xref: /netbsd-src/sys/arch/acorn32/podulebus/sfas.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: sfas.c,v 1.16 2006/03/08 23:46:22 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Van Jacobson of Lawrence Berkeley Laboratory.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)scsi.c	7.5 (Berkeley) 5/4/91
35  */
36 
37 /*
38  * Copyright (c) 1995 Scott Stevens
39  * Copyright (c) 1995 Daniel Widenfalk
40  * Copyright (c) 1994 Christian E. Hopps
41  *
42  * This code is derived from software contributed to Berkeley by
43  * Van Jacobson of Lawrence Berkeley Laboratory.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. All advertising materials mentioning features or use of this software
54  *    must display the following acknowledgement:
55  *	This product includes software developed by the University of
56  *	California, Berkeley and its contributors.
57  * 4. Neither the name of the University nor the names of its contributors
58  *    may be used to endorse or promote products derived from this software
59  *    without specific prior written permission.
60  *
61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71  * SUCH DAMAGE.
72  *
73  *	@(#)scsi.c	7.5 (Berkeley) 5/4/91
74  */
75 
76 /*
77  * Emulex FAS216 scsi adaptor driver
78  */
79 
80 /*
81  * Modified for NetBSD/arm32 by Scott Stevens
82  */
83 
84 #include <sys/cdefs.h>
85 __KERNEL_RCSID(0, "$NetBSD: sfas.c,v 1.16 2006/03/08 23:46:22 lukem Exp $");
86 
87 #include <sys/param.h>
88 #include <sys/systm.h>
89 #include <sys/device.h>
90 #include <sys/buf.h>
91 #include <sys/proc.h>
92 
93 #include <dev/scsipi/scsi_all.h>
94 #include <dev/scsipi/scsipi_all.h>
95 #include <dev/scsipi/scsiconf.h>
96 
97 #include <uvm/uvm_extern.h>
98 
99 #include <machine/pmap.h>
100 #include <machine/cpu.h>
101 #include <machine/io.h>
102 #include <machine/intr.h>
103 #include <arm/arm32/katelib.h>
104 #include <acorn32/podulebus/podulebus.h>
105 #include <acorn32/podulebus/sfasreg.h>
106 #include <acorn32/podulebus/sfasvar.h>
107 
108 void sfas_minphys(struct buf *);
109 void sfas_init_nexus(struct sfas_softc *, struct nexus *);
110 void sfasinitialize(struct sfas_softc *);
111 void sfas_scsi_request(struct scsipi_channel *, scsipi_adapter_req_t, void *);
112 void sfas_donextcmd(struct sfas_softc *, struct sfas_pending *);
113 void sfas_scsidone(struct sfas_softc *, struct scsipi_xfer *, int);
114 void sfasintr(struct sfas_softc *);
115 void sfasiwait(struct sfas_softc *);
116 void sfas_ixfer(void *, int);
117 void sfasreset(struct sfas_softc *, int);
118 int  sfasselect(struct sfas_softc *, struct sfas_pending *, unsigned char *,
119 		int, unsigned char *, int, int);
120 void sfasicmd(struct sfas_softc *, struct sfas_pending *);
121 void sfasgo(struct sfas_softc *, struct sfas_pending *);
122 void sfas_save_pointers(struct sfas_softc *);
123 void sfas_restore_pointers(struct sfas_softc *);
124 void sfas_build_sdtrm(struct sfas_softc *, int, int);
125 int sfas_select_unit(struct sfas_softc *, short);
126 struct nexus *sfas_arbitate_target(struct sfas_softc *, int);
127 void sfas_setup_nexus(struct sfas_softc *, struct nexus *,
128 		      struct sfas_pending *, unsigned char *, int,
129 		      unsigned char *, int, int);
130 int sfas_pretests(struct sfas_softc *, sfas_regmap_p);
131 int sfas_midaction(struct sfas_softc *, sfas_regmap_p, struct nexus *);
132 int sfas_postaction(struct sfas_softc *, sfas_regmap_p, struct nexus *);
133 
134 /*
135  * Initialize these to make 'em patchable. Defaults to enable sync and discon.
136  */
137 u_char	sfas_inhibit_sync[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
138 u_char	sfas_inhibit_disc[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
139 
140 #define DEBUG
141 #ifdef DEBUG
142 #define QPRINTF(a) if (sfas_debug > 1) printf a
143 int	sfas_debug = 2;
144 #else
145 #define QPRINTF
146 #endif
147 
148 /*
149  * default minphys routine for sfas based controllers
150  */
151 void
152 sfas_minphys(bp)
153 	struct buf *bp;
154 {
155 
156 	/*
157 	 * No max transfer at this level.
158 	 */
159 	minphys(bp);
160 }
161 
162 /*
163  * Initialize the nexus structs.
164  */
165 void
166 sfas_init_nexus(dev, nexus)
167 	struct sfas_softc *dev;
168 	struct nexus	  *nexus;
169 {
170 	bzero(nexus, sizeof(struct nexus));
171 
172 	nexus->state	= SFAS_NS_IDLE;
173 	nexus->period	= 200;
174 	nexus->offset	= 0;
175 	nexus->syncper	= 5;
176 	nexus->syncoff	= 0;
177 	nexus->config3	= dev->sc_config3 & ~SFAS_CFG3_FASTSCSI;
178 }
179 
180 void
181 sfasinitialize(dev)
182 	struct sfas_softc *dev;
183 {
184 	u_int		*pte;
185 	int		 i;
186 
187 	dev->sc_led_status = 0;
188 
189 	TAILQ_INIT(&dev->sc_xs_pending);
190 	TAILQ_INIT(&dev->sc_xs_free);
191 
192 /*
193  * Initialize the sfas_pending structs and link them into the free list. We
194  * have to set vm_link_data.pages to 0 or the vm FIX won't work.
195  */
196 	for(i=0; i<MAXPENDING; i++) {
197 		TAILQ_INSERT_TAIL(&dev->sc_xs_free, &dev->sc_xs_store[i],
198 				  link);
199 	}
200 
201 /*
202  * Calculate the correct clock conversion factor 2 <= factor <= 8, i.e. set
203  * the factor to clock_freq / 5 (int).
