0) {
1009 		if (xs->resid != 0)
1010 			printf("resid=%d ", xs->resid);
1011 		if (xs->error == XS_SENSE)
1012 			printf("sense=0x%02x\n", xs->sense.error_code);
1013 		else
1014 			printf("error=%d\n", xs->error);
1015 	}
1016 #endif
1017 
1018 	/*
1019 	 * Remove the ACB from whatever queue it happens to be on.
1020 	 */
1021 	if (acb->flags & ACB_NEXUS)
1022 		ti->lubusy &= ~(1 << sc_link->lun);
1023 	if (acb == sc->sc_nexus) {
1024 		sc->sc_nexus = NULL;
1025 		sc->sc_state = SPC_IDLE;
1026 		spc_sched(sc);
1027 	} else
1028 		spc_dequeue(sc, acb);
1029 
1030 	spc_free_acb(sc, acb, xs->flags);
1031 	ti->cmds++;
1032 	scsi_done(xs);
1033 }
1034 
1035 void
1036 spc_dequeue(sc, acb)
1037 	struct spc_softc *sc;
1038 	struct spc_acb *acb;
1039 {
1040 
1041 	if (acb->flags & ACB_NEXUS) {
1042 		TAILQ_REMOVE(&sc->nexus_list, acb, chain);
1043 	} else {
1044 		TAILQ_REMOVE(&sc->ready_list, acb, chain);
1045 	}
1046 }
1047 
1048 /*
1049  * INTERRUPT/PROTOCOL ENGINE
1050  */
1051 
1052 #define IS1BYTEMSG(m) (((m) != 0x01 && (m) < 0x20) || (m) >= 0x80)
1053 #define IS2BYTEMSG(m) (((m) & 0xf0) == 0x20)
1054 #define ISEXTMSG(m) ((m) == 0x01)
1055 
1056 /*
1057  * Precondition:
1058  * The SCSI bus is already in the MSGI phase and there is a message byte
1059  * on the bus, along with an asserted REQ signal.
1060  */
1061 void
1062 spc_msgin(sc)
1063 	register struct spc_softc *sc;
1064 {
1065 	int n;
1066 
1067 	SPC_TRACE(("spc_msgin  "));
1068 
1069 	if (sc->sc_prevphase == PH_MSGIN) {
1070 		/* This is a continuation of the previous message. */
1071 		n = sc->sc_imp - sc->sc_imess;
1072 		goto nextbyte;
1073 	}
1074 
1075 	/* This is a new MESSAGE IN phase.  Clean up our state. */
1076 	sc->sc_flags &= ~SPC_DROP_MSGIN;
1077 
1078 nextmsg:
1079 	n = 0;
1080 	sc->sc_imp = &sc->sc_imess[n];
1081 
1082 nextbyte:
1083 	/*
1084 	 * Read a whole message, but don't ack the last byte.  If we reject the
1085 	 * message, we have to assert ATN during the message transfer phase
1086 	 * itself.
1087 	 */
1088 	for (;;) {
1089 #if 0
1090 		for (;;) {
1091 			if ((PSNS & PSNS_REQ) != 0)
1092 				break;
1093 			/* Wait for REQINIT.  XXX Need timeout. */
1094 		}
1095 #endif
1096 		if (INTS != 0) {
1097 			/*
1098 			 * Target left MESSAGE IN, probably because it
1099 			 * a) noticed our ATN signal, or
1100 			 * b) ran out of messages.
1101 			 */
1102 			goto out;
1103 		}
1104 
1105 		/* If parity error, just dump everything on the floor. */
1106 		if ((SERR & (SERR_SCSI_PAR|SERR_SPC_PAR)) != 0) {
1107 			sc->sc_flags |= SPC_DROP_MSGIN;
1108 			spc_sched_msgout(sc, SEND_PARITY_ERROR);
1109 		}
1110 
1111 		/* send TRANSFER command. */
1112 		TCH = 0;
1113 		TCM = 0;
1114 		TCL = 1;
1115 		PCTL = sc->sc_phase | PCTL_BFINT_ENAB;
1116 		SCMD = SCMD_XFR; /* | SCMD_PROG_XFR */
1117 		for (;;) {
1118 			/*if ((SSTS & SSTS_BUSY) != 0 && (SSTS & SSTS_DREG_EMPTY) != 0)*/
1119 			if ((SSTS & SSTS_DREG_EMPTY) == 0)
1120 				break;
1121 			if (INTS != 0)
1122 				goto out;
1123 		}
1124 
1125 		/* Gather incoming message bytes if needed. */
1126 		if ((sc->sc_flags & SPC_DROP_MSGIN) == 0) {
1127 			if (n >= SPC_MAX_MSG_LEN) {
1128 				(void) DREG;
1129 				sc->sc_flags |= SPC_DROP_MSGIN;
1130 				spc_sched_msgout(sc, SEND_REJECT);
1131 			} else {
1132 				*sc->sc_imp++ = DREG;
1133 				n++;
1134 				/*
1135 				 * This testing is suboptimal, but most
1136 				 * messages will be of the one byte variety, so
1137 				 * it should not affect performance
1138 				 * significantly.
1139 				 */
1140 				if (n == 1 && IS1BYTEMSG(sc->sc_imess[0]))
1141 					break;
1142 				if (n == 2 && IS2BYTEMSG(sc->sc_imess[0]))
1143 					break;
1144 				if (n >= 3 && ISEXTMSG(sc->sc_imess[0]) &&
1145 				    n == sc->sc_imess[1] + 2)
1146 					break;
1147 			}
1148 		} else
1149 			(void) DREG;
1150 
1151 		/*
1152 		 * If we reach this spot we're either:
1153 		 * a) in the middle of a multi-byte message, or
1154 		 * b) dropping bytes.
