xref: /openbsd/sys/dev/ic/ncr53c9x.c (revision 91f110e0)
1 /*	$OpenBSD: ncr53c9x.c,v 1.57 2014/01/26 17:26:55 miod Exp $	*/
2 /*     $NetBSD: ncr53c9x.c,v 1.56 2000/11/30 14:41:46 thorpej Exp $    */
3 
4 /*
5  * Copyright (c) 1996 Charles M. Hannum.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by Charles M. Hannum.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1994 Peter Galbavy
35  * Copyright (c) 1995 Paul Kranenburg
36  * All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  *
47  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
48  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
49  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
50  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
51  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
52  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
53  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
55  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
56  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
57  * POSSIBILITY OF SUCH DAMAGE.
58  */
59 
60 /*
61  * Based on aic6360 by Jarle Greipsland
62  *
63  * Acknowledgements: Many of the algorithms used in this driver are
64  * inspired by the work of Julian Elischer (julian@tfs.com) and
65  * Charles Hannum (mycroft@duality.gnu.ai.mit.edu).  Thanks a million!
66  */
67 
68 #include <sys/types.h>
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/kernel.h>
72 #include <sys/errno.h>
73 #include <sys/ioctl.h>
74 #include <sys/device.h>
75 #include <sys/buf.h>
76 #include <sys/malloc.h>
77 #include <sys/proc.h>
78 #include <sys/queue.h>
79 #include <sys/pool.h>
80 
81 #include <scsi/scsi_all.h>
82 #include <scsi/scsiconf.h>
83 #include <scsi/scsi_message.h>
84 
85 #include <machine/cpu.h>
86 
87 #include <dev/ic/ncr53c9xreg.h>
88 #include <dev/ic/ncr53c9xvar.h>
89 
90 #ifdef NCR53C9X_DEBUG
91 int ncr53c9x_debug = 0; /*NCR_SHOWPHASE|NCR_SHOWMISC|NCR_SHOWTRAC|NCR_SHOWCMDS;*/
92 #endif
93 #ifdef DEBUG
94 int ncr53c9x_notag = 0;
95 #endif
96 
97 /*static*/ void	ncr53c9x_readregs(struct ncr53c9x_softc *);
98 /*static*/ void	ncr53c9x_select(struct ncr53c9x_softc *,
99 					    struct ncr53c9x_ecb *);
100 /*static*/ int ncr53c9x_reselect(struct ncr53c9x_softc *, int, int, int);
101 /*static*/ void	ncr53c9x_scsi_reset(struct ncr53c9x_softc *);
102 /*static*/ int	ncr53c9x_poll(struct ncr53c9x_softc *,
103 					    struct scsi_xfer *, int);
104 /*static*/ void	ncr53c9x_sched(struct ncr53c9x_softc *);
105 /*static*/ void	ncr53c9x_done(struct ncr53c9x_softc *,
106 					    struct ncr53c9x_ecb *);
107 /*static*/ void	ncr53c9x_msgin(struct ncr53c9x_softc *);
108 /*static*/ void	ncr53c9x_msgout(struct ncr53c9x_softc *);
109 /*static*/ void	ncr53c9x_timeout(void *arg);
110 /*static*/ void	ncr53c9x_abort(struct ncr53c9x_softc *,
111 					    struct ncr53c9x_ecb *);
112 /*static*/ void ncr53c9x_dequeue(struct ncr53c9x_softc *,
113 					    struct ncr53c9x_ecb *);
114 
115 void ncr53c9x_sense(struct ncr53c9x_softc *,
116 					    struct ncr53c9x_ecb *);
117 void ncr53c9x_free_ecb(void *, void *);
118 void *ncr53c9x_get_ecb(void *);
119 
120 static inline int ncr53c9x_stp2cpb(struct ncr53c9x_softc *, int);
121 static inline void ncr53c9x_setsync(struct ncr53c9x_softc *,
122 					    struct ncr53c9x_tinfo *);
123 static struct ncr53c9x_linfo *ncr53c9x_lunsearch(struct ncr53c9x_tinfo *,
124     int64_t lun);
125 
126 static void ncr53c9x_wrfifo(struct ncr53c9x_softc *, u_char *, int);
127 static int ncr53c9x_rdfifo(struct ncr53c9x_softc *, int);
128 #define NCR_RDFIFO_START	0
129 #define NCR_RDFIFO_CONTINUE	1
130 
131 #define NCR_SET_COUNT(sc, size) do {						\
132 			NCR_WRITE_REG((sc), NCR_TCL, (size));			\
133 			NCR_WRITE_REG((sc), NCR_TCM, (size) >> 8);		\
134 			if ((sc->sc_cfg2 & NCRCFG2_FE) ||			\
135 			    (sc->sc_rev == NCR_VARIANT_FAS366)) {		\
136 				NCR_WRITE_REG((sc), NCR_TCH, (size) >> 16);	\
137 			}							\
138 			if (sc->sc_rev == NCR_VARIANT_FAS366) {			\
139 				NCR_WRITE_REG(sc, NCR_RCH, 0);			\
140 			}							\
141 } while (0)
142 
143 static int ecb_pool_initialized = 0;
144 static struct scsi_iopool ecb_iopool;
145 static struct pool ecb_pool;
146 
147 struct cfdriver esp_cd = {
148 	NULL, "esp", DV_DULL
149 };
150 
151 void	ncr53c9x_scsi_cmd(struct scsi_xfer *);
152 int	ncr53c9x_scsi_probe(struct scsi_link *);
153 void	ncr53c9x_scsi_free(struct scsi_link *);
154 
155 struct scsi_adapter ncr53c9x_adapter = {
156 	ncr53c9x_scsi_cmd,	/* cmd */
157 	scsi_minphys,		/* minphys */
158 	ncr53c9x_scsi_probe,	/* lun probe */
159 	ncr53c9x_scsi_free,	/* lun free */
160 	NULL			/* ioctl */
161 };
162 
163 /*
164  * Names for the NCR53c9x variants, corresponding to the variant tags
165  * in ncr53c9xvar.h.
166  */
167 const char *ncr53c9x_variant_names[] = {
168 	"ESP100",
169 	"ESP100A",
170 	"ESP200",
171 	"NCR53C94",
172 	"NCR53C96",
173 	"ESP406",
174 	"FAS408",
175 	"FAS216",
176 	"AM53C974",
177 	"FAS366/HME",
178 };
179 
180 /*
181  * Search linked list for LUN info by LUN id.
182  */
183 static struct ncr53c9x_linfo *
184 ncr53c9x_lunsearch(ti, lun)
185 	struct ncr53c9x_tinfo *ti;
186 	int64_t lun;
187 {
188 	struct ncr53c9x_linfo *li;
189 	LIST_FOREACH(li, &ti->luns, link)
190 	    if (li->lun == lun)
191 		    return (li);
192 	return (NULL);
193 }
194 
195 /*
196  * Attach this instance, and then all the sub-devices
197  */
198 void
199 ncr53c9x_attach(sc)
200 	struct ncr53c9x_softc *sc;
201 {
202 	struct scsibus_attach_args saa;
203 
204 	/*
205 	 * Allocate SCSI message buffers.
206 	 * Front-ends can override allocation to avoid alignment
207 	 * handling in the DMA engines. Note that ncr53c9x_msgout()
208 	 * can request a 1 byte DMA transfer.
209 	 */
210 	if (sc->sc_omess == NULL)
211 		sc->sc_omess = malloc(NCR_MAX_MSG_LEN, M_DEVBUF, M_NOWAIT);
212 
213 	if (sc->sc_imess == NULL)
214 		sc->sc_imess = malloc(NCR_MAX_MSG_LEN+1, M_DEVBUF, M_NOWAIT);
215 
216 	if (sc->sc_omess == NULL || sc->sc_imess == NULL) {
217 		printf("out of memory\n");
218 		return;
219 	}
220 
221 	/*
222 	 * Note, the front-end has set us up to print the chip variation.
223 	 */
224 	if (sc->sc_rev >= NCR_VARIANT_MAX) {
225 		printf("\n%s: unknown variant %d, devices not attached\n",
226 		    sc->sc_dev.dv_xname, sc->sc_rev);
227 		return;
228 	}
229 
230 	printf(": %s, %dMHz\n", ncr53c9x_variant_names[sc->sc_rev],
231 	    sc->sc_freq);
232 
233 	sc->sc_ccf = FREQTOCCF(sc->sc_freq);
234 
235 	/* The value *must not* be == 1. Make it 2 */
236 	if (sc->sc_ccf == 1)
237 		sc->sc_ccf = 2;
238 
239 	/*
240 	 * The recommended timeout is 250ms. This register is loaded
241 	 * with a value calculated as follows, from the docs:
242 	 *
243 	 *		(timout period) x (CLK frequency)
244 	 *	reg = -------------------------------------
245 	 *		 8192 x (Clock Conversion Factor)
246 	 *
247 	 * Since CCF has a linear relation to CLK, this generally computes
248 	 * to the constant of 153.
249 	 */
250 	sc->sc_timeout = ((250 * 1000) * sc->sc_freq) / (8192 * sc->sc_ccf);
251 
252 	/* CCF register only has 3 bits; 0 is actually 8 */
253 	sc->sc_ccf &= 7;
254 
255 	/* Find how many targets we need to support */
256 	switch (sc->sc_rev) {
257 	case NCR_VARIANT_FAS366:
258 		sc->sc_ntarg = 16;
259 		break;
260 	default:
261 		sc->sc_ntarg = 8;
262 		break;
263 	}
264 
265 	/* Reset state & bus */
266 	sc->sc_cfflags = sc->sc_dev.dv_cfdata->cf_flags;
267 	sc->sc_state = 0;
268 	ncr53c9x_init(sc, 1);
269 
270 	/*
271 	 * fill in the prototype scsi_link.
272 	 */
273 	sc->sc_link.adapter_softc = sc;
274 	sc->sc_link.adapter_target = sc->sc_id;
275 	sc->sc_link.adapter = &ncr53c9x_adapter;
276 	sc->sc_link.openings = 2;
277 	sc->sc_link.adapter_buswidth = sc->sc_ntarg;
278 	sc->sc_link.pool = &ecb_iopool;
279 
280 	bzero(&saa, sizeof(saa));
281 	saa.saa_sc_link = &sc->sc_link;
282 
283 	/*
284 	 * Now try to attach all the sub-devices
285 	 */
286 	config_found(&sc->sc_dev, &saa, scsiprint);
287 }
288 
289 /*
290  * This is the generic ncr53c9x reset function. It does not reset the SCSI bus,
291  * only this controller, but kills any on-going commands, and also stops
292  * and resets the DMA.
293  *
294  * After reset, registers are loaded with the defaults from the attach
295  * routine above.
296  */
297 void
298 ncr53c9x_reset(sc)
299 	struct ncr53c9x_softc *sc;
300 {
301 
302 	/* reset DMA first */
303 	NCRDMA_RESET(sc);
304 
305 	/* reset SCSI chip */
306 	NCRCMD(sc, NCRCMD_RSTCHIP);
307 	NCRCMD(sc, NCRCMD_NOP);
308 	DELAY(500);
309 
310 	/* do these backwards, and fall through */
311 	switch (sc->sc_rev) {
312 	case NCR_VARIANT_ESP406:
313 	case NCR_VARIANT_FAS408:
314 		NCR_WRITE_REG(sc, NCR_CFG5, sc->sc_cfg5 | NCRCFG5_SINT);
315 		NCR_WRITE_REG(sc, NCR_CFG4, sc->sc_cfg4);
316 	case NCR_VARIANT_AM53C974:
317 	case NCR_VARIANT_FAS216:
318 	case NCR_VARIANT_NCR53C94:
319 	case NCR_VARIANT_NCR53C96:
320 	case NCR_VARIANT_ESP200:
321 		sc->sc_features |= NCR_F_HASCFG3;
322 		NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
323 	case NCR_VARIANT_ESP100A:
324 		sc->sc_features |= NCR_F_SELATN3;
325 		NCR_WRITE_REG(sc, NCR_CFG2, sc->sc_cfg2);
326 	case NCR_VARIANT_ESP100:
327 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
328 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
329 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
330 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
331 		break;
332 	case NCR_VARIANT_FAS366:
333 		sc->sc_features |=
334 		    NCR_F_SELATN3 | NCR_F_HASCFG3 | NCR_F_FASTSCSI;
335 		sc->sc_cfg3 = NCRFASCFG3_FASTCLK | NCRFASCFG3_OBAUTO;
336 		sc->sc_cfg3_fscsi = NCRFASCFG3_FASTSCSI;
337 		NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
338 		sc->sc_cfg2 = 0; /* NCRCFG2_HMEFE | NCRCFG2_HME32 */
339 		NCR_WRITE_REG(sc, NCR_CFG2, sc->sc_cfg2);
340 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
341 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
342 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
343 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
344 		break;
345 	default:
346 		printf("%s: unknown revision code, assuming ESP100\n",
347 		    sc->sc_dev.dv_xname);
348 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
349 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
350 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
351 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
352 	}
353 
354 	if (sc->sc_rev == NCR_VARIANT_AM53C974)
355 		NCR_WRITE_REG(sc, NCR_AMDCFG4, sc->sc_cfg4);
356 
357 #if 0
358 	printf("%s: ncr53c9x_reset: revision %d\n",
359 	    sc->sc_dev.dv_xname, sc->sc_rev);
360 	printf("%s: ncr53c9x_reset: cfg1 0x%x, cfg2 0x%x, cfg3 0x%x, ccf 0x%x, timeout 0x%x\n",
361 	    sc->sc_dev.dv_xname,
362 	    sc->sc_cfg1, sc->sc_cfg2, sc->sc_cfg3,
363 	    sc->sc_ccf, sc->sc_timeout);
364 #endif
365 }
366 
367 /*
368  * Reset the SCSI bus, but not the chip
369  */
370 void
371 ncr53c9x_scsi_reset(sc)
372 	struct ncr53c9x_softc *sc;
373 {
374 
375 	(*sc->sc_glue->gl_dma_stop)(sc);
376 
377 	printf("%s: resetting SCSI bus\n", sc->sc_dev.dv_xname);
378 	NCRCMD(sc, NCRCMD_RSTSCSI);
379 }
380 
381 /*
382  * Initialize ncr53c9x state machine
383  */
384 void
385 ncr53c9x_init(sc, doreset)
386 	struct ncr53c9x_softc *sc;
387 	int doreset;
388 {
389 	struct ncr53c9x_ecb *ecb;
390 	struct ncr53c9x_linfo *li;
391 	int r, i;
392 
393 	NCR_TRACE(("[NCR_INIT(%d) %d] ", doreset, sc->sc_state));
394 
395 	if (!ecb_pool_initialized) {
396 		/* All instances share this pool */
397 		pool_init(&ecb_pool, sizeof(struct ncr53c9x_ecb), 0, 0, 0,
398 		    "ncr53c9x_ecb", NULL);
399 		pool_setipl(&ecb_pool, IPL_BIO);
400 		scsi_iopool_init(&ecb_iopool, NULL,
401 		    ncr53c9x_get_ecb, ncr53c9x_free_ecb);
402 		ecb_pool_initialized = 1;
403 	}
404 
405 	if (sc->sc_state == 0) {
406 		/* First time through; initialize. */
407 
408 		TAILQ_INIT(&sc->ready_list);
409 		sc->sc_nexus = NULL;
410 		bzero(sc->sc_tinfo, sizeof(sc->sc_tinfo));
411 		for (r = 0; r < sc->sc_ntarg; r++) {
412 			LIST_INIT(&sc->sc_tinfo[r].luns);
413 		}
414 	} else {
415 		/* Cancel any active commands. */
416 		sc->sc_state = NCR_CLEANING;
417 		sc->sc_msgify = 0;
418 		if ((ecb = sc->sc_nexus) != NULL) {
419 			ecb->xs->error = XS_TIMEOUT;
420 			ncr53c9x_done(sc, ecb);
421 		}
422 		for (r = 0; r < sc->sc_ntarg; r++) {
423 			LIST_FOREACH(li, &sc->sc_tinfo[r].luns, link) {
424 				if ((ecb = li->untagged)) {
425 					li->untagged = NULL;
426 					/*
427 					 * XXXXXXX
428 					 * Should we terminate a command
429 					 * that never reached the disk?