204  */
205 	if (dev->sc_clock_freq <= 10)
206 		dev->sc_clock_conv_fact = 2;
207 	if (dev->sc_clock_freq <= 40)
208 		dev->sc_clock_conv_fact = 2+((dev->sc_clock_freq-10)/5);
209 	else
210 		panic("sfasinitialize: Clock frequence too high");
211 
212 /* Setup and save the basic configuration registers */
213 	dev->sc_config1 = (dev->sc_host_id & SFAS_CFG1_BUS_ID_MASK);
214 	dev->sc_config2 = SFAS_CFG2_FEATURES_ENABLE;
215 	dev->sc_config3 = (dev->sc_clock_freq > 25 ? SFAS_CFG3_FASTCLK : 0);
216 
217 /* Precalculate timeout value and clock period. */
218 /* Ekkk ... floating point in the kernel !!!! */
219 /*	dev->sc_timeout_val  = 1+dev->sc_timeout*dev->sc_clock_freq/
220 				 (7.682*dev->sc_clock_conv_fact);*/
221 	dev->sc_timeout_val  = 1+dev->sc_timeout*dev->sc_clock_freq/
222 				 ((7682*dev->sc_clock_conv_fact)/1000);
223 	dev->sc_clock_period = 1000/dev->sc_clock_freq;
224 
225 	sfasreset(dev, 1 | 2);	/* Reset Chip and Bus */
226 
227 	dev->sc_units_disconnected = 0;
228 	dev->sc_msg_in_len = 0;
229 	dev->sc_msg_out_len = 0;
230 
231 	dev->sc_flags = 0;
232 
233 	for(i=0; i<8; i++)
234 		sfas_init_nexus(dev, &dev->sc_nexus[i]);
235 
236 	if (dev->sc_ixfer == NULL)
237 		dev->sc_ixfer = sfas_ixfer;
238 
239 /*
240  * Setup bump buffer.
241  */
242 	dev->sc_bump_va = (u_char *)uvm_km_alloc(kernel_map, dev->sc_bump_sz, 0,
243 	    UVM_KMF_WIRED | UVM_KMF_ZERO);
244 	(void) pmap_extract(pmap_kernel(), (vaddr_t)dev->sc_bump_va,
245 	    (paddr_t *)&dev->sc_bump_pa);
246 
247 /*
248  * Setup pages to noncachable, that way we don't have to flush the cache
249  * every time we need "bumped" transfer.
250  */
251 	pte = vtopte((vaddr_t) dev->sc_bump_va);
252 	*pte &= ~(L2_C | L2_B);
253 	PTE_SYNC(pte);
254 	cpu_tlb_flushD();
255 	cpu_dcache_wbinv_range((vm_offset_t)dev->sc_bump_va, PAGE_SIZE);
256 
257 	printf(" dmabuf V0x%08x P0x%08x", (u_int)dev->sc_bump_va, (u_int)dev->sc_bump_pa);
258 }
259 
260 
261 /*
262  * used by specific sfas controller
263  */
264 void
265 sfas_scsi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
266 								void *arg)
267 {
268 	struct scsipi_xfer *xs;
269 	struct sfas_softc	*dev = (void *)chan->chan_adapter->adapt_dev;
270 	struct scsipi_periph	*periph;
271 	struct sfas_pending	*pendp;
272 	int			 flags, s, target;
273 
274 	switch (req) {
275 	case ADAPTER_REQ_RUN_XFER:
276 		xs = arg;
277 		periph = xs->xs_periph;
278 		flags = xs->xs_control;
279 		target = periph->periph_target;
280 
281 		if (flags & XS_CTL_DATA_UIO)
282 			panic("sfas: scsi data uio requested");
283 
284 		if ((flags & XS_CTL_POLL) && (dev->sc_flags & SFAS_ACTIVE))
285 			panic("sfas_scsicmd: busy");
286 
287 /* Get hold of a sfas_pending block. */
288 		s = splbio();
289 		pendp = dev->sc_xs_free.tqh_first;
290 		if (pendp == NULL) {
291 			xs->error = XS_RESOURCE_SHORTAGE;
292 			scsipi_done(xs);
293 			splx(s);
294 			return;
295 		}
296 		TAILQ_REMOVE(&dev->sc_xs_free, pendp, link);
297 		pendp->xs = xs;
298 		splx(s);
299 
300 
301 /* If the chip if busy OR the unit is busy, we have to wait for out turn. */
302 		if ((dev->sc_flags & SFAS_ACTIVE) ||
303 		    (dev->sc_nexus[target].flags & SFAS_NF_UNIT_BUSY)) {
304 			s = splbio();
305 			TAILQ_INSERT_TAIL(&dev->sc_xs_pending, pendp, link);
306 			splx(s);
307 		} else
308 			sfas_donextcmd(dev, pendp);
309 
310 		return;
311 
312 	case ADAPTER_REQ_GROW_RESOURCES:
313 	case ADAPTER_REQ_SET_XFER_MODE:
314 		/* XXX Not supported. */
315 		return;
316 	}
317 }
318 
319 /*
320  * Actually select the unit, whereby the whole scsi-process is started.
321  */
322 void
323 sfas_donextcmd(dev, pendp)
324 	struct sfas_softc	*dev;
325 	struct sfas_pending	*pendp;
326 {
327 	int	s;
328 
329 /*
330  * Special case for scsi unit reset. I think this is waterproof. We first
331  * select the unit during splbio. We then cycle through the generated
332  * interrupts until the interrupt routine signals that the unit has
333  * acknowledged the reset. After that we have to wait a reset to select
334  * delay before anything else can happend.
335  */
336 	if (pendp->xs->xs_control & XS_CTL_RESET) {
337 		struct nexus	*nexus;
338 
339 		s = splbio();
340 		while(!sfasselect(dev, pendp, 0, 0, 0, 0, SFAS_SELECT_K)) {
341 			splx(s);
342 			delay(10);
343 			s = splbio();
344 		}
345 
346 		nexus = dev->sc_cur_nexus;
347 		while(nexus->flags & SFAS_NF_UNIT_BUSY) {
348 			sfasiwait(dev);
349 			sfasintr(dev);
350 		}
351 
352 		nexus->flags |= SFAS_NF_UNIT_BUSY;
353 		splx(s);
354 
355 		sfasreset(dev, 0);
356 
357 		s = splbio();
358 		nexus->flags &= ~SFAS_NF_UNIT_BUSY;
359 		splx(s);
360 	}
361 
362 /*
363  * If we are polling, go to splbio and perform the command, else we poke
364  * the scsi-bus via sfasgo to get the interrupt machine going.