1155 		 */
1156 
1157 #if 0
1158 		/* Ack the last byte read. */
1159 		/*(void) DREG;*/
1160 		while ((PSNS & ACKI) != 0)
1161 			;
1162 #endif
1163 	}
1164 
1165 	SPC_MISC(("n=%d imess=0x%02x  ", n, sc->sc_imess[0]));
1166 
1167 	/* We now have a complete message.  Parse it. */
1168 	switch (sc->sc_state) {
1169 		struct spc_acb *acb;
1170 		struct scsi_link *sc_link;
1171 		struct spc_tinfo *ti;
1172 
1173 	case SPC_CONNECTED:
1174 		SPC_ASSERT(sc->sc_nexus != NULL);
1175 		acb = sc->sc_nexus;
1176 		ti = &sc->sc_tinfo[acb->xs->sc_link->target];
1177 
1178 		switch (sc->sc_imess[0]) {
1179 		case MSG_CMDCOMPLETE:
1180 			if (sc->sc_dleft < 0) {
1181 				sc_link = acb->xs->sc_link;
1182 				printf("%s: %d extra bytes from %d:%d\n",
1183 				    sc->sc_dev.dv_xname, -sc->sc_dleft,
1184 				    sc_link->target, sc_link->lun);
1185 				acb->data_length = 0;
1186 			}
1187 			acb->xs->resid = acb->data_length = sc->sc_dleft;
1188 			sc->sc_state = SPC_CMDCOMPLETE;
1189 			break;
1190 
1191 		case MSG_PARITY_ERROR:
1192 			/* Resend the last message. */
1193 			spc_sched_msgout(sc, sc->sc_lastmsg);
1194 			break;
1195 
1196 		case MSG_MESSAGE_REJECT:
1197 			SPC_MISC(("message rejected %02x  ", sc->sc_lastmsg));
1198 			switch (sc->sc_lastmsg) {
1199 #if SPC_USE_SYNCHRONOUS + SPC_USE_WIDE
1200 			case SEND_IDENTIFY:
1201 				ti->flags &= ~(DO_SYNC | DO_WIDE);
1202 				ti->period = ti->offset = 0;
1203 				spc_setsync(sc, ti);
1204 				ti->width = 0;
1205 				break;
1206 #endif
1207 #if SPC_USE_SYNCHRONOUS
1208 			case SEND_SDTR:
1209 				ti->flags &= ~DO_SYNC;
1210 				ti->period = ti->offset = 0;
1211 				spc_setsync(sc, ti);
1212 				break;
1213 #endif
1214 #if SPC_USE_WIDE
1215 			case SEND_WDTR:
1216 				ti->flags &= ~DO_WIDE;
1217 				ti->width = 0;
1218 				break;
1219 #endif
1220 			case SEND_INIT_DET_ERR:
1221 				spc_sched_msgout(sc, SEND_ABORT);
1222 				break;
1223 			}
1224 			break;
1225 
1226 		case MSG_NOOP:
1227 			break;
1228 
1229 		case MSG_DISCONNECT:
1230 			ti->dconns++;
1231 			sc->sc_state = SPC_DISCONNECT;
1232 			break;
1233 
1234 		case MSG_SAVEDATAPOINTER:
1235 			acb->data_addr = sc->sc_dp;
1236 			acb->data_length = sc->sc_dleft;
1237 			break;
1238 
1239 		case MSG_RESTOREPOINTERS:
1240 			sc->sc_dp = acb->data_addr;
1241 			sc->sc_dleft = acb->data_length;
1242 			sc->sc_cp = (u_char *)&acb->scsi_cmd;
1243 			sc->sc_cleft = acb->scsi_cmd_length;
1244 			break;
1245 
1246 		case MSG_EXTENDED:
1247 			switch (sc->sc_imess[2]) {
1248 #if SPC_USE_SYNCHRONOUS
1249 			case MSG_EXT_SDTR:
1250 				if (sc->sc_imess[1] != 3)
1251 					goto reject;
1252 				ti->period = sc->sc_imess[3];
1253 				ti->offset = sc->sc_imess[4];
1254 				ti->flags &= ~DO_SYNC;
1255 				if (ti->offset == 0) {
1256 				} else if (ti->period < sc->sc_minsync ||
1257 					   ti->period > sc->sc_maxsync ||
1258 					   ti->offset > 8) {
1259 					ti->period = ti->offset = 0;
1260 					spc_sched_msgout(sc, SEND_SDTR);
1261 				} else {
1262 					sc_print_addr(acb->xs->sc_link);
1263 					printf("sync, offset %d, period %dnsec\n",
1264 					    ti->offset, ti->period * 4);
1265 				}
1266 				spc_setsync(sc, ti);
1267 				break;
1268 #endif
1269 
1270 #if SPC_USE_WIDE
1271 			case MSG_EXT_WDTR:
1272 				if (sc->sc_imess[1] != 2)
1273 					goto reject;
1274 				ti->width = sc->sc_imess[3];
1275 				ti->flags &= ~DO_WIDE;
1276 				if (ti->width == 0) {
1277 				} else if (ti->width > SPC_MAX_WIDTH) {
1278 					ti->width = 0;
1279 					spc_sched_msgout(sc, SEND_WDTR);
1280 				} else {
1281 					sc_print_addr(acb->xs->sc_link);
1282 					printf("wide, width %d\n",
1283 					    1 << (3 + ti->width));
1284 				}
1285 				break;
1286 #endif
1287 
1288 			default:
1289 				printf("%s: unrecognized MESSAGE EXTENDED; sending REJECT\n",
1290 				    sc->sc_dev.dv_xname);
1291 				SPC_BREAK();
1292 				goto reject;
1293 			}
1294 			break;
1295 
1296 		default:
1297 			printf("%s: unrecognized MESSAGE; sending REJECT\n",
1298 			    sc->sc_dev.dv_xname);
1299 			SPC_BREAK();
1300 		reject:
1301 			spc_sched_msgout(sc, SEND_REJECT);
1302 			break;
1303 		}
1304 		break;
1305 
1306 	case SPC_RESELECTED:
1307 		if (!MSG_ISIDENTIFY(sc->sc_imess[0])) {
1308 			printf("%s: reselect without IDENTIFY; sending DEVICE RESET\n",
1309 			    sc->sc_dev.dv_xname);
1310 			SPC_BREAK();
1311 			goto reset;
1312 		}
1313 
1314 		(void) spc_reselect(sc, sc->sc_imess[0]);
1315 		break;
1316 
1317 	default:
1318 		printf("%s: unexpected MESSAGE IN; sending DEVICE RESET\n",
1319 		    sc->sc_dev.dv_xname);
1320 		SPC_BREAK();
1321 	reset:
1322 		spc_sched_msgout(sc, SEND_DEV_RESET);
1323 		break;
1324 
1325 	abort:
1326 		spc_sched_msgout(sc, SEND_ABORT);
1327 		break;
1328 	}
1329 
1330 	/* Ack the last message byte. */
1331 #if 0 /* XXX? */
1332 	(void) DREG;
1333 	while ((PSNS & ACKI) != 0)
1334 		;
1335 #endif
1336 
1337 	/* Go get the next message, if any. */
1338 	goto nextmsg;
1339 
1340 out:
1341 	SCMD = SCMD_RST_ACK;
1342 	SPC_MISC(("n=%d imess=0x%02x  ", n, sc->sc_imess[0]));
1343 }
1344 
1345 /*
1346  * Send the highest priority, scheduled message.