430 					 */
431 					li->busy = 0;
432 					ecb->xs->error = XS_TIMEOUT;
433 					ncr53c9x_done(sc, ecb);
434 				}
435 				for (i = 0; i < 256; i++)
436 					if ((ecb = li->queued[i])) {
437 						li->queued[i] = NULL;
438 						ecb->xs->error = XS_TIMEOUT;
439 						ncr53c9x_done(sc, ecb);
440 					}
441 				li->used = 0;
442 			}
443 		}
444 	}
445 
446 	/*
447 	 * reset the chip to a known state
448 	 */
449 	ncr53c9x_reset(sc);
450 
451 	sc->sc_phase = sc->sc_prevphase = INVALID_PHASE;
452 	for (r = 0; r < sc->sc_ntarg; r++) {
453 		struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[r];
454 /* XXX - config flags per target: low bits: no reselect; high bits: no synch */
455 
456                 ti->flags = ((!(sc->sc_cfflags & (1 << (r + 16))) &&
457 		    sc->sc_minsync) ? 0 : T_SYNCHOFF) |
458 		    ((sc->sc_cfflags & (1 << r)) ?  T_RSELECTOFF : 0) |
459 		    T_NEED_TO_RESET;
460 #ifdef DEBUG
461 		 if (ncr53c9x_notag)
462 			 ti->flags &= ~T_TAG;
463 #endif
464 		ti->period = sc->sc_minsync;
465 		ti->offset = 0;
466 		ti->cfg3 = 0;
467 	}
468 
469 	if (doreset) {
470 		sc->sc_state = NCR_SBR;
471 		NCRCMD(sc, NCRCMD_RSTSCSI);
472 		/*
473 		 * XXX gross...
474 		 * On some systems, commands issued too close to a reset
475 		 * do not work correctly. We'll force a short delay on
476 		 * known-to-be-sensitive chips.
477 		 */
478 		switch (sc->sc_rev) {
479 		case NCR_VARIANT_NCR53C94:
480 			DELAY(600000);	/* 600ms */
481 			break;
482 		case NCR_VARIANT_NCR53C96:
483 			DELAY(100000);	/* 100ms */
484 			break;
485 		}
486 	} else {
487 		sc->sc_state = NCR_IDLE;
488 		ncr53c9x_sched(sc);
489 	}
490 }
491 
492 /*
493  * Read the NCR registers, and save their contents for later use.
494  * NCR_STAT, NCR_STEP & NCR_INTR are mostly zeroed out when reading
495  * NCR_INTR - so make sure it is the last read.
496  *
497  * I think that (from reading the docs) most bits in these registers
498  * only make sense when he DMA CSR has an interrupt showing. Call only
499  * if an interrupt is pending.
500  */
501 __inline__ void
502 ncr53c9x_readregs(sc)
503 	struct ncr53c9x_softc *sc;
504 {
505 
506 	sc->sc_espstat = NCR_READ_REG(sc, NCR_STAT);
507 	/* Only the stepo bits are of interest */
508 	sc->sc_espstep = NCR_READ_REG(sc, NCR_STEP) & NCRSTEP_MASK;
509 
510 	if (sc->sc_rev == NCR_VARIANT_FAS366)
511 		sc->sc_espstat2 = NCR_READ_REG(sc, NCR_STAT2);
512 
513 	sc->sc_espintr = NCR_READ_REG(sc, NCR_INTR);
514 
515 	if (sc->sc_glue->gl_clear_latched_intr != NULL)
516 		(*sc->sc_glue->gl_clear_latched_intr)(sc);
517 
518 	/*
519 	 * Determine the SCSI bus phase, return either a real SCSI bus phase
520 	 * or some pseudo phase we use to detect certain exceptions.
521 	 */
522 
523 	sc->sc_phase = (sc->sc_espintr & NCRINTR_DIS)
524 			? /* Disconnected */ BUSFREE_PHASE
525 			: sc->sc_espstat & NCRSTAT_PHASE;
526 
527 	NCR_MISC(("regs[intr=%02x,stat=%02x,step=%02x,stat2=%02x] ",
528 		sc->sc_espintr, sc->sc_espstat, sc->sc_espstep, sc->sc_espstat2));
529 }
530 
531 /*
532  * Convert Synchronous Transfer Period to chip register Clock Per Byte value.
533  */
534 static inline int
535 ncr53c9x_stp2cpb(sc, period)
536 	struct ncr53c9x_softc *sc;
537 	int period;
538 {
539 	int v;
540 	v = (sc->sc_freq * period) / 250;
541 	if (ncr53c9x_cpb2stp(sc, v) < period)
542 		/* Correct round-down error */
543 		v++;
544 	return (v);
545 }
546 
547 static inline void
548 ncr53c9x_setsync(sc, ti)
549 	struct ncr53c9x_softc *sc;
550 	struct ncr53c9x_tinfo *ti;
551 {
552 	u_char syncoff, synctp;
553 	u_char cfg3 = sc->sc_cfg3 | ti->cfg3;
554 
555 	if (ti->flags & T_SYNCMODE) {
556 		syncoff = ti->offset;
557 		synctp = ncr53c9x_stp2cpb(sc, ti->period);
558 		if (sc->sc_features & NCR_F_FASTSCSI) {
559 			/*
560 			 * If the period is 200ns or less (ti->period <= 50),
561 			 * put the chip in Fast SCSI mode.
562 			 */
563 			if (ti->period <= 50)
564 				/*
565 				 * There are (at least) 4 variations of the
566 				 * configuration 3 register.  The drive attach
567 				 * routine sets the appropriate bit to put the
568 				 * chip into Fast SCSI mode so that it doesn't
569 				 * have to be figured out here each time.
570 				 */
571 				cfg3 |= (sc->sc_rev == NCR_VARIANT_AM53C974) ?
572 				    NCRAMDCFG3_FSCSI : NCRCFG3_FSCSI;
573 		}
574 
575 		/*
576 		 * Am53c974 requires different SYNCTP values when the
577 		 * FSCSI bit is off.
578 		 */
579 		if (sc->sc_rev == NCR_VARIANT_AM53C974 &&
580 		    (cfg3 & NCRAMDCFG3_FSCSI) == 0)
581 			synctp--;
582 	} else {
583 		syncoff = 0;
584 		synctp = 0;
585 	}
586 
587 	if (sc->sc_features & NCR_F_HASCFG3)
588 		NCR_WRITE_REG(sc, NCR_CFG3, cfg3);
589 
590 	NCR_WRITE_REG(sc, NCR_SYNCOFF, syncoff);
591 	NCR_WRITE_REG(sc, NCR_SYNCTP, synctp);
592 }
593 
594 /*
595  * Send a command to a target, set the driver state to NCR_SELECTING
596  * and let the caller take care of the rest.
597  *
598  * Keeping this as a function allows me to say that this may be done
599  * by DMA instead of programmed I/O soon.
600  */
601 void
602 ncr53c9x_select(sc, ecb)
603 	struct ncr53c9x_softc *sc;
604 	struct ncr53c9x_ecb *ecb;
605 {
606 	struct scsi_link *sc_link = ecb->xs->sc_link;
607 	int target = sc_link->target;
608 	int lun = sc_link->lun;
609 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[target];
610 	int tiflags = ti->flags;
611 	u_char *cmd;
612 	int clen;
613 	int selatn3, selatns;
614 	size_t dmasize;
615 
616 	NCR_TRACE(("[ncr53c9x_select(t%d,l%d,cmd:%x,tag%x,%x)] ",
617 		   target, lun, ecb->cmd.cmd.opcode, ecb->tag[0], ecb->tag[1]));
618 
619 	sc->sc_state = NCR_SELECTING;
620 	/*
621 	 * Schedule the timeout now, the first time we will go away
622 	 * expecting to come back due to an interrupt, because it is
623 	 * always possible that the interrupt may never happen.
624 	 */
625 	if ((ecb->xs->flags & SCSI_POLL) == 0) {
626 		int timeout = ecb->timeout;
627 
628 		if (timeout > 1000000)
629 			timeout = (timeout / 1000) * hz;
630 		else
631 			timeout = (timeout * hz) / 1000;
632 		timeout_add(&ecb->to, timeout);
633 	}
634 
635 	/*
636 	 * The docs say the target register is never reset, and I
637 	 * can't think of a better place to set it
638 	 */
639 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
640 		NCRCMD(sc, NCRCMD_FLUSH);
641 		NCR_WRITE_REG(sc, NCR_SELID, target | NCR_BUSID_HME);
642 	} else {
643 		NCR_WRITE_REG(sc, NCR_SELID, target);
644 	}
645 	ncr53c9x_setsync(sc, ti);
646 
647 	if ((ecb->flags & ECB_SENSE) != 0) {
648 		/*
649 		 * For REQUEST SENSE, we should not send an IDENTIFY or
650 		 * otherwise mangle the target.  There should be no MESSAGE IN
651 		 * phase.
652 		 */
653 		if (sc->sc_features & NCR_F_DMASELECT) {
654 			/* setup DMA transfer for command */
655 			dmasize = clen = ecb->clen;
656 			sc->sc_cmdlen = clen;
657 			sc->sc_cmdp = (caddr_t)&ecb->cmd.cmd;
658 
659 			NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen, 0,
660 			    &dmasize);
661 			/* Program the SCSI counter */
662 			NCR_SET_COUNT(sc, dmasize);
663 
664 			if (sc->sc_rev != NCR_VARIANT_FAS366)
665 				NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
666 
667 			/* And get the targets attention */
668 			NCRCMD(sc, NCRCMD_SELNATN | NCRCMD_DMA);
669 			NCRDMA_GO(sc);
670 		} else {
671 			ncr53c9x_wrfifo(sc, (u_char *)&ecb->cmd.cmd, ecb->clen);
672 			NCRCMD(sc, NCRCMD_SELNATN);
673 		}
674 		return;
675 	}
676 
677 	selatn3 = selatns = 0;
678 	if (ecb->tag[0] != 0) {
679 		if (sc->sc_features & NCR_F_SELATN3)
680 			/* use SELATN3 to send tag messages */
681 			selatn3 = 1;
682 		else
683 			/* We don't have SELATN3; use SELATNS to send tags */
684 			selatns = 1;
685 	}
686 
687 	if (ti->flags & T_NEGOTIATE) {
688 		/* We have to use SELATNS to send sync/wide messages */
689 		selatn3 = 0;
690 		selatns = 1;
691 	}
692 
693 	cmd = (u_char *)&ecb->cmd.cmd;
694 
695 	if (selatn3) {
696 		/* We'll use tags with SELATN3 */
697 		clen = ecb->clen + 3;
698 		cmd -= 3;
699 		cmd[0] = MSG_IDENTIFY(lun, 1);	/* msg[0] */
700 		cmd[1] = ecb->tag[0];		/* msg[1] */
701 		cmd[2] = ecb->tag[1];		/* msg[2] */
702 	} else {
703 		/* We don't have tags, or will send messages with SELATNS */
704 		clen = ecb->clen + 1;
705 		cmd -= 1;
706 		cmd[0] = MSG_IDENTIFY(lun, (tiflags & T_RSELECTOFF) == 0);
707 	}
708 
709 	if ((sc->sc_features & NCR_F_DMASELECT) && !selatns) {
710 
711 		/* setup DMA transfer for command */
712 		dmasize = clen;
713 		sc->sc_cmdlen = clen;
714 		sc->sc_cmdp = cmd;
715 
716 		NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen, 0, &dmasize);
717 		/* Program the SCSI counter */
718 		NCR_SET_COUNT(sc, dmasize);
719 
720 		/* load the count in */
721 		/* if (sc->sc_rev != NCR_VARIANT_FAS366) */
722 			NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
723 
724 		/* And get the targets attention */
725 		if (selatn3) {
726 			sc->sc_msgout = SEND_TAG;
727 			sc->sc_flags |= NCR_ATN;
728 			NCRCMD(sc, NCRCMD_SELATN3 | NCRCMD_DMA);
729 		} else
730 			NCRCMD(sc, NCRCMD_SELATN | NCRCMD_DMA);
731 		NCRDMA_GO(sc);
732 		return;
733 	}
734 
735 	/*
736 	 * Who am I. This is where we tell the target that we are
737 	 * happy for it to disconnect etc.
