xref: /openbsd-src/sys/dev/ic/ncr53c9x.c (revision f1dd7b858388b4a23f4f67a4957ec5ff656ebbe8)
1 /*	$OpenBSD: ncr53c9x.c,v 1.78 2021/03/07 06:21:38 jsg 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/param.h>
69 #include <sys/systm.h>
70 #include <sys/kernel.h>
71 #include <sys/errno.h>
72 #include <sys/ioctl.h>
73 #include <sys/device.h>
74 #include <sys/malloc.h>
75 #include <sys/queue.h>
76 #include <sys/pool.h>
77 
78 #include <scsi/scsi_all.h>
79 #include <scsi/scsiconf.h>
80 #include <scsi/scsi_message.h>
81 
82 #include <machine/cpu.h>
83 
84 #include <dev/ic/ncr53c9xreg.h>
85 #include <dev/ic/ncr53c9xvar.h>
86 
87 #ifdef NCR53C9X_DEBUG
88 int ncr53c9x_debug = 0; /*NCR_SHOWPHASE|NCR_SHOWMISC|NCR_SHOWTRAC|NCR_SHOWCMDS;*/
89 #endif
90 #ifdef DEBUG
91 int ncr53c9x_notag = 0;
92 #endif
93 
94 /*static*/ void	ncr53c9x_readregs(struct ncr53c9x_softc *);
95 /*static*/ void	ncr53c9x_select(struct ncr53c9x_softc *,
96 					    struct ncr53c9x_ecb *);
97 /*static*/ int ncr53c9x_reselect(struct ncr53c9x_softc *, int, int, int);
98 /*static*/ void	ncr53c9x_scsi_reset(struct ncr53c9x_softc *);
99 /*static*/ int	ncr53c9x_poll(struct ncr53c9x_softc *,
100 					    struct scsi_xfer *, int);
101 /*static*/ void	ncr53c9x_sched(struct ncr53c9x_softc *);
102 /*static*/ void	ncr53c9x_done(struct ncr53c9x_softc *,
103 					    struct ncr53c9x_ecb *);
104 /*static*/ void	ncr53c9x_msgin(struct ncr53c9x_softc *);
105 /*static*/ void	ncr53c9x_msgout(struct ncr53c9x_softc *);
106 /*static*/ void	ncr53c9x_timeout(void *arg);
107 /*static*/ void	ncr53c9x_abort(struct ncr53c9x_softc *,
108 					    struct ncr53c9x_ecb *);
109 /*static*/ void ncr53c9x_dequeue(struct ncr53c9x_softc *,
110 					    struct ncr53c9x_ecb *);
111 
112 void ncr53c9x_sense(struct ncr53c9x_softc *,
113 					    struct ncr53c9x_ecb *);
114 void ncr53c9x_free_ecb(void *, void *);
115 void *ncr53c9x_get_ecb(void *);
116 
117 static inline int ncr53c9x_stp2cpb(struct ncr53c9x_softc *, int);
118 static inline void ncr53c9x_setsync(struct ncr53c9x_softc *,
119 					    struct ncr53c9x_tinfo *);
120 static struct ncr53c9x_linfo *ncr53c9x_lunsearch(struct ncr53c9x_tinfo *,
121     int64_t lun);
122 
123 static void ncr53c9x_wrfifo(struct ncr53c9x_softc *, u_char *, int);
124 static int ncr53c9x_rdfifo(struct ncr53c9x_softc *, int);
125 #define NCR_RDFIFO_START	0
126 #define NCR_RDFIFO_CONTINUE	1
127 
128 #define NCR_SET_COUNT(sc, size) do {						\
129 			NCR_WRITE_REG((sc), NCR_TCL, (size));			\
130 			NCR_WRITE_REG((sc), NCR_TCM, (size) >> 8);		\
131 			if ((sc->sc_cfg2 & NCRCFG2_FE) ||			\
132 			    (sc->sc_rev == NCR_VARIANT_FAS366)) {		\
133 				NCR_WRITE_REG((sc), NCR_TCH, (size) >> 16);	\
134 			}							\
135 			if (sc->sc_rev == NCR_VARIANT_FAS366) {			\
136 				NCR_WRITE_REG(sc, NCR_RCH, 0);			\
137 			}							\
138 } while (0)
139 
140 static int ecb_pool_initialized = 0;
141 static struct scsi_iopool ecb_iopool;
142 static struct pool ecb_pool;
143 
144 struct cfdriver esp_cd = {
145 	NULL, "esp", DV_DULL
146 };
147 
148 void	ncr53c9x_scsi_cmd(struct scsi_xfer *);
149 int	ncr53c9x_scsi_probe(struct scsi_link *);
150 void	ncr53c9x_scsi_free(struct scsi_link *);
151 
152 struct scsi_adapter ncr53c9x_switch = {
153 	ncr53c9x_scsi_cmd, NULL, ncr53c9x_scsi_probe,
154 	ncr53c9x_scsi_free, NULL
155 };
156 
157 /*
158  * Names for the NCR53c9x variants, corresponding to the variant tags
159  * in ncr53c9xvar.h.
160  */
161 const char *ncr53c9x_variant_names[] = {
162 	"ESP100",
163 	"ESP100A",
164 	"ESP200",
165 	"NCR53C94",
166 	"NCR53C96",
167 	"ESP406",
168 	"FAS408",
169 	"FAS216",
170 	"AM53C974",
171 	"FAS366/HME",
172 };
173 
174 /*
175  * Search linked list for LUN info by LUN id.
176  */
177 static struct ncr53c9x_linfo *
178 ncr53c9x_lunsearch(struct ncr53c9x_tinfo *ti, int64_t lun)
179 {
180 	struct ncr53c9x_linfo *li;
181 	LIST_FOREACH(li, &ti->luns, link)
182 	    if (li->lun == lun)
183 		    return (li);
184 	return (NULL);
185 }
186 
187 /*
188  * Attach this instance, and then all the sub-devices
189  */
190 void
191 ncr53c9x_attach(struct ncr53c9x_softc *sc)
192 {
193 	struct scsibus_attach_args saa;
194 
195 	/*
196 	 * Allocate SCSI message buffers.
197 	 * Front-ends can override allocation to avoid alignment
198 	 * handling in the DMA engines. Note that ncr53c9x_msgout()
199 	 * can request a 1 byte DMA transfer.
200 	 */
201 	if (sc->sc_omess == NULL)
202 		sc->sc_omess = malloc(NCR_MAX_MSG_LEN, M_DEVBUF, M_NOWAIT);
203 
204 	if (sc->sc_imess == NULL)
205 		sc->sc_imess = malloc(NCR_MAX_MSG_LEN+1, M_DEVBUF, M_NOWAIT);
206 
207 	if (sc->sc_omess == NULL || sc->sc_imess == NULL) {
208 		printf("out of memory\n");
209 		return;
210 	}
211 
212 	/*
213 	 * Note, the front-end has set us up to print the chip variation.
214 	 */
215 	if (sc->sc_rev >= NCR_VARIANT_MAX) {
216 		printf("\n%s: unknown variant %d, devices not attached\n",
217 		    sc->sc_dev.dv_xname, sc->sc_rev);
218 		return;
219 	}
220 
221 	printf(": %s, %dMHz\n", ncr53c9x_variant_names[sc->sc_rev],
222 	    sc->sc_freq);
223 
224 	sc->sc_ccf = FREQTOCCF(sc->sc_freq);
225 
226 	/* The value *must not* be == 1. Make it 2 */
227 	if (sc->sc_ccf == 1)
228 		sc->sc_ccf = 2;
229 
230 	/*
231 	 * The recommended timeout is 250ms. This register is loaded
232 	 * with a value calculated as follows, from the docs:
233 	 *
234 	 *		(timout period) x (CLK frequency)
235 	 *	reg = -------------------------------------
236 	 *		 8192 x (Clock Conversion Factor)
237 	 *
238 	 * Since CCF has a linear relation to CLK, this generally computes
239 	 * to the constant of 153.
240 	 */
241 	sc->sc_timeout = ((250 * 1000) * sc->sc_freq) / (8192 * sc->sc_ccf);
242 
243 	/* CCF register only has 3 bits; 0 is actually 8 */
244 	sc->sc_ccf &= 7;
245 
246 	/* Find how many targets we need to support */
247 	switch (sc->sc_rev) {
248 	case NCR_VARIANT_FAS366:
249 		sc->sc_ntarg = 16;
250 		break;
251 	default:
252 		sc->sc_ntarg = 8;
253 		break;
254 	}
255 
256 	/* Reset state & bus */
257 	sc->sc_cfflags = sc->sc_dev.dv_cfdata->cf_flags;
258 	sc->sc_state = 0;
259 	ncr53c9x_init(sc, 1);
260 
261 	saa.saa_adapter_softc = sc;
262 	saa.saa_adapter_target = sc->sc_id;
263 	saa.saa_adapter = &ncr53c9x_switch;
264 	saa.saa_adapter_buswidth = sc->sc_ntarg;
265 	saa.saa_luns = 8;
266 	saa.saa_openings = 2;
267 	saa.saa_pool = &ecb_iopool;
268 	saa.saa_quirks = saa.saa_flags = 0;
269 	saa.saa_wwpn = saa.saa_wwnn = 0;
270 
271 	config_found(&sc->sc_dev, &saa, scsiprint);
272 }
273 
274 /*
275  * This is the generic ncr53c9x reset function. It does not reset the SCSI bus,
276  * only this controller, but kills any on-going commands, and also stops
277  * and resets the DMA.
278  *
279  * After reset, registers are loaded with the defaults from the attach
280  * routine above.
281  */
282 void
283 ncr53c9x_reset(struct ncr53c9x_softc *sc)
284 {
285 
286 	/* reset DMA first */
287 	NCRDMA_RESET(sc);
288 
289 	/* reset SCSI chip */
290 	NCRCMD(sc, NCRCMD_RSTCHIP);
291 	NCRCMD(sc, NCRCMD_NOP);
292 	DELAY(500);
293 
294 	/* do these backwards, and fall through */
295 	switch (sc->sc_rev) {
296 	case NCR_VARIANT_ESP406:
297 	case NCR_VARIANT_FAS408:
298 		NCR_WRITE_REG(sc, NCR_CFG5, sc->sc_cfg5 | NCRCFG5_SINT);
299 		NCR_WRITE_REG(sc, NCR_CFG4, sc->sc_cfg4);
300 	case NCR_VARIANT_AM53C974:
301 	case NCR_VARIANT_FAS216:
302 	case NCR_VARIANT_NCR53C94:
303 	case NCR_VARIANT_NCR53C96:
304 	case NCR_VARIANT_ESP200:
305 		sc->sc_features |= NCR_F_HASCFG3;
306 		NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
307 	case NCR_VARIANT_ESP100A:
308 		sc->sc_features |= NCR_F_SELATN3;
309 		NCR_WRITE_REG(sc, NCR_CFG2, sc->sc_cfg2);
310 	case NCR_VARIANT_ESP100:
311 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
312 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
313 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
314 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
315 		break;
316 	case NCR_VARIANT_FAS366:
317 		sc->sc_features |=
318 		    NCR_F_SELATN3 | NCR_F_HASCFG3 | NCR_F_FASTSCSI;
319 		sc->sc_cfg3 = NCRFASCFG3_FASTCLK | NCRFASCFG3_OBAUTO;
320 		sc->sc_cfg3_fscsi = NCRFASCFG3_FASTSCSI;
321 		NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
322 		sc->sc_cfg2 = 0; /* NCRCFG2_HMEFE | NCRCFG2_HME32 */
323 		NCR_WRITE_REG(sc, NCR_CFG2, sc->sc_cfg2);
324 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
325 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
326 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
327 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
328 		break;
329 	default:
330 		printf("%s: unknown revision code, assuming ESP100\n",
331 		    sc->sc_dev.dv_xname);
332 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
333 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
334 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
335 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
336 	}
337 
338 	if (sc->sc_rev == NCR_VARIANT_AM53C974)
339 		NCR_WRITE_REG(sc, NCR_AMDCFG4, sc->sc_cfg4);
340 
341 #if 0
342 	printf("%s: ncr53c9x_reset: revision %d\n",
343 	    sc->sc_dev.dv_xname, sc->sc_rev);
344 	printf("%s: ncr53c9x_reset: cfg1 0x%x, cfg2 0x%x, cfg3 0x%x, ccf 0x%x, timeout 0x%x\n",
345 	    sc->sc_dev.dv_xname,
346 	    sc->sc_cfg1, sc->sc_cfg2, sc->sc_cfg3,
347 	    sc->sc_ccf, sc->sc_timeout);
348 #endif
349 }
350 
351 /*
352  * Reset the SCSI bus, but not the chip
353  */
354 void
355 ncr53c9x_scsi_reset(struct ncr53c9x_softc *sc)
356 {
357 
358 	(*sc->sc_glue->gl_dma_stop)(sc);
359 
360 	printf("%s: resetting SCSI bus\n", sc->sc_dev.dv_xname);
361 	NCRCMD(sc, NCRCMD_RSTSCSI);
362 }
363 
364 /*
365  * Initialize ncr53c9x state machine
366  */
367 void
368 ncr53c9x_init(struct ncr53c9x_softc *sc, int doreset)
369 {
370 	struct ncr53c9x_ecb *ecb;
371 	struct ncr53c9x_linfo *li;
372 	int r, i;
373 
374 	NCR_TRACE(("[NCR_INIT(%d) %d] ", doreset, sc->sc_state));
375 
376 	if (!ecb_pool_initialized) {
377 		/* All instances share this pool */
378 		pool_init(&ecb_pool, sizeof(struct ncr53c9x_ecb), 0, IPL_BIO,
379 		    0, "ncr53c9x_ecb", NULL);
380 		scsi_iopool_init(&ecb_iopool, NULL,
381 		    ncr53c9x_get_ecb, ncr53c9x_free_ecb);
382 		ecb_pool_initialized = 1;
383 	}
384 
385 	if (sc->sc_state == 0) {
386 		/* First time through; initialize. */
387 
388 		TAILQ_INIT(&sc->ready_list);
389 		sc->sc_nexus = NULL;
390 		bzero(sc->sc_tinfo, sizeof(sc->sc_tinfo));
391 		for (r = 0; r < sc->sc_ntarg; r++) {
392 			LIST_INIT(&sc->sc_tinfo[r].luns);
393 		}
394 	} else {
395 		/* Cancel any active commands. */
396 		sc->sc_state = NCR_CLEANING;
397 		sc->sc_msgify = 0;
398 		if ((ecb = sc->sc_nexus) != NULL) {
399 			ecb->xs->error = XS_TIMEOUT;
400 			ncr53c9x_done(sc, ecb);
401 		}
402 		for (r = 0; r < sc->sc_ntarg; r++) {
403 			LIST_FOREACH(li, &sc->sc_tinfo[r].luns, link) {
404 				if ((ecb = li->untagged)) {
405 					li->untagged = NULL;
406 					/*
407 					 * XXXXXXX
408 					 * Should we terminate a command
409 					 * that never reached the disk?