1347  */
1348 void
1349 spc_msgout(sc)
1350 	register struct spc_softc *sc;
1351 {
1352 	struct spc_tinfo *ti;
1353 	int n;
1354 
1355 	SPC_TRACE(("spc_msgout  "));
1356 
1357 	if (sc->sc_prevphase == PH_MSGOUT) {
1358 		if (sc->sc_omp == sc->sc_omess) {
1359 			/*
1360 			 * This is a retransmission.
1361 			 *
1362 			 * We get here if the target stayed in MESSAGE OUT
1363 			 * phase.  Section 5.1.9.2 of the SCSI 2 spec indicates
1364 			 * that all of the previously transmitted messages must
1365 			 * be sent again, in the same order.  Therefore, we
1366 			 * requeue all the previously transmitted messages, and
1367 			 * start again from the top.  Our simple priority
1368 			 * scheme keeps the messages in the right order.
1369 			 */
1370 			SPC_MISC(("retransmitting  "));
1371 			sc->sc_msgpriq |= sc->sc_msgoutq;
1372 			/*
1373 			 * Set ATN.  If we're just sending a trivial 1-byte
1374 			 * message, we'll clear ATN later on anyway.
1375 			 */
1376 			SCMD = SCMD_SET_ATN; /* XXX? */
1377 		} else {
1378 			/* This is a continuation of the previous message. */
1379 			n = sc->sc_omp - sc->sc_omess;
1380 			goto nextbyte;
1381 		}
1382 	}
1383 
1384 	/* No messages transmitted so far. */
1385 	sc->sc_msgoutq = 0;
1386 	sc->sc_lastmsg = 0;
1387 
1388 nextmsg:
1389 	/* Pick up highest priority message. */
1390 	sc->sc_currmsg = sc->sc_msgpriq & -sc->sc_msgpriq;
1391 	sc->sc_msgpriq &= ~sc->sc_currmsg;
1392 	sc->sc_msgoutq |= sc->sc_currmsg;
1393 
1394 	/* Build the outgoing message data. */
1395 	switch (sc->sc_currmsg) {
1396 	case SEND_IDENTIFY:
1397 		SPC_ASSERT(sc->sc_nexus != NULL);
1398 		sc->sc_omess[0] =
1399 		    MSG_IDENTIFY(sc->sc_nexus->xs->sc_link->lun, 1);
1400 		n = 1;
1401 		break;
1402 
1403 #if SPC_USE_SYNCHRONOUS
1404 	case SEND_SDTR:
1405 		SPC_ASSERT(sc->sc_nexus != NULL);
1406 		ti = &sc->sc_tinfo[sc->sc_nexus->xs->sc_link->target];
1407 		sc->sc_omess[4] = MSG_EXTENDED;
1408 		sc->sc_omess[3] = 3;
1409 		sc->sc_omess[2] = MSG_EXT_SDTR;
1410 		sc->sc_omess[1] = ti->period >> 2;
1411 		sc->sc_omess[0] = ti->offset;
1412 		n = 5;
1413 		break;
1414 #endif
1415 
1416 #if SPC_USE_WIDE
1417 	case SEND_WDTR:
1418 		SPC_ASSERT(sc->sc_nexus != NULL);
1419 		ti = &sc->sc_tinfo[sc->sc_nexus->xs->sc_link->target];
1420 		sc->sc_omess[3] = MSG_EXTENDED;
1421 		sc->sc_omess[2] = 2;
1422 		sc->sc_omess[1] = MSG_EXT_WDTR;
1423 		sc->sc_omess[0] = ti->width;
1424 		n = 4;
1425 		break;
1426 #endif
1427 
1428 	case SEND_DEV_RESET:
1429 		sc->sc_flags |= SPC_ABORTING;
1430 		sc->sc_omess[0] = MSG_BUS_DEV_RESET;
1431 		n = 1;
1432 		break;
1433 
1434 	case SEND_REJECT:
1435 		sc->sc_omess[0] = MSG_MESSAGE_REJECT;
1436 		n = 1;
1437 		break;
1438 
1439 	case SEND_PARITY_ERROR:
1440 		sc->sc_omess[0] = MSG_PARITY_ERROR;
1441 		n = 1;
1442 		break;
1443 
1444 	case SEND_INIT_DET_ERR:
1445 		sc->sc_omess[0] = MSG_INITIATOR_DET_ERR;
1446 		n = 1;
1447 		break;
1448 
1449 	case SEND_ABORT:
1450 		sc->sc_flags |= SPC_ABORTING;
1451 		sc->sc_omess[0] = MSG_ABORT;
1452 		n = 1;
1453 		break;
1454 
1455 	default:
1456 		printf("%s: unexpected MESSAGE OUT; sending NOOP\n",
1457 		    sc->sc_dev.dv_xname);
1458 		SPC_BREAK();
1459 		sc->sc_omess[0] = MSG_NOOP;
1460 		n = 1;
1461 		break;
1462 	}
1463 	sc->sc_omp = &sc->sc_omess[n];
1464 
1465 nextbyte:
1466 	/* Send message bytes. */
1467 	/* send TRANSFER command. */
1468 	TCH = n >> 16;
1469 	TCM = n >> 8;
1470 	TCL = n;
1471 	PCTL = sc->sc_phase | PCTL_BFINT_ENAB;
1472 	SCMD = SCMD_XFR; /* | SCMD_PROG_XFR */
1473 	for (;;) {
1474 		if ((SSTS & SSTS_BUSY) != 0)
1475 			break;
1476 		if (INTS != 0)
1477 			goto out;
1478 	}
1479 	for (;;) {
1480 #if 0
1481 		for (;;) {
1482 			if ((PSNS & PSNS_REQ) != 0)
1483 				break;
1484 			/* Wait for REQINIT.  XXX Need timeout. */
1485 		}
1486 #endif
1487 		if (INTS != 0) {
1488 			/*
1489 			 * Target left MESSAGE OUT, possibly to reject
1490 			 * our message.