738 	 */
739 
740 	/* Now get the command into the FIFO */
741 	ncr53c9x_wrfifo(sc, cmd, clen);
742 
743 	/* And get the targets attention */
744 	if (selatns) {
745 		NCR_MISC(("SELATNS \n"));
746 		/* Arbitrate, select and stop after IDENTIFY message */
747 		NCRCMD(sc, NCRCMD_SELATNS);
748 	} else if (selatn3) {
749 		sc->sc_msgout = SEND_TAG;
750 		sc->sc_flags |= NCR_ATN;
751 		NCRCMD(sc, NCRCMD_SELATN3);
752 	} else
753 		NCRCMD(sc, NCRCMD_SELATN);
754 }
755 
756 /*
757  * DRIVER FUNCTIONS CALLABLE FROM HIGHER LEVEL DRIVERS
758  */
759 
760 void *
761 ncr53c9x_get_ecb(void *null)
762 {
763 	struct ncr53c9x_ecb *ecb;
764 
765 	ecb = pool_get(&ecb_pool, M_NOWAIT|M_ZERO);
766 	if (ecb == NULL)
767 		return (NULL);
768 
769 	timeout_set(&ecb->to, ncr53c9x_timeout, ecb);
770 	ecb->flags |= ECB_ALLOC;
771 
772 	return (ecb);
773 }
774 
775 void
776 ncr53c9x_free_ecb(void *null, void *ecb)
777 {
778 	pool_put(&ecb_pool, ecb);
779 }
780 
781 int
782 ncr53c9x_scsi_probe(struct scsi_link *sc_link)
783 {
784 	struct ncr53c9x_softc *sc = sc_link->adapter_softc;
785 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
786 	struct ncr53c9x_linfo *li;
787 	int64_t lun = sc_link->lun;
788 	int s;
789 
790 	/* Initialize LUN info and add to list. */
791 	li = malloc(sizeof(*li), M_DEVBUF, M_WAITOK | M_ZERO);
792 	if (li == NULL)
793 		return (ENOMEM);
794 
795 	li->last_used = time_second;
796 	li->lun = lun;
797 
798 	s = splbio();
799 	LIST_INSERT_HEAD(&ti->luns, li, link);
800 	if (lun < NCR_NLUN)
801 		ti->lun[lun] = li;
802 	splx(s);
803 
804 	return (0);
805 
806 }
807 
808 void
809 ncr53c9x_scsi_free(struct scsi_link *sc_link)
810 {
811 	struct ncr53c9x_softc *sc = sc_link->adapter_softc;
812 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
813 	struct ncr53c9x_linfo *li;
814 	int64_t lun = sc_link->lun;
815 	int s;
816 
817 	s = splbio();
818 	li = TINFO_LUN(ti, lun);
819 
820 	LIST_REMOVE(li, link);
821 	if (lun < NCR_NLUN)
822 		ti->lun[lun] = NULL;
823 	splx(s);
824 
825 	free(li, M_DEVBUF);
826 }
827 
828 /*
829  * Start a SCSI-command
830  * This function is called by the higher level SCSI-driver to queue/run
831  * SCSI-commands.
832  */
833 void
834 ncr53c9x_scsi_cmd(xs)
835 	struct scsi_xfer *xs;
836 {
837 	struct scsi_link *sc_link = xs->sc_link;
838 	struct ncr53c9x_softc *sc = sc_link->adapter_softc;
839 	struct ncr53c9x_ecb *ecb;
840 	struct ncr53c9x_tinfo *ti;
841 	struct ncr53c9x_linfo *li;
842 	int64_t lun = sc_link->lun;
843 	int s, flags;
844 
845 	NCR_TRACE(("[ncr53c9x_scsi_cmd] "));
846 	NCR_CMDS(("[0x%x, %d]->%d ", (int)xs->cmd->opcode, xs->cmdlen,
847 	    sc_link->target));
848 
849 	/*
850 	 * Commands larger than 12 bytes seem to confuse the chip
851 	 * (at least on FAS366 flavours).
852 	 */
853 	if (xs->cmdlen > 12) {
854 		memset(&xs->sense, 0, sizeof(xs->sense));
855 		/* sense data borrowed from gdt(4) */
856 		xs->sense.error_code = SSD_ERRCODE_VALID | SSD_ERRCODE_CURRENT;
857 		xs->sense.flags = SKEY_ILLEGAL_REQUEST;
858 		xs->sense.add_sense_code = 0x20; /* illcmd */
859 		xs->error = XS_SENSE;
860 		scsi_done(xs);
861 		return;
862 	}
863 
864 	flags = xs->flags;
865 	ti = &sc->sc_tinfo[sc_link->target];
866 	li = TINFO_LUN(ti, lun);
867 
868 	/* Initialize ecb */
869 	ecb = xs->io;
870 	ecb->xs = xs;
871 	ecb->timeout = xs->timeout;
872 
873 	if (flags & SCSI_RESET) {
874 		ecb->flags |= ECB_RESET;
875 		ecb->clen = 0;
876 		ecb->dleft = 0;
877 	} else {
878 		bcopy(xs->cmd, &ecb->cmd.cmd, xs->cmdlen);
879 		ecb->clen = xs->cmdlen;
880 		ecb->daddr = xs->data;
881 		ecb->dleft = xs->datalen;
882 	}
883 	ecb->stat = 0;
884 
885 	s = splbio();
886 
887 	TAILQ_INSERT_TAIL(&sc->ready_list, ecb, chain);
888 	ecb->flags |= ECB_READY;
889 	if (sc->sc_state == NCR_IDLE)
890 		ncr53c9x_sched(sc);
891 
892 	splx(s);
893 
894 	if ((flags & SCSI_POLL) == 0)
895 		return;
896 
897 	/* Not allowed to use interrupts, use polling instead */
898 	if (ncr53c9x_poll(sc, xs, ecb->timeout)) {
899 		ncr53c9x_timeout(ecb);
900 		if (ncr53c9x_poll(sc, xs, ecb->timeout))
901 			ncr53c9x_timeout(ecb);
902 	}
903 }
904 
905 /*
906  * Used when interrupt driven I/O isn't allowed, e.g. during boot.
907  */
908 int
909 ncr53c9x_poll(sc, xs, count)
910 	struct ncr53c9x_softc *sc;
911 	struct scsi_xfer *xs;
912 	int count;
913 {
914 	int s;
915 
916 	NCR_TRACE(("[ncr53c9x_poll] "));
917 	while (count) {
918 		if (NCRDMA_ISINTR(sc)) {
919 			s = splbio();
920 			ncr53c9x_intr(sc);
921 			splx(s);
922 		}
923 #if alternatively
924 		if (NCR_READ_REG(sc, NCR_STAT) & NCRSTAT_INT) {
925 			s = splbio();
926 			ncr53c9x_intr(sc);
927 			splx(s);
928 		}
929 #endif
930 		if ((xs->flags & ITSDONE) != 0)
931 			return (0);
932 		s = splbio();
933 		if (sc->sc_state == NCR_IDLE) {
934 			NCR_TRACE(("[ncr53c9x_poll: rescheduling] "));
935 			ncr53c9x_sched(sc);
936 		}
937 		splx(s);
938 		DELAY(1000);
939 		count--;
940 	}
941 	return (1);
942 }
943 
944 
945 /*
946  * LOW LEVEL SCSI UTILITIES
947  */
948 
949 /*
950  * Schedule a scsi operation.  This has now been pulled out of the interrupt
951  * handler so that we may call it from ncr53c9x_scsi_cmd and ncr53c9x_done.
952  * This may save us an unnecessary interrupt just to get things going.
953  * Should only be called when state == NCR_IDLE and at bio pl.
954  */
955 void
956 ncr53c9x_sched(sc)
957 	struct ncr53c9x_softc *sc;
958 {
959 	struct ncr53c9x_ecb *ecb;
960 	struct scsi_link *sc_link;
961 	struct ncr53c9x_tinfo *ti;
962 	int lun;
963 	struct ncr53c9x_linfo *li;
964 	int s, tag;
965 
966 	NCR_TRACE(("[ncr53c9x_sched] "));
967 	if (sc->sc_state != NCR_IDLE)
968 		panic("ncr53c9x_sched: not IDLE (state=%d)", sc->sc_state);
969 
970 	/*
971 	 * Find first ecb in ready queue that is for a target/lunit
972 	 * combinations that is not busy.
973 	 */
974 	TAILQ_FOREACH(ecb, &sc->ready_list, chain) {
975 		sc_link = ecb->xs->sc_link;
976 		ti = &sc->sc_tinfo[sc_link->target];
977 		lun = sc_link->lun;
978 
979 		/* Select type of tag for this command */
980 		if ((ti->flags & (T_RSELECTOFF)) != 0)
981 			tag = 0;
982 		else if ((ti->flags & T_TAG) == 0)
983 			tag = 0;
984 		else if ((ecb->flags & ECB_SENSE) != 0)
985 			tag = 0;
986 		else
987 			tag = MSG_SIMPLE_Q_TAG;
988 #if 0
989 		/* XXXX Use tags for polled commands? */
990 		if (ecb->xs->flags & SCSI_POLL)
991 			tag = 0;
992 #endif
993 		s = splbio();
994 		li = TINFO_LUN(ti, lun);
995 		if (!li) {
996 			/* Initialize LUN info and add to list. */
997 			if ((li = malloc(sizeof(*li), M_DEVBUF,
998 			    M_NOWAIT | M_ZERO)) == NULL) {
999 				splx(s);
1000 				continue;
1001 			}
1002 			li->lun = lun;
1003 
1004 			LIST_INSERT_HEAD(&ti->luns, li, link);
1005 			if (lun < NCR_NLUN)
1006 				ti->lun[lun] = li;
1007 		}
1008 		li->last_used = time_second;
1009 		if (!tag) {
1010 			/* Try to issue this as an un-tagged command */
1011 			if (!li->untagged)
1012 				li->untagged = ecb;
1013 		}
1014 		if (li->untagged) {
1015 			tag = 0;
1016 			if ((li->busy != 1) && !li->used) {
1017 				/* We need to issue this untagged command now */
1018 				ecb = li->untagged;
1019 				sc_link = ecb->xs->sc_link;
1020 			}
1021 			else {
1022 				/* Not ready yet */
1023 				splx(s);
1024 				continue;
1025 			}
1026 		}
1027 		ecb->tag[0] = tag;
1028 		if (tag) {
1029 			int i;
1030 
1031 			/* Allocate a tag */
1032 			if (li->used == 255) {
1033 				/* no free tags */
1034 				splx(s);
1035 				continue;
1036 			}
1037 			/* Start from the last used location */
1038 			for (i=li->avail; i<256; i++) {
1039 				if (li->queued[i] == NULL)
1040 					break;
1041 			}
1042 			/* Couldn't find one, start again from the beginning */
1043 			if (i == 256) {
1044 				for (i = 0; i<256; i++) {
1045 					if (li->queued[i] == NULL)
1046 						break;
1047 				}
1048 			}
1049 #ifdef DIAGNOSTIC
1050 			if (i == 256)
1051 				panic("ncr53c9x_sched: tag alloc failure");
1052 #endif
1053 
1054 			/* Save where to start next time. */
1055 			li->avail = i+1;
1056 			li->used++;
1057 
1058 			li->queued[i] = ecb;
1059 			ecb->tag[1] = i;
1060 		}
1061 		splx(s);
1062 		if (li->untagged && (li->busy != 1)) {
1063 			li->busy = 1;
1064 			TAILQ_REMOVE(&sc->ready_list, ecb, chain);
1065 			ecb->flags &= ~ECB_READY;
1066 			sc->sc_nexus = ecb;
1067 			ncr53c9x_select(sc, ecb);
1068 			break;
1069 		}
1070 		if (!li->untagged && tag) {
1071 			TAILQ_REMOVE(&sc->ready_list, ecb, chain);
1072 			ecb->flags &= ~ECB_READY;
1073 			sc->sc_nexus = ecb;
1074 			ncr53c9x_select(sc, ecb);
1075 			break;
1076 		} else
1077 			NCR_MISC(("%d:%d busy\n",
1078 				  sc_link->target,
1079 				  sc_link->lun));
1080 	}
1081 }
1082 
1083 void
1084 ncr53c9x_sense(sc, ecb)
1085 	struct ncr53c9x_softc *sc;
1086 	struct ncr53c9x_ecb *ecb;
1087 {
1088 	struct scsi_xfer *xs = ecb->xs;
1089 	struct scsi_link *sc_link = xs->sc_link;
1090 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
1091 	struct scsi_sense *ss = (void *)&ecb->cmd.cmd;
1092 	struct ncr53c9x_linfo *li;
1093 	int lun = sc_link->lun;
1094 
1095 	NCR_MISC(("requesting sense "));
1096 	/* Next, setup a request sense command block */
1097 	bzero(ss, sizeof(*ss));
1098 	ss->opcode = REQUEST_SENSE;
1099 	ss->byte2 = sc_link->lun << 5;
1100 	ss->length = sizeof(struct scsi_sense_data);
1101 	ecb->clen = sizeof(*ss);
1102 	ecb->daddr = (char *)&xs->sense;
1103 	ecb->dleft = sizeof(struct scsi_sense_data);
1104 	ecb->flags |= ECB_SENSE;
1105 	ecb->timeout = NCR_SENSE_TIMEOUT;
1106 	ti->senses++;
1107 	li = TINFO_LUN(ti, lun);
1108 	if (li->busy) li->busy = 0;
1109 	ncr53c9x_dequeue(sc, ecb);
1110 	li->untagged = ecb;
1111 	li->busy = 2;
1112 	if (ecb == sc->sc_nexus) {
1113 		ncr53c9x_select(sc, ecb);
1114 	} else {
1115 		TAILQ_INSERT_HEAD(&sc->ready_list, ecb, chain);
1116 		ecb->flags |= ECB_READY;
1117 		if (sc->sc_state == NCR_IDLE)
1118 			ncr53c9x_sched(sc);
1119 	}
1120 }
1121 
1122 /*
1123  * POST PROCESSING OF SCSI_CMD (usually current)
1124  */
1125 void
1126 ncr53c9x_done(sc, ecb)
1127 	struct ncr53c9x_softc *sc;
1128 	struct ncr53c9x_ecb *ecb;
1129 {
1130 	struct scsi_xfer *xs = ecb->xs;
1131 	struct scsi_link *sc_link = xs->sc_link;
1132 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
1133 	int lun = sc_link->lun;
1134 	struct ncr53c9x_linfo *li = TINFO_LUN(ti, lun);
1135 
1136 	NCR_TRACE(("[ncr53c9x_done(error:%x)] ", xs->error));
1137 
1138 	timeout_del(&ecb->to);
1139 
1140 	if (ecb->stat == SCSI_QUEUE_FULL) {
1141 		/*
1142 		 * Set current throttle -- we should reset
1143 		 * this periodically
1144 		 */
1145 		sc_link->openings = li->used - 1;
1146 		printf("\n%s: QFULL -- throttling to %d commands\n",
1147 		    sc->sc_dev.dv_xname, sc_link->openings);
1148 	}
1149 
1150 	/*
1151 	 * Now, if we've come here with no error code, i.e. we've kept the
1152 	 * initial XS_NOERROR, and the status code signals that we should
1153 	 * check sense, we'll need to set up a request sense cmd block and
1154 	 * push the command back into the ready queue *before* any other
1155 	 * commands for this target/lunit, else we lose the sense info.