410 					 */
411 					li->busy = 0;
412 					ecb->xs->error = XS_TIMEOUT;
413 					ncr53c9x_done(sc, ecb);
414 				}
415 				for (i = 0; i < 256; i++)
416 					if ((ecb = li->queued[i])) {
417 						li->queued[i] = NULL;
418 						ecb->xs->error = XS_TIMEOUT;
419 						ncr53c9x_done(sc, ecb);
420 					}
421 				li->used = 0;
422 			}
423 		}
424 	}
425 
426 	/*
427 	 * reset the chip to a known state
428 	 */
429 	ncr53c9x_reset(sc);
430 
431 	sc->sc_phase = sc->sc_prevphase = INVALID_PHASE;
432 	for (r = 0; r < sc->sc_ntarg; r++) {
433 		struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[r];
434 /* XXX - config flags per target: low bits: no reselect; high bits: no synch */
435 
436                 ti->flags = ((!(sc->sc_cfflags & (1 << (r + 16))) &&
437 		    sc->sc_minsync) ? 0 : T_SYNCHOFF) |
438 		    ((sc->sc_cfflags & (1 << r)) ?  T_RSELECTOFF : 0) |
439 		    T_NEED_TO_RESET;
440 #ifdef DEBUG
441 		 if (ncr53c9x_notag)
442 			 ti->flags &= ~T_TAG;
443 #endif
444 		ti->period = sc->sc_minsync;
445 		ti->offset = 0;
446 		ti->cfg3 = 0;
447 	}
448 
449 	if (doreset) {
450 		sc->sc_state = NCR_SBR;
451 		NCRCMD(sc, NCRCMD_RSTSCSI);
452 		/*
453 		 * XXX gross...
454 		 * On some systems, commands issued too close to a reset
455 		 * do not work correctly. We'll force a short delay on
456 		 * known-to-be-sensitive chips.
457 		 */
458 		switch (sc->sc_rev) {
459 		case NCR_VARIANT_NCR53C94:
460 			DELAY(600000);	/* 600ms */
461 			break;
462 		case NCR_VARIANT_NCR53C96:
463 			DELAY(100000);	/* 100ms */
464 			break;
465 		}
466 	} else {
467 		sc->sc_state = NCR_IDLE;
468 		ncr53c9x_sched(sc);
469 	}
470 }
471 
472 /*
473  * Read the NCR registers, and save their contents for later use.
474  * NCR_STAT, NCR_STEP & NCR_INTR are mostly zeroed out when reading
475  * NCR_INTR - so make sure it is the last read.
476  *
477  * I think that (from reading the docs) most bits in these registers
478  * only make sense when he DMA CSR has an interrupt showing. Call only
479  * if an interrupt is pending.
480  */
481 __inline__ void
482 ncr53c9x_readregs(struct ncr53c9x_softc *sc)
483 {
484 
485 	sc->sc_espstat = NCR_READ_REG(sc, NCR_STAT);
486 	/* Only the stepo bits are of interest */
487 	sc->sc_espstep = NCR_READ_REG(sc, NCR_STEP) & NCRSTEP_MASK;
488 
489 	if (sc->sc_rev == NCR_VARIANT_FAS366)
490 		sc->sc_espstat2 = NCR_READ_REG(sc, NCR_STAT2);
491 
492 	sc->sc_espintr = NCR_READ_REG(sc, NCR_INTR);
493 
494 	if (sc->sc_glue->gl_clear_latched_intr != NULL)
495 		(*sc->sc_glue->gl_clear_latched_intr)(sc);
496 
497 	/*
498 	 * Determine the SCSI bus phase, return either a real SCSI bus phase
499 	 * or some pseudo phase we use to detect certain exceptions.
500 	 */
501 
502 	sc->sc_phase = (sc->sc_espintr & NCRINTR_DIS)
503 			? /* Disconnected */ BUSFREE_PHASE
504 			: sc->sc_espstat & NCRSTAT_PHASE;
505 
506 	NCR_MISC(("regs[intr=%02x,stat=%02x,step=%02x,stat2=%02x] ",
507 		sc->sc_espintr, sc->sc_espstat, sc->sc_espstep, sc->sc_espstat2));
508 }
509 
510 /*
511  * Convert Synchronous Transfer Period to chip register Clock Per Byte value.
512  */
513 static inline int
514 ncr53c9x_stp2cpb(struct ncr53c9x_softc *sc, int period)
515 {
516 	int v;
517 	v = (sc->sc_freq * period) / 250;
518 	if (ncr53c9x_cpb2stp(sc, v) < period)
519 		/* Correct round-down error */
520 		v++;
521 	return (v);
522 }
523 
524 static inline void
525 ncr53c9x_setsync(struct ncr53c9x_softc *sc, struct ncr53c9x_tinfo *ti)
526 {
527 	u_char syncoff, synctp;
528 	u_char cfg3 = sc->sc_cfg3 | ti->cfg3;
529 
530 	if (ti->flags & T_SYNCMODE) {
531 		syncoff = ti->offset;
532 		synctp = ncr53c9x_stp2cpb(sc, ti->period);
533 		if (sc->sc_features & NCR_F_FASTSCSI) {
534 			/*
535 			 * If the period is 200ns or less (ti->period <= 50),
536 			 * put the chip in Fast SCSI mode.
537 			 */
538 			if (ti->period <= 50)
539 				/*
540 				 * There are (at least) 4 variations of the
541 				 * configuration 3 register.  The drive attach
542 				 * routine sets the appropriate bit to put the
543 				 * chip into Fast SCSI mode so that it doesn't
544 				 * have to be figured out here each time.
545 				 */
546 				cfg3 |= (sc->sc_rev == NCR_VARIANT_AM53C974) ?
547 				    NCRAMDCFG3_FSCSI : NCRCFG3_FSCSI;
548 		}
549 
550 		/*
551 		 * Am53c974 requires different SYNCTP values when the
552 		 * FSCSI bit is off.
553 		 */
554 		if (sc->sc_rev == NCR_VARIANT_AM53C974 &&
555 		    (cfg3 & NCRAMDCFG3_FSCSI) == 0)
556 			synctp--;
557 	} else {
558 		syncoff = 0;
559 		synctp = 0;
560 	}
561 
562 	if (sc->sc_features & NCR_F_HASCFG3)
563 		NCR_WRITE_REG(sc, NCR_CFG3, cfg3);
564 
565 	NCR_WRITE_REG(sc, NCR_SYNCOFF, syncoff);
566 	NCR_WRITE_REG(sc, NCR_SYNCTP, synctp);
567 }
568 
569 /*
570  * Send a command to a target, set the driver state to NCR_SELECTING
571  * and let the caller take care of the rest.
572  *
573  * Keeping this as a function allows me to say that this may be done
574  * by DMA instead of programmed I/O soon.
575  */
576 void
577 ncr53c9x_select(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
578 {
579 	struct scsi_link *sc_link = ecb->xs->sc_link;
580 	int target = sc_link->target;
581 	int lun = sc_link->lun;
582 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[target];
583 	int tiflags = ti->flags;
584 	u_char *cmd;
585 	int clen;
586 	int selatn3, selatns;
587 	size_t dmasize;
588 
589 	NCR_TRACE(("[ncr53c9x_select(t%d,l%d,cmd:%x,tag%x,%x)] ",
590 		   target, lun, ecb->cmd.cmd.opcode, ecb->tag[0], ecb->tag[1]));
591 
592 	sc->sc_state = NCR_SELECTING;
593 	/*
594 	 * Schedule the timeout now, the first time we will go away
595 	 * expecting to come back due to an interrupt, because it is
596 	 * always possible that the interrupt may never happen.
597 	 */
598 	if ((ecb->xs->flags & SCSI_POLL) == 0) {
599 		int timeout = ecb->timeout;
600 
601 		if (timeout > 1000000)
602 			timeout = (timeout / 1000) * hz;
603 		else
604 			timeout = (timeout * hz) / 1000;
605 		timeout_add(&ecb->to, timeout);
606 	}
607 
608 	/*
609 	 * The docs say the target register is never reset, and I
610 	 * can't think of a better place to set it
611 	 */
612 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
613 		NCRCMD(sc, NCRCMD_FLUSH);
614 		NCR_WRITE_REG(sc, NCR_SELID, target | NCR_BUSID_HME);
615 	} else {
616 		NCR_WRITE_REG(sc, NCR_SELID, target);
617 	}
618 	ncr53c9x_setsync(sc, ti);
619 
620 	if ((ecb->flags & ECB_SENSE) != 0) {
621 		/*
622 		 * For REQUEST SENSE, we should not send an IDENTIFY or
623 		 * otherwise mangle the target.  There should be no MESSAGE IN
624 		 * phase.
625 		 */
626 		if (sc->sc_features & NCR_F_DMASELECT) {
627 			/* setup DMA transfer for command */
628 			dmasize = clen = ecb->clen;
629 			sc->sc_cmdlen = clen;
630 			sc->sc_cmdp = (caddr_t)&ecb->cmd.cmd;
631 
632 			NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen, 0,
633 			    &dmasize);
634 			/* Program the SCSI counter */
635 			NCR_SET_COUNT(sc, dmasize);
636 
637 			if (sc->sc_rev != NCR_VARIANT_FAS366)
638 				NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
639 
640 			/* And get the targets attention */
641 			NCRCMD(sc, NCRCMD_SELNATN | NCRCMD_DMA);
642 			NCRDMA_GO(sc);
643 		} else {
644 			ncr53c9x_wrfifo(sc, (u_char *)&ecb->cmd.cmd, ecb->clen);
645 			sc->sc_cmdlen = 0;
646 			NCRCMD(sc, NCRCMD_SELNATN);
647 		}
648 		return;
649 	}
650 
651 	selatn3 = selatns = 0;
652 	if (ecb->tag[0] != 0) {
653 		if (sc->sc_features & NCR_F_SELATN3)
654 			/* use SELATN3 to send tag messages */
655 			selatn3 = 1;
656 		else
657 			/* We don't have SELATN3; use SELATNS to send tags */
658 			selatns = 1;
659 	}
660 
661 	if (ti->flags & T_NEGOTIATE) {
662 		/* We have to use SELATNS to send sync/wide messages */
663 		selatn3 = 0;
664 		selatns = 1;
665 	}
666 
667 	cmd = (u_char *)&ecb->cmd.cmd;
668 
669 	if (selatn3) {
670 		/* We'll use tags with SELATN3 */
671 		clen = ecb->clen + 3;
672 		cmd -= 3;
673 		cmd[0] = MSG_IDENTIFY(lun, 1);	/* msg[0] */
674 		cmd[1] = ecb->tag[0];		/* msg[1] */
675 		cmd[2] = ecb->tag[1];		/* msg[2] */
676 	} else {
677 		/* We don't have tags, or will send messages with SELATNS */
678 		clen = ecb->clen + 1;
679 		cmd -= 1;
680 		cmd[0] = MSG_IDENTIFY(lun, (tiflags & T_RSELECTOFF) == 0);
681 	}
682 
683 	if ((sc->sc_features & NCR_F_DMASELECT) && !selatns) {
684 
685 		/* setup DMA transfer for command */
686 		dmasize = clen;
687 		sc->sc_cmdlen = clen;
688 		sc->sc_cmdp = cmd;
689 
690 		NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen, 0, &dmasize);
691 		/* Program the SCSI counter */
692 		NCR_SET_COUNT(sc, dmasize);
693 
694 		/* load the count in */
695 		/* if (sc->sc_rev != NCR_VARIANT_FAS366) */
696 			NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
697 
698 		/* And get the targets attention */
699 		if (selatn3) {
700 			sc->sc_msgout = SEND_TAG;
701 			sc->sc_flags |= NCR_ATN;
702 			NCRCMD(sc, NCRCMD_SELATN3 | NCRCMD_DMA);
703 		} else
704 			NCRCMD(sc, NCRCMD_SELATN | NCRCMD_DMA);
705 		NCRDMA_GO(sc);
706 		return;
707 	}
708 
709 	/*
710 	 * Who am I. This is where we tell the target that we are
711 	 * happy for it to disconnect etc.