1491 			 *
1492 			 * If this is the last message being sent, then we
1493 			 * deassert ATN, since either the target is going to
1494 			 * ignore this message, or it's going to ask for a
1495 			 * retransmission via MESSAGE PARITY ERROR (in which
1496 			 * case we reassert ATN anyway).
1497 			 */
1498 #if 0
1499 			if (sc->sc_msgpriq == 0)
1500 				SCMD = SCMD_RST_ATN;
1501 #endif
1502 			goto out;
1503 		}
1504 
1505 #if 0
1506 		/* Clear ATN before last byte if this is the last message. */
1507 		if (n == 1 && sc->sc_msgpriq == 0)
1508 			SCMD = SCMD_RST_ATN;
1509 #endif
1510 
1511 		while ((SSTS & SSTS_DREG_FULL) != 0)
1512 			;
1513 		/* Send message byte. */
1514 		DREG = *--sc->sc_omp;
1515 		--n;
1516 		/* Keep track of the last message we've sent any bytes of. */
1517 		sc->sc_lastmsg = sc->sc_currmsg;
1518 #if 0
1519 		/* Wait for ACK to be negated.  XXX Need timeout. */
1520 		while ((PSNS & ACKI) != 0)
1521 			;
1522 #endif
1523 
1524 		if (n == 0)
1525 			break;
1526 	}
1527 
1528 	/* We get here only if the entire message has been transmitted. */
1529 	if (sc->sc_msgpriq != 0) {
1530 		/* There are more outgoing messages. */
1531 		goto nextmsg;
1532 	}
1533 
1534 	/*
1535 	 * The last message has been transmitted.  We need to remember the last
1536 	 * message transmitted (in case the target switches to MESSAGE IN phase
1537 	 * and sends a MESSAGE REJECT), and the list of messages transmitted
1538 	 * this time around (in case the target stays in MESSAGE OUT phase to
1539 	 * request a retransmit).
1540 	 */
1541 
1542 out:
1543 	/* Disable REQ/ACK protocol. */
1544 }
1545 
1546 /*
1547  * This new revision has been optimized (I tried) to make the common case fast,
1548  * and the rarer cases (as a result) somewhat more comlex
1549  */
1550 int
1551 spc_dataout_pio(sc, p, n)
1552 	register struct spc_softc *sc;
1553 	u_char *p;
1554 	int n;
1555 {
1556 	register u_char intstat = 0;
1557 	int out = 0;
1558 #define DOUTAMOUNT 8		/* Full FIFO */
1559 
1560 	/* send TRANSFER command. */
1561 	TCH = n >> 16;
1562 	TCM = n >> 8;
1563 	TCL = n;
1564 	PCTL = sc->sc_phase | PCTL_BFINT_ENAB;
1565 	SCMD = SCMD_XFR;
1566 	for (;;) {
1567 		if ((SSTS & SSTS_BUSY) != 0)
1568 			break;
1569 		if (INTS != 0)
1570 			break;
1571 	}
1572 
1573 	/*
1574 	 * I have tried to make the main loop as tight as possible.  This
1575 	 * means that some of the code following the loop is a bit more
1576 	 * complex than otherwise.
1577 	 */
1578 	while (n > 0) {
1579 		int xfer;
1580 
1581 		for (;;) {
1582 			intstat = INTS;
1583 			/* $B%P%C%U%!$,6u$K$J$k$^$GBT$D(B */
1584 			if ((SSTS & SSTS_DREG_EMPTY) != 0)
1585 				break;
1586 			/* $B$?$@$73d$j9~$_$,F~$C$F$-$?$iH4$1$k(B */
1587 			if (intstat != 0)
1588 				goto phasechange;
1589 		}
1590 
1591 		xfer = min(DOUTAMOUNT, n);
1592 
1593 		SPC_MISC(("%d> ", xfer));
1594 
1595 		n -= xfer;
1596 		out += xfer;
1597 
1598 		while (xfer-- > 0) {
1599 			DREG = *p++;
1600 		}
1601 	}
1602 
1603 	if (out == 0) {
1604 		for (;;) {
1605 			if (INTS != 0)
1606 				break;
1607 		}
1608 		SPC_MISC(("extra data  "));
1609 	} else {
1610 		/* See the bytes off chip */
1611 		for (;;) {
1612 			/* $B%P%C%U%!$,6u$K$J$k$^$GBT$D(B */
1613 			if ((SSTS & SSTS_DREG_EMPTY) != 0)
1614 				break;
1615 			intstat = INTS;
1616 			/* $B$?$@$73d$j9~$_$,F~$C$F$-$?$iH4$1$k(B */
1617 			if (intstat != 0)
1618 				goto phasechange;
1619 		}
1620 	}
1621 
1622 phasechange:
1623 	/* Stop the FIFO data path. */
1624 
1625 	if (intstat != 0) {
1626 		/* Some sort of phase change. */
1627 		int amount;
1628 
1629 		amount = (TCH << 16) | (TCM << 8) | TCL;
1630 		if (amount > 0) {
1631 			out -= amount;
1632 			SPC_MISC(("+%d ", amount));
1633 		}
1634 	}
1635 	/* Turn on ENREQINIT again. */
1636 
1637 	return out;
1638 }
1639 
1640 /*
1641  * For now, uses a pretty dumb algorithm, hangs around until all data has been
1642  * transferred.  This, is OK for fast targets, but not so smart for slow
1643  * targets which don't disconnect or for huge transfers.