365  */
366 	if (pendp->xs->xs_control & XS_CTL_POLL) {
367 		s = splbio();
368 		sfasicmd(dev, pendp);
369 		TAILQ_INSERT_TAIL(&dev->sc_xs_free, pendp, link);
370 		splx(s);
371 	} else {
372 		sfasgo(dev, pendp);
373 	}
374 }
375 
376 void
377 sfas_scsidone(dev, xs, stat)
378 	struct sfas_softc *dev;
379 	struct scsipi_xfer *xs;
380 	int		 stat;
381 {
382 	struct sfas_pending	*pendp;
383 	int			 s;
384 
385 	xs->status = stat;
386 
387 	if (stat == 0)
388 		xs->resid = 0;
389 	else {
390 		switch(stat) {
391 		case SCSI_CHECK:
392 		case SCSI_BUSY:
393 			xs->error = XS_BUSY;
394 			break;
395 		case -1:
396 			xs->error = XS_DRIVER_STUFFUP;
397 			QPRINTF(("sfas_scsicmd() bad %x\n", stat));
398 			break;
399 		default:
400 			xs->error = XS_TIMEOUT;
401 			break;
402 		}
403 	}
404 
405 /* Steal the next command from the queue so that one unit can't hog the bus. */
406 	s = splbio();
407 	pendp = dev->sc_xs_pending.tqh_first;
408 	while(pendp) {
409 		if (!(dev->sc_nexus[pendp->xs->xs_periph->periph_target].flags &
410 		      SFAS_NF_UNIT_BUSY))
411 			break;
412 		pendp = pendp->link.tqe_next;
413 	}
414 
415 	if (pendp != NULL) {
416 		TAILQ_REMOVE(&dev->sc_xs_pending, pendp, link);
417 	}
418 
419 	splx(s);
420 	scsipi_done(xs);
421 
422 	if (pendp)
423 		sfas_donextcmd(dev, pendp);
424 }
425 
426 /*
427  * There are two kinds of reset:
428  *  1) CHIP-bus reset. This also implies a SCSI-bus reset.
429  *  2) SCSI-bus reset.
430  * After the appropriate resets have been performed we wait a reset to select
431  * delay time.
432  */
433 void
434 sfasreset(dev, how)
435 	struct sfas_softc *dev;
436 	int		 how;
437 {
438 	sfas_regmap_p	rp;
439 	int		i, s;
440 
441 	rp = dev->sc_fas;
442 
443 	if (how & 1) {
444 		for(i=0; i<8; i++)
445 			sfas_init_nexus(dev, &dev->sc_nexus[i]);
446 
447 		*rp->sfas_command = SFAS_CMD_RESET_CHIP;
448 		delay(1);
449 		*rp->sfas_command = SFAS_CMD_NOP;
450 
451 		*rp->sfas_config1 = dev->sc_config1;
452 		*rp->sfas_config2 = dev->sc_config2;
453 		*rp->sfas_config3 = dev->sc_config3;
454 		*rp->sfas_timeout = dev->sc_timeout_val;
455 		*rp->sfas_clkconv = dev->sc_clock_conv_fact &
456 					SFAS_CLOCK_CONVERSION_MASK;
457 	}
458 
459 	if (how & 2) {
460 		for(i=0; i<8; i++)
461 			sfas_init_nexus(dev, &dev->sc_nexus[i]);
462 
463 		s = splbio();
464 
465 		*rp->sfas_command = SFAS_CMD_RESET_SCSI_BUS;
466 		delay(100);
467 
468 /* Skip interrupt generated by RESET_SCSI_BUS */
469 		while(*rp->sfas_status & SFAS_STAT_INTERRUPT_PENDING) {
470 			dev->sc_status = *rp->sfas_status;
471 			dev->sc_interrupt = *rp->sfas_interrupt;
472 
473 			delay(100);
474 		}
475 
476 		dev->sc_status = *rp->sfas_status;
477 		dev->sc_interrupt = *rp->sfas_interrupt;
478 
479 		splx(s);
480 	}
481 
482 	if (dev->sc_config_flags & SFAS_SLOW_START)
483 		delay(4*250000); /* RESET to SELECT DELAY*4 for slow devices */
484 	else
485 		delay(250000);	 /* RESET to SELECT DELAY */
486 }
487 
488 /*
489  * Save active data pointers to the nexus block currently active.
490  */
491 void
492 sfas_save_pointers(dev)
493 	struct sfas_softc *dev;
494 {
495 	struct nexus	*nx;
496 
497 	nx = dev->sc_cur_nexus;
498 	if (nx) {
499 		nx->cur_link	= dev->sc_cur_link;
500 		nx->max_link	= dev->sc_max_link;
501 		nx->buf		= dev->sc_buf;
502 		nx->len		= dev->sc_len;
503 		nx->dma_len	= dev->sc_dma_len;
504 		nx->dma_buf	= dev->sc_dma_buf;
505 		nx->dma_blk_flg	= dev->sc_dma_blk_flg;
506 		nx->dma_blk_len	= dev->sc_dma_blk_len;
507 		nx->dma_blk_ptr	= dev->sc_dma_blk_ptr;
508 	}
509 }
510 
511 /*
512  * Restore data pointers from the currently active nexus block.
513  */
514 void
515 sfas_restore_pointers(dev)
516 	struct sfas_softc *dev;
517 {
518 	struct nexus	*nx;
519 
520 	nx = dev->sc_cur_nexus;
521 	if (nx) {
522 		dev->sc_cur_link    = nx->cur_link;
523 		dev->sc_max_link    = nx->max_link;
524 		dev->sc_buf	    = nx->buf;
525 		dev->sc_len	    = nx->len;
526 		dev->sc_dma_len	    = nx->dma_len;
527 		dev->sc_dma_buf	    = nx->dma_buf;
528 		dev->sc_dma_blk_flg = nx->dma_blk_flg;
529 		dev->sc_dma_blk_len = nx->dma_blk_len;
530 		dev->sc_dma_blk_ptr = nx->dma_blk_ptr;
531 		dev->sc_chain	    = nx->dma;
532 		dev->sc_unit	    = (nx->lun_unit & 0x0F);
533 		dev->sc_lun	    = (nx->lun_unit & 0xF0) >> 4;
534 	}
535 }
536 
537 /*
538  * sfasiwait is used during interrupt and polled IO to wait for an event from
539  * the FAS chip. This function MUST NOT BE CALLED without interrupt disabled.