712 	 */
713 
714 	/* Now get the command into the FIFO */
715 	sc->sc_cmdlen = 0;
716 	ncr53c9x_wrfifo(sc, cmd, clen);
717 
718 	/* And get the targets attention */
719 	if (selatns) {
720 		NCR_MISC(("SELATNS \n"));
721 		/* Arbitrate, select and stop after IDENTIFY message */
722 		NCRCMD(sc, NCRCMD_SELATNS);
723 	} else if (selatn3) {
724 		sc->sc_msgout = SEND_TAG;
725 		sc->sc_flags |= NCR_ATN;
726 		NCRCMD(sc, NCRCMD_SELATN3);
727 	} else
728 		NCRCMD(sc, NCRCMD_SELATN);
729 }
730 
731 /*
732  * DRIVER FUNCTIONS CALLABLE FROM HIGHER LEVEL DRIVERS
733  */
734 
735 void *
736 ncr53c9x_get_ecb(void *null)
737 {
738 	struct ncr53c9x_ecb *ecb;
739 
740 	ecb = pool_get(&ecb_pool, M_NOWAIT|M_ZERO);
741 	if (ecb == NULL)
742 		return (NULL);
743 
744 	timeout_set(&ecb->to, ncr53c9x_timeout, ecb);
745 	ecb->flags |= ECB_ALLOC;
746 
747 	return (ecb);
748 }
749 
750 void
751 ncr53c9x_free_ecb(void *null, void *ecb)
752 {
753 	pool_put(&ecb_pool, ecb);
754 }
755 
756 int
757 ncr53c9x_scsi_probe(struct scsi_link *sc_link)
758 {
759 	struct ncr53c9x_softc *sc = sc_link->bus->sb_adapter_softc;
760 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
761 	struct ncr53c9x_linfo *li;
762 	int64_t lun = sc_link->lun;
763 	int s;
764 
765 	/* Initialize LUN info and add to list. */
766 	li = malloc(sizeof(*li), M_DEVBUF, M_WAITOK | M_ZERO);
767 	if (li == NULL)
768 		return (ENOMEM);
769 
770 	li->last_used = getuptime();
771 	li->lun = lun;
772 
773 	s = splbio();
774 	LIST_INSERT_HEAD(&ti->luns, li, link);
775 	if (lun < NCR_NLUN)
776 		ti->lun[lun] = li;
777 	splx(s);
778 
779 	return (0);
780 
781 }
782 
783 void
784 ncr53c9x_scsi_free(struct scsi_link *sc_link)
785 {
786 	struct ncr53c9x_softc *sc = sc_link->bus->sb_adapter_softc;
787 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
788 	struct ncr53c9x_linfo *li;
789 	int64_t lun = sc_link->lun;
790 	int s;
791 
792 	s = splbio();
793 	li = TINFO_LUN(ti, lun);
794 
795 	LIST_REMOVE(li, link);
796 	if (lun < NCR_NLUN)
797 		ti->lun[lun] = NULL;
798 	splx(s);
799 
800 	free(li, M_DEVBUF, 0);
801 }
802 
803 /*
804  * Start a SCSI-command
805  * This function is called by the higher level SCSI-driver to queue/run
806  * SCSI-commands.
807  */
808 void
809 ncr53c9x_scsi_cmd(struct scsi_xfer *xs)
810 {
811 	struct scsi_link *sc_link = xs->sc_link;
812 	struct ncr53c9x_softc *sc = sc_link->bus->sb_adapter_softc;
813 	struct ncr53c9x_ecb *ecb;
814 	struct ncr53c9x_tinfo *ti;
815 	struct ncr53c9x_linfo *li;
816 	int64_t lun = sc_link->lun;
817 	int s, flags;
818 
819 	NCR_TRACE(("[ncr53c9x_scsi_cmd] "));
820 	NCR_CMDS(("[0x%x, %d]->%d ", (int)xs->cmd.opcode, xs->cmdlen,
821 	    sc_link->target));
822 
823 	/*
824 	 * Commands larger than 12 bytes seem to confuse the chip
825 	 * (at least on FAS366 flavours).
826 	 */
827 	if (xs->cmdlen > 12) {
828 		memset(&xs->sense, 0, sizeof(xs->sense));
829 		/* sense data borrowed from gdt(4) */
830 		xs->sense.error_code = SSD_ERRCODE_VALID | SSD_ERRCODE_CURRENT;
831 		xs->sense.flags = SKEY_ILLEGAL_REQUEST;
832 		xs->sense.add_sense_code = 0x20; /* illcmd */
833 		xs->error = XS_SENSE;
834 		scsi_done(xs);
835 		return;
836 	}
837 
838 	flags = xs->flags;
839 	ti = &sc->sc_tinfo[sc_link->target];
840 	li = TINFO_LUN(ti, lun);
841 
842 	/* Initialize ecb */
843 	ecb = xs->io;
844 	ecb->xs = xs;
845 	ecb->timeout = xs->timeout;
846 
847 	if (flags & SCSI_RESET) {
848 		ecb->flags |= ECB_RESET;
849 		ecb->clen = 0;
850 		ecb->dleft = 0;
851 	} else {
852 		bcopy(&xs->cmd, &ecb->cmd.cmd, xs->cmdlen);
853 		ecb->clen = xs->cmdlen;
854 		ecb->daddr = xs->data;
855 		ecb->dleft = xs->datalen;
856 	}
857 	ecb->stat = 0;
858 
859 	s = splbio();
860 
861 	TAILQ_INSERT_TAIL(&sc->ready_list, ecb, chain);
862 	ecb->flags |= ECB_READY;
863 	if (sc->sc_state == NCR_IDLE)
864 		ncr53c9x_sched(sc);
865 
866 	splx(s);
867 
868 	if ((flags & SCSI_POLL) == 0)
869 		return;
870 
871 	/* Not allowed to use interrupts, use polling instead */
872 	if (ncr53c9x_poll(sc, xs, ecb->timeout)) {
873 		ncr53c9x_timeout(ecb);
874 		if (ncr53c9x_poll(sc, xs, ecb->timeout))
875 			ncr53c9x_timeout(ecb);
876 	}
877 }
878 
879 /*
880  * Used when interrupt driven I/O isn't allowed, e.g. during boot.
881  */
882 int
883 ncr53c9x_poll(struct ncr53c9x_softc *sc, struct scsi_xfer *xs, int count)
884 {
885 	int s;
886 
887 	NCR_TRACE(("[ncr53c9x_poll] "));
888 	while (count) {
889 		if (NCRDMA_ISINTR(sc)) {
890 			s = splbio();
891 			ncr53c9x_intr(sc);
892 			splx(s);
893 		}
894 #if alternatively
895 		if (NCR_READ_REG(sc, NCR_STAT) & NCRSTAT_INT) {
896 			s = splbio();
897 			ncr53c9x_intr(sc);
898 			splx(s);
899 		}
900 #endif
901 		if ((xs->flags & ITSDONE) != 0)
902 			return (0);
903 		s = splbio();
904 		if (sc->sc_state == NCR_IDLE) {
905 			NCR_TRACE(("[ncr53c9x_poll: rescheduling] "));
906 			ncr53c9x_sched(sc);
907 		}
908 		splx(s);
909 		DELAY(1000);
910 		count--;
911 	}
912 	return (1);
913 }
914 
915 
916 /*
917  * LOW LEVEL SCSI UTILITIES
918  */
919 
920 /*
921  * Schedule a scsi operation.  This has now been pulled out of the interrupt
922  * handler so that we may call it from ncr53c9x_scsi_cmd and ncr53c9x_done.
923  * This may save us an unnecessary interrupt just to get things going.
924  * Should only be called when state == NCR_IDLE and at bio pl.
925  */
926 void
927 ncr53c9x_sched(struct ncr53c9x_softc *sc)
928 {
929 	struct ncr53c9x_ecb *ecb;
930 	struct scsi_link *sc_link;
931 	struct ncr53c9x_tinfo *ti;
932 	int lun;
933 	struct ncr53c9x_linfo *li;
934 	int s, tag;
935 
936 	NCR_TRACE(("[ncr53c9x_sched] "));
937 	if (sc->sc_state != NCR_IDLE)
938 		panic("ncr53c9x_sched: not IDLE (state=%d)", sc->sc_state);
939 
940 	/*
941 	 * Find first ecb in ready queue that is for a target/lunit
942 	 * combinations that is not busy.
943 	 */
944 	TAILQ_FOREACH(ecb, &sc->ready_list, chain) {
945 		sc_link = ecb->xs->sc_link;
946 		ti = &sc->sc_tinfo[sc_link->target];
947 		lun = sc_link->lun;
948 
949 		/* Select type of tag for this command */
950 		if ((ti->flags & (T_RSELECTOFF)) != 0)
951 			tag = 0;
952 		else if ((ti->flags & T_TAG) == 0)
953 			tag = 0;
954 		else if ((ecb->flags & ECB_SENSE) != 0)
955 			tag = 0;
956 		else
957 			tag = MSG_SIMPLE_Q_TAG;
958 #if 0
959 		/* XXXX Use tags for polled commands? */
960 		if (ecb->xs->flags & SCSI_POLL)
961 			tag = 0;
962 #endif
963 		s = splbio();
964 		li = TINFO_LUN(ti, lun);
965 		if (!li) {
966 			/* Initialize LUN info and add to list. */
967 			if ((li = malloc(sizeof(*li), M_DEVBUF,
968 			    M_NOWAIT | M_ZERO)) == NULL) {
969 				splx(s);
970 				continue;
971 			}
972 			li->lun = lun;
973 
974 			LIST_INSERT_HEAD(&ti->luns, li, link);
975 			if (lun < NCR_NLUN)
976 				ti->lun[lun] = li;
977 		}
978 		li->last_used = getuptime();
979 		if (!tag) {
980 			/* Try to issue this as an un-tagged command */
981 			if (!li->untagged)
982 				li->untagged = ecb;
983 		}
984 		if (li->untagged) {
985 			tag = 0;
986 			if ((li->busy != 1) && !li->used) {
987 				/* We need to issue this untagged command now */
988 				ecb = li->untagged;
989 				sc_link = ecb->xs->sc_link;
990 			}
991 			else {
992 				/* Not ready yet */
993 				splx(s);
994 				continue;
995 			}
996 		}
997 		ecb->tag[0] = tag;
998 		if (tag) {
999 			int i;
1000 
1001 			/* Allocate a tag */
1002 			if (li->used == 255) {
1003 				/* no free tags */
1004 				splx(s);
1005 				continue;
1006 			}
1007 			/* Start from the last used location */
1008 			for (i=li->avail; i<256; i++) {
1009 				if (li->queued[i] == NULL)
1010 					break;
1011 			}
1012 			/* Couldn't find one, start again from the beginning */
1013 			if (i == 256) {
1014 				for (i = 0; i<256; i++) {
1015 					if (li->queued[i] == NULL)
1016 						break;
1017 				}
1018 			}
1019 #ifdef DIAGNOSTIC
1020 			if (i == 256)
1021 				panic("ncr53c9x_sched: tag alloc failure");
1022 #endif
1023 
1024 			/* Save where to start next time. */
1025 			li->avail = i+1;
1026 			li->used++;
1027 
1028 			li->queued[i] = ecb;
1029 			ecb->tag[1] = i;
1030 		}
1031 		splx(s);
1032 		if (li->untagged && (li->busy != 1)) {
1033 			li->busy = 1;
1034 			TAILQ_REMOVE(&sc->ready_list, ecb, chain);
1035 			ecb->flags &= ~ECB_READY;
1036 			sc->sc_nexus = ecb;
1037 			ncr53c9x_select(sc, ecb);
1038 			break;
1039 		}
1040 		if (!li->untagged && tag) {
1041 			TAILQ_REMOVE(&sc->ready_list, ecb, chain);
1042 			ecb->flags &= ~ECB_READY;
1043 			sc->sc_nexus = ecb;
1044 			ncr53c9x_select(sc, ecb);
1045 			break;
1046 		} else
1047 			NCR_MISC(("%d:%d busy\n",
1048 				  sc_link->target,
1049 				  sc_link->lun));
1050 	}
1051 }
1052 
1053 void
1054 ncr53c9x_sense(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
1055 {
1056 	struct scsi_xfer *xs = ecb->xs;
1057 	struct scsi_link *sc_link = xs->sc_link;
1058 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
1059 	struct scsi_sense *ss = (void *)&ecb->cmd.cmd;
1060 	struct ncr53c9x_linfo *li;
1061 	int lun = sc_link->lun;
1062 
1063 	NCR_MISC(("requesting sense "));
1064 	/* Next, setup a request sense command block */
1065 	bzero(ss, sizeof(*ss));
1066 	ss->opcode = REQUEST_SENSE;
1067 	ss->byte2 = sc_link->lun << 5;
1068 	ss->length = sizeof(struct scsi_sense_data);
1069 	ecb->clen = sizeof(*ss);
1070 	ecb->daddr = (char *)&xs->sense;
1071 	ecb->dleft = sizeof(struct scsi_sense_data);
1072 	ecb->flags |= ECB_SENSE;
1073 	ecb->timeout = NCR_SENSE_TIMEOUT;
1074 	ti->senses++;
1075 	li = TINFO_LUN(ti, lun);
1076 	if (li->busy) li->busy = 0;
1077 	ncr53c9x_dequeue(sc, ecb);
1078 	li->untagged = ecb;
1079 	li->busy = 2;
1080 	if (ecb == sc->sc_nexus) {
1081 		ncr53c9x_select(sc, ecb);
1082 	} else {
1083 		TAILQ_INSERT_HEAD(&sc->ready_list, ecb, chain);
1084 		ecb->flags |= ECB_READY;
1085 		if (sc->sc_state == NCR_IDLE)
1086 			ncr53c9x_sched(sc);
1087 	}
1088 }
1089 
1090 /*
1091  * POST PROCESSING OF SCSI_CMD (usually current)
1092  */
1093 void
1094 ncr53c9x_done(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
1095 {
1096 	struct scsi_xfer *xs = ecb->xs;
1097 	struct scsi_link *sc_link = xs->sc_link;
1098 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
1099 	int lun = sc_link->lun;
1100 	struct ncr53c9x_linfo *li = TINFO_LUN(ti, lun);
1101 
1102 	NCR_TRACE(("[ncr53c9x_done(error:%x)] ", xs->error));
1103 
1104 	timeout_del(&ecb->to);
1105 
1106 	if (ecb->stat == SCSI_QUEUE_FULL) {
1107 		/*
1108 		 * Set current throttle -- we should reset
1109 		 * this periodically
1110 		 */
1111 		sc_link->openings = li->used - 1;
1112 		printf("\n%s: QFULL -- throttling to %d commands\n",
1113 		    sc->sc_dev.dv_xname, sc_link->openings);
1114 	}
1115 
1116 	/*
1117 	 * Now, if we've come here with no error code, i.e. we've kept the
1118 	 * initial XS_NOERROR, and the status code signals that we should
1119 	 * check sense, we'll need to set up a request sense cmd block and
1120 	 * push the command back into the ready queue *before* any other
1121 	 * commands for this target/lunit, else we lose the sense info.