1644  */
1645 int
1646 spc_datain_pio(sc, p, n)
1647 	register struct spc_softc *sc;
1648 	u_char *p;
1649 	int n;
1650 {
1651 	register u_short intstat;
1652 	int in = 0;
1653 #define DINAMOUNT 8		/* Full FIFO */
1654 
1655 	/* send TRANSFER command. */
1656 	TCH = n >> 16;
1657 	TCM = n >> 8;
1658 	TCL = n;
1659 	PCTL = sc->sc_phase | PCTL_BFINT_ENAB;
1660 	SCMD = SCMD_XFR;
1661 	for (;;) {
1662 		if ((SSTS & SSTS_BUSY) != 0)
1663 			break;
1664 		if (INTS != 0)
1665 			goto phasechange;
1666 	}
1667 
1668 	/*
1669 	 * We leave this loop if one or more of the following is true:
1670 	 * a) phase != PH_DATAIN && FIFOs are empty
1671 	 * b) reset has occurred or busfree is detected.
1672 	 */
1673 	while (n > 0) {
1674 		int xfer;
1675 
1676 #define INTSMASK 0xff
1677 		/* Wait for fifo half full or phase mismatch */
1678 		for (;;) {
1679 			intstat = (SSTS << 8) | INTS;
1680 			if ((intstat & (INTSMASK | (SSTS_DREG_FULL << 8))) != 0)
1681 				break;
1682 			if ((intstat & (SSTS_DREG_EMPTY << 8)) == 0)
1683 				break;
1684 		}
1685 
1686 #if 1
1687 		if ((intstat & INTSMASK) != 0)
1688 			goto phasechange;
1689 #else
1690 		if ((intstat & INTSMASK) != 0 &&
1691 		    (intstat & (SSTS_DREG_EMPTY << 8)))
1692 			goto phasechange;
1693 #endif
1694 		if ((intstat & (SSTS_DREG_FULL << 8)) != 0)
1695 			xfer = min(DINAMOUNT, n);
1696 		else
1697 			xfer = min(1, n);
1698 
1699 		SPC_MISC((">%d ", xfer));
1700 
1701 		n -= xfer;
1702 		in += xfer;
1703 
1704 		while (xfer-- > 0) {
1705 			*p++ = DREG;
1706 		}
1707 
1708 		if ((intstat & INTSMASK) != 0)
1709 			goto phasechange;
1710 	}
1711 
1712 	/*
1713 	 * Some SCSI-devices are rude enough to transfer more data than what
1714 	 * was requested, e.g. 2048 bytes from a CD-ROM instead of the
1715 	 * requested 512.  Test for progress, i.e. real transfers.  If no real
1716 	 * transfers have been performed (n is probably already zero) and the
1717 	 * FIFO is not empty, waste some bytes....
1718 	 */
1719 	if (in == 0) {
1720 		for (;;) {
1721 			if (INTS != 0)
1722 				break;
1723 		}
1724 		SPC_MISC(("extra data  "));
1725 	}
1726 
1727 phasechange:
1728 	/* Stop the FIFO data path. */
1729 
1730 	/* Turn on ENREQINIT again. */
1731 
1732 	return in;
1733 }
1734 
1735 /*
1736  * Catch an interrupt from the adaptor
1737  */
1738 /*
1739  * This is the workhorse routine of the driver.
1740  * Deficiencies (for now):
1741  * 1) always uses programmed I/O
1742  */
1743 int
1744 spcintr(unit)
1745 	int unit;
1746 {
1747 	register struct spc_softc *sc = spc_cd.cd_devs[unit]; /* XXX */
1748 	u_char ints;
1749 	register struct spc_acb *acb;
1750 	register struct scsi_link *sc_link;
1751 	struct spc_tinfo *ti;
1752 	int n;
1753 
1754 	/*
1755 	 * $B3d$j9~$_6X;_$K$9$k(B
1756 	 */
1757 	SCTL &= ~SCTL_INTR_ENAB;
1758 
1759 	SPC_TRACE(("spcintr  "));
1760 
1761 loop:
1762 	/*
1763 	 * $BA4E>Aw$,40A4$K=*N;$9$k$^$G%k!<%W$9$k(B
1764 	 */
1765 	/*
1766 	 * First check for abnormal conditions, such as reset.
1767 	 */
1768 #if 1 /* XXX? */
1769 	while ((ints = INTS) == 0)
1770 		delay(1);
1771 	SPC_MISC(("ints = 0x%x  ", ints));
1772 #else /* usually? */
1773 	ints = INTS;
1774 #endif
1775 	if ((ints & INTS_RST) != 0) {
1776 		printf("%s: SCSI bus reset\n", sc->sc_dev.dv_xname);
1777 		goto reset;
1778 	}
1779 
1780 	/*
1781 	 * Check for less serious errors.
1782 	 */
1783 	if ((SERR & (SERR_SCSI_PAR|SERR_SPC_PAR)) != 0) {
1784 		printf("%s: SCSI bus parity error\n", sc->sc_dev.dv_xname);
1785 		if (sc->sc_prevphase == PH_MSGIN) {
1786 			sc->sc_flags |= SPC_DROP_MSGIN;
1787 			spc_sched_msgout(sc, SEND_PARITY_ERROR);
1788 		} else
1789 			spc_sched_msgout(sc, SEND_INIT_DET_ERR);
1790 	}
1791 
1792 	/*
1793 	 * If we're not already busy doing something test for the following
1794 	 * conditions:
1795 	 * 1) We have been reselected by something
1796 	 * 2) We have selected something successfully
1797 	 * 3) Our selection process has timed out
1798 	 * 4) This is really a bus free interrupt just to get a new command
1799 	 *    going?