540  */
541 void
542 sfasiwait(dev)
543 	struct sfas_softc *dev;
544 {
545 	sfas_regmap_p	rp;
546 
547 /*
548  * If SFAS_DONT_WAIT is set, we have already grabbed the interrupt info
549  * elsewhere. So we don't have to wait for it.
550  */
551 	if (dev->sc_flags & SFAS_DONT_WAIT) {
552 		dev->sc_flags &= ~SFAS_DONT_WAIT;
553 		return;
554 	}
555 
556 	rp = dev->sc_fas;
557 
558 /* Wait for FAS chip to signal an interrupt. */
559 	while(!(*rp->sfas_status & SFAS_STAT_INTERRUPT_PENDING))
560 		delay(1);
561 
562 /* Grab interrupt info from chip. */
563 	dev->sc_status = *rp->sfas_status;
564 	dev->sc_interrupt = *rp->sfas_interrupt;
565 	if (dev->sc_interrupt & SFAS_INT_RESELECTED) {
566 		dev->sc_resel[0] = *rp->sfas_fifo;
567 		dev->sc_resel[1] = *rp->sfas_fifo;
568 	}
569 }
570 
571 /*
572  * Transfer info to/from device. sfas_ixfer uses polled IO+sfasiwait so the
573  * rules that apply to sfasiwait also applies here.
574  */
575 void
576 sfas_ixfer(v, polling)
577 	void *v;
578 	int polling;
579 {
580 	struct sfas_softc *dev = v;
581 	sfas_regmap_p	 rp;
582 	u_char		*buf;
583 	int		 len, mode, phase;
584 
585 	rp = dev->sc_fas;
586 	buf = dev->sc_buf;
587 	len = dev->sc_len;
588 
589 /*
590  * Decode the scsi phase to determine whether we are reading or writing.
591  * mode == 1 => READ, mode == 0 => WRITE
592  */
593 	phase = dev->sc_status & SFAS_STAT_PHASE_MASK;
594 	mode = (phase == SFAS_PHASE_DATA_IN);
595 
596 	while(len && ((dev->sc_status & SFAS_STAT_PHASE_MASK) == phase))
597 		if (mode) {
598 			*rp->sfas_command = SFAS_CMD_TRANSFER_INFO;
599 
600 			sfasiwait(dev);
601 
602 			*buf++ = *rp->sfas_fifo;
603 			len--;
604 		} else {
605 			len--;
606 			*rp->sfas_fifo = *buf++;
607 			*rp->sfas_command = SFAS_CMD_TRANSFER_INFO;
608 
609 			sfasiwait(dev);
610 		}
611 
612 /* Update buffer pointers to reflect the sent/received data. */
613 	dev->sc_buf = buf;
614 	dev->sc_len = len;
615 
616 /*
617  * Since the last sfasiwait will be a phase-change, we can't wait for it
618  * again later, so we have to signal that.
619  * Since this may be called from an interrupt initiated routine then we
620  * must call sfasintr again to avoid losing an interrupt. Phew!
621  */
622 	if(polling)
623 		dev->sc_flags |= SFAS_DONT_WAIT;
624 	else
625 		sfasintr(dev);
626 }
627 
628 /*
629  * Build a Synchronous Data Transfer Request message
630  */
631 void
632 sfas_build_sdtrm(dev, period, offset)
633 	struct sfas_softc *dev;
634 	int		  period;
635 	int		  offset;
636 {
637 	dev->sc_msg_out[0] = 0x01;
638 	dev->sc_msg_out[1] = 0x03;
639 	dev->sc_msg_out[2] = 0x01;
640 	dev->sc_msg_out[3] = period/4;
641 	dev->sc_msg_out[4] = offset;
642 	dev->sc_msg_out_len= 5;
643 }
644 
645 /*
646  * Arbitate the scsi bus and select the unit
647  */
648 int
649 sfas_select_unit(dev, target)
650 	struct sfas_softc *dev;
651 	short		  target;
652 {
653 	sfas_regmap_p	 rp;
654 	struct nexus	*nexus;
655 	int		 s, retcode, i;
656 	u_char		 cmd;
657 
658 	s = splbio();	/* Do this at splbio so that we won't be disturbed. */
659 
660 	retcode = 0;
661 
662 	nexus = &dev->sc_nexus[target];
663 
664 /*
665  * Check if the chip is busy. If not the we mark it as so and hope that nobody
666  * reselects us until we have grabbed the bus.
667  */
668 	if (!(dev->sc_flags & SFAS_ACTIVE) && !dev->sc_sel_nexus) {
669 		dev->sc_flags |= SFAS_ACTIVE;
670 
671 		rp = dev->sc_fas;
672 
673 		*rp->sfas_syncper = nexus->syncper;
674 		*rp->sfas_syncoff = nexus->syncoff;
675 		*rp->sfas_config3 = nexus->config3;
676 
677 		*rp->sfas_config1 = dev->sc_config1;
678 		*rp->sfas_timeout = dev->sc_timeout_val;
679 		*rp->sfas_dest_id = target;
680 
681 /* If nobody has stolen the bus, we can send a select command to the chip. */
682 		if (!(*rp->sfas_status & SFAS_STAT_INTERRUPT_PENDING)) {
683 			*rp->sfas_fifo = nexus->ID;
684 			if ((nexus->flags & (SFAS_NF_DO_SDTR | SFAS_NF_RESET))
685 			    || (dev->sc_msg_out_len != 0))
686 				cmd = SFAS_CMD_SEL_ATN_STOP;
687 			else {
688 				for(i=0; i<nexus->clen; i++)
689 					*rp->sfas_fifo = nexus->cbuf[i];
690 
691 				cmd = SFAS_CMD_SEL_ATN;
692 			}
693 
694 			dev->sc_sel_nexus = nexus;
695 
696 			*rp->sfas_command = cmd;
697 			retcode = 1;
698 			nexus->flags &= ~SFAS_NF_RETRY_SELECT;
699 		} else
700 			nexus->flags |= SFAS_NF_RETRY_SELECT;
701 	} else
702 		nexus->flags |= SFAS_NF_RETRY_SELECT;
703 
704 	splx(s);
705 	return(retcode);
706 }
707 
708 /*
709  * Grab the nexus if available else return 0.