1122 	 * We don't support chk sense conditions for the request sense cmd.
1123 	 */
1124 	if (xs->error == XS_NOERROR) {
1125 		xs->status = ecb->stat;
1126 		if ((ecb->flags & ECB_ABORT) != 0) {
1127 			xs->error = XS_TIMEOUT;
1128 		} else if ((ecb->flags & ECB_SENSE) != 0) {
1129 			xs->error = XS_SENSE;
1130 		} else if ((ecb->stat & ST_MASK) == SCSI_CHECK) {
1131 			/* First, save the return values */
1132 			xs->resid = ecb->dleft;
1133 			ncr53c9x_sense(sc, ecb);
1134 			return;
1135 		} else {
1136 			xs->resid = ecb->dleft;
1137 		}
1138 	}
1139 
1140 #ifdef NCR53C9X_DEBUG
1141 	if (ncr53c9x_debug & NCR_SHOWMISC) {
1142 		if (xs->resid != 0)
1143 			printf("resid=%lu ", (unsigned long)xs->resid);
1144 		if (xs->error == XS_SENSE)
1145 			printf("sense=0x%02x\n", xs->sense.error_code);
1146 		else
1147 			printf("error=%d\n", xs->error);
1148 	}
1149 #endif
1150 
1151 	/*
1152 	 * Remove the ECB from whatever queue it's on.
1153 	 */
1154 	ncr53c9x_dequeue(sc, ecb);
1155 	if (ecb == sc->sc_nexus) {
1156 		sc->sc_nexus = NULL;
1157 		if (sc->sc_state != NCR_CLEANING) {
1158 			sc->sc_state = NCR_IDLE;
1159 			ncr53c9x_sched(sc);
1160 		}
1161 	}
1162 
1163 	ti->cmds++;
1164 	scsi_done(xs);
1165 }
1166 
1167 void
1168 ncr53c9x_dequeue(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
1169 {
1170 	struct ncr53c9x_tinfo *ti =
1171 	    &sc->sc_tinfo[ecb->xs->sc_link->target];
1172 	struct ncr53c9x_linfo *li;
1173 	int64_t lun = ecb->xs->sc_link->lun;
1174 
1175 	li = TINFO_LUN(ti, lun);
1176 #ifdef DIAGNOSTIC
1177 	if ((!li) || (li->lun != lun))
1178 		panic("ncr53c9x_dequeue: lun %llx for ecb %p does not exist",
1179 		    (long long)lun, ecb);
1180 #endif
1181 	if (li->untagged == ecb) {
1182 		li->busy = 0;
1183 		li->untagged = NULL;
1184 	}
1185 	if (ecb->tag[0] && li->queued[ecb->tag[1]]) {
1186 #ifdef DIAGNOSTIC
1187 		if (li->queued[ecb->tag[1]] && (li->queued[ecb->tag[1]] != ecb))
1188 			panic("ncr53c9x_dequeue: slot %d for lun %llx has %p "
1189 			    "instead of ecb %p", ecb->tag[1],
1190 			    (long long)lun,
1191 			    li->queued[ecb->tag[1]], ecb);
1192 #endif
1193 		li->queued[ecb->tag[1]] = NULL;
1194 		li->used --;
1195 
1196 	}
1197 	if (ecb->flags & ECB_READY) {
1198 		ecb->flags &= ~ECB_READY;
1199 		TAILQ_REMOVE(&sc->ready_list, ecb, chain);
1200 	}
1201  }
1202 
1203 /*
1204  * INTERRUPT/PROTOCOL ENGINE
1205  */
1206 
1207 /*
1208  * Schedule an outgoing message by prioritizing it, and asserting
1209  * attention on the bus. We can only do this when we are the initiator
1210  * else there will be an illegal command interrupt.
1211  */
1212 #define ncr53c9x_sched_msgout(m) \
1213 	do {							\
1214 		NCR_MISC(("ncr53c9x_sched_msgout %x %d ", m, __LINE__));	\
1215 		NCRCMD(sc, NCRCMD_SETATN);			\
1216 		sc->sc_flags |= NCR_ATN;			\
1217 		sc->sc_msgpriq |= (m);				\
1218 	} while (0)
1219 
1220 static void
1221 ncr53c9x_flushfifo(struct ncr53c9x_softc *sc)
1222 {
1223 	NCR_MISC(("[flushfifo] "));
1224 
1225 	NCRCMD(sc, NCRCMD_FLUSH);
1226 
1227 	if (sc->sc_phase == COMMAND_PHASE ||
1228 	    sc->sc_phase == MESSAGE_OUT_PHASE)
1229 		DELAY(2);
1230 }
1231 
1232 static int
1233 ncr53c9x_rdfifo(struct ncr53c9x_softc *sc, int how)
1234 {
1235 	int i, n;
1236 	u_char *buf;
1237 
1238 	switch(how) {
1239 	case NCR_RDFIFO_START:
1240 		buf = sc->sc_imess;
1241 		sc->sc_imlen = 0;
1242 		break;
1243 	case NCR_RDFIFO_CONTINUE:
1244 		buf = sc->sc_imess + sc->sc_imlen;
1245 		break;
1246 	default:
1247 		panic("ncr53c9x_rdfifo: bad flag");
1248 		break;
1249 	}
1250 
1251 	/*
1252 	 * XXX buffer (sc_imess) size for message
1253 	 */
1254 
1255 	n = NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF;
1256 
1257 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
1258 		n *= 2;
1259 
1260 		for (i = 0; i < n; i++)
1261 			buf[i] = NCR_READ_REG(sc, NCR_FIFO);
1262 
1263 		if (sc->sc_espstat2 & FAS_STAT2_ISHUTTLE) {
1264 
1265 			NCR_WRITE_REG(sc, NCR_FIFO, 0);
1266 			buf[i++] = NCR_READ_REG(sc, NCR_FIFO);
1267 
1268 			NCR_READ_REG(sc, NCR_FIFO);
1269 
1270 			ncr53c9x_flushfifo(sc);
1271 		}
1272 	} else {
1273 		for (i = 0; i < n; i++)
1274 			buf[i] = NCR_READ_REG(sc, NCR_FIFO);
1275 	}
1276 
1277 	sc->sc_imlen += i;
1278 
1279 #ifdef NCR53C9X_DEBUG
1280 	{
1281 		int j;
1282 
1283 		NCR_TRACE(("\n[rdfifo %s (%d):",
1284 		    (how == NCR_RDFIFO_START) ? "start" : "cont",
1285 		    (int)sc->sc_imlen));
1286 		if (ncr53c9x_debug & NCR_SHOWTRAC) {
1287 			for (j = 0; j < sc->sc_imlen; j++)
1288 				printf(" %02x", sc->sc_imess[j]);
1289 			printf("]\n");
1290 		}
1291 	}
1292 #endif
1293 	return sc->sc_imlen;
1294 }
1295 
1296 static void
1297 ncr53c9x_wrfifo(struct ncr53c9x_softc *sc, u_char *p, int len)
1298 {
1299 	int i;
1300 
1301 #ifdef NCR53C9X_DEBUG
1302 	NCR_MISC(("[wrfifo(%d):", len));
1303 	if (ncr53c9x_debug & NCR_SHOWTRAC) {
1304 		for (i = 0; i < len; i++)
1305 			printf(" %02x", p[i]);
1306 		printf("]\n");
1307 	}
1308 #endif
1309 
1310 	for (i = 0; i < len; i++) {
1311 		NCR_WRITE_REG(sc, NCR_FIFO, p[i]);
1312 
1313 		if (sc->sc_rev == NCR_VARIANT_FAS366)
1314 			NCR_WRITE_REG(sc, NCR_FIFO, 0);
1315 	}
1316 }
1317 
1318 int
1319 ncr53c9x_reselect(struct ncr53c9x_softc *sc, int message, int tagtype,
1320     int tagid)
1321 {
1322 	u_char selid, target, lun;
1323 	struct ncr53c9x_ecb *ecb = NULL;
1324 	struct ncr53c9x_tinfo *ti;
1325 	struct ncr53c9x_linfo *li;
1326 
1327 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
1328 		target = sc->sc_selid;
1329 	} else {
1330 		/*
1331 		 * The SCSI chip made a snapshot of the data bus while the reselection
1332 		 * was being negotiated.  This enables us to determine which target did
1333 		 * the reselect.
1334 		 */
1335 		selid = sc->sc_selid & ~(1 << sc->sc_id);
1336 		if (selid & (selid - 1)) {
1337 			printf("%s: reselect with invalid selid %02x;"
1338 			    " sending DEVICE RESET\n", sc->sc_dev.dv_xname, selid);
1339 			goto reset;
1340 
1341 		}
1342 		target = ffs(selid) - 1;
1343 	}
1344 	lun = message & 0x07;
1345 
1346 	/*
1347 	 * Search wait queue for disconnected cmd
1348 	 * The list should be short, so I haven't bothered with
1349 	 * any more sophisticated structures than a simple
1350 	 * singly linked list.
1351 	 */
1352 	ti = &sc->sc_tinfo[target];
1353 	li = TINFO_LUN(ti, lun);
1354 
1355 	/*
1356 	 * We can get as far as the LUN with the IDENTIFY
1357 	 * message.  Check to see if we're running an
1358 	 * un-tagged command.  Otherwise ack the IDENTIFY
1359 	 * and wait for a tag message.
1360 	 */
1361 	if (li != NULL) {
1362 		if (li->untagged != NULL && li->busy)
1363 			ecb = li->untagged;
1364 		else if (tagtype != MSG_SIMPLE_Q_TAG) {
1365 			/* Wait for tag to come by */
1366 			sc->sc_state = NCR_IDENTIFIED;
1367 			return (0);
1368 		} else if (tagtype) ecb = li->queued[tagid];
1369 	}
1370 	if (ecb == NULL) {
1371 		printf("%s: reselect from target %d lun %d tag %x:%x with no nexus;"
1372 		    " sending ABORT\n", sc->sc_dev.dv_xname, target, lun, tagtype, tagid);
1373 		goto abort;
1374 	}
1375 
1376 	/* Make this nexus active again. */
1377 	sc->sc_state = NCR_CONNECTED;
1378 	sc->sc_nexus = ecb;
1379 	ncr53c9x_setsync(sc, ti);
1380 
1381 	if (ecb->flags & ECB_RESET)
1382 		ncr53c9x_sched_msgout(SEND_DEV_RESET);
1383 	else if (ecb->flags & ECB_ABORT)
1384 		ncr53c9x_sched_msgout(SEND_ABORT);
1385 
1386 	/* Do an implicit RESTORE POINTERS. */
1387 	sc->sc_dp = ecb->daddr;
1388 	sc->sc_dleft = ecb->dleft;
1389 
1390 	return (0);
1391 
1392 reset:
1393 	ncr53c9x_sched_msgout(SEND_DEV_RESET);
1394 	return (1);
1395 
1396 abort:
1397 	ncr53c9x_sched_msgout(SEND_ABORT);
1398 	return (1);
1399 }
1400 
1401 static inline int
1402 __verify_msg_format(u_char *p, int len)
1403 {
1404 
1405 	if (len == 1 && IS1BYTEMSG(p[0]))
1406 		return 1;
1407 	if (len == 2 && IS2BYTEMSG(p[0]))
1408 		return 1;
1409 	if (len >= 3 && ISEXTMSG(p[0]) &&
1410 	    len == p[1] + 2)
1411 		return 1;
1412 
1413 	return 0;
1414 }
1415 
1416 /*
1417  * Get an incoming message as initiator.
1418  *
1419  * The SCSI bus must already be in MESSAGE_IN_PHASE and there is a
1420  * byte in the FIFO
1421  */
1422 void
1423 ncr53c9x_msgin(struct ncr53c9x_softc *sc)
1424 {
1425 
1426 	NCR_TRACE(("[ncr53c9x_msgin(curmsglen:%ld)] ", (long)sc->sc_imlen));
1427 
1428 	if (sc->sc_imlen == 0) {
1429 		printf("%s: msgin: no msg byte available\n", sc->sc_dev.dv_xname);
1430 		return;
1431 	}
1432 
1433 	/*
1434 	 * Prepare for a new message.  A message should (according
1435 	 * to the SCSI standard) be transmitted in one single
1436 	 * MESSAGE_IN_PHASE. If we have been in some other phase,
1437 	 * then this is a new message.
1438 	 */
1439 	if (sc->sc_prevphase != MESSAGE_IN_PHASE && sc->sc_state != NCR_RESELECTED) {
1440 		printf("%s: phase change, dropping message, prev %d, state %d\n",
1441 		    sc->sc_dev.dv_xname, sc->sc_prevphase, sc->sc_state);
1442 		sc->sc_flags &= ~NCR_DROP_MSGI;
1443 		sc->sc_imlen = 0;
1444 	}
1445 
1446 	NCR_TRACE(("<msgbyte:0x%02x>", sc->sc_imess[0]));
1447 
1448 	/*
1449 	 * If we're going to reject the message, don't bother storing
1450 	 * the incoming bytes.  But still, we need to ACK them.