1800 	 * 5) Spurious interrupt?
1801 	 */
1802 	switch (sc->sc_state) {
1803 	case SPC_IDLE:
1804 	case SPC_SELECTING:
1805 
1806 		if ((ints & INTS_SEL) != 0) {
1807 			/*
1808 			 * We don't currently support target mode.
1809 			 */
1810 			printf("%s: target mode selected; going to BUS FREE\n",
1811 			    sc->sc_dev.dv_xname);
1812 
1813 			goto sched;
1814 		} else if ((ints & INTS_RESEL) != 0) {
1815 			SPC_MISC(("reselected  "));
1816 
1817 			/*
1818 			 * If we're trying to select a target ourselves,
1819 			 * push our command back into the ready list.
1820 			 */
1821 			if (sc->sc_state == SPC_SELECTING) {
1822 				SPC_MISC(("backoff selector  "));
1823 				SPC_ASSERT(sc->sc_nexus != NULL);
1824 				acb = sc->sc_nexus;
1825 				sc->sc_nexus = NULL;
1826 				TAILQ_INSERT_HEAD(&sc->ready_list, acb, chain);
1827 			}
1828 
1829 			/* Save reselection ID. */
1830 			sc->sc_selid = TEMP;
1831 
1832 			sc->sc_state = SPC_RESELECTED;
1833 		} else if ((ints & INTS_CMD_DONE) != 0) {
1834 			SPC_MISC(("selected  "));
1835 
1836 			/*
1837 			 * We have selected a target. Things to do:
1838 			 * a) Determine what message(s) to send.
1839 			 * b) Verify that we're still selecting the target.
1840 			 * c) Mark device as busy.
1841 			 */
1842 			if (sc->sc_state != SPC_SELECTING) {
1843 				printf("%s: selection out while idle; resetting\n",
1844 				    sc->sc_dev.dv_xname);
1845 				SPC_BREAK();
1846 				goto reset;
1847 			}
1848 			SPC_ASSERT(sc->sc_nexus != NULL);
1849 			acb = sc->sc_nexus;
1850 			sc_link = acb->xs->sc_link;
1851 			ti = &sc->sc_tinfo[sc_link->target];
1852 
1853 			sc->sc_msgpriq = SEND_IDENTIFY;
1854 			if (acb->flags & ACB_RESET)
1855 				sc->sc_msgpriq |= SEND_DEV_RESET;
1856 			else if (acb->flags & ACB_ABORT)
1857 				sc->sc_msgpriq |= SEND_ABORT;
1858 			else {
1859 #if SPC_USE_SYNCHRONOUS
1860 				if ((ti->flags & DO_SYNC) != 0)
1861 					sc->sc_msgpriq |= SEND_SDTR;
1862 #endif
1863 #if SPC_USE_WIDE
1864 				if ((ti->flags & DO_WIDE) != 0)
1865 					sc->sc_msgpriq |= SEND_WDTR;
1866 #endif
1867 			}
1868 
1869 			acb->flags |= ACB_NEXUS;
1870 			ti->lubusy |= (1 << sc_link->lun);
1871 
1872 			/* Do an implicit RESTORE POINTERS. */
1873 			sc->sc_dp = acb->data_addr;
1874 			sc->sc_dleft = acb->data_length;
1875 			sc->sc_cp = (u_char *)&acb->scsi_cmd;
1876 			sc->sc_cleft = acb->scsi_cmd_length;
1877 
1878 			/* On our first connection, schedule a timeout. */
1879 			if ((acb->xs->flags & SCSI_POLL) == 0)
1880 				timeout(spc_timeout, acb, (acb->timeout * hz) / 1000);
1881 
1882 			sc->sc_state = SPC_CONNECTED;
1883 		} else if ((ints & INTS_TIMEOUT) != 0) {
1884 			SPC_MISC(("selection timeout  "));
1885 
1886 			if (sc->sc_state != SPC_SELECTING) {
1887 				printf("%s: selection timeout while idle; resetting\n",
1888 				    sc->sc_dev.dv_xname);
1889 				SPC_BREAK();
1890 				goto reset;
1891 			}
1892 			SPC_ASSERT(sc->sc_nexus != NULL);
1893 			acb = sc->sc_nexus;
1894 
1895 			delay(250);
1896 
1897 			acb->xs->error = XS_SELTIMEOUT;
1898 			goto finish;
1899 		} else {
1900 			if (sc->sc_state != SPC_IDLE) {
1901 				printf("%s: BUS FREE while not idle; state=%d\n",
1902 				    sc->sc_dev.dv_xname, sc->sc_state);
1903 				SPC_BREAK();
1904 				goto out;
1905 			}
1906 
1907 			goto sched;
1908 		}
1909 
1910 		/*
1911 		 * Turn off selection stuff, and prepare to catch bus free
1912 		 * interrupts, parity errors, and phase changes.
1913 		 */
1914 
1915 		sc->sc_flags = 0;
1916 		sc->sc_prevphase = PH_INVALID;
1917 		goto dophase;
1918 	}
1919 
1920 	if ((ints & INTS_DISCON) != 0) {
1921 		/* We've gone to BUS FREE phase. */
1922 		PCTL &= ~PCTL_BFINT_ENAB; /* disable disconnect interrupt */
1923 		INTS = ints; /* XXX reset interrput */
1924 
1925 		switch (sc->sc_state) {
1926 		case SPC_RESELECTED:
1927 			goto sched;
1928 
1929 		case SPC_CONNECTED:
1930 			SPC_ASSERT(sc->sc_nexus != NULL);
1931 			acb = sc->sc_nexus;
1932 
1933 #if SPC_USE_SYNCHRONOUS + SPC_USE_WIDE
1934 			if (sc->sc_prevphase == PH_MSGOUT) {
1935 				/*
1936 				 * If the target went to BUS FREE phase during
1937 				 * or immediately after sending a SDTR or WDTR
1938 				 * message, disable negotiation.