710  */
711 struct nexus *
712 sfas_arbitate_target(dev, target)
713 	struct sfas_softc *dev;
714 	int		  target;
715 {
716 	struct nexus	*nexus;
717 	int		 s;
718 
719 /*
720  * This is realy simple. Raise interrupt level to splbio. Grab the nexus and
721  * leave.
722  */
723 	nexus = &dev->sc_nexus[target];
724 
725 	s = splbio();
726 
727 	if (nexus->flags & SFAS_NF_UNIT_BUSY)
728 		nexus = 0;
729 	else
730 		nexus->flags |= SFAS_NF_UNIT_BUSY;
731 
732 	splx(s);
733 	return(nexus);
734 }
735 
736 /*
737  * Setup a nexus for use. Initializes command, buffer pointers and DMA chain.
738  */
739 void
740 sfas_setup_nexus(dev, nexus, pendp, cbuf, clen, buf, len, mode)
741 	struct sfas_softc	*dev;
742 	struct nexus		*nexus;
743 	struct sfas_pending	*pendp;
744 	unsigned char		*cbuf;
745 	int			 clen;
746 	unsigned char		*buf;
747 	int			 len;
748 	int			 mode;
749 {
750 	char	sync, target, lun;
751 
752 	target = pendp->xs->xs_periph->periph_target;
753 	lun    = pendp->xs->xs_periph->periph_lun;
754 
755 /*
756  * Adopt mode to reflect the config flags.
757  * If we can't use DMA we can't use synch transfer. Also check the
758  * sfas_inhibit_xxx[target] flags.
759  */
760 	if ((dev->sc_config_flags & (SFAS_NO_SYNCH | SFAS_NO_DMA)) ||
761 	    sfas_inhibit_sync[(int)target])
762 		mode &= ~SFAS_SELECT_S;
763 
764 	if ((dev->sc_config_flags & SFAS_NO_RESELECT) ||
765 	    sfas_inhibit_disc[(int)target])
766 		mode &= ~SFAS_SELECT_R;
767 
768 	nexus->xs		= pendp->xs;
769 
770 /* Setup the nexus struct. */
771 	nexus->ID	   = ((mode & SFAS_SELECT_R) ? 0xC0 : 0x80) | lun;
772 	nexus->clen	   = clen;
773 	bcopy(cbuf, nexus->cbuf, nexus->clen);
774 	nexus->cbuf[1] |= lun << 5;		/* Fix the lun bits */
775 	nexus->cur_link	   = 0;
776 	nexus->dma_len	   = 0;
777 	nexus->dma_buf	   = 0;
778 	nexus->dma_blk_len = 0;
779 	nexus->dma_blk_ptr = 0;
780 	nexus->len	   = len;
781 	nexus->buf	   = buf;
782 	nexus->lun_unit	   = (lun << 4) | target;
783 	nexus->state	   = SFAS_NS_SELECTED;
784 
785 /* We must keep these flags. All else must be zero. */
786 	nexus->flags	  &= SFAS_NF_UNIT_BUSY
787 			   | SFAS_NF_SYNC_TESTED | SFAS_NF_SELECT_ME;
788 
789 	if (mode & SFAS_SELECT_I)
790 		nexus->flags |= SFAS_NF_IMMEDIATE;
791 	if (mode & SFAS_SELECT_K)
792 		nexus->flags |= SFAS_NF_RESET;
793 
794 	sync  = ((mode & SFAS_SELECT_S) ? 1 : 0);
795 
796 /* We can't use sync during polled IO. */
797 	if (sync && (mode & SFAS_SELECT_I))
798 		sync = 0;
799 
800 	if (!sync &&
801 	    ((nexus->flags & SFAS_NF_SYNC_TESTED) && (nexus->offset != 0))) {
802 		/*
803 		 * If the scsi unit is set to synch transfer and we don't want
804 		 * that, we have to renegotiate.
805 		 */
806 
807 		nexus->flags |= SFAS_NF_DO_SDTR;
808 		nexus->period = 200;
809 		nexus->offset = 0;
810 	} else if (sync && !(nexus->flags & SFAS_NF_SYNC_TESTED)) {
811 		/*
812 		 * If the scsi unit is not set to synch transfer and we want
813 		 * that, we have to negotiate. This should realy base the
814 		 * period on the clock frequence rather than just check if
815 		 * >25 MHz
816 		 */
817 
818 		nexus->flags |= SFAS_NF_DO_SDTR;
819 		nexus->period = ((dev->sc_clock_freq>25) ? 100 : 200);
820 		nexus->offset = 8;
821 
822 		/* If the user has a long cable, we want to limit the period */
823 		if ((nexus->period == 100) &&
824 		    (dev->sc_config_flags & SFAS_SLOW_CABLE))
825 			nexus->period = 200;
826 	}
827 
828 /*
829  * Fake a DMA-block for polled IO. This way we can use the same code to handle
830  * reselection. Much nicer this way.
831  */
832 	if ((mode & SFAS_SELECT_I) || (dev->sc_config_flags & SFAS_NO_DMA)) {
833 		nexus->dma[0].ptr = buf;
834 		nexus->dma[0].len = len;
835 		nexus->dma[0].flg = SFAS_CHAIN_PRG;
836 		nexus->max_link   = 1;
837 	} else {
838 		nexus->max_link = dev->sc_build_dma_chain(dev, nexus->dma,
839 							  buf, len);
840 	}
841 
842 /* Flush the caches. */
843 
844 	if (len && !(mode & SFAS_SELECT_I))
845 		cpu_dcache_wbinv_range((vm_offset_t)buf, len);
846 }
847 
848 int
849 sfasselect(dev, pendp, cbuf, clen, buf, len, mode)
850 	struct sfas_softc	*dev;
851 	struct sfas_pending	*pendp;
852 	unsigned char		*cbuf;
853 	int			 clen;
854 	unsigned char		*buf;
855 	int			 len;
856 	int			 mode;
857 {
858 	struct nexus	*nexus;
859 
860 /* Get the nexus struct. */
861 	nexus = sfas_arbitate_target(dev, pendp->xs->xs_periph->periph_target);
862 	if (nexus == NULL)
863 		return(0);
864 
865 /* Setup the nexus struct. */
866 	sfas_setup_nexus(dev, nexus, pendp, cbuf, clen, buf, len, mode);
867 
868 /* Post it to the interrupt machine. */
869 	sfas_select_unit(dev, pendp->xs->xs_periph->periph_target);
870 
871 	return(1);
872 }
873 
874 void
875 sfasgo(dev, pendp)
876 	struct sfas_softc   *dev;
877 	struct sfas_pending *pendp;
878 {
879 	int	 s;
880 	char	*buf;
881 
882 	buf    = pendp->xs->data;
883 
884 	if (sfasselect(dev, pendp, (char *)pendp->xs->cmd, pendp->xs->cmdlen,
885 		      buf, pendp->xs->datalen, SFAS_SELECT_RS)) {
886 		/*
887 		 * We got the command going so the sfas_pending struct is now
888 		 * free to reuse.