1156 	 * We don't support chk sense conditions for the request sense cmd.
1157 	 */
1158 	if (xs->error == XS_NOERROR) {
1159 		xs->status = ecb->stat;
1160 		if ((ecb->flags & ECB_ABORT) != 0) {
1161 			xs->error = XS_TIMEOUT;
1162 		} else if ((ecb->flags & ECB_SENSE) != 0) {
1163 			xs->error = XS_SENSE;
1164 		} else if ((ecb->stat & ST_MASK) == SCSI_CHECK) {
1165 			/* First, save the return values */
1166 			xs->resid = ecb->dleft;
1167 			ncr53c9x_sense(sc, ecb);
1168 			return;
1169 		} else {
1170 			xs->resid = ecb->dleft;
1171 		}
1172 	}
1173 
1174 #ifdef NCR53C9X_DEBUG
1175 	if (ncr53c9x_debug & NCR_SHOWMISC) {
1176 		if (xs->resid != 0)
1177 			printf("resid=%lu ", (unsigned long)xs->resid);
1178 		if (xs->error == XS_SENSE)
1179 			printf("sense=0x%02x\n", xs->sense.error_code);
1180 		else
1181 			printf("error=%d\n", xs->error);
1182 	}
1183 #endif
1184 
1185 	/*
1186 	 * Remove the ECB from whatever queue it's on.
1187 	 */
1188 	ncr53c9x_dequeue(sc, ecb);
1189 	if (ecb == sc->sc_nexus) {
1190 		sc->sc_nexus = NULL;
1191 		if (sc->sc_state != NCR_CLEANING) {
1192 			sc->sc_state = NCR_IDLE;
1193 			ncr53c9x_sched(sc);
1194 		}
1195 	}
1196 
1197 	ti->cmds++;
1198 	scsi_done(xs);
1199 }
1200 
1201 void
1202 ncr53c9x_dequeue(sc, ecb)
1203 	struct ncr53c9x_softc *sc;
1204 	struct ncr53c9x_ecb *ecb;
1205 {
1206 	struct ncr53c9x_tinfo *ti =
1207 	    &sc->sc_tinfo[ecb->xs->sc_link->target];
1208 	struct ncr53c9x_linfo *li;
1209 	int64_t lun = ecb->xs->sc_link->lun;
1210 
1211 	li = TINFO_LUN(ti, lun);
1212 #ifdef DIAGNOSTIC
1213 	if ((!li) || (li->lun != lun))
1214 		panic("ncr53c9x_dequeue: lun %qx for ecb %p does not exist",
1215 		    (long long)lun, ecb);
1216 #endif
1217 	if (li->untagged == ecb) {
1218 		li->busy = 0;
1219 		li->untagged = NULL;
1220 	}
1221 	if (ecb->tag[0] && li->queued[ecb->tag[1]]) {
1222 #ifdef DIAGNOSTIC
1223 		if (li->queued[ecb->tag[1]] && (li->queued[ecb->tag[1]] != ecb))
1224 			panic("ncr53c9x_dequeue: slot %d for lun %qx has %p "
1225 			    "instead of ecb %p", ecb->tag[1],
1226 			    (long long)lun,
1227 			    li->queued[ecb->tag[1]], ecb);
1228 #endif
1229 		li->queued[ecb->tag[1]] = NULL;
1230 		li->used --;
1231 
1232 	}
1233 	if (ecb->flags & ECB_READY) {
1234 		ecb->flags &= ~ECB_READY;
1235 		TAILQ_REMOVE(&sc->ready_list, ecb, chain);
1236 	}
1237  }
1238 
1239 /*
1240  * INTERRUPT/PROTOCOL ENGINE
1241  */
1242 
1243 /*
1244  * Schedule an outgoing message by prioritizing it, and asserting
1245  * attention on the bus. We can only do this when we are the initiator
1246  * else there will be an illegal command interrupt.
1247  */
1248 #define ncr53c9x_sched_msgout(m) \
1249 	do {							\
1250 		NCR_MISC(("ncr53c9x_sched_msgout %x %d ", m, __LINE__));	\
1251 		NCRCMD(sc, NCRCMD_SETATN);			\
1252 		sc->sc_flags |= NCR_ATN;			\
1253 		sc->sc_msgpriq |= (m);				\
1254 	} while (0)
1255 
1256 static void
1257 ncr53c9x_flushfifo(struct ncr53c9x_softc *sc)
1258 {
1259 	NCR_MISC(("[flushfifo] "));
1260 
1261 	NCRCMD(sc, NCRCMD_FLUSH);
1262 
1263 	if (sc->sc_phase == COMMAND_PHASE ||
1264 	    sc->sc_phase == MESSAGE_OUT_PHASE)
1265 		DELAY(2);
1266 }
1267 
1268 static int
1269 ncr53c9x_rdfifo(struct ncr53c9x_softc *sc, int how)
1270 {
1271 	int i, n;
1272 	u_char *buf;
1273 
1274 	switch(how) {
1275 	case NCR_RDFIFO_START:
1276 		buf = sc->sc_imess;
1277 		sc->sc_imlen = 0;
1278 		break;
1279 	case NCR_RDFIFO_CONTINUE:
1280 		buf = sc->sc_imess + sc->sc_imlen;
1281 		break;
1282 	default:
1283 		panic("ncr53c9x_rdfifo: bad flag");
1284 		break;
1285 	}
1286 
1287 	/*
1288 	 * XXX buffer (sc_imess) size for message
1289 	 */
1290 
1291 	n = NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF;
1292 
1293 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
1294 		n *= 2;
1295 
1296 		for (i = 0; i < n; i++)
1297 			buf[i] = NCR_READ_REG(sc, NCR_FIFO);
1298 
1299 		if (sc->sc_espstat2 & FAS_STAT2_ISHUTTLE) {
1300 
1301 			NCR_WRITE_REG(sc, NCR_FIFO, 0);
1302 			buf[i++] = NCR_READ_REG(sc, NCR_FIFO);
1303 
1304 			NCR_READ_REG(sc, NCR_FIFO);
1305 
1306 			ncr53c9x_flushfifo(sc);
1307 		}
1308 	} else {
1309 		for (i = 0; i < n; i++)
1310 			buf[i] = NCR_READ_REG(sc, NCR_FIFO);
1311 	}
1312 
1313 	sc->sc_imlen += i;
1314 
1315 #ifdef NCR53C9X_DEBUG
1316 	{
1317 		int j;
1318 
1319 		NCR_TRACE(("\n[rdfifo %s (%d):",
1320 		    (how == NCR_RDFIFO_START) ? "start" : "cont",
1321 		    (int)sc->sc_imlen));
1322 		if (ncr53c9x_debug & NCR_SHOWTRAC) {
1323 			for (j = 0; j < sc->sc_imlen; j++)
1324 				printf(" %02x", sc->sc_imess[j]);
1325 			printf("]\n");
1326 		}
1327 	}
1328 #endif
1329 	return sc->sc_imlen;
1330 }
1331 
1332 static void
1333 ncr53c9x_wrfifo(struct ncr53c9x_softc *sc, u_char *p, int len)
1334 {
1335 	int i;
1336 
1337 #ifdef NCR53C9X_DEBUG
1338 	NCR_MISC(("[wrfifo(%d):", len));
1339 	if (ncr53c9x_debug & NCR_SHOWTRAC) {
1340 		for (i = 0; i < len; i++)
1341 			printf(" %02x", p[i]);
1342 		printf("]\n");
1343 	}
1344 #endif
1345 
1346 	for (i = 0; i < len; i++) {
1347 		NCR_WRITE_REG(sc, NCR_FIFO, p[i]);
1348 
1349 		if (sc->sc_rev == NCR_VARIANT_FAS366)
1350 			NCR_WRITE_REG(sc, NCR_FIFO, 0);
1351 	}
1352 }
1353 
1354 int
1355 ncr53c9x_reselect(sc, message, tagtype, tagid)
1356 	struct ncr53c9x_softc *sc;
1357 	int message;
1358 	int tagtype;
1359 	int tagid;
1360 {
1361 	u_char selid, target, lun;
1362 	struct ncr53c9x_ecb *ecb = NULL;
1363 	struct ncr53c9x_tinfo *ti;
1364 	struct ncr53c9x_linfo *li;
1365 
1366 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
1367 		target = sc->sc_selid;
1368 	} else {
1369 		/*
1370 		 * The SCSI chip made a snapshot of the data bus while the reselection
1371 		 * was being negotiated.  This enables us to determine which target did
1372 		 * the reselect.
1373 		 */
1374 		selid = sc->sc_selid & ~(1 << sc->sc_id);
1375 		if (selid & (selid - 1)) {
1376 			printf("%s: reselect with invalid selid %02x;"
1377 			    " sending DEVICE RESET\n", sc->sc_dev.dv_xname, selid);
1378 			goto reset;
1379 
1380 		}
1381 		target = ffs(selid) - 1;
1382 	}
1383 	lun = message & 0x07;
1384 
1385 	/*
1386 	 * Search wait queue for disconnected cmd
1387 	 * The list should be short, so I haven't bothered with
1388 	 * any more sophisticated structures than a simple
1389 	 * singly linked list.
1390 	 */
1391 	ti = &sc->sc_tinfo[target];
1392 	li = TINFO_LUN(ti, lun);
1393 
1394 	/*
1395 	 * We can get as far as the LUN with the IDENTIFY
1396 	 * message.  Check to see if we're running an
1397 	 * un-tagged command.  Otherwise ack the IDENTIFY
1398 	 * and wait for a tag message.
1399 	 */
1400 	if (li != NULL) {
1401 		if (li->untagged != NULL && li->busy)
1402 			ecb = li->untagged;
1403 		else if (tagtype != MSG_SIMPLE_Q_TAG) {
1404 			/* Wait for tag to come by */
1405 			sc->sc_state = NCR_IDENTIFIED;
1406 			return (0);
1407 		} else if (tagtype) ecb = li->queued[tagid];
1408 	}
1409 	if (ecb == NULL) {
1410 		printf("%s: reselect from target %d lun %d tag %x:%x with no nexus;"
1411 		    " sending ABORT\n", sc->sc_dev.dv_xname, target, lun, tagtype, tagid);
1412 		goto abort;
1413 	}
1414 
1415 	/* Make this nexus active again. */
1416 	sc->sc_state = NCR_CONNECTED;
1417 	sc->sc_nexus = ecb;
1418 	ncr53c9x_setsync(sc, ti);
1419 
1420 	if (ecb->flags & ECB_RESET)
1421 		ncr53c9x_sched_msgout(SEND_DEV_RESET);
1422 	else if (ecb->flags & ECB_ABORT)
1423 		ncr53c9x_sched_msgout(SEND_ABORT);
1424 
1425 	/* Do an implicit RESTORE POINTERS. */
1426 	sc->sc_dp = ecb->daddr;
1427 	sc->sc_dleft = ecb->dleft;
1428 
1429 	return (0);
1430 
1431 reset:
1432 	ncr53c9x_sched_msgout(SEND_DEV_RESET);
1433 	return (1);
1434 
1435 abort:
1436 	ncr53c9x_sched_msgout(SEND_ABORT);
1437 	return (1);
1438 }
1439 
1440 static inline int
1441 __verify_msg_format(u_char *p, int len)
1442 {
1443 
1444 	if (len == 1 && IS1BYTEMSG(p[0]))
1445 		return 1;
1446 	if (len == 2 && IS2BYTEMSG(p[0]))
1447 		return 1;
1448 	if (len >= 3 && ISEXTMSG(p[0]) &&
1449 	    len == p[1] + 2)
1450 		return 1;
1451 
1452 	return 0;
1453 }
1454 
1455 /*
1456  * Get an incoming message as initiator.
1457  *
1458  * The SCSI bus must already be in MESSAGE_IN_PHASE and there is a
1459  * byte in the FIFO
1460  */
1461 void
1462 ncr53c9x_msgin(sc)
1463 	struct ncr53c9x_softc *sc;
1464 {
1465 
1466 	NCR_TRACE(("[ncr53c9x_msgin(curmsglen:%ld)] ", (long)sc->sc_imlen));
1467 
1468 	if (sc->sc_imlen == 0) {
1469 		printf("%s: msgin: no msg byte available\n", sc->sc_dev.dv_xname);
1470 		return;
1471 	}
1472 
1473 	/*
1474 	 * Prepare for a new message.  A message should (according
1475 	 * to the SCSI standard) be transmitted in one single
1476 	 * MESSAGE_IN_PHASE. If we have been in some other phase,
1477 	 * then this is a new message.