1451 	 */
1452 	if ((sc->sc_flags & NCR_DROP_MSGI)) {
1453 		NCRCMD(sc, NCRCMD_MSGOK);
1454 		printf("<dropping msg byte %x>",
1455 			sc->sc_imess[sc->sc_imlen]);
1456 		return;
1457 	}
1458 
1459 	if (sc->sc_imlen >= NCR_MAX_MSG_LEN) {
1460 		ncr53c9x_sched_msgout(SEND_REJECT);
1461 		sc->sc_flags |= NCR_DROP_MSGI;
1462 	} else {
1463 		u_char *pb;
1464 		int plen;
1465 
1466 		switch (sc->sc_state) {
1467 			/*
1468 			 * if received message is the first of reselection
1469 			 * then first byte is selid, and then message
1470 			 */
1471 		case NCR_RESELECTED:
1472 			pb = sc->sc_imess + 1;
1473 			plen = sc->sc_imlen - 1;
1474 			break;
1475 		default:
1476 			pb = sc->sc_imess;
1477 			plen = sc->sc_imlen;
1478 			break;
1479 		}
1480 
1481 		if (__verify_msg_format(pb, plen))
1482 			goto gotit;
1483 	}
1484 
1485 	/* Ack what we have so far */
1486 	NCRCMD(sc, NCRCMD_MSGOK);
1487 	return;
1488 
1489 gotit:
1490 	NCR_MSGS(("gotmsg(%x) state %d", sc->sc_imess[0], sc->sc_state));
1491 	/* we got complete message, flush the imess, XXX nobody uses imlen below */
1492 	sc->sc_imlen = 0;
1493 
1494 	/*
1495 	 * Now we should have a complete message (1 byte, 2 byte
1496 	 * and moderately long extended messages).  We only handle
1497 	 * extended messages which total length is shorter than
1498 	 * NCR_MAX_MSG_LEN.  Longer messages will be amputated.
1499 	 */
1500 	switch (sc->sc_state) {
1501 		struct ncr53c9x_ecb *ecb;
1502 		struct ncr53c9x_tinfo *ti;
1503 		struct ncr53c9x_linfo *li;
1504 		int lun;
1505 
1506 	case NCR_CONNECTED:
1507 		ecb = sc->sc_nexus;
1508 		ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
1509 
1510 		switch (sc->sc_imess[0]) {
1511 		case MSG_CMDCOMPLETE:
1512 			NCR_MSGS(("cmdcomplete "));
1513 			if (sc->sc_dleft < 0) {
1514 				sc_print_addr(ecb->xs->sc_link);
1515 				printf("got %ld extra bytes\n",
1516 				    -(long)sc->sc_dleft);
1517 				sc->sc_dleft = 0;
1518 			}
1519 			ecb->dleft = (ecb->flags & ECB_TENTATIVE_DONE)
1520 				? 0
1521 				: sc->sc_dleft;
1522 			if ((ecb->flags & ECB_SENSE) == 0)
1523 				ecb->xs->resid = ecb->dleft;
1524 			sc->sc_state = NCR_CMDCOMPLETE;
1525 			break;
1526 
1527 		case MSG_MESSAGE_REJECT:
1528 			NCR_MSGS(("msg reject (msgout=%x) ", sc->sc_msgout));
1529 			switch (sc->sc_msgout) {
1530 			case SEND_TAG:
1531 				/* Target does not like tagged queuing.
1532 				 *  - Flush the command queue
1533 				 *  - Disable tagged queuing for the target
1534 				 *  - Dequeue ecb from the queued array.
1535 				 */
1536 				printf("%s: tagged queuing rejected: target %d\n",
1537 				    sc->sc_dev.dv_xname, ecb->xs->sc_link->target);
1538 
1539 				NCR_MSGS(("(rejected sent tag)"));
1540 				NCRCMD(sc, NCRCMD_FLUSH);
1541 				DELAY(1);
1542 				ti->flags &= ~T_TAG;
1543 				lun = ecb->xs->sc_link->lun;
1544 				li = TINFO_LUN(ti, lun);
1545 				if (ecb->tag[0] &&
1546 				    li->queued[ecb->tag[1]] != NULL) {
1547 					li->queued[ecb->tag[1]] = NULL;
1548 					li->used--;
1549 				}
1550 				ecb->tag[0] = ecb->tag[1] = 0;
1551 				li->untagged = ecb;
1552 				li->busy = 1;
1553 				break;
1554 
1555 			case SEND_SDTR:
1556 				printf("%s: sync transfer rejected: target %d\n",
1557 				    sc->sc_dev.dv_xname, ecb->xs->sc_link->target);
1558 				sc->sc_flags &= ~NCR_SYNCHNEGO;
1559 				ti->flags &= ~(T_NEGOTIATE | T_SYNCMODE);
1560 				ncr53c9x_setsync(sc, ti);
1561 				break;
1562 
1563 			case SEND_WDTR:
1564 				printf("%s: wide transfer rejected: target %d\n",
1565 				    sc->sc_dev.dv_xname, ecb->xs->sc_link->target);
1566 				ti->flags &= ~T_WIDE;
1567 				ti->width = 0;
1568 				break;
1569 
1570 			case SEND_INIT_DET_ERR:
1571 				goto abort;
1572 			}
1573 			break;
1574 
1575 		case MSG_NOOP:
1576 			NCR_MSGS(("noop "));
1577 			break;
1578 
1579 		case MSG_HEAD_OF_Q_TAG:
1580 		case MSG_SIMPLE_Q_TAG:
1581 		case MSG_ORDERED_Q_TAG:
1582 			NCR_MSGS(("TAG %x:%x", sc->sc_imess[0], sc->sc_imess[1]));
1583 			break;
1584 
1585 		case MSG_DISCONNECT:
1586 			NCR_MSGS(("disconnect "));
1587 			ti->dconns++;
1588 			sc->sc_state = NCR_DISCONNECT;
1589 
1590 			/*
1591 			 * Mark the fact that all bytes have moved. The
1592 			 * target may not bother to do a SAVE POINTERS
1593 			 * at this stage. This flag will set the residual
1594 			 * count to zero on MSG COMPLETE.
1595 			 */
1596 			if (sc->sc_dleft == 0)
1597 				ecb->flags |= ECB_TENTATIVE_DONE;
1598 
1599 			break;
1600 
1601 		case MSG_SAVEDATAPOINTER:
1602 			NCR_MSGS(("save datapointer "));
1603 			ecb->daddr = sc->sc_dp;
1604 			ecb->dleft = sc->sc_dleft;
1605 			break;
1606 
1607 		case MSG_RESTOREPOINTERS:
1608 			NCR_MSGS(("restore datapointer "));
1609 			sc->sc_dp = ecb->daddr;
1610 			sc->sc_dleft = ecb->dleft;
1611 			break;
1612 
1613 		case MSG_EXTENDED:
1614 			NCR_MSGS(("extended(%x) ", sc->sc_imess[2]));
1615 			switch (sc->sc_imess[2]) {
1616 			case MSG_EXT_SDTR:
1617 				NCR_MSGS(("SDTR period %d, offset %d ",
1618 					sc->sc_imess[3], sc->sc_imess[4]));
1619 				if (sc->sc_imess[1] != 3)
1620 					goto reject;
1621 				ti->period = sc->sc_imess[3];
1622 				ti->offset = sc->sc_imess[4];
1623 				ti->flags &= ~T_NEGOTIATE;
1624 				if (sc->sc_minsync == 0 ||
1625 				    ti->offset == 0 ||
1626 				    ti->period > 124) {
1627 #ifdef NCR53C9X_DEBUG
1628 					sc_print_addr(ecb->xs->sc_link);
1629 					printf("async mode\n");
1630 #endif
1631 					if ((sc->sc_flags&NCR_SYNCHNEGO)
1632 					    == 0) {
1633 						/*
1634 						 * target initiated negotiation
1635 						 */
1636 						ti->offset = 0;
1637 						ti->flags &= ~T_SYNCMODE;
1638 						ncr53c9x_sched_msgout(
1639 						    SEND_SDTR);
1640 					} else {
1641 						/* we are async */
1642 						ti->flags &= ~T_SYNCMODE;
1643 					}
1644 				} else {
1645 #ifdef NCR53C9X_DEBUG
1646 					int r, s;
1647 #endif
1648 					int p;
1649 
1650 					p = ncr53c9x_stp2cpb(sc, ti->period);
1651 					ti->period = ncr53c9x_cpb2stp(sc, p);
1652 #ifdef NCR53C9X_DEBUG
1653 					sc_print_addr(ecb->xs->sc_link);
1654 					r = 250/ti->period;
1655 					s = (100*250)/ti->period - 100*r;
1656 					printf("max sync rate %d.%02dMB/s\n",
1657 						r, s);
1658 #endif
1659 					if ((sc->sc_flags&NCR_SYNCHNEGO) == 0) {
1660 						/*
1661 						 * target initiated negotiation
1662 						 */
1663 						if (ti->period <
1664 						    sc->sc_minsync)
1665 							ti->period =
1666 							    sc->sc_minsync;
1667 						if (ti->offset > 15)
1668 							ti->offset = 15;
1669 						ti->flags &= ~T_SYNCMODE;
1670 						ncr53c9x_sched_msgout(
1671 						    SEND_SDTR);
1672 					} else {
1673 						/* we are sync */
1674 						ti->flags |= T_SYNCMODE;
1675 					}
1676 				}
1677 				sc->sc_flags &= ~NCR_SYNCHNEGO;
1678 				ncr53c9x_setsync(sc, ti);
1679 				break;
1680 
1681 			case MSG_EXT_WDTR:
1682 				printf("%s: wide mode %d\n",
1683 				    sc->sc_dev.dv_xname, sc->sc_imess[3]);
1684 				if (sc->sc_imess[3] == 1) {
1685 					ti->cfg3 |= NCRFASCFG3_EWIDE;
1686 					ncr53c9x_setsync(sc, ti);
1687 				} else
1688 					ti->width = 0;
1689 				ti->flags &= ~T_WIDE;
1690 				break;
1691 			default:
1692 				sc_print_addr(ecb->xs->sc_link);
1693 				printf("unrecognized MESSAGE EXTENDED;"
1694 				    " sending REJECT\n");
1695 				goto reject;
1696 			}
1697 			break;
1698 
1699 		default:
1700 			NCR_MSGS(("ident "));
1701 			sc_print_addr(ecb->xs->sc_link);
1702 			printf("unrecognized MESSAGE; sending REJECT\n");
1703 		reject:
1704 			ncr53c9x_sched_msgout(SEND_REJECT);
1705 			break;
1706 		}
1707 		break;
1708 
1709 	case NCR_IDENTIFIED:
1710 		/*
1711 		 * IDENTIFY message was received and queue tag is expected now
1712 		 */
1713 		if ((sc->sc_imess[0] != MSG_SIMPLE_Q_TAG) ||
1714 		    (sc->sc_msgify == 0)) {
1715 			printf("%s: TAG reselect without IDENTIFY;"
1716 			    " MSG %x;"
1717 			    " sending DEVICE RESET\n",
1718 			    sc->sc_dev.dv_xname,
1719 			    sc->sc_imess[0]);
1720 			goto reset;
1721 		}
1722 		(void) ncr53c9x_reselect(sc, sc->sc_msgify,
1723 		    sc->sc_imess[0], sc->sc_imess[1]);
1724 		break;
1725 
1726 	case NCR_RESELECTED:
1727 		if (MSG_ISIDENTIFY(sc->sc_imess[1])) {
1728 			sc->sc_msgify = sc->sc_imess[1];
1729 		} else {
1730 			printf("%s: reselect without IDENTIFY;"
1731 			    " MSG %x;"
1732 			    " sending DEVICE RESET\n",
1733 			    sc->sc_dev.dv_xname,
1734 			    sc->sc_imess[1]);
1735 			goto reset;
1736 		}
1737 		(void) ncr53c9x_reselect(sc, sc->sc_msgify, 0, 0);
1738 		break;
1739 
1740 	default:
1741 		printf("%s: unexpected MESSAGE IN; sending DEVICE RESET\n",
1742 		    sc->sc_dev.dv_xname);
1743 	reset:
1744 		ncr53c9x_sched_msgout(SEND_DEV_RESET);
1745 		break;
1746 
1747 	abort:
1748 		ncr53c9x_sched_msgout(SEND_ABORT);
1749 		break;
1750 	}
1751 
1752 	/* if we have more messages to send set ATN */
1753 	if (sc->sc_msgpriq)
1754 		NCRCMD(sc, NCRCMD_SETATN);
1755 
1756 	/* Ack last message byte */
1757 	NCRCMD(sc, NCRCMD_MSGOK);
1758 
1759 	/* Done, reset message pointer. */
1760 	sc->sc_flags &= ~NCR_DROP_MSGI;
1761 	sc->sc_imlen = 0;
1762 }
1763 
1764 
1765 /*
1766  * Send the highest priority, scheduled message
1767  */
1768 void
1769 ncr53c9x_msgout(struct ncr53c9x_softc *sc)
1770 {
1771 	struct ncr53c9x_tinfo *ti;
1772 	struct ncr53c9x_ecb *ecb;
1773 	size_t size;
1774 
1775 	NCR_TRACE(("[ncr53c9x_msgout(priq:%x, prevphase:%x)]",
1776 	    sc->sc_msgpriq, sc->sc_prevphase));
1777 
1778 	/*
1779 	 * XXX - the NCR_ATN flag is not in sync with the actual ATN
1780 	 *	 condition on the SCSI bus. The 53c9x chip
1781 	 *	 automatically turns off ATN before sending the
1782 	 *	 message byte.  (see also the comment below in the
1783 	 *	 default case when picking out a message to send)
1784 	 */
1785 	if (sc->sc_flags & NCR_ATN) {
1786 		if (sc->sc_prevphase != MESSAGE_OUT_PHASE) {
1787 		new:
1788 			NCRCMD(sc, NCRCMD_FLUSH);
1789 /*			DELAY(1); */
1790 			sc->sc_msgoutq = 0;
1791 			sc->sc_omlen = 0;
1792 		}
1793 	} else {
1794 		if (sc->sc_prevphase == MESSAGE_OUT_PHASE) {
1795 			ncr53c9x_sched_msgout(sc->sc_msgoutq);
1796 			goto new;
1797 		} else {
1798 			printf("%s at line %d: unexpected MESSAGE OUT phase\n",
1799 			    sc->sc_dev.dv_xname, __LINE__);
1800 		}
1801 	}
1802 
1803 	if (sc->sc_omlen == 0) {
1804 		/* Pick up highest priority message */
1805 		sc->sc_msgout = sc->sc_msgpriq & -sc->sc_msgpriq;
1806 		sc->sc_msgoutq |= sc->sc_msgout;
1807 		sc->sc_msgpriq &= ~sc->sc_msgout;
1808 		sc->sc_omlen = 1;		/* "Default" message len */
1809 		switch (sc->sc_msgout) {
1810 		case SEND_SDTR:
1811 			ecb = sc->sc_nexus;
1812 			ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
1813 			sc->sc_omess[0] = MSG_EXTENDED;
1814 			sc->sc_omess[1] = 3;
1815 			sc->sc_omess[2] = MSG_EXT_SDTR;
1816 			sc->sc_omess[3] = ti->period;
1817 			sc->sc_omess[4] = ti->offset;
1818 			sc->sc_omlen = 5;
1819 			if ((sc->sc_flags & NCR_SYNCHNEGO) == 0) {
1820 				ti->flags |= T_SYNCMODE;
1821 				ncr53c9x_setsync(sc, ti);
1822 			}
1823 			break;
1824 		case SEND_WDTR:
1825 			ecb = sc->sc_nexus;
1826 			ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
1827 			sc->sc_omess[0] = MSG_EXTENDED;
1828 			sc->sc_omess[1] = 2;
1829 			sc->sc_omess[2] = MSG_EXT_WDTR;
1830 			sc->sc_omess[3] = ti->width;
1831 			sc->sc_omlen = 4;
1832 			break;
1833 		case SEND_IDENTIFY:
1834 			if (sc->sc_state != NCR_CONNECTED) {
1835 				printf("%s at line %d: no nexus\n",
1836 				    sc->sc_dev.dv_xname, __LINE__);
1837 			}
1838 			ecb = sc->sc_nexus;
1839 			sc->sc_omess[0] =
1840 			    MSG_IDENTIFY(ecb->xs->sc_link->lun, 0);
1841 			break;
1842 		case SEND_TAG:
1843 			if (sc->sc_state != NCR_CONNECTED) {
1844 				printf("%s at line %d: no nexus\n",
1845 				    sc->sc_dev.dv_xname, __LINE__);
1846 			}
1847 			ecb = sc->sc_nexus;
1848 			sc->sc_omess[0] = ecb->tag[0];
1849 			sc->sc_omess[1] = ecb->tag[1];
1850 			sc->sc_omlen = 2;
1851 			break;
1852 		case SEND_DEV_RESET:
1853 			sc->sc_flags |= NCR_ABORTING;
1854 			sc->sc_omess[0] = MSG_BUS_DEV_RESET;
1855 			ecb = sc->sc_nexus;
1856 			ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
1857 			ti->flags &= ~T_SYNCMODE;
1858 			if ((ti->flags & T_SYNCHOFF) == 0)
1859 				/* We can re-start sync negotiation */
1860 				ti->flags |= T_NEGOTIATE;
1861 			break;
1862 		case SEND_PARITY_ERROR:
1863 			sc->sc_omess[0] = MSG_PARITY_ERROR;
1864 			break;
1865 		case SEND_ABORT:
1866 			sc->sc_flags |= NCR_ABORTING;
1867 			sc->sc_omess[0] = MSG_ABORT;
1868 			break;
1869 		case SEND_INIT_DET_ERR:
1870 			sc->sc_omess[0] = MSG_INITIATOR_DET_ERR;
1871 			break;
1872 		case SEND_REJECT:
1873 			sc->sc_omess[0] = MSG_MESSAGE_REJECT;
1874 			break;
1875 		default:
1876 			/*
1877 			 * We normally do not get here, since the chip
1878 			 * automatically turns off ATN before the last
1879 			 * byte of a message is sent to the target.