1939 				 */
1940 				sc_link = acb->xs->sc_link;
1941 				ti = &sc->sc_tinfo[sc_link->target];
1942 				switch (sc->sc_lastmsg) {
1943 #if SPC_USE_SYNCHRONOUS
1944 				case SEND_SDTR:
1945 					ti->flags &= ~DO_SYNC;
1946 					ti->period = ti->offset = 0;
1947 					break;
1948 #endif
1949 #if SPC_USE_WIDE
1950 				case SEND_WDTR:
1951 					ti->flags &= ~DO_WIDE;
1952 					ti->width = 0;
1953 					break;
1954 #endif
1955 				}
1956 			}
1957 #endif
1958 
1959 			if ((sc->sc_flags & SPC_ABORTING) == 0) {
1960 				/*
1961 				 * Section 5.1.1 of the SCSI 2 spec suggests
1962 				 * issuing a REQUEST SENSE following an
1963 				 * unexpected disconnect.  Some devices go into
1964 				 * a contingent allegiance condition when
1965 				 * disconnecting, and this is necessary to
1966 				 * clean up their state.
1967 				 */
1968 				printf("%s: unexpected disconnect; sending REQUEST SENSE\n",
1969 				    sc->sc_dev.dv_xname);
1970 				SPC_BREAK();
1971 				spc_sense(sc, acb);
1972 				goto out;
1973 			}
1974 
1975 			acb->xs->error = XS_DRIVER_STUFFUP;
1976 			goto finish;
1977 
1978 		case SPC_DISCONNECT:
1979 			SPC_ASSERT(sc->sc_nexus != NULL);
1980 			acb = sc->sc_nexus;
1981 			TAILQ_INSERT_HEAD(&sc->nexus_list, acb, chain);
1982 			sc->sc_nexus = NULL;
1983 			goto sched;
1984 
1985 		case SPC_CMDCOMPLETE:
1986 			SPC_ASSERT(sc->sc_nexus != NULL);
1987 			acb = sc->sc_nexus;
1988 			goto finish;
1989 		}
1990 	}
1991 	else if ((ints & INTS_CMD_DONE) != 0 &&
1992 		 sc->sc_prevphase == PH_MSGIN && sc->sc_state != SPC_CONNECTED)
1993 		goto out;
1994 
1995 dophase:
1996 #if 0
1997 	if ((PSNS & PSNS_REQ) == 0) {
1998 		/* Wait for REQINIT. */
1999 		goto out;
2000 	}
2001 #else
2002 	INTS = ints;
2003 	ints = 0;
2004 	while ((PSNS & PSNS_REQ) == 0)
2005 		delay(1);	/* need timeout XXX */
2006 #endif
2007 
2008 	/*
2009 	 * $B%U%'!<%:$K$h$C$F>uBVA+0\$9$k(B
2010 	 */
2011 	sc->sc_phase = PSNS & PH_MASK;
2012 /*	PCTL = sc->sc_phase;*/
2013 
2014 	switch (sc->sc_phase) {
2015 	case PH_MSGOUT:
2016 		if (sc->sc_state != SPC_CONNECTED &&
2017 		    sc->sc_state != SPC_RESELECTED)
2018 			break;
2019 		spc_msgout(sc);
2020 		sc->sc_prevphase = PH_MSGOUT;
2021 		goto loop;
2022 
2023 	case PH_MSGIN:
2024 		if (sc->sc_state != SPC_CONNECTED &&
2025 		    sc->sc_state != SPC_RESELECTED)
2026 			break;
2027 		spc_msgin(sc);
2028 		sc->sc_prevphase = PH_MSGIN;
2029 		goto loop;
2030 
2031 	case PH_CMD:
2032 		if (sc->sc_state != SPC_CONNECTED)
2033 			break;
2034 #if SPC_DEBUG
2035 		if ((spc_debug & SPC_SHOWMISC) != 0) {
2036 			SPC_ASSERT(sc->sc_nexus != NULL);
2037 			acb = sc->sc_nexus;
2038 			printf("cmd=0x%02x+%d  ",
2039 			    acb->scsi_cmd.opcode, acb->scsi_cmd_length-1);
2040 		}
2041 #endif
2042 		n = spc_dataout_pio(sc, sc->sc_cp, sc->sc_cleft);
2043 		sc->sc_cp += n;
2044 		sc->sc_cleft -= n;
2045 		sc->sc_prevphase = PH_CMD;
2046 		goto loop;
2047 
2048 	case PH_DATAOUT:
2049 		if (sc->sc_state != SPC_CONNECTED)
2050 			break;
2051 		SPC_MISC(("dataout dleft=%d  ", sc->sc_dleft));
2052 		n = spc_dataout_pio(sc, sc->sc_dp, sc->sc_dleft);
2053 		sc->sc_dp += n;
2054 		sc->sc_dleft -= n;
2055 		sc->sc_prevphase = PH_DATAOUT;
2056 		goto loop;
2057 
2058 	case PH_DATAIN:
2059 		if (sc->sc_state != SPC_CONNECTED)
2060 			break;
2061 		SPC_MISC(("datain  "));
2062 		n = spc_datain_pio(sc, sc->sc_dp, sc->sc_dleft);
2063 		sc->sc_dp += n;
2064 		sc->sc_dleft -= n;
2065 		sc->sc_prevphase = PH_DATAIN;
2066 		goto loop;
2067 
2068 	case PH_STAT:
2069 		if (sc->sc_state != SPC_CONNECTED)
2070 			break;
2071 		SPC_ASSERT(sc->sc_nexus != NULL);
2072 		acb = sc->sc_nexus;
2073 		/*acb->target_stat = DREG;*/
2074 		spc_datain_pio(sc, &acb->target_stat, 1);
2075 		SPC_MISC(("target_stat=0x%02x  ", acb->target_stat));
2076 		sc->sc_prevphase = PH_STAT;
2077 		goto loop;
2078 	}
2079 
2080 	printf("%s: unexpected bus phase; resetting\n", sc->sc_dev.dv_xname);
2081 	SPC_BREAK();
2082 reset:
2083 	spc_init(sc);
2084 	return 1;
2085 
2086 finish:
2087 	untimeout(spc_timeout, acb);
2088 	INTS = ints;
2089 	ints = 0;
2090 	spc_done(sc, acb);
2091 	goto out;
2092 
2093 sched:
2094 	sc->sc_state = SPC_IDLE;
2095 	spc_sched(sc);
2096 	goto out;
2097 
2098 out:
2099 	if (ints)
2100 		INTS = ints;
2101 	SCTL |= SCTL_INTR_ENAB;
2102 	return 1;
2103 }
2104 
2105 void
2106 spc_abort(sc, acb)
2107 	struct spc_softc *sc;
2108 	struct spc_acb *acb;
2109 {
2110 
2111 	/* 2 secs for the abort */
2112 	acb->timeout = SPC_ABORT_TIMEOUT;
2113 	acb->flags |= ACB_ABORT;
2114 
2115 	if (acb == sc->sc_nexus) {
2116 		/*
2117 		 * If we're still selecting, the message will be scheduled
2118 		 * after selection is complete.