1478 	 */
1479 	if (sc->sc_prevphase != MESSAGE_IN_PHASE && sc->sc_state != NCR_RESELECTED) {
1480 		printf("%s: phase change, dropping message, prev %d, state %d\n",
1481 		    sc->sc_dev.dv_xname, sc->sc_prevphase, sc->sc_state);
1482 		sc->sc_flags &= ~NCR_DROP_MSGI;
1483 		sc->sc_imlen = 0;
1484 	}
1485 
1486 	NCR_TRACE(("<msgbyte:0x%02x>", sc->sc_imess[0]));
1487 
1488 	/*
1489 	 * If we're going to reject the message, don't bother storing
1490 	 * the incoming bytes.  But still, we need to ACK them.
1491 	 */
1492 	if ((sc->sc_flags & NCR_DROP_MSGI)) {
1493 		NCRCMD(sc, NCRCMD_MSGOK);
1494 		printf("<dropping msg byte %x>",
1495 			sc->sc_imess[sc->sc_imlen]);
1496 		return;
1497 	}
1498 
1499 	if (sc->sc_imlen >= NCR_MAX_MSG_LEN) {
1500 		ncr53c9x_sched_msgout(SEND_REJECT);
1501 		sc->sc_flags |= NCR_DROP_MSGI;
1502 	} else {
1503 		u_char *pb;
1504 		int plen;
1505 
1506 		switch (sc->sc_state) {
1507 			/*
1508 			 * if received message is the first of reselection
1509 			 * then first byte is selid, and then message
1510 			 */
1511 		case NCR_RESELECTED:
1512 			pb = sc->sc_imess + 1;
1513 			plen = sc->sc_imlen - 1;
1514 			break;
1515 		default:
1516 			pb = sc->sc_imess;
1517 			plen = sc->sc_imlen;
1518 			break;
1519 		}
1520 
1521 		if (__verify_msg_format(pb, plen))
1522 			goto gotit;
1523 	}
1524 
1525 	/* Ack what we have so far */
1526 	NCRCMD(sc, NCRCMD_MSGOK);
1527 	return;
1528 
1529 gotit:
1530 	NCR_MSGS(("gotmsg(%x) state %d", sc->sc_imess[0], sc->sc_state));
1531 	/* we got complete message, flush the imess, XXX nobody uses imlen below */
1532 	sc->sc_imlen = 0;
1533 
1534 	/*
1535 	 * Now we should have a complete message (1 byte, 2 byte
1536 	 * and moderately long extended messages).  We only handle
1537 	 * extended messages which total length is shorter than
1538 	 * NCR_MAX_MSG_LEN.  Longer messages will be amputated.
1539 	 */
1540 	switch (sc->sc_state) {
1541 		struct ncr53c9x_ecb *ecb;
1542 		struct ncr53c9x_tinfo *ti;
1543 		struct ncr53c9x_linfo *li;
1544 		int lun;
1545 
1546 	case NCR_CONNECTED:
1547 		ecb = sc->sc_nexus;
1548 		ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
1549 
1550 		switch (sc->sc_imess[0]) {
1551 		case MSG_CMDCOMPLETE:
1552 			NCR_MSGS(("cmdcomplete "));
1553 			if (sc->sc_dleft < 0) {
1554 				sc_print_addr(ecb->xs->sc_link);
1555 				printf("got %ld extra bytes\n",
1556 				    -(long)sc->sc_dleft);
1557 				sc->sc_dleft = 0;
1558 			}
1559 			ecb->dleft = (ecb->flags & ECB_TENTATIVE_DONE)
1560 				? 0
1561 				: sc->sc_dleft;
1562 			if ((ecb->flags & ECB_SENSE) == 0)
1563 				ecb->xs->resid = ecb->dleft;
1564 			sc->sc_state = NCR_CMDCOMPLETE;
1565 			break;
1566 
1567 		case MSG_MESSAGE_REJECT:
1568 			NCR_MSGS(("msg reject (msgout=%x) ", sc->sc_msgout));
1569 			switch (sc->sc_msgout) {
1570 			case SEND_TAG:
1571 				/* Target does not like tagged queuing.
1572 				 *  - Flush the command queue
1573 				 *  - Disable tagged queuing for the target
1574 				 *  - Dequeue ecb from the queued array.
1575 				 */
1576 				printf("%s: tagged queuing rejected: target %d\n",
1577 				    sc->sc_dev.dv_xname, ecb->xs->sc_link->target);
1578 
1579 				NCR_MSGS(("(rejected sent tag)"));
1580 				NCRCMD(sc, NCRCMD_FLUSH);
1581 				DELAY(1);
1582 				ti->flags &= ~T_TAG;
1583 				lun = ecb->xs->sc_link->lun;
1584 				li = TINFO_LUN(ti, lun);
1585 				if (ecb->tag[0] &&
1586 				    li->queued[ecb->tag[1]] != NULL) {
1587 					li->queued[ecb->tag[1]] = NULL;
1588 					li->used--;
1589 				}
1590 				ecb->tag[0] = ecb->tag[1] = 0;
1591 				li->untagged = ecb;
1592 				li->busy = 1;
1593 				break;
1594 
1595 			case SEND_SDTR:
1596 				printf("%s: sync transfer rejected: target %d\n",
1597 				    sc->sc_dev.dv_xname, ecb->xs->sc_link->target);
1598 				sc->sc_flags &= ~NCR_SYNCHNEGO;
1599 				ti->flags &= ~(T_NEGOTIATE | T_SYNCMODE);
1600 				ncr53c9x_setsync(sc, ti);
1601 				break;
1602 
1603 			case SEND_WDTR:
1604 				printf("%s: wide transfer rejected: target %d\n",
1605 				    sc->sc_dev.dv_xname, ecb->xs->sc_link->target);
1606 				ti->flags &= ~T_WIDE;
1607 				ti->width = 0;
1608 				break;
1609 
1610 			case SEND_INIT_DET_ERR:
1611 				goto abort;
1612 			}
1613 			break;
1614 
1615 		case MSG_NOOP:
1616 			NCR_MSGS(("noop "));
1617 			break;
1618 
1619 		case MSG_HEAD_OF_Q_TAG:
1620 		case MSG_SIMPLE_Q_TAG:
1621 		case MSG_ORDERED_Q_TAG:
1622 			NCR_MSGS(("TAG %x:%x", sc->sc_imess[0], sc->sc_imess[1]));
1623 			break;
1624 
1625 		case MSG_DISCONNECT:
1626 			NCR_MSGS(("disconnect "));
1627 			ti->dconns++;
1628 			sc->sc_state = NCR_DISCONNECT;
1629 
1630 			/*
1631 			 * Mark the fact that all bytes have moved. The
1632 			 * target may not bother to do a SAVE POINTERS
1633 			 * at this stage. This flag will set the residual
1634 			 * count to zero on MSG COMPLETE.
1635 			 */
1636 			if (sc->sc_dleft == 0)
1637 				ecb->flags |= ECB_TENTATIVE_DONE;
1638 
1639 			break;
1640 
1641 		case MSG_SAVEDATAPOINTER:
1642 			NCR_MSGS(("save datapointer "));
1643 			ecb->daddr = sc->sc_dp;
1644 			ecb->dleft = sc->sc_dleft;
1645 			break;
1646 
1647 		case MSG_RESTOREPOINTERS:
1648 			NCR_MSGS(("restore datapointer "));
1649 			sc->sc_dp = ecb->daddr;
1650 			sc->sc_dleft = ecb->dleft;
1651 			break;
1652 
1653 		case MSG_EXTENDED:
1654 			NCR_MSGS(("extended(%x) ", sc->sc_imess[2]));
1655 			switch (sc->sc_imess[2]) {
1656 			case MSG_EXT_SDTR:
1657 				NCR_MSGS(("SDTR period %d, offset %d ",
1658 					sc->sc_imess[3], sc->sc_imess[4]));
1659 				if (sc->sc_imess[1] != 3)
1660 					goto reject;
1661 				ti->period = sc->sc_imess[3];
1662 				ti->offset = sc->sc_imess[4];
1663 				ti->flags &= ~T_NEGOTIATE;
1664 				if (sc->sc_minsync == 0 ||
1665 				    ti->offset == 0 ||
1666 				    ti->period > 124) {
1667 #ifdef NCR53C9X_DEBUG
1668 					sc_print_addr(ecb->xs->sc_link);
1669 					printf("async mode\n");
1670 #endif
1671 					if ((sc->sc_flags&NCR_SYNCHNEGO)
1672 					    == 0) {
1673 						/*
1674 						 * target initiated negotiation
1675 						 */
1676 						ti->offset = 0;
1677 						ti->flags &= ~T_SYNCMODE;
1678 						ncr53c9x_sched_msgout(
1679 						    SEND_SDTR);
1680 					} else {
1681 						/* we are async */
1682 						ti->flags &= ~T_SYNCMODE;
1683 					}
1684 				} else {
1685 #ifdef NCR53C9X_DEBUG
1686 					int r, s;
1687 #endif
1688 					int p;
1689 
1690 					p = ncr53c9x_stp2cpb(sc, ti->period);
1691 					ti->period = ncr53c9x_cpb2stp(sc, p);
1692 #ifdef NCR53C9X_DEBUG
1693 					sc_print_addr(ecb->xs->sc_link);
1694 					r = 250/ti->period;
1695 					s = (100*250)/ti->period - 100*r;
1696 					printf("max sync rate %d.%02dMB/s\n",
1697 						r, s);
1698 #endif
1699 					if ((sc->sc_flags&NCR_SYNCHNEGO) == 0) {
1700 						/*
1701 						 * target initiated negotiation
1702 						 */
1703 						if (ti->period <
1704 						    sc->sc_minsync)
1705 							ti->period =
1706 							    sc->sc_minsync;
1707 						if (ti->offset > 15)
1708 							ti->offset = 15;
1709 						ti->flags &= ~T_SYNCMODE;
1710 						ncr53c9x_sched_msgout(
1711 						    SEND_SDTR);
1712 					} else {
1713 						/* we are sync */
1714 						ti->flags |= T_SYNCMODE;
1715 					}
1716 				}
1717 				sc->sc_flags &= ~NCR_SYNCHNEGO;
1718 				ncr53c9x_setsync(sc, ti);
1719 				break;
1720 
1721 			case MSG_EXT_WDTR:
1722 				printf("%s: wide mode %d\n",
1723 				    sc->sc_dev.dv_xname, sc->sc_imess[3]);
1724 				if (sc->sc_imess[3] == 1) {
1725 					ti->cfg3 |= NCRFASCFG3_EWIDE;
1726 					ncr53c9x_setsync(sc, ti);
1727 				} else
1728 					ti->width = 0;
1729 				ti->flags &= ~T_WIDE;
1730 				break;
1731 			default:
1732 				sc_print_addr(ecb->xs->sc_link);
1733 				printf("unrecognized MESSAGE EXTENDED;"
1734 				    " sending REJECT\n");
1735 				goto reject;
1736 			}
1737 			break;
1738 
1739 		default:
1740 			NCR_MSGS(("ident "));
1741 			sc_print_addr(ecb->xs->sc_link);
1742 			printf("unrecognized MESSAGE; sending REJECT\n");
1743 		reject:
1744 			ncr53c9x_sched_msgout(SEND_REJECT);
1745 			break;
1746 		}
1747 		break;
1748 
1749 	case NCR_IDENTIFIED:
1750 		/*
1751 		 * IDENTIFY message was received and queue tag is expected now
1752 		 */
1753 		if ((sc->sc_imess[0] != MSG_SIMPLE_Q_TAG) ||
1754 		    (sc->sc_msgify == 0)) {
1755 			printf("%s: TAG reselect without IDENTIFY;"
1756 			    " MSG %x;"
1757 			    " sending DEVICE RESET\n",
1758 			    sc->sc_dev.dv_xname,
1759 			    sc->sc_imess[0]);
1760 			goto reset;
1761 		}
1762 		(void) ncr53c9x_reselect(sc, sc->sc_msgify,
1763 		    sc->sc_imess[0], sc->sc_imess[1]);
1764 		break;
1765 
1766 	case NCR_RESELECTED:
1767 		if (MSG_ISIDENTIFY(sc->sc_imess[1])) {
1768 			sc->sc_msgify = sc->sc_imess[1];
1769 		} else {
1770 			printf("%s: reselect without IDENTIFY;"
1771 			    " MSG %x;"
1772 			    " sending DEVICE RESET\n",
1773 			    sc->sc_dev.dv_xname,
1774 			    sc->sc_imess[1]);
1775 			goto reset;
1776 		}
1777 		(void) ncr53c9x_reselect(sc, sc->sc_msgify, 0, 0);
1778 		break;
1779 
1780 	default:
1781 		printf("%s: unexpected MESSAGE IN; sending DEVICE RESET\n",
1782 		    sc->sc_dev.dv_xname);
1783 	reset:
1784 		ncr53c9x_sched_msgout(SEND_DEV_RESET);
1785 		break;
1786 
1787 	abort:
1788 		ncr53c9x_sched_msgout(SEND_ABORT);
1789 		break;
1790 	}
1791 
1792 	/* if we have more messages to send set ATN */
1793 	if (sc->sc_msgpriq)
1794 		NCRCMD(sc, NCRCMD_SETATN);
1795 
1796 	/* Ack last message byte */
1797 	NCRCMD(sc, NCRCMD_MSGOK);
1798 
1799 	/* Done, reset message pointer. */
1800 	sc->sc_flags &= ~NCR_DROP_MSGI;
1801 	sc->sc_imlen = 0;
1802 }
1803 
1804 
1805 /*
1806  * Send the highest priority, scheduled message
1807  */
1808 void
1809 ncr53c9x_msgout(sc)
1810 	struct ncr53c9x_softc *sc;
1811 {
1812 	struct ncr53c9x_tinfo *ti;
1813 	struct ncr53c9x_ecb *ecb;
1814 	size_t size;
1815 
1816 	NCR_TRACE(("[ncr53c9x_msgout(priq:%x, prevphase:%x)]",
1817 	    sc->sc_msgpriq, sc->sc_prevphase));
1818 
1819 	/*
1820 	 * XXX - the NCR_ATN flag is not in sync with the actual ATN
1821 	 *	 condition on the SCSI bus. The 53c9x chip
1822 	 *	 automatically turns off ATN before sending the