1880 			 * However, if the target rejects our (multi-byte)
1881 			 * message early by switching to MSG IN phase
1882 			 * ATN remains on, so the target may return to
1883 			 * MSG OUT phase. If there are no scheduled messages
1884 			 * left we send a NO-OP.
1885 			 *
1886 			 * XXX - Note that this leaves no useful purpose for
1887 			 * the NCR_ATN flag.
1888 			 */
1889 			sc->sc_flags &= ~NCR_ATN;
1890 			sc->sc_omess[0] = MSG_NOOP;
1891 			break;
1892 		}
1893 		sc->sc_omp = sc->sc_omess;
1894 	}
1895 
1896 #ifdef DEBUG
1897 	{
1898 		int i;
1899 
1900 		for (i = 0; i<sc->sc_omlen; i++)
1901 			NCR_MISC(("<msgbyte:0x%02x>", sc->sc_omess[i]));
1902 	}
1903 #endif
1904 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
1905 		/*
1906 		 * XXX fifo size
1907 		 */
1908 		ncr53c9x_flushfifo(sc);
1909 		ncr53c9x_wrfifo(sc, sc->sc_omp, sc->sc_omlen);
1910 		sc->sc_cmdlen = 0;
1911 		NCRCMD(sc, NCRCMD_TRANS);
1912 	} else {
1913 		/* (re)send the message */
1914 		size = min(sc->sc_omlen, sc->sc_maxxfer);
1915 		NCRDMA_SETUP(sc, &sc->sc_omp, &sc->sc_omlen, 0, &size);
1916 		/* Program the SCSI counter */
1917 		NCR_SET_COUNT(sc, size);
1918 
1919                /* Load the count in and start the message-out transfer */
1920 		NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
1921 		NCRCMD(sc, NCRCMD_TRANS|NCRCMD_DMA);
1922 		NCRDMA_GO(sc);
1923 	}
1924 }
1925 
1926 /*
1927  * This is the most critical part of the driver, and has to know
1928  * how to deal with *all* error conditions and phases from the SCSI
1929  * bus. If there are no errors and the DMA was active, then call the
1930  * DMA pseudo-interrupt handler. If this returns 1, then that was it
1931  * and we can return from here without further processing.
1932  *
1933  * Most of this needs verifying.
1934  */
1935 int sdebug = 0;
1936 int
1937 ncr53c9x_intr(void *arg)
1938 {
1939 	struct ncr53c9x_softc *sc = arg;
1940 	struct ncr53c9x_ecb *ecb;
1941 	struct scsi_link *sc_link;
1942 	struct ncr53c9x_tinfo *ti;
1943 	size_t size;
1944 	int nfifo;
1945 
1946 	NCR_TRACE(("[ncr53c9x_intr: state %d] ", sc->sc_state));
1947 
1948 	if (!NCRDMA_ISINTR(sc))
1949 		return (0);
1950 
1951 again:
1952 	/* and what do the registers say... */
1953 	ncr53c9x_readregs(sc);
1954 
1955 	/*
1956 	 * At the moment, only a SCSI Bus Reset or Illegal
1957 	 * Command are classed as errors. A disconnect is a
1958 	 * valid condition, and we let the code check is the
1959 	 * "NCR_BUSFREE_OK" flag was set before declaring it
1960 	 * and error.
1961 	 *
1962 	 * Also, the status register tells us about "Gross
1963 	 * Errors" and "Parity errors". Only the Gross Error
1964 	 * is really bad, and the parity errors are dealt
1965 	 * with later
1966 	 *
1967 	 * TODO
1968 	 *      If there are too many parity error, go to slow
1969 	 *      cable mode ?
1970 	 */
1971 
1972 	/* SCSI Reset */
1973 	if (sc->sc_espintr & NCRINTR_SBR) {
1974 		if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
1975 			NCRCMD(sc, NCRCMD_FLUSH);
1976 			DELAY(1);
1977 		}
1978 		if (sc->sc_state != NCR_SBR) {
1979 			printf("%s: SCSI bus reset\n",
1980 				sc->sc_dev.dv_xname);
1981 			ncr53c9x_init(sc, 0); /* Restart everything */
1982 			return (1);
1983 		}
1984 #if 0
1985 /*XXX*/		printf("<expected bus reset: "
1986 			"[intr %x, stat %x, step %d]>\n",
1987 			sc->sc_espintr, sc->sc_espstat,
1988 			sc->sc_espstep);
1989 #endif
1990 		if (sc->sc_nexus)
1991 			panic("%s: nexus in reset state",
1992 		      sc->sc_dev.dv_xname);
1993 		goto sched;
1994 	}
1995 
1996 	ecb = sc->sc_nexus;
1997 
1998 #define NCRINTR_ERR (NCRINTR_SBR|NCRINTR_ILL)
1999 	if (sc->sc_espintr & NCRINTR_ERR ||
2000 	    sc->sc_espstat & NCRSTAT_GE) {
2001 
2002 		if (sc->sc_espstat & NCRSTAT_GE) {
2003 			/* Gross Error; no target ? */
2004 			if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2005 				NCRCMD(sc, NCRCMD_FLUSH);
2006 				DELAY(1);
2007 			}
2008 			if (sc->sc_state == NCR_CONNECTED ||
2009 			    sc->sc_state == NCR_SELECTING) {
2010 				ecb->xs->error = XS_TIMEOUT;
2011 				ncr53c9x_done(sc, ecb);
2012 			}
2013 			return (1);
2014 		}
2015 
2016 		if (sc->sc_espintr & NCRINTR_ILL) {
2017 			if (sc->sc_flags & NCR_EXPECT_ILLCMD) {
2018 				/*
2019 				 * Eat away "Illegal command" interrupt
2020 				 * on a ESP100 caused by a re-selection
2021 				 * while we were trying to select
2022 				 * another target.
2023 				 */
2024 #ifdef DEBUG
2025 				printf("%s: ESP100 work-around activated\n",
2026 					sc->sc_dev.dv_xname);
2027 #endif
2028 				sc->sc_flags &= ~NCR_EXPECT_ILLCMD;
2029 				return (1);
2030 			}
2031 			/* illegal command, out of sync ? */
2032 			printf("%s: illegal command: 0x%x "
2033 			    "(state %d, phase %x, prevphase %x)\n",
2034 				sc->sc_dev.dv_xname, sc->sc_lastcmd,
2035 				sc->sc_state, sc->sc_phase,
2036 				sc->sc_prevphase);
2037 			if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2038 				NCRCMD(sc, NCRCMD_FLUSH);
2039 				DELAY(1);
2040 			}
2041 			ncr53c9x_init(sc, 1); /* Restart everything */
2042 			return (1);
2043 		}
2044 	}
2045 	sc->sc_flags &= ~NCR_EXPECT_ILLCMD;
2046 
2047 	/*
2048 	 * Call if DMA is active.
2049 	 *
2050 	 * If DMA_INTR returns true, then maybe go 'round the loop
2051 	 * again in case there is no more DMA queued, but a phase
2052 	 * change is expected.
2053 	 */
2054 	if (NCRDMA_ISACTIVE(sc)) {
2055 		int r = NCRDMA_INTR(sc);
2056 		if (r == -1) {
2057 			printf("%s: DMA error; resetting\n",
2058 				sc->sc_dev.dv_xname);
2059 			ncr53c9x_init(sc, 1);
2060 			return (1);
2061 		}
2062 		/* If DMA active here, then go back to work... */
2063 		if (NCRDMA_ISACTIVE(sc))
2064 			return (1);
2065 
2066 		if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
2067 			/*
2068 			 * DMA not completed.  If we can not find a
2069 			 * acceptable explanation, print a diagnostic.
2070 			 */
2071 			if (sc->sc_state == NCR_SELECTING)
2072 				/*
2073 				 * This can happen if we are reselected
2074 				 * while using DMA to select a target.
2075 				 */
2076 				/*void*/;
2077 			else if (sc->sc_prevphase == MESSAGE_OUT_PHASE){
2078 				/*
2079 				 * Our (multi-byte) message (eg SDTR)
2080 				 * was interrupted by the target to
2081 				 * send a MSG REJECT.
2082 				 * Print diagnostic if current phase
2083 				 * is not MESSAGE IN.
2084 				 */
2085 				if (sc->sc_phase != MESSAGE_IN_PHASE)
2086 				    printf("%s: !TC on MSG OUT"
2087 				       " [intr %x, stat %x, step %d]"
2088 				       " prevphase %x, resid %lx\n",
2089 					sc->sc_dev.dv_xname,
2090 					sc->sc_espintr,
2091 					sc->sc_espstat,
2092 					sc->sc_espstep,
2093 					sc->sc_prevphase,
2094 					(u_long)sc->sc_omlen);
2095 			} else if (sc->sc_dleft == 0) {
2096 				/*
2097 				 * The DMA operation was started for
2098 				 * a DATA transfer. Print a diagnostic
2099 				 * if the DMA counter and TC bit
2100 				 * appear to be out of sync.
2101 				 */
2102 				printf("%s: !TC on DATA XFER"
2103 				       " [intr %x, stat %x, step %d]"
2104 				       " prevphase %x, resid %x\n",
2105 					sc->sc_dev.dv_xname,
2106 					sc->sc_espintr,
2107 					sc->sc_espstat,
2108 					sc->sc_espstep,
2109 					sc->sc_prevphase,
2110 					ecb?ecb->dleft:-1);
2111 			}
2112 		}
2113 	}
2114 
2115 	/*
2116 	 * check for less serious errors
2117 	 */
2118 	if (sc->sc_espstat & NCRSTAT_PE) {
2119 		printf("%s: SCSI bus parity error\n", sc->sc_dev.dv_xname);
2120 		if (sc->sc_prevphase == MESSAGE_IN_PHASE)
2121 			ncr53c9x_sched_msgout(SEND_PARITY_ERROR);
2122 		else
2123 			ncr53c9x_sched_msgout(SEND_INIT_DET_ERR);
2124 	}
2125 
2126 	if (sc->sc_espintr & NCRINTR_DIS) {
2127 		sc->sc_msgify = 0;
2128 		NCR_MISC(("<DISC [intr %x, stat %x, step %d]>",
2129 			sc->sc_espintr,sc->sc_espstat,sc->sc_espstep));
2130 		if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2131 			NCRCMD(sc, NCRCMD_FLUSH);
2132 /*			DELAY(1); */
2133 		}
2134 		/*
2135 		 * This command must (apparently) be issued within
2136 		 * 250mS of a disconnect. So here you are...