2119 		 */
2120 		if (sc->sc_state == SPC_CONNECTED)
2121 			spc_sched_msgout(sc, SEND_ABORT);
2122 	} else {
2123 		spc_dequeue(sc, acb);
2124 		TAILQ_INSERT_HEAD(&sc->ready_list, acb, chain);
2125 		if (sc->sc_state == SPC_IDLE)
2126 			spc_sched(sc);
2127 	}
2128 }
2129 
2130 void
2131 spc_timeout(arg)
2132 	void *arg;
2133 {
2134 	struct spc_acb *acb = arg;
2135 	struct scsi_xfer *xs = acb->xs;
2136 	struct scsi_link *sc_link = xs->sc_link;
2137 	struct spc_softc *sc = sc_link->adapter_softc;
2138 	int s;
2139 
2140 	sc_print_addr(sc_link);
2141 	printf("timed out");
2142 
2143 	s = splbio();
2144 
2145 	if (acb->flags & ACB_ABORT) {
2146 		/* abort timed out */
2147 		printf(" AGAIN\n");
2148 		/* XXX Must reset! */
2149 	} else {
2150 		/* abort the operation that has timed out */
2151 		printf("\n");
2152 		acb->xs->error = XS_TIMEOUT;
2153 		spc_abort(sc, acb);
2154 	}
2155 
2156 	splx(s);
2157 }
2158 
2159 #ifdef SPC_DEBUG
2160 /*
2161  * The following functions are mostly used for debugging purposes, either
2162  * directly called from the driver or from the kernel debugger.
2163  */
2164 
2165 void
2166 spc_show_scsi_cmd(acb)
2167 	struct spc_acb *acb;
2168 {
2169 	u_char  *b = (u_char *)&acb->scsi_cmd;
2170 	struct scsi_link *sc_link = acb->xs->sc_link;
2171 	int i;
2172 
2173 	sc_print_addr(sc_link);
2174 	if ((acb->xs->flags & SCSI_RESET) == 0) {
2175 		for (i = 0; i < acb->scsi_cmd_length; i++) {
2176 			if (i)
2177 				printf(",");
2178 			printf("%x", b[i]);
2179 		}
2180 		printf("\n");
2181 	} else
2182 		printf("RESET\n");
2183 }
2184 
2185 void
2186 spc_print_acb(acb)
2187 	struct spc_acb *acb;
2188 {
2189 
2190 	printf("acb@%x xs=%x flags=%x", acb, acb->xs, acb->flags);
2191 	printf(" dp=%x dleft=%d target_stat=%x\n",
2192 	    (long)acb->data_addr, acb->data_length, acb->target_stat);
2193 	spc_show_scsi_cmd(acb);
2194 }
2195 
2196 void
2197 spc_print_active_acb()
2198 {
2199 	struct spc_acb *acb;
2200 	struct spc_softc *sc = spc_cd.cd_devs[0]; /* XXX */
2201 
2202 	printf("ready list:\n");
2203 	for (acb = sc->ready_list.tqh_first; acb != NULL;
2204 	    acb = acb->chain.tqe_next)
2205 		spc_print_acb(acb);
2206 	printf("nexus:\n");
2207 	if (sc->sc_nexus != NULL)
2208 		spc_print_acb(sc->sc_nexus);
2209 	printf("nexus list:\n");
2210 	for (acb = sc->nexus_list.tqh_first; acb != NULL;
2211 	    acb = acb->chain.tqe_next)
2212 		spc_print_acb(acb);
2213 }
2214 
2215 void
2216 spc_dump_driver(sc)
2217 	struct spc_softc *sc;
2218 {
2219 	struct spc_tinfo *ti;
2220 	int i;
2221 
2222 	printf("nexus=%x prevphase=%x\n", sc->sc_nexus, sc->sc_prevphase);
2223 	printf("state=%x msgin=%x msgpriq=%x msgoutq=%x lastmsg=%x currmsg=%x\n",
2224 	    sc->sc_state, sc->sc_imess[0],
2225 	    sc->sc_msgpriq, sc->sc_msgoutq, sc->sc_lastmsg, sc->sc_currmsg);
2226 	for (i = 0; i < 7; i++) {
2227 		ti = &sc->sc_tinfo[i];
2228 		printf("tinfo%d: %d cmds %d disconnects %d timeouts",
2229 		    i, ti->cmds, ti->dconns, ti->touts);
2230 		printf(" %d senses flags=%x\n", ti->senses, ti->flags);
2231 	}
2232 }
2233 #endif
2234