1823 	 *	 message byte.  (see also the comment below in the
1824 	 *	 default case when picking out a message to send)
1825 	 */
1826 	if (sc->sc_flags & NCR_ATN) {
1827 		if (sc->sc_prevphase != MESSAGE_OUT_PHASE) {
1828 		new:
1829 			NCRCMD(sc, NCRCMD_FLUSH);
1830 /*			DELAY(1); */
1831 			sc->sc_msgoutq = 0;
1832 			sc->sc_omlen = 0;
1833 		}
1834 	} else {
1835 		if (sc->sc_prevphase == MESSAGE_OUT_PHASE) {
1836 			ncr53c9x_sched_msgout(sc->sc_msgoutq);
1837 			goto new;
1838 		} else {
1839 			printf("%s at line %d: unexpected MESSAGE OUT phase\n",
1840 			    sc->sc_dev.dv_xname, __LINE__);
1841 		}
1842 	}
1843 
1844 	if (sc->sc_omlen == 0) {
1845 		/* Pick up highest priority message */
1846 		sc->sc_msgout = sc->sc_msgpriq & -sc->sc_msgpriq;
1847 		sc->sc_msgoutq |= sc->sc_msgout;
1848 		sc->sc_msgpriq &= ~sc->sc_msgout;
1849 		sc->sc_omlen = 1;		/* "Default" message len */
1850 		switch (sc->sc_msgout) {
1851 		case SEND_SDTR:
1852 			ecb = sc->sc_nexus;
1853 			ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
1854 			sc->sc_omess[0] = MSG_EXTENDED;
1855 			sc->sc_omess[1] = 3;
1856 			sc->sc_omess[2] = MSG_EXT_SDTR;
1857 			sc->sc_omess[3] = ti->period;
1858 			sc->sc_omess[4] = ti->offset;
1859 			sc->sc_omlen = 5;
1860 			if ((sc->sc_flags & NCR_SYNCHNEGO) == 0) {
1861 				ti->flags |= T_SYNCMODE;
1862 				ncr53c9x_setsync(sc, ti);
1863 			}
1864 			break;
1865 		case SEND_WDTR:
1866 			ecb = sc->sc_nexus;
1867 			ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
1868 			sc->sc_omess[0] = MSG_EXTENDED;
1869 			sc->sc_omess[1] = 2;
1870 			sc->sc_omess[2] = MSG_EXT_WDTR;
1871 			sc->sc_omess[3] = ti->width;
1872 			sc->sc_omlen = 4;
1873 			break;
1874 		case SEND_IDENTIFY:
1875 			if (sc->sc_state != NCR_CONNECTED) {
1876 				printf("%s at line %d: no nexus\n",
1877 				    sc->sc_dev.dv_xname, __LINE__);
1878 			}
1879 			ecb = sc->sc_nexus;
1880 			sc->sc_omess[0] =
1881 			    MSG_IDENTIFY(ecb->xs->sc_link->lun, 0);
1882 			break;
1883 		case SEND_TAG:
1884 			if (sc->sc_state != NCR_CONNECTED) {
1885 				printf("%s at line %d: no nexus\n",
1886 				    sc->sc_dev.dv_xname, __LINE__);
1887 			}
1888 			ecb = sc->sc_nexus;
1889 			sc->sc_omess[0] = ecb->tag[0];
1890 			sc->sc_omess[1] = ecb->tag[1];
1891 			sc->sc_omlen = 2;
1892 			break;
1893 		case SEND_DEV_RESET:
1894 			sc->sc_flags |= NCR_ABORTING;
1895 			sc->sc_omess[0] = MSG_BUS_DEV_RESET;
1896 			ecb = sc->sc_nexus;
1897 			ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
1898 			ti->flags &= ~T_SYNCMODE;
1899 			if ((ti->flags & T_SYNCHOFF) == 0)
1900 				/* We can re-start sync negotiation */
1901 				ti->flags |= T_NEGOTIATE;
1902 			break;
1903 		case SEND_PARITY_ERROR:
1904 			sc->sc_omess[0] = MSG_PARITY_ERROR;
1905 			break;
1906 		case SEND_ABORT:
1907 			sc->sc_flags |= NCR_ABORTING;
1908 			sc->sc_omess[0] = MSG_ABORT;
1909 			break;
1910 		case SEND_INIT_DET_ERR:
1911 			sc->sc_omess[0] = MSG_INITIATOR_DET_ERR;
1912 			break;
1913 		case SEND_REJECT:
1914 			sc->sc_omess[0] = MSG_MESSAGE_REJECT;
1915 			break;
1916 		default:
1917 			/*
1918 			 * We normally do not get here, since the chip
1919 			 * automatically turns off ATN before the last
1920 			 * byte of a message is sent to the target.
1921 			 * However, if the target rejects our (multi-byte)
1922 			 * message early by switching to MSG IN phase
1923 			 * ATN remains on, so the target may return to
1924 			 * MSG OUT phase. If there are no scheduled messages
1925 			 * left we send a NO-OP.
1926 			 *
1927 			 * XXX - Note that this leaves no useful purpose for
1928 			 * the NCR_ATN flag.
1929 			 */
1930 			sc->sc_flags &= ~NCR_ATN;
1931 			sc->sc_omess[0] = MSG_NOOP;
1932 			break;
1933 		}
1934 		sc->sc_omp = sc->sc_omess;
1935 	}
1936 
1937 #ifdef DEBUG
1938 	{
1939 		int i;
1940 
1941 		for (i = 0; i<sc->sc_omlen; i++)
1942 			NCR_MISC(("<msgbyte:0x%02x>", sc->sc_omess[i]));
1943 	}
1944 #endif
1945 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
1946 		/*
1947 		 * XXX fifo size
1948 		 */
1949 		ncr53c9x_flushfifo(sc);
1950 		ncr53c9x_wrfifo(sc, sc->sc_omp, sc->sc_omlen);
1951 		NCRCMD(sc, NCRCMD_TRANS);
1952 	} else {
1953 		/* (re)send the message */
1954 		size = min(sc->sc_omlen, sc->sc_maxxfer);
1955 		NCRDMA_SETUP(sc, &sc->sc_omp, &sc->sc_omlen, 0, &size);
1956 		/* Program the SCSI counter */
1957 		NCR_SET_COUNT(sc, size);
1958 
1959                /* Load the count in and start the message-out transfer */
1960 		NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
1961 		NCRCMD(sc, NCRCMD_TRANS|NCRCMD_DMA);
1962 		NCRDMA_GO(sc);
1963 	}
1964 }
1965 
1966 /*
1967  * This is the most critical part of the driver, and has to know
1968  * how to deal with *all* error conditions and phases from the SCSI
1969  * bus. If there are no errors and the DMA was active, then call the
1970  * DMA pseudo-interrupt handler. If this returns 1, then that was it
1971  * and we can return from here without further processing.
1972  *
1973  * Most of this needs verifying.
1974  */
1975 int sdebug = 0;
1976 int
1977 ncr53c9x_intr(arg)
1978 	void *arg;
1979 {
1980 	struct ncr53c9x_softc *sc = arg;
1981 	struct ncr53c9x_ecb *ecb;
1982 	struct scsi_link *sc_link;
1983 	struct ncr53c9x_tinfo *ti;
1984 	size_t size;
1985 	int nfifo;
1986 
1987 	NCR_TRACE(("[ncr53c9x_intr: state %d] ", sc->sc_state));
1988 
1989 	if (!NCRDMA_ISINTR(sc))
1990 		return (0);
1991 
1992 again:
1993 	/* and what do the registers say... */
1994 	ncr53c9x_readregs(sc);
1995 
1996 	/*
1997 	 * At the moment, only a SCSI Bus Reset or Illegal
1998 	 * Command are classed as errors. A disconnect is a
1999 	 * valid condition, and we let the code check is the
2000 	 * "NCR_BUSFREE_OK" flag was set before declaring it
2001 	 * and error.
2002 	 *
2003 	 * Also, the status register tells us about "Gross
2004 	 * Errors" and "Parity errors". Only the Gross Error
2005 	 * is really bad, and the parity errors are dealt
2006 	 * with later
2007 	 *
2008 	 * TODO
2009 	 *      If there are too many parity error, go to slow
2010 	 *      cable mode ?
2011 	 */
2012 
2013 	/* SCSI Reset */
2014 	if (sc->sc_espintr & NCRINTR_SBR) {
2015 		if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2016 			NCRCMD(sc, NCRCMD_FLUSH);
2017 			DELAY(1);
2018 		}
2019 		if (sc->sc_state != NCR_SBR) {
2020 			printf("%s: SCSI bus reset\n",
2021 				sc->sc_dev.dv_xname);
2022 			ncr53c9x_init(sc, 0); /* Restart everything */
2023 			return (1);
2024 		}
2025 #if 0
2026 /*XXX*/		printf("<expected bus reset: "
2027 			"[intr %x, stat %x, step %d]>\n",
2028 			sc->sc_espintr, sc->sc_espstat,
2029 			sc->sc_espstep);
2030 #endif
2031 		if (sc->sc_nexus)
2032 			panic("%s: nexus in reset state",
2033 		      sc->sc_dev.dv_xname);
2034 		goto sched;
2035 	}
2036 
2037 	ecb = sc->sc_nexus;
2038 
2039 #define NCRINTR_ERR (NCRINTR_SBR|NCRINTR_ILL)
2040 	if (sc->sc_espintr & NCRINTR_ERR ||
2041 	    sc->sc_espstat & NCRSTAT_GE) {
2042 
2043 		if (sc->sc_espstat & NCRSTAT_GE) {
2044 			/* Gross Error; no target ? */
2045 			if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2046 				NCRCMD(sc, NCRCMD_FLUSH);
2047 				DELAY(1);
2048 			}
2049 			if (sc->sc_state == NCR_CONNECTED ||
2050 			    sc->sc_state == NCR_SELECTING) {
2051 				ecb->xs->error = XS_TIMEOUT;
2052 				ncr53c9x_done(sc, ecb);
2053 			}
2054 			return (1);
2055 		}
2056 
2057 		if (sc->sc_espintr & NCRINTR_ILL) {
2058 			if (sc->sc_flags & NCR_EXPECT_ILLCMD) {
2059 				/*
2060 				 * Eat away "Illegal command" interrupt
2061 				 * on a ESP100 caused by a re-selection
2062 				 * while we were trying to select
2063 				 * another target.
2064 				 */
2065 #ifdef DEBUG
2066 				printf("%s: ESP100 work-around activated\n",
2067 					sc->sc_dev.dv_xname);
2068 #endif
2069 				sc->sc_flags &= ~NCR_EXPECT_ILLCMD;
2070 				return (1);
2071 			}
2072 			/* illegal command, out of sync ? */
2073 			printf("%s: illegal command: 0x%x "
2074 			    "(state %d, phase %x, prevphase %x)\n",
2075 				sc->sc_dev.dv_xname, sc->sc_lastcmd,
2076 				sc->sc_state, sc->sc_phase,
2077 				sc->sc_prevphase);
2078 			if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2079 				NCRCMD(sc, NCRCMD_FLUSH);
2080 				DELAY(1);
2081 			}
2082 			ncr53c9x_init(sc, 1); /* Restart everything */
2083 			return (1);
2084 		}
2085 	}
2086 	sc->sc_flags &= ~NCR_EXPECT_ILLCMD;
2087 
2088 	/*
2089 	 * Call if DMA is active.
2090 	 *
2091 	 * If DMA_INTR returns true, then maybe go 'round the loop
2092 	 * again in case there is no more DMA queued, but a phase
2093 	 * change is expected.
2094 	 */
2095 	if (NCRDMA_ISACTIVE(sc)) {
2096 		int r = NCRDMA_INTR(sc);
2097 		if (r == -1) {
2098 			printf("%s: DMA error; resetting\n",
2099 				sc->sc_dev.dv_xname);
2100 			ncr53c9x_init(sc, 1);
2101 			return (1);
2102 		}
2103 		/* If DMA active here, then go back to work... */
2104 		if (NCRDMA_ISACTIVE(sc))
2105 			return (1);
2106 
2107 		if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
2108 			/*
2109 			 * DMA not completed.  If we can not find a
2110 			 * acceptable explanation, print a diagnostic.
2111 			 */
2112 			if (sc->sc_state == NCR_SELECTING)
2113 				/*
2114 				 * This can happen if we are reselected
2115 				 * while using DMA to select a target.
2116 				 */
2117 				/*void*/;
2118 			else if (sc->sc_prevphase == MESSAGE_OUT_PHASE){
2119 				/*
2120 				 * Our (multi-byte) message (eg SDTR)
2121 				 * was interrupted by the target to
2122 				 * send a MSG REJECT.
2123 				 * Print diagnostic if current phase
2124 				 * is not MESSAGE IN.
2125 				 */
2126 				if (sc->sc_phase != MESSAGE_IN_PHASE)
2127 				    printf("%s: !TC on MSG OUT"
2128 				       " [intr %x, stat %x, step %d]"
2129 				       " prevphase %x, resid %lx\n",
2130 					sc->sc_dev.dv_xname,
2131 					sc->sc_espintr,
2132 					sc->sc_espstat,
2133 					sc->sc_espstep,
2134 					sc->sc_prevphase,
2135 					(u_long)sc->sc_omlen);
2136 			} else if (sc->sc_dleft == 0) {
2137 				/*
2138 				 * The DMA operation was started for
2139 				 * a DATA transfer. Print a diagnostic
2140 				 * if the DMA counter and TC bit
2141 				 * appear to be out of sync.