2137 		 */
2138 		NCRCMD(sc, NCRCMD_ENSEL);
2139 
2140 		switch (sc->sc_state) {
2141 		case NCR_RESELECTED:
2142 			goto sched;
2143 
2144 		case NCR_SELECTING:
2145 			ecb->xs->error = XS_SELTIMEOUT;
2146 			goto finish;
2147 
2148 		case NCR_CONNECTED:
2149 			if ((sc->sc_flags & NCR_SYNCHNEGO)) {
2150 #ifdef NCR53C9X_DEBUG
2151 				if (ecb)
2152 					sc_print_addr(ecb->xs->sc_link);
2153 				printf("sync nego not completed!\n");
2154 #endif
2155 				ti = &sc->sc_tinfo[ecb->xs->sc_link->target];
2156 				sc->sc_flags &= ~NCR_SYNCHNEGO;
2157 				ti->flags &= ~(T_NEGOTIATE | T_SYNCMODE);
2158 			}
2159 
2160 			/* it may be OK to disconnect */
2161 			if ((sc->sc_flags & NCR_ABORTING) == 0) {
2162 				/*
2163 				 * Section 5.1.1 of the SCSI 2 spec
2164 				 * suggests issuing a REQUEST SENSE
2165 				 * following an unexpected disconnect.
2166 				 * Some devices go into a contingent
2167 				 * allegiance condition when
2168 				 * disconnecting, and this is necessary
2169 				 * to clean up their state.
2170 				 */
2171 				printf("%s: unexpected disconnect; ",
2172 				    sc->sc_dev.dv_xname);
2173 				if (ecb->flags & ECB_SENSE) {
2174 					printf("resetting\n");
2175 					goto reset;
2176 				}
2177 				printf("sending REQUEST SENSE\n");
2178 				timeout_del(&ecb->to);
2179 				ncr53c9x_sense(sc, ecb);
2180 				goto out;
2181 			}
2182 
2183 			ecb->xs->error = XS_TIMEOUT;
2184 			goto finish;
2185 
2186 		case NCR_DISCONNECT:
2187 			sc->sc_nexus = NULL;
2188 			goto sched;
2189 
2190 		case NCR_CMDCOMPLETE:
2191 			goto finish;
2192 		}
2193 	}
2194 
2195 	switch (sc->sc_state) {
2196 
2197 	case NCR_SBR:
2198 		printf("%s: waiting for SCSI Bus Reset to happen\n",
2199 			sc->sc_dev.dv_xname);
2200 		return (1);
2201 
2202 	case NCR_RESELECTED:
2203 		/*
2204 		 * we must be continuing a message ?
2205 		 */
2206 		if (sc->sc_phase != MESSAGE_IN_PHASE) {
2207 			printf("%s: target didn't identify\n",
2208 				sc->sc_dev.dv_xname);
2209 			ncr53c9x_init(sc, 1);
2210 			return (1);
2211 		}
2212 printf("<<RESELECT CONT'd>>");
2213 #if XXXX
2214 		ncr53c9x_msgin(sc);
2215 		if (sc->sc_state != NCR_CONNECTED) {
2216 			/* IDENTIFY fail?! */
2217 			printf("%s: identify failed\n",
2218 				sc->sc_dev.dv_xname);
2219 			ncr53c9x_init(sc, 1);
2220 			return (1);
2221 		}
2222 #endif
2223 		break;
2224 
2225 	case NCR_IDENTIFIED:
2226 		ecb = sc->sc_nexus;
2227 		if (sc->sc_phase != MESSAGE_IN_PHASE) {
2228 			int i = (NCR_READ_REG(sc, NCR_FFLAG)
2229 			    & NCRFIFO_FF);
2230 			/*
2231 			 * Things are seriously fucked up.
2232 			 * Pull the brakes, i.e. reset
2233 			 */
2234 			printf("%s: target didn't send tag: %d bytes in fifo\n",
2235 			    sc->sc_dev.dv_xname, i);
2236 			/* Drain and display fifo */
2237 			while (i-- > 0)
2238 				printf("[%d] ", NCR_READ_REG(sc, NCR_FIFO));
2239 			ncr53c9x_init(sc, 1);
2240 			return (1);
2241 		} else
2242 			goto msgin;
2243 
2244 		break;
2245 	case NCR_IDLE:
2246 	case NCR_SELECTING:
2247 		ecb = sc->sc_nexus;
2248 		if (sc->sc_espintr & NCRINTR_RESEL) {
2249 			sc->sc_msgpriq = sc->sc_msgout = sc->sc_msgoutq = 0;
2250 			sc->sc_flags = 0;
2251 			/*
2252 			 * If we're trying to select a
2253 			 * target ourselves, push our command
2254 			 * back into the ready list.
2255 			 */
2256 			if (sc->sc_state == NCR_SELECTING) {
2257 				NCR_MISC(("backoff selector "));
2258 				timeout_del(&ecb->to);
2259 				ncr53c9x_dequeue(sc, ecb);
2260 				TAILQ_INSERT_HEAD(&sc->ready_list, ecb, chain);
2261 				ecb->flags |= ECB_READY;
2262 				ecb = sc->sc_nexus = NULL;
2263 			}
2264 			sc->sc_state = NCR_RESELECTED;
2265 			if (sc->sc_phase != MESSAGE_IN_PHASE) {
2266 				/*
2267 				 * Things are seriously fucked up.
2268 				 * Pull the brakes, i.e. reset
2269 				 */
2270 				printf("%s: target didn't identify\n",
2271 					sc->sc_dev.dv_xname);
2272 				ncr53c9x_init(sc, 1);
2273 				return (1);
2274 			}
2275 			/*
2276 			 * The C90 only inhibits FIFO writes until
2277 			 * reselection is complete, instead of
2278 			 * waiting until the interrupt status register
2279 			 * has been read. So, if the reselect happens
2280 			 * while we were entering a command bytes (for
2281 			 * another target) some of those bytes can
2282 			 * appear in the FIFO here, after the
2283 			 * interrupt is taken.
2284 			 */
2285 			nfifo = ncr53c9x_rdfifo(sc, NCR_RDFIFO_START);
2286 
2287 			if (nfifo < 2 ||
2288 			    (nfifo > 2 &&
2289 			     sc->sc_rev != NCR_VARIANT_ESP100)) {
2290 				printf("%s: RESELECT: "
2291 				    "%d bytes in FIFO! "
2292 				    "[intr %x, stat %x, step %d, prevphase %x]\n",
2293 					sc->sc_dev.dv_xname,
2294 					nfifo,
2295 					sc->sc_espintr,
2296 					sc->sc_espstat,
2297 					sc->sc_espstep,
2298 					sc->sc_prevphase);
2299 				ncr53c9x_init(sc, 1);
2300 				return (1);
2301 			}
2302 			sc->sc_selid = sc->sc_imess[0];
2303 			NCR_MISC(("selid=%2x ", sc->sc_selid));
2304 
2305 			/* Handle identify message */
2306 			ncr53c9x_msgin(sc);
2307 			if (nfifo != 2) {
2308 				/*
2309 				 * Note: this should not happen
2310 				 * with `dmaselect' on.
2311 				 */
2312 				sc->sc_flags |= NCR_EXPECT_ILLCMD;
2313 				NCRCMD(sc, NCRCMD_FLUSH);
2314 			} else if (sc->sc_features & NCR_F_DMASELECT &&
2315 				   sc->sc_rev == NCR_VARIANT_ESP100) {
2316 				sc->sc_flags |= NCR_EXPECT_ILLCMD;
2317 			}
2318 
2319 			if (sc->sc_state != NCR_CONNECTED &&
2320 			    sc->sc_state != NCR_IDENTIFIED) {
2321 				/* IDENTIFY fail?! */
2322 				printf("%s: identify failed, state %d, intr %02x\n",
2323 					sc->sc_dev.dv_xname, sc->sc_state,
2324 				    sc->sc_espintr);
2325 				ncr53c9x_init(sc, 1);
2326 				return (1);
2327 			}
2328 			goto shortcut; /* ie. next phase expected soon */
2329 		}
2330 
2331 #define	NCRINTR_DONE	(NCRINTR_FC|NCRINTR_BS)
2332 		if ((sc->sc_espintr & NCRINTR_DONE) == NCRINTR_DONE) {
2333 			/*
2334 			 * Arbitration won; examine the `step' register
2335 			 * to determine how far the selection could progress.
2336 			 */
2337 			ecb = sc->sc_nexus;
2338 			if (!ecb)
2339 				panic("ncr53c9x: no nexus");
2340 
2341 			sc_link = ecb->xs->sc_link;
2342 			ti = &sc->sc_tinfo[sc_link->target];
2343 
2344 			switch (sc->sc_espstep) {
2345 			case 0:
2346 				/*
2347 				 * The target did not respond with a
2348 				 * message out phase - probably an old
2349 				 * device that doesn't recognize ATN.
2350 				 * Clear ATN and just continue, the
2351 				 * target should be in the command
2352 				 * phase.
2353 				 * XXXX check for command phase?
2354 				 */
2355 				NCRCMD(sc, NCRCMD_RSTATN);
2356 				break;
2357 			case 1:
2358 				if ((ti->flags & T_NEGOTIATE) == 0 &&
2359 				    ecb->tag[0] == 0) {
2360 					printf("%s: step 1 & !NEG\n",
2361 						sc->sc_dev.dv_xname);
2362 					goto reset;
2363 				}
2364 				if (sc->sc_phase != MESSAGE_OUT_PHASE) {
2365 					printf("%s: !MSGOUT\n",
2366 						sc->sc_dev.dv_xname);
2367 					goto reset;
2368 				}
2369 				if (ti->flags & T_WIDE) {
2370 					ncr53c9x_sched_msgout(SEND_WDTR);
2371 				}
2372 				if (ti->flags & T_NEGOTIATE) {
2373 					/* Start negotiating */
2374 					ti->period = sc->sc_minsync;
2375 					ti->offset = 15;
2376 					sc->sc_flags |= NCR_SYNCHNEGO;
2377 					if (ecb->tag[0])
2378 						ncr53c9x_sched_msgout(SEND_TAG|SEND_SDTR);
2379 					else
2380 						ncr53c9x_sched_msgout(SEND_SDTR);
2381 				} else {
2382 					/* Could not do ATN3 so send TAG */
2383 					ncr53c9x_sched_msgout(SEND_TAG);
2384 				}
2385 				sc->sc_prevphase = MESSAGE_OUT_PHASE; /* XXXX */
2386 				break;
2387 			case 3:
2388 				/*
2389 				 * Grr, this is supposed to mean
2390 				 * "target left command phase  prematurely".
2391 				 * It seems to happen regularly when
2392 				 * sync mode is on.
2393 				 * Look at FIFO to see if command went out.
2394 				 * (Timing problems?)
2395 				 */
2396 				if (sc->sc_features & NCR_F_DMASELECT) {
2397 					if (sc->sc_cmdlen == 0)
2398 						/* Hope for the best.. */
2399 						break;
2400 				} else if ((NCR_READ_REG(sc, NCR_FFLAG)
2401 					    & NCRFIFO_FF) == 0) {
2402 					/* Hope for the best.. */
2403 					break;
2404 				}
2405 				printf("(%s:%d:%d): selection failed;"
2406 					" %d left in FIFO "
2407 					"[intr %x, stat %x, step %d]\n",
2408 					sc->sc_dev.dv_xname,
2409 					sc_link->target,
2410 					sc_link->lun,
2411 					NCR_READ_REG(sc, NCR_FFLAG)
2412 					 & NCRFIFO_FF,
2413 					sc->sc_espintr, sc->sc_espstat,
2414 					sc->sc_espstep);
2415 				NCRCMD(sc, NCRCMD_FLUSH);
2416 				ncr53c9x_sched_msgout(SEND_ABORT);
2417 				return (1);
2418 			case 2:
2419 				/* Select stuck at Command Phase */
2420 				NCRCMD(sc, NCRCMD_FLUSH);
2421 				break;
2422 			case 4:
2423 				if (sc->sc_features & NCR_F_DMASELECT &&
2424 				    sc->sc_cmdlen != 0)
2425 					printf("(%s:%d:%d): select; "
2426 					       "%lu left in DMA buffer "
2427 					"[intr %x, stat %x, step %d]\n",
2428 						sc->sc_dev.dv_xname,
2429 						sc_link->target,
2430 						sc_link->lun,
2431 						(u_long)sc->sc_cmdlen,
2432 						sc->sc_espintr,
2433 						sc->sc_espstat,
2434 						sc->sc_espstep);
2435 				/* So far, everything went fine */
2436 				break;
2437 			}
2438 
2439 			sc->sc_prevphase = INVALID_PHASE; /* ?? */
2440 			/* Do an implicit RESTORE POINTERS. */
2441 			sc->sc_dp = ecb->daddr;
2442 			sc->sc_dleft = ecb->dleft;
2443 			sc->sc_state = NCR_CONNECTED;
2444 			break;
2445 
2446 		} else {
2447 
2448 			printf("%s: unexpected status after select"
2449 				": [intr %x, stat %x, step %x]\n",
2450 				sc->sc_dev.dv_xname,
2451 				sc->sc_espintr, sc->sc_espstat,
2452 				sc->sc_espstep);
2453 			NCRCMD(sc, NCRCMD_FLUSH);
2454 			DELAY(1);
2455 			goto reset;
2456 		}
2457 		if (sc->sc_state == NCR_IDLE) {
2458 			printf("%s: stray interrupt\n",
2459 			    sc->sc_dev.dv_xname);
2460 				return (0);
2461 		}
2462 		break;
2463 
2464 	case NCR_CONNECTED:
2465 		if (sc->sc_flags & NCR_ICCS) {
2466 			/* "Initiate Command Complete Steps" in progress */
2467 			u_char msg;
2468 
2469 			sc->sc_flags &= ~NCR_ICCS;
2470 
2471 			if (!(sc->sc_espintr & NCRINTR_DONE)) {
2472 				printf("%s: ICCS: "
2473 				      ": [intr %x, stat %x, step %x]\n",
2474 					sc->sc_dev.dv_xname,
2475 					sc->sc_espintr, sc->sc_espstat,
2476 					sc->sc_espstep);
2477 			}
2478 			ncr53c9x_rdfifo(sc, NCR_RDFIFO_START);
2479 			if (sc->sc_imlen < 2)
2480 				printf("%s: can't get status, only %d bytes\n",
2481 				    sc->sc_dev.dv_xname, (int)sc->sc_imlen);
2482 			ecb->stat = sc->sc_imess[sc->sc_imlen - 2];
2483 			msg = sc->sc_imess[sc->sc_imlen - 1];
2484 			NCR_PHASE(("<stat:(%x,%x)>", ecb->stat, msg));
2485 			if (msg == MSG_CMDCOMPLETE) {
2486 				ecb->dleft = (ecb->flags & ECB_TENTATIVE_DONE)
2487 					? 0
2488 					: sc->sc_dleft;
2489 				if ((ecb->flags & ECB_SENSE) == 0)
2490 					ecb->xs->resid = ecb->dleft;
2491 				sc->sc_state = NCR_CMDCOMPLETE;
2492 			} else
2493 				printf("%s: STATUS_PHASE: msg %d\n",
2494 					sc->sc_dev.dv_xname, msg);
2495 			sc->sc_imlen = 0;
2496 			NCRCMD(sc, NCRCMD_MSGOK);
2497 			goto shortcut; /* ie. wait for disconnect */
2498 		}
2499 		break;
2500 	default:
2501 		/* Don't panic: reset. */
2502 		printf("%s: invalid state: %d\n",
2503 		      sc->sc_dev.dv_xname,
2504 		      sc->sc_state);
2505 		ncr53c9x_scsi_reset(sc);
2506 		goto out;
2507 		break;
2508 	}
2509 
2510 	/*
2511 	 * Driver is now in state NCR_CONNECTED, i.e. we
2512 	 * have a current command working the SCSI bus.