889 		 */
890 
891 		s = splbio();
892 		TAILQ_INSERT_TAIL(&dev->sc_xs_free, pendp, link);
893 		splx(s);
894 	} else {
895 		/*
896 		 * We couldn't make the command fly so we have to wait. The
897 		 * struct MUST be inserted at the head to keep the order of
898 		 * the commands.
899 		 */
900 
901 		s = splbio();
902 		TAILQ_INSERT_HEAD(&dev->sc_xs_pending, pendp, link);
903 		splx(s);
904 	}
905 
906 	return;
907 }
908 
909 /*
910  * Part one of the interrupt machine. Error checks and reselection test.
911  * We don't know if we have an active nexus here!
912  */
913 int
914 sfas_pretests(dev, rp)
915 	struct sfas_softc *dev;
916 	sfas_regmap_p	  rp;
917 {
918 	struct nexus	*nexus;
919 	int		 i, s;
920 
921 	if (dev->sc_interrupt & SFAS_INT_SCSI_RESET_DETECTED) {
922 		/*
923 		 * Cleanup and notify user. Lets hope that this is all we
924 		 * have to do
925 		 */
926 
927 		for(i=0; i<8; i++) {
928 			if (dev->sc_nexus[i].xs)
929 				sfas_scsidone(dev, dev->sc_nexus[i].xs, -2);
930 
931 			sfas_init_nexus(dev, &dev->sc_nexus[i]);
932 		}
933 		printf("sfasintr: SCSI-RESET detected!");
934 		return(-1);
935 	}
936 
937 	if (dev->sc_interrupt & SFAS_INT_ILLEGAL_COMMAND) {
938 		/* Something went terrible wrong! Dump some data and panic! */
939 
940 		printf("FIFO:");
941 		while(*rp->sfas_fifo_flags & SFAS_FIFO_COUNT_MASK)
942 			printf(" %x", *rp->sfas_fifo);
943 		printf("\n");
944 
945 		printf("CMD: %x\n", *rp->sfas_command);
946 		panic("sfasintr: ILLEGAL COMMAND!");
947 	}
948 
949 	if (dev->sc_interrupt & SFAS_INT_RESELECTED) {
950 		/* We were reselected. Set the chip as busy */
951 
952 		s = splbio();
953 		dev->sc_flags |= SFAS_ACTIVE;
954 		if (dev->sc_sel_nexus) {
955 			dev->sc_sel_nexus->flags |= SFAS_NF_SELECT_ME;
956 			dev->sc_sel_nexus = 0;
957 		}
958 		splx(s);
959 
960 		if (dev->sc_units_disconnected) {
961 			/* Find out who reselected us. */
962 
963 			dev->sc_resel[0] &= ~(1<<dev->sc_host_id);
964 
965 			for(i=0; i<8; i++)
966 				if (dev->sc_resel[0] & (1<<i))
967 					break;
968 
969 			if (i == 8)
970 				panic("Illegal reselection!");
971 
972 			if (dev->sc_nexus[i].state == SFAS_NS_DISCONNECTED) {
973 				/*
974 				 * This unit had disconnected, so we reconnect
975 				 * it.
976 				 */
977 
978 				dev->sc_cur_nexus = &dev->sc_nexus[i];
979 				nexus = dev->sc_cur_nexus;
980 
981 				*rp->sfas_syncper = nexus->syncper;
982 				*rp->sfas_syncoff = nexus->syncoff;
983 				*rp->sfas_config3 = nexus->config3;
984 
985 				*rp->sfas_dest_id = i & 7;
986 
987 				dev->sc_units_disconnected--;
988 				dev->sc_msg_in_len= 0;
989 
990 				/* Restore active pointers. */
991 				sfas_restore_pointers(dev);
992 
993 				nexus->state = SFAS_NS_RESELECTED;
994 
995 				*rp->sfas_command = SFAS_CMD_MESSAGE_ACCEPTED;
996 
997 				return(1);
998 			}
999 		}
1000 
1001 		/* Somehow we got an illegal reselection. Dump and panic. */
1002 		printf("sfasintr: resel[0] %x resel[1] %x disconnected %d\n",
1003 		       dev->sc_resel[0], dev->sc_resel[1],
1004 		       dev->sc_units_disconnected);
1005 		panic("sfasintr: Unexpected reselection!");
1006 	}
1007 
1008 	return(0);
1009 }
1010 
1011 /*
1012  * Part two of the interrupt machine. Handle disconnection and post command
1013  * processing. We know that we have an active nexus here.
1014  */
1015 int
1016 sfas_midaction(dev, rp, nexus)
1017 	struct sfas_softc *dev;
1018 	sfas_regmap_p	  rp;
1019 	struct nexus	 *nexus;
1020 {
1021 	int	i, left, len, s;
1022 	u_char	status, msg;
1023 
1024 	if (dev->sc_interrupt & SFAS_INT_DISCONNECT) {
1025 		s = splbio();
1026 		dev->sc_cur_nexus = 0;
1027 
1028 		/* Mark chip as busy and clean up the chip FIFO. */
1029 		dev->sc_flags &= ~SFAS_ACTIVE;
1030 		*rp->sfas_command = SFAS_CMD_FLUSH_FIFO;
1031 
1032 		/* Let the nexus state reflect what we have to do. */
1033 		switch(nexus->state) {
1034 		case SFAS_NS_SELECTED:
1035 			dev->sc_sel_nexus = 0;
1036 			nexus->flags &= ~SFAS_NF_SELECT_ME;
1037 
1038 			/*
1039 			 * We were trying to select the unit. Probably no unit
1040 			 * at this ID.