2142 				 */
2143 				printf("%s: !TC on DATA XFER"
2144 				       " [intr %x, stat %x, step %d]"
2145 				       " prevphase %x, resid %x\n",
2146 					sc->sc_dev.dv_xname,
2147 					sc->sc_espintr,
2148 					sc->sc_espstat,
2149 					sc->sc_espstep,
2150 					sc->sc_prevphase,
2151 					ecb?ecb->dleft:-1);
2152 			}
2153 		}
2154 	}
2155 
2156 	/*
2157 	 * check for less serious errors
2158 	 */
2159 	if (sc->sc_espstat & NCRSTAT_PE) {
2160 		printf("%s: SCSI bus parity error\n", sc->sc_dev.dv_xname);
2161 		if (sc->sc_prevphase == MESSAGE_IN_PHASE)
2162 			ncr53c9x_sched_msgout(SEND_PARITY_ERROR);
2163 		else
2164 			ncr53c9x_sched_msgout(SEND_INIT_DET_ERR);
2165 	}
2166 
2167 	if (sc->sc_espintr & NCRINTR_DIS) {
2168 		sc->sc_msgify = 0;
2169 		NCR_MISC(("<DISC [intr %x, stat %x, step %d]>",
2170 			sc->sc_espintr,sc->sc_espstat,sc->sc_espstep));
2171 		if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2172 			NCRCMD(sc, NCRCMD_FLUSH);
2173 /*			DELAY(1); */
2174 		}
2175 		/*
2176 		 * This command must (apparently) be issued within
2177 		 * 250mS of a disconnect. So here you are...
2178 		 */
2179 		NCRCMD(sc, NCRCMD_ENSEL);
2180 
2181 		switch (sc->sc_state) {
2182 		case NCR_RESELECTED:
2183 			goto sched;
2184 
2185 		case NCR_SELECTING:
2186 			ecb->xs->error = XS_SELTIMEOUT;
2187 			goto finish;
2188 
2189 		case NCR_CONNECTED:
2190 			if ((sc->sc_flags & NCR_SYNCHNEGO)) {
2191 #ifdef NCR53C9X_DEBUG
2192 				if (ecb)
2193 					sc_print_addr(ecb->xs->sc_link);
2194 				printf("sync nego not completed!\n");
2195 #endif
2196 				ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
2197 				sc->sc_flags &= ~NCR_SYNCHNEGO;
2198 				ti->flags &= ~(T_NEGOTIATE | T_SYNCMODE);
2199 			}
2200 
2201 			/* it may be OK to disconnect */
2202 			if ((sc->sc_flags & NCR_ABORTING) == 0) {
2203 				/*
2204 				 * Section 5.1.1 of the SCSI 2 spec
2205 				 * suggests issuing a REQUEST SENSE
2206 				 * following an unexpected disconnect.
2207 				 * Some devices go into a contingent
2208 				 * allegiance condition when
2209 				 * disconnecting, and this is necessary
2210 				 * to clean up their state.
2211 				 */
2212 				printf("%s: unexpected disconnect; ",
2213 				    sc->sc_dev.dv_xname);
2214 				if (ecb->flags & ECB_SENSE) {
2215 					printf("resetting\n");
2216 					goto reset;
2217 				}
2218 				printf("sending REQUEST SENSE\n");
2219 				timeout_del(&ecb->to);
2220 				ncr53c9x_sense(sc, ecb);
2221 				goto out;
2222 			}
2223 
2224 			ecb->xs->error = XS_TIMEOUT;
2225 			goto finish;
2226 
2227 		case NCR_DISCONNECT:
2228 			sc->sc_nexus = NULL;
2229 			goto sched;
2230 
2231 		case NCR_CMDCOMPLETE:
2232 			goto finish;
2233 		}
2234 	}
2235 
2236 	switch (sc->sc_state) {
2237 
2238 	case NCR_SBR:
2239 		printf("%s: waiting for SCSI Bus Reset to happen\n",
2240 			sc->sc_dev.dv_xname);
2241 		return (1);
2242 
2243 	case NCR_RESELECTED:
2244 		/*
2245 		 * we must be continuing a message ?
2246 		 */
2247 		if (sc->sc_phase != MESSAGE_IN_PHASE) {
2248 			printf("%s: target didn't identify\n",
2249 				sc->sc_dev.dv_xname);
2250 			ncr53c9x_init(sc, 1);
2251 			return (1);
2252 		}
2253 printf("<<RESELECT CONT'd>>");
2254 #if XXXX
2255 		ncr53c9x_msgin(sc);
2256 		if (sc->sc_state != NCR_CONNECTED) {
2257 			/* IDENTIFY fail?! */
2258 			printf("%s: identify failed\n",
2259 				sc->sc_dev.dv_xname);
2260 			ncr53c9x_init(sc, 1);
2261 			return (1);
2262 		}
2263 #endif
2264 		break;
2265 
2266 	case NCR_IDENTIFIED:
2267 		ecb = sc->sc_nexus;
2268 		if (sc->sc_phase != MESSAGE_IN_PHASE) {
2269 			int i = (NCR_READ_REG(sc, NCR_FFLAG)
2270 			    & NCRFIFO_FF);
2271 			/*
2272 			 * Things are seriously fucked up.
2273 			 * Pull the brakes, i.e. reset
2274 			 */
2275 			printf("%s: target didn't send tag: %d bytes in fifo\n",
2276 			    sc->sc_dev.dv_xname, i);
2277 			/* Drain and display fifo */
2278 			while (i-- > 0)
2279 				printf("[%d] ", NCR_READ_REG(sc, NCR_FIFO));
2280 			ncr53c9x_init(sc, 1);
2281 			return (1);
2282 		} else
2283 			goto msgin;
2284 
2285 		break;
2286 	case NCR_IDLE:
2287 	case NCR_SELECTING:
2288 		ecb = sc->sc_nexus;
2289 		if (sc->sc_espintr & NCRINTR_RESEL) {
2290 			sc->sc_msgpriq = sc->sc_msgout = sc->sc_msgoutq = 0;
2291 			sc->sc_flags = 0;
2292 			/*
2293 			 * If we're trying to select a
2294 			 * target ourselves, push our command
2295 			 * back into the ready list.
2296 			 */
2297 			if (sc->sc_state == NCR_SELECTING) {
2298 				NCR_MISC(("backoff selector "));
2299 				timeout_del(&ecb->to);
2300 				ncr53c9x_dequeue(sc, ecb);
2301 				TAILQ_INSERT_HEAD(&sc->ready_list, ecb, chain);
2302 				ecb->flags |= ECB_READY;
2303 				ecb = sc->sc_nexus = NULL;
2304 			}
2305 			sc->sc_state = NCR_RESELECTED;
2306 			if (sc->sc_phase != MESSAGE_IN_PHASE) {
2307 				/*
2308 				 * Things are seriously fucked up.
2309 				 * Pull the brakes, i.e. reset
2310 				 */
2311 				printf("%s: target didn't identify\n",
2312 					sc->sc_dev.dv_xname);
2313 				ncr53c9x_init(sc, 1);
2314 				return (1);
2315 			}
2316 			/*
2317 			 * The C90 only inhibits FIFO writes until
2318 			 * reselection is complete, instead of
2319 			 * waiting until the interrupt status register
2320 			 * has been read. So, if the reselect happens
2321 			 * while we were entering a command bytes (for
2322 			 * another target) some of those bytes can
2323 			 * appear in the FIFO here, after the
2324 			 * interrupt is taken.
2325 			 */
2326 			nfifo = ncr53c9x_rdfifo(sc, NCR_RDFIFO_START);
2327 
2328 			if (nfifo < 2 ||
2329 			    (nfifo > 2 &&
2330 			     sc->sc_rev != NCR_VARIANT_ESP100)) {
2331 				printf("%s: RESELECT: "
2332 				    "%d bytes in FIFO! "
2333 				    "[intr %x, stat %x, step %d, prevphase %x]\n",
2334 					sc->sc_dev.dv_xname,
2335 					nfifo,
2336 					sc->sc_espintr,
2337 					sc->sc_espstat,
2338 					sc->sc_espstep,
2339 					sc->sc_prevphase);
2340 				ncr53c9x_init(sc, 1);
2341 				return (1);
2342 			}
2343 			sc->sc_selid = sc->sc_imess[0];
2344 			NCR_MISC(("selid=%2x ", sc->sc_selid));
2345 
2346 			/* Handle identify message */
2347 			ncr53c9x_msgin(sc);
2348 			if (nfifo != 2) {
2349 				/*
2350 				 * Note: this should not happen
2351 				 * with `dmaselect' on.
2352 				 */
2353 				sc->sc_flags |= NCR_EXPECT_ILLCMD;
2354 				NCRCMD(sc, NCRCMD_FLUSH);
2355 			} else if (sc->sc_features & NCR_F_DMASELECT &&
2356 				   sc->sc_rev == NCR_VARIANT_ESP100) {
2357 				sc->sc_flags |= NCR_EXPECT_ILLCMD;
2358 			}
2359 
2360 			if (sc->sc_state != NCR_CONNECTED &&
2361 			    sc->sc_state != NCR_IDENTIFIED) {
2362 				/* IDENTIFY fail?! */
2363 				printf("%s: identify failed, state %d, intr %02x\n",
2364 					sc->sc_dev.dv_xname, sc->sc_state,
2365 				    sc->sc_espintr);
2366 				ncr53c9x_init(sc, 1);
2367 				return (1);
2368 			}
2369 			goto shortcut; /* ie. next phase expected soon */
2370 		}
2371 
2372 #define	NCRINTR_DONE	(NCRINTR_FC|NCRINTR_BS)
2373 		if ((sc->sc_espintr & NCRINTR_DONE) == NCRINTR_DONE) {
2374 			/*
2375 			 * Arbitration won; examine the `step' register
2376 			 * to determine how far the selection could progress.
2377 			 */
2378 			ecb = sc->sc_nexus;
2379 			if (!ecb)
2380 				panic("ncr53c9x: no nexus");
2381 
2382 			sc_link = ecb->xs->sc_link;
2383 			ti = &sc->sc_tinfo[sc_link->target];
2384 
2385 			switch (sc->sc_espstep) {
2386 			case 0:
2387 				/*
2388 				 * The target did not respond with a
2389 				 * message out phase - probably an old
2390 				 * device that doesn't recognize ATN.
2391 				 * Clear ATN and just continue, the
2392 				 * target should be in the command
2393 				 * phase.
2394 				 * XXXX check for command phase?
2395 				 */
2396 				NCRCMD(sc, NCRCMD_RSTATN);
2397 				break;
2398 			case 1:
2399 				if ((ti->flags & T_NEGOTIATE) == 0 &&
2400 				    ecb->tag[0] == 0) {
2401 					printf("%s: step 1 & !NEG\n",
2402 						sc->sc_dev.dv_xname);
2403 					goto reset;
2404 				}
2405 				if (sc->sc_phase != MESSAGE_OUT_PHASE) {
2406 					printf("%s: !MSGOUT\n",
2407 						sc->sc_dev.dv_xname);
2408 					goto reset;
2409 				}
2410 				if (ti->flags & T_WIDE) {
2411 					ncr53c9x_sched_msgout(SEND_WDTR);
2412 				}
2413 				if (ti->flags & T_NEGOTIATE) {
2414 					/* Start negotiating */
2415 					ti->period = sc->sc_minsync;
2416 					ti->offset = 15;
2417 					sc->sc_flags |= NCR_SYNCHNEGO;
2418 					if (ecb->tag[0])
2419 						ncr53c9x_sched_msgout(SEND_TAG|SEND_SDTR);
2420 					else
2421 						ncr53c9x_sched_msgout(SEND_SDTR);
2422 				} else {
2423 					/* Could not do ATN3 so send TAG */
2424 					ncr53c9x_sched_msgout(SEND_TAG);
2425 				}
2426 				sc->sc_prevphase = MESSAGE_OUT_PHASE; /* XXXX */
2427 				break;
2428 			case 3:
2429 				/*
2430 				 * Grr, this is supposed to mean
2431 				 * "target left command phase  prematurely".
2432 				 * It seems to happen regularly when
2433 				 * sync mode is on.
2434 				 * Look at FIFO to see if command went out.
2435 				 * (Timing problems?)