2513 	 */
2514 	if (sc->sc_state != NCR_CONNECTED || ecb == NULL) {
2515 		panic("ncr53c9x no nexus");
2516 	}
2517 
2518 	switch (sc->sc_phase) {
2519 	case MESSAGE_OUT_PHASE:
2520 		NCR_PHASE(("MESSAGE_OUT_PHASE "));
2521 		ncr53c9x_msgout(sc);
2522 		sc->sc_prevphase = MESSAGE_OUT_PHASE;
2523 		break;
2524 	case MESSAGE_IN_PHASE:
2525 msgin:
2526 		NCR_PHASE(("MESSAGE_IN_PHASE "));
2527 		if (sc->sc_espintr & NCRINTR_BS) {
2528 			if ((sc->sc_rev != NCR_VARIANT_FAS366) ||
2529 			    !(sc->sc_espstat2 & FAS_STAT2_EMPTY)) {
2530 				NCRCMD(sc, NCRCMD_FLUSH);
2531 			}
2532 			sc->sc_flags |= NCR_WAITI;
2533 			NCRCMD(sc, NCRCMD_TRANS);
2534 		} else if (sc->sc_espintr & NCRINTR_FC) {
2535 			if ((sc->sc_flags & NCR_WAITI) == 0) {
2536 				printf("%s: MSGIN: unexpected FC bit: "
2537 					"[intr %x, stat %x, step %x]\n",
2538 				sc->sc_dev.dv_xname,
2539 				sc->sc_espintr, sc->sc_espstat,
2540 				sc->sc_espstep);
2541 			}
2542 			sc->sc_flags &= ~NCR_WAITI;
2543 			ncr53c9x_rdfifo(sc,
2544 			    (sc->sc_prevphase == sc->sc_phase) ?
2545 			    NCR_RDFIFO_CONTINUE : NCR_RDFIFO_START);
2546 			ncr53c9x_msgin(sc);
2547 		} else {
2548 			printf("%s: MSGIN: weird bits: "
2549 				"[intr %x, stat %x, step %x]\n",
2550 				sc->sc_dev.dv_xname,
2551 				sc->sc_espintr, sc->sc_espstat,
2552 				sc->sc_espstep);
2553 		}
2554 		sc->sc_prevphase = MESSAGE_IN_PHASE;
2555 		goto shortcut;	/* i.e. expect data to be ready */
2556 		break;
2557 	case COMMAND_PHASE:
2558 		/*
2559 		 * Send the command block. Normally we don't see this
2560 		 * phase because the SEL_ATN command takes care of
2561 		 * all this. However, we end up here if either the
2562 		 * target or we wanted to exchange some more messages
2563 		 * first (e.g. to start negotiations).
2564 		 */
2565 
2566 		NCR_PHASE(("COMMAND_PHASE 0x%02x (%d) ",
2567 			ecb->cmd.cmd.opcode, ecb->clen));
2568 		if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
2569 			NCRCMD(sc, NCRCMD_FLUSH);
2570 /*			DELAY(1); */
2571 		}
2572 		if (sc->sc_features & NCR_F_DMASELECT) {
2573 			/* setup DMA transfer for command */
2574 			size = ecb->clen;
2575 			sc->sc_cmdlen = size;
2576 			sc->sc_cmdp = (caddr_t)&ecb->cmd.cmd;
2577 			NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen,
2578 				     0, &size);
2579 			/* Program the SCSI counter */
2580 			NCR_SET_COUNT(sc, size);
2581 
2582 			/* load the count in */
2583 			NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
2584 
2585 			/* start the command transfer */
2586 			NCRCMD(sc, NCRCMD_TRANS | NCRCMD_DMA);
2587 			NCRDMA_GO(sc);
2588 		} else {
2589 			ncr53c9x_wrfifo(sc, (u_char *)&ecb->cmd.cmd, ecb->clen);
2590 			sc->sc_cmdlen = 0;
2591 			NCRCMD(sc, NCRCMD_TRANS);
2592 		}
2593 		sc->sc_prevphase = COMMAND_PHASE;
2594 		break;
2595 	case DATA_OUT_PHASE:
2596 		NCR_PHASE(("DATA_OUT_PHASE [%ld] ",(long)sc->sc_dleft));
2597 		NCRCMD(sc, NCRCMD_FLUSH);
2598 		size = min(sc->sc_dleft, sc->sc_maxxfer);
2599 		NCRDMA_SETUP(sc, &sc->sc_dp, &sc->sc_dleft,
2600 			  0, &size);
2601 		sc->sc_prevphase = DATA_OUT_PHASE;
2602 		goto setup_xfer;
2603 	case DATA_IN_PHASE:
2604 		NCR_PHASE(("DATA_IN_PHASE "));
2605 		if (sc->sc_rev == NCR_VARIANT_ESP100)
2606 			NCRCMD(sc, NCRCMD_FLUSH);
2607 		size = min(sc->sc_dleft, sc->sc_maxxfer);
2608 		NCRDMA_SETUP(sc, &sc->sc_dp, &sc->sc_dleft,
2609 			  1, &size);
2610 		sc->sc_prevphase = DATA_IN_PHASE;
2611 	setup_xfer:
2612 		/* Target returned to data phase: wipe "done" memory */
2613 		ecb->flags &= ~ECB_TENTATIVE_DONE;
2614 
2615 		/* Program the SCSI counter */
2616 		NCR_SET_COUNT(sc, size);
2617 
2618 		/* load the count in */
2619 		NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
2620 
2621 		/*
2622 		 * Note that if `size' is 0, we've already transceived
2623 		 * all the bytes we want but we're still in DATA PHASE.
2624 		 * Apparently, the device needs padding. Also, a
2625 		 * transfer size of 0 means "maximum" to the chip
2626 		 * DMA logic.
2627 		 */
2628 		NCRCMD(sc,
2629 		       (size==0?NCRCMD_TRPAD:NCRCMD_TRANS)|NCRCMD_DMA);
2630 		NCRDMA_GO(sc);
2631 		return (1);
2632 	case STATUS_PHASE:
2633 		NCR_PHASE(("STATUS_PHASE "));
2634 		sc->sc_flags |= NCR_ICCS;
2635 		NCRCMD(sc, NCRCMD_ICCS);
2636 		sc->sc_prevphase = STATUS_PHASE;
2637 		goto shortcut;	/* i.e. expect status results soon */
2638 		break;
2639 	case INVALID_PHASE:
2640 		break;
2641 	default:
2642 		printf("%s: unexpected bus phase; resetting\n",
2643 		    sc->sc_dev.dv_xname);
2644 		goto reset;
2645 	}
2646 
2647 out:
2648 	return (1);
2649 
2650 reset:
2651 	ncr53c9x_init(sc, 1);
2652 	goto out;
2653 
2654 finish:
2655 	ncr53c9x_done(sc, ecb);
2656 	goto out;
2657 
2658 sched:
2659 	sc->sc_state = NCR_IDLE;
2660 	ncr53c9x_sched(sc);
2661 	goto out;
2662 
2663 shortcut:
2664 	/*
2665 	 * The idea is that many of the SCSI operations take very little
2666 	 * time, and going away and getting interrupted is too high an
2667 	 * overhead to pay. For example, selecting, sending a message
2668 	 * and command and then doing some work can be done in one "pass".
2669 	 *
2670 	 * The delay is a heuristic. It is 2 when at 20MHz, 2 at 25MHz and 1
2671 	 * at 40MHz. This needs testing.
2672 	 */
2673 	{
2674 		struct timeval wait, cur;
2675 
2676 		microuptime(&wait);
2677 		wait.tv_usec += 50/sc->sc_freq;
2678 		if (wait.tv_usec >= 1000000) {
2679 			wait.tv_sec++;
2680 			wait.tv_usec -= 1000000;
2681 		}
2682 		do {
2683 			if (NCRDMA_ISINTR(sc))
2684 				goto again;
2685 			microuptime(&cur);
2686 		} while (timercmp(&cur, &wait, <=));
2687 	}
2688 	goto out;
2689 }
2690 
2691 void
2692 ncr53c9x_abort(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
2693 {
2694 
2695 	/* 2 secs for the abort */
2696 	ecb->timeout = NCR_ABORT_TIMEOUT;
2697 	ecb->flags |= ECB_ABORT;
2698 
2699 	if (ecb == sc->sc_nexus) {
2700 		int timeout = ecb->timeout;
2701 
2702 		/*
2703 		 * If we're still selecting, the message will be scheduled
2704 		 * after selection is complete.
2705 		 */
2706 		if (sc->sc_state == NCR_CONNECTED)
2707 			ncr53c9x_sched_msgout(SEND_ABORT);
2708 
2709 		/*
2710 		 * Reschedule timeout.
2711 		 */
2712 		if (timeout > 1000000)
2713 			timeout = (timeout / 1000) * hz;
2714 		else
2715 			timeout = (timeout * hz) / 1000;
2716 		timeout_add(&ecb->to, timeout);
2717 	} else {
2718 		/*
2719 		 * Just leave the command where it is.
2720 		 * XXX - what choice do we have but to reset the SCSI
2721 		 *	 eventually?
2722 		 */
2723 		if (sc->sc_state == NCR_IDLE)
2724 			ncr53c9x_sched(sc);
2725 	}
2726 }
2727 
2728 void
2729 ncr53c9x_timeout(void *arg)
2730 {
2731 	struct ncr53c9x_ecb *ecb = arg;
2732 	struct scsi_xfer *xs = ecb->xs;
2733 	struct scsi_link *sc_link = xs->sc_link;
2734 	struct ncr53c9x_softc *sc = sc_link->bus->sb_adapter_softc;
2735 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[sc_link->target];
2736 	int s;
2737 
2738 	sc_print_addr(sc_link);
2739 	printf("timed out [ecb %p (flags 0x%x, dleft %x, stat %x)], "
2740 	       "<state %d, nexus %p, phase(l %x, c %x, p %x), resid %lx, "
2741 	       "msg(q %x,o %x) %s>",
2742 		ecb, ecb->flags, ecb->dleft, ecb->stat,
2743 		sc->sc_state, sc->sc_nexus,
2744 		NCR_READ_REG(sc, NCR_STAT),
2745 		sc->sc_phase, sc->sc_prevphase,
2746 		(long)sc->sc_dleft, sc->sc_msgpriq, sc->sc_msgout,
2747 		NCRDMA_ISACTIVE(sc) ? "DMA active" : "");
2748 #if NCR53C9X_DEBUG > 1
2749 	printf("TRACE: %s.", ecb->trace);
2750 #endif
2751 
2752 	s = splbio();
2753 
2754 	if (ecb->flags & ECB_ABORT) {
2755 		/* abort timed out */
2756 		printf(" AGAIN\n");
2757 
2758 		ncr53c9x_init(sc, 1);
2759 	} else {
2760 		/* abort the operation that has timed out */
2761 		printf("\n");
2762 		xs->error = XS_TIMEOUT;
2763 		ncr53c9x_abort(sc, ecb);
2764 
2765 		/* Disable sync mode if stuck in a data phase */
2766 		if (ecb == sc->sc_nexus &&
2767 		    (ti->flags & T_SYNCMODE) != 0 &&
2768 		    (sc->sc_phase & (MSGI|CDI)) == 0) {
2769 			sc_print_addr(sc_link);
2770 			printf("sync negotiation disabled\n");
2771 			sc->sc_cfflags |= (1 << (sc_link->target + 16));
2772 		}
2773 	}
2774 
2775 	splx(s);
2776 }
2777