1041 			 */
1042 			nexus->xs->resid = dev->sc_len;
1043 
1044 			nexus->status = -2;
1045 			nexus->flags &= ~SFAS_NF_UNIT_BUSY;
1046 			nexus->state = SFAS_NS_FINISHED;
1047 			break;
1048 
1049 		case SFAS_NS_DONE:
1050 			/* All done. */
1051 			nexus->xs->resid = dev->sc_len;
1052 
1053 			nexus->flags &= ~SFAS_NF_UNIT_BUSY;
1054 			nexus->state  = SFAS_NS_FINISHED;
1055 			dev->sc_led(dev, 0);
1056 			break;
1057 
1058 		case SFAS_NS_DISCONNECTING:
1059 			/*
1060 			 * We have received a DISCONNECT message, so we are
1061 			 * doing a normal disconnection.
1062 			 */
1063 			nexus->state = SFAS_NS_DISCONNECTED;
1064 
1065 			dev->sc_units_disconnected++;
1066 			break;
1067 
1068 		case SFAS_NS_RESET:
1069 			/*
1070 			 * We were reseting this SCSI-unit. Clean up the
1071 			 * nexus struct.
1072 			 */
1073 			dev->sc_led(dev, 0);
1074 			sfas_init_nexus(dev, nexus);
1075 			break;
1076 
1077 		default:
1078 			/*
1079 			 * Unexpected disconnection! Cleanup and exit. This
1080 			 * shouldn't cause any problems.
1081 			 */
1082 			printf("sfasintr: Unexpected disconnection\n");
1083 			printf("sfasintr: u %x s %d p %d f %x c %x\n",
1084 			       nexus->lun_unit, nexus->state,
1085 			       dev->sc_status & SFAS_STAT_PHASE_MASK,
1086 			       nexus->flags, nexus->cbuf[0]);
1087 
1088 			nexus->xs->resid = dev->sc_len;
1089 
1090 			nexus->flags &= ~SFAS_NF_UNIT_BUSY;
1091 			nexus->state = SFAS_NS_FINISHED;
1092 			nexus->status = -3;
1093 
1094 			dev->sc_led(dev, 0);
1095 			break;
1096 		}
1097 
1098 		/*
1099 		 * If we have disconnected units, we MUST enable reselection
1100 		 * within 250ms.
1101 		 */
1102 		if (dev->sc_units_disconnected &&
1103 		    !(dev->sc_flags & SFAS_ACTIVE))
1104 			*rp->sfas_command = SFAS_CMD_ENABLE_RESEL;
1105 
1106 		splx(s);
1107 
1108 		/* Select the first pre-initialized nexus we find. */
1109 		for(i=0; i<8; i++)
1110 			if (dev->sc_nexus[i].flags & (SFAS_NF_SELECT_ME | SFAS_NF_RETRY_SELECT))
1111 				if (sfas_select_unit(dev, i) == 2)
1112 					break;
1113 
1114 		/* We are done with this nexus! */
1115 		if (nexus->state == SFAS_NS_FINISHED)
1116 			sfas_scsidone(dev, nexus->xs, nexus->status);
1117 
1118 		return(1);
1119 	}
1120 
1121 	switch(nexus->state) {
1122 	case SFAS_NS_SELECTED:
1123 		dev->sc_cur_nexus = nexus;
1124 		dev->sc_sel_nexus = 0;
1125 
1126 		nexus->flags &= ~SFAS_NF_SELECT_ME;
1127 
1128 		/*
1129 		 * We have selected a unit. Setup chip, restore pointers and
1130 		 * light the led.
1131 		 */
1132 		*rp->sfas_syncper = nexus->syncper;
1133 		*rp->sfas_syncoff = nexus->syncoff;
1134 		*rp->sfas_config3 = nexus->config3;
1135 
1136 		sfas_restore_pointers(dev);
1137 
1138 		nexus->status	= 0xFF;
1139 		dev->sc_msg_in[0] = 0xFF;
1140 		dev->sc_msg_in_len= 0;
1141 
1142 		dev->sc_led(dev, 1);
1143 
1144 		break;
1145 
1146 	case SFAS_NS_DATA_IN:
1147 	case SFAS_NS_DATA_OUT:
1148 		/* We have transfered data. */
1149 		if (dev->sc_dma_len)
1150 			if (dev->sc_cur_link < dev->sc_max_link) {
1151 				/*
1152 				 * Clean up DMA and at the same time get how
1153 				 * many bytes that were NOT transfered.
1154 				 */
1155 			  left = dev->sc_setup_dma(dev, 0, 0, SFAS_DMA_CLEAR);
1156 			  len  = dev->sc_dma_len;
1157 
1158 			  if (nexus->state == SFAS_NS_DATA_IN) {
1159 			    /*
1160 			     * If we were bumping we may have had an odd length
1161 			     * which means that there may be bytes left in the
1162 			     * fifo. We also need to move the data from the
1163 			     * bump buffer to the actual memory.
1164 			     */
1165 			    if (dev->sc_dma_buf == dev->sc_bump_pa)
1166 			    {
1167 			      while((*rp->sfas_fifo_flags&SFAS_FIFO_COUNT_MASK)
1168 				    && left)
1169 				dev->sc_bump_va[len-(left--)] = *rp->sfas_fifo;
1170 
1171 			      bcopy(dev->sc_bump_va, dev->sc_buf, len-left);
1172 			    }
1173 			  } else {
1174 			    /* Count any unsent bytes and flush them. */
1175 			    left+= *rp->sfas_fifo_flags & SFAS_FIFO_COUNT_MASK;
1176 			    *rp->sfas_command = SFAS_CMD_FLUSH_FIFO;
1177 			  }
1178 
1179 			  /*
1180 			   * Update pointers/length to reflect the transfered
1181 			   * data.
1182 			   */
1183 			  dev->sc_len -= len-left;
1184 			  dev->sc_buf += len-left;
1185 
1186 			  dev->sc_dma_buf = (char *)dev->sc_dma_buf + len-left;
1187 			  dev->sc_dma_len = left;
1188 
1189 			  dev->sc_dma_blk_ptr = (char *)dev->sc_dma_blk_ptr +
1190 				  len-left;
1191 			  dev->sc_dma_blk_len -= len-left;
1192 
1193 			  /*
1194 			   * If it was the end of a DMA block, we select the
1195 			   * next to begin with.