2436 				 */
2437 				if (sc->sc_features & NCR_F_DMASELECT) {
2438 					if (sc->sc_cmdlen == 0)
2439 						/* Hope for the best.. */
2440 						break;
2441 				} else if ((NCR_READ_REG(sc, NCR_FFLAG)
2442 					    & NCRFIFO_FF) == 0) {
2443 					/* Hope for the best.. */
2444 					break;
2445 				}
2446 				printf("(%s:%d:%d): selection failed;"
2447 					" %d left in FIFO "
2448 					"[intr %x, stat %x, step %d]\n",
2449 					sc->sc_dev.dv_xname,
2450 					sc_link->target,
2451 					sc_link->lun,
2452 					NCR_READ_REG(sc, NCR_FFLAG)
2453 					 & NCRFIFO_FF,
2454 					sc->sc_espintr, sc->sc_espstat,
2455 					sc->sc_espstep);
2456 				NCRCMD(sc, NCRCMD_FLUSH);
2457 				ncr53c9x_sched_msgout(SEND_ABORT);
2458 				return (1);
2459 			case 2:
2460 				/* Select stuck at Command Phase */
2461 				NCRCMD(sc, NCRCMD_FLUSH);
2462 				break;
2463 			case 4:
2464 				if (sc->sc_features & NCR_F_DMASELECT &&
2465 				    sc->sc_cmdlen != 0)
2466 					printf("(%s:%d:%d): select; "
2467 					       "%lu left in DMA buffer "
2468 					"[intr %x, stat %x, step %d]\n",
2469 						sc->sc_dev.dv_xname,
2470 						sc_link->target,
2471 						sc_link->lun,
2472 						(u_long)sc->sc_cmdlen,
2473 						sc->sc_espintr,
2474 						sc->sc_espstat,
2475 						sc->sc_espstep);
2476 				/* So far, everything went fine */
2477 				break;
2478 			}
2479 
2480 			sc->sc_prevphase = INVALID_PHASE; /* ?? */
2481 			/* Do an implicit RESTORE POINTERS. */
2482 			sc->sc_dp = ecb->daddr;
2483 			sc->sc_dleft = ecb->dleft;
2484 			sc->sc_state = NCR_CONNECTED;
2485 			break;
2486 
2487 		} else {
2488 
2489 			printf("%s: unexpected status after select"
2490 				": [intr %x, stat %x, step %x]\n",
2491 				sc->sc_dev.dv_xname,
2492 				sc->sc_espintr, sc->sc_espstat,
2493 				sc->sc_espstep);
2494 			NCRCMD(sc, NCRCMD_FLUSH);
2495 			DELAY(1);
2496 			goto reset;
2497 		}
2498 		if (sc->sc_state == NCR_IDLE) {
2499 			printf("%s: stray interrupt\n",
2500 			    sc->sc_dev.dv_xname);
2501 				return (0);
2502 		}
2503 		break;
2504 
2505 	case NCR_CONNECTED:
2506 		if (sc->sc_flags & NCR_ICCS) {
2507 			/* "Initiate Command Complete Steps" in progress */
2508 			u_char msg;
2509 
2510 			sc->sc_flags &= ~NCR_ICCS;
2511 
2512 			if (!(sc->sc_espintr & NCRINTR_DONE)) {
2513 				printf("%s: ICCS: "
2514 				      ": [intr %x, stat %x, step %x]\n",
2515 					sc->sc_dev.dv_xname,
2516 					sc->sc_espintr, sc->sc_espstat,
2517 					sc->sc_espstep);
2518 			}
2519 			ncr53c9x_rdfifo(sc, NCR_RDFIFO_START);
2520 			if (sc->sc_imlen < 2)
2521 				printf("%s: can't get status, only %d bytes\n",
2522 				    sc->sc_dev.dv_xname, (int)sc->sc_imlen);
2523 			ecb->stat = sc->sc_imess[sc->sc_imlen - 2];
2524 			msg = sc->sc_imess[sc->sc_imlen - 1];
2525 			NCR_PHASE(("<stat:(%x,%x)>", ecb->stat, msg));
2526 			if (msg == MSG_CMDCOMPLETE) {
2527 				ecb->dleft = (ecb->flags & ECB_TENTATIVE_DONE)
2528 					? 0
2529 					: sc->sc_dleft;
2530 				if ((ecb->flags & ECB_SENSE) == 0)
2531 					ecb->xs->resid = ecb->dleft;
2532 				sc->sc_state = NCR_CMDCOMPLETE;
2533 			} else
2534 				printf("%s: STATUS_PHASE: msg %d\n",
2535 					sc->sc_dev.dv_xname, msg);
2536 			sc->sc_imlen = 0;
2537 			NCRCMD(sc, NCRCMD_MSGOK);
2538 			goto shortcut; /* ie. wait for disconnect */
2539 		}
2540 		break;
2541 	default:
2542 		/* Don't panic: reset. */
2543 		printf("%s: invalid state: %d\n",
2544 		      sc->sc_dev.dv_xname,
2545 		      sc->sc_state);
2546 		ncr53c9x_scsi_reset(sc);
2547 		goto out;
2548 		break;
2549 	}
2550 
2551 	/*
2552 	 * Driver is now in state NCR_CONNECTED, i.e. we
2553 	 * have a current command working the SCSI bus.
2554 	 */
2555 	if (sc->sc_state != NCR_CONNECTED || ecb == NULL) {
2556 		panic("ncr53c9x no nexus");
2557 	}
2558 
2559 	switch (sc->sc_phase) {
2560 	case MESSAGE_OUT_PHASE:
2561 		NCR_PHASE(("MESSAGE_OUT_PHASE "));
2562 		ncr53c9x_msgout(sc);
2563 		sc->sc_prevphase = MESSAGE_OUT_PHASE;
2564 		break;
2565 	case MESSAGE_IN_PHASE:
2566 msgin:
2567 		NCR_PHASE(("MESSAGE_IN_PHASE "));
2568 		if (sc->sc_espintr & NCRINTR_BS) {
2569 			if ((sc->sc_rev != NCR_VARIANT_FAS366) ||
2570 			    !(sc->sc_espstat2 & FAS_STAT2_EMPTY)) {
2571 				NCRCMD(sc, NCRCMD_FLUSH);
2572 			}
2573 			sc->sc_flags |= NCR_WAITI;
2574 			NCRCMD(sc, NCRCMD_TRANS);
2575 		} else if (sc->sc_espintr & NCRINTR_FC) {
2576 			if ((sc->sc_flags & NCR_WAITI) == 0) {
2577 				printf("%s: MSGIN: unexpected FC bit: "
2578 					"[intr %x, stat %x, step %x]\n",
2579 				sc->sc_dev.dv_xname,
2580 				sc->sc_espintr, sc->sc_espstat,
2581 				sc->sc_espstep);
2582 			}
2583 			sc->sc_flags &= ~NCR_WAITI;
2584 			ncr53c9x_rdfifo(sc,
2585 			    (sc->sc_prevphase == sc->sc_phase) ?
2586 			    NCR_RDFIFO_CONTINUE : NCR_RDFIFO_START);
2587 			ncr53c9x_msgin(sc);
2588 		} else {
2589 			printf("%s: MSGIN: weird bits: "
2590 				"[intr %x, stat %x, step %x]\n",
2591 				sc->sc_dev.dv_xname,
2592 				sc->sc_espintr, sc->sc_espstat,
2593 				sc->sc_espstep);
2594 		}
2595 		sc->sc_prevphase = MESSAGE_IN_PHASE;
2596 		goto shortcut;	/* i.e. expect data to be ready */
2597 		break;
2598 	case COMMAND_PHASE:
2599 		/*
2600 		 * Send the command block. Normally we don't see this
2601 		 * phase because the SEL_ATN command takes care of
2602 		 * all this. However, we end up here if either the
2603 		 * target or we wanted to exchange some more messages
2604 		 * first (e.g. to start negotiations).
2605 		 */
2606 
2607 		NCR_PHASE(("COMMAND_PHASE 0x%02x (%d) ",
2608 			ecb->cmd.cmd.opcode, ecb->clen));
2609 		if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2610 			NCRCMD(sc, NCRCMD_FLUSH);
2611 /*			DELAY(1); */
2612 		}
2613 		if (sc->sc_features & NCR_F_DMASELECT) {
2614 			/* setup DMA transfer for command */
2615 			size = ecb->clen;
2616 			sc->sc_cmdlen = size;
2617 			sc->sc_cmdp = (caddr_t)&ecb->cmd.cmd;
2618 			NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen,
2619 				     0, &size);
2620 			/* Program the SCSI counter */
2621 			NCR_SET_COUNT(sc, size);
2622 
2623 			/* load the count in */
2624 			NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
2625 
2626 			/* start the command transfer */
2627 			NCRCMD(sc, NCRCMD_TRANS | NCRCMD_DMA);
2628 			NCRDMA_GO(sc);
2629 		} else {
2630 			ncr53c9x_wrfifo(sc, (u_char *)&ecb->cmd.cmd, ecb->clen);
2631 			NCRCMD(sc, NCRCMD_TRANS);
2632 		}
2633 		sc->sc_prevphase = COMMAND_PHASE;
2634 		break;
2635 	case DATA_OUT_PHASE:
2636 		NCR_PHASE(("DATA_OUT_PHASE [%ld] ",(long)sc->sc_dleft));
2637 		NCRCMD(sc, NCRCMD_FLUSH);
2638 		size = min(sc->sc_dleft, sc->sc_maxxfer);
2639 		NCRDMA_SETUP(sc, &sc->sc_dp, &sc->sc_dleft,
2640 			  0, &size);
2641 		sc->sc_prevphase = DATA_OUT_PHASE;
2642 		goto setup_xfer;
2643 	case DATA_IN_PHASE:
2644 		NCR_PHASE(("DATA_IN_PHASE "));
2645 		if (sc->sc_rev == NCR_VARIANT_ESP100)
2646 			NCRCMD(sc, NCRCMD_FLUSH);
2647 		size = min(sc->sc_dleft, sc->sc_maxxfer);
2648 		NCRDMA_SETUP(sc, &sc->sc_dp, &sc->sc_dleft,
2649 			  1, &size);
2650 		sc->sc_prevphase = DATA_IN_PHASE;
2651 	setup_xfer:
2652 		/* Target returned to data phase: wipe "done" memory */
2653 		ecb->flags &= ~ECB_TENTATIVE_DONE;
2654 
2655 		/* Program the SCSI counter */
2656 		NCR_SET_COUNT(sc, size);
2657 
2658 		/* load the count in */
2659 		NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
2660 
2661 		/*
2662 		 * Note that if `size' is 0, we've already transceived
2663 		 * all the bytes we want but we're still in DATA PHASE.
2664 		 * Apparently, the device needs padding. Also, a
2665 		 * transfer size of 0 means "maximum" to the chip
2666 		 * DMA logic.
2667 		 */
2668 		NCRCMD(sc,
2669 		       (size==0?NCRCMD_TRPAD:NCRCMD_TRANS)|NCRCMD_DMA);
2670 		NCRDMA_GO(sc);
2671 		return (1);
2672 	case STATUS_PHASE:
2673 		NCR_PHASE(("STATUS_PHASE "));
2674 		sc->sc_flags |= NCR_ICCS;
2675 		NCRCMD(sc, NCRCMD_ICCS);
2676 		sc->sc_prevphase = STATUS_PHASE;
2677 		goto shortcut;	/* i.e. expect status results soon */
2678 		break;
2679 	case INVALID_PHASE:
2680 		break;
2681 	default:
2682 		printf("%s: unexpected bus phase; resetting\n",
2683 		    sc->sc_dev.dv_xname);
2684 		goto reset;
2685 	}
2686 
2687 out:
2688 	return (1);
2689 
2690 reset:
2691 	ncr53c9x_init(sc, 1);
2692 	goto out;
2693 
2694 finish:
2695 	ncr53c9x_done(sc, ecb);
2696 	goto out;
2697 
2698 sched:
2699 	sc->sc_state = NCR_IDLE;
2700 	ncr53c9x_sched(sc);
2701 	goto out;
2702 
2703 shortcut:
2704 	/*
2705 	 * The idea is that many of the SCSI operations take very little
2706 	 * time, and going away and getting interrupted is too high an
2707 	 * overhead to pay. For example, selecting, sending a message
2708 	 * and command and then doing some work can be done in one "pass".
2709 	 *
2710 	 * The delay is a heuristic. It is 2 when at 20MHz, 2 at 25MHz and 1
2711 	 * at 40MHz. This needs testing.
2712 	 */
2713 	{
2714 		struct timeval wait, cur;
2715 
2716 		microtime(&wait);
2717 		wait.tv_usec += 50/sc->sc_freq;
2718 		if (wait.tv_usec > 1000000) {
2719 			wait.tv_sec++;
2720 			wait.tv_usec -= 1000000;
2721 		}
2722 		do {
2723 			if (NCRDMA_ISINTR(sc))
2724 				goto again;
2725 			microtime(&cur);
2726 		} while (timercmp(&cur, &wait, <=));
2727 	}
2728 	goto out;
2729 }
2730 
2731 void
2732 ncr53c9x_abort(sc, ecb)
2733 	struct ncr53c9x_softc *sc;
2734 	struct ncr53c9x_ecb *ecb;
2735 {
2736 
2737 	/* 2 secs for the abort */
2738 	ecb->timeout = NCR_ABORT_TIMEOUT;
2739 	ecb->flags |= ECB_ABORT;
2740 
2741 	if (ecb == sc->sc_nexus) {
2742 		int timeout = ecb->timeout;
2743 
2744 		/*
2745 		 * If we're still selecting, the message will be scheduled
2746 		 * after selection is complete.
2747 		 */
2748 		if (sc->sc_state == NCR_CONNECTED)
2749 			ncr53c9x_sched_msgout(SEND_ABORT);
2750 
2751 		/*
2752 		 * Reschedule timeout.
2753 		 */
2754 		if (timeout > 1000000)
2755 			timeout = (timeout / 1000) * hz;
2756 		else
2757 			timeout = (timeout * hz) / 1000;
2758 		timeout_add(&ecb->to, timeout);
2759 	} else {
2760 		/*
2761 		 * Just leave the command where it is.
2762 		 * XXX - what choice do we have but to reset the SCSI
2763 		 *	 eventually?
2764 		 */
2765 		if (sc->sc_state == NCR_IDLE)
2766 			ncr53c9x_sched(sc);
2767 	}
2768 }
2769 
2770 void
2771 ncr53c9x_timeout(arg)
2772 	void *arg;
2773 {
2774 	struct ncr53c9x_ecb *ecb = arg;
2775 	struct scsi_xfer *xs = ecb->xs;
2776 	struct scsi_link *sc_link = xs->sc_link;
2777 	struct ncr53c9x_softc *sc = sc_link->adapter_softc;
2778 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
2779 	int s;
2780 
2781 	sc_print_addr(sc_link);
2782 	printf("timed out [ecb %p (flags 0x%x, dleft %x, stat %x)], "
2783 	       "<state %d, nexus %p, phase(l %x, c %x, p %x), resid %lx, "
2784 	       "msg(q %x,o %x) %s>",
2785 		ecb, ecb->flags, ecb->dleft, ecb->stat,
2786 		sc->sc_state, sc->sc_nexus,
2787 		NCR_READ_REG(sc, NCR_STAT),
2788 		sc->sc_phase, sc->sc_prevphase,
2789 		(long)sc->sc_dleft, sc->sc_msgpriq, sc->sc_msgout,
2790 		NCRDMA_ISACTIVE(sc) ? "DMA active" : "");
2791 #if NCR53C9X_DEBUG > 1
2792 	printf("TRACE: %s.", ecb->trace);
2793 #endif
2794 
2795 	s = splbio();
2796 
2797 	if (ecb->flags & ECB_ABORT) {
2798 		/* abort timed out */
2799 		printf(" AGAIN\n");
2800 
2801 		ncr53c9x_init(sc, 1);
2802 	} else {
2803 		/* abort the operation that has timed out */
2804 		printf("\n");
2805 		xs->error = XS_TIMEOUT;
2806 		ncr53c9x_abort(sc, ecb);
2807 
2808 		/* Disable sync mode if stuck in a data phase */
2809 		if (ecb == sc->sc_nexus &&
2810 		    (ti->flags & T_SYNCMODE) != 0 &&
2811 		    (sc->sc_phase & (MSGI|CDI)) == 0) {
2812 			sc_print_addr(sc_link);
2813 			printf("sync negotiation disabled\n");
2814 			sc->sc_cfflags |= (1 << (sc_link->target + 16));
2815 		}
2816 	}
2817 
2818 	splx(s);
2819 }
2820