1196 			   */
1197 			  if (!dev->sc_dma_blk_len)
1198 			    dev->sc_cur_link++;
1199 			}
1200 		break;
1201 
1202 	case SFAS_NS_STATUS:
1203 		/*
1204 		 * If we were not sensing, grab the status byte. If we were
1205 		 * sensing and we got a bad status, let the user know.
1206 		 */
1207 
1208 		status = *rp->sfas_fifo;
1209 		msg = *rp->sfas_fifo;
1210 
1211 		nexus->status = status;
1212 		if (status != 0)
1213 			nexus->status = -1;
1214 
1215 		/*
1216 		 * Preload the command complete message. Handeled in
1217 		 * sfas_postaction.
1218 		 */
1219 		dev->sc_msg_in[0] = msg;
1220 		dev->sc_msg_in_len = 1;
1221 		nexus->flags |= SFAS_NF_HAS_MSG;
1222 		break;
1223 
1224 	default:
1225 		break;
1226 	}
1227 
1228 	return(0);
1229 }
1230 
1231 /*
1232  * Part three of the interrupt machine. Handle phase changes (and repeated
1233  * phase passes). We know that we have an active nexus here.
1234  */
1235 int
1236 sfas_postaction(dev, rp, nexus)
1237 	struct sfas_softc *dev;
1238 	sfas_regmap_p	  rp;
1239 	struct nexus	 *nexus;
1240 {
1241 	int	i, len;
1242 	u_char	cmd;
1243 	short	offset, period;
1244 
1245 	cmd = 0;
1246 
1247 	switch(dev->sc_status & SFAS_STAT_PHASE_MASK) {
1248 	case SFAS_PHASE_DATA_OUT:
1249 	case SFAS_PHASE_DATA_IN:
1250 		if ((dev->sc_status & SFAS_STAT_PHASE_MASK) ==
1251 		    SFAS_PHASE_DATA_OUT)
1252 			nexus->state = SFAS_NS_DATA_OUT;
1253 		else
1254 			nexus->state = SFAS_NS_DATA_IN;
1255 
1256 		/* Make DMA ready to accept new data. Load active pointers
1257 		 * from the DMA block. */
1258 		dev->sc_setup_dma(dev, 0, 0, SFAS_DMA_CLEAR);
1259 		if (dev->sc_cur_link < dev->sc_max_link) {
1260 		  if (!dev->sc_dma_blk_len) {
1261 		    dev->sc_dma_blk_ptr = dev->sc_chain[dev->sc_cur_link].ptr;
1262 		    dev->sc_dma_blk_len = dev->sc_chain[dev->sc_cur_link].len;
1263 		    dev->sc_dma_blk_flg = dev->sc_chain[dev->sc_cur_link].flg;
1264 		  }
1265 
1266 		  /* We should use polled IO here. */
1267 		  if (dev->sc_dma_blk_flg == SFAS_CHAIN_PRG) {
1268 			dev->sc_ixfer(dev, nexus->xs->xs_control & XS_CTL_POLL);
1269 			dev->sc_cur_link++;
1270 			dev->sc_dma_len = 0;
1271 			break;
1272 		  }
1273 		  else if (dev->sc_dma_blk_flg == SFAS_CHAIN_BUMP)
1274 			len = dev->sc_dma_blk_len;
1275 		  else
1276 			len = dev->sc_need_bump(dev, dev->sc_dma_blk_ptr,
1277 						dev->sc_dma_blk_len);
1278 
1279 		  /*
1280 		   * If len != 0 we must bump the data, else we just DMA it
1281 		   * straight into memory.
1282 		   */
1283 		  if (len) {
1284 			dev->sc_dma_buf = dev->sc_bump_pa;
1285 			dev->sc_dma_len = len;
1286 
1287 			if (nexus->state == SFAS_NS_DATA_OUT)
1288 			  bcopy(dev->sc_buf, dev->sc_bump_va, dev->sc_dma_len);
1289 		  } else {
1290 			dev->sc_dma_buf = dev->sc_dma_blk_ptr;
1291 			dev->sc_dma_len = dev->sc_dma_blk_len;
1292 		  }
1293 
1294 		  /* Load DMA with address and length of transfer. */
1295 		  dev->sc_setup_dma(dev, dev->sc_dma_buf, dev->sc_dma_len,
1296 				    ((nexus->state == SFAS_NS_DATA_OUT) ?
1297 				     SFAS_DMA_WRITE : SFAS_DMA_READ));
1298 
1299 /*		  printf("Using DMA !!!!\n");*/
1300 		  cmd = SFAS_CMD_TRANSFER_INFO | SFAS_CMD_DMA;
1301 		} else {
1302 			/*
1303 			 * Hmmm, the unit wants more info than we have or has
1304 			 * more than we want. Let the chip handle that.
1305 			 */
1306 
1307 			*rp->sfas_tc_low = 0; /* was 256 but this does not make sense */
1308 			*rp->sfas_tc_mid = 1;
1309 			*rp->sfas_tc_high = 0;
1310 			cmd = SFAS_CMD_TRANSFER_PAD;
1311 		}
1312 		break;
1313 
1314 	case SFAS_PHASE_COMMAND:
1315 		/* The scsi unit wants the command, send it. */
1316 		nexus->state = SFAS_NS_SVC;
1317 
1318 		*rp->sfas_command = SFAS_CMD_FLUSH_FIFO;
1319 		for(i=0; i<5; i++);
1320 
1321 		for(i=0; i<nexus->clen; i++)
1322 			*rp->sfas_fifo = nexus->cbuf[i];
1323 		cmd = SFAS_CMD_TRANSFER_INFO;
1324 		break;
1325 
1326 	case SFAS_PHASE_STATUS:
1327 		/*
1328 		 * We've got status phase. Request status and command
1329 		 * complete message.
1330 		 */
1331 		nexus->state = SFAS_NS_STATUS;
1332 		cmd = SFAS_CMD_COMMAND_COMPLETE;
1333 		break;
1334 
1335 	case SFAS_PHASE_MESSAGE_OUT:
1336 		/*
1337 		 * Either the scsi unit wants us to send a message or we have
1338 		 * asked for it by seting the ATN bit.
1339 		 */
1340 		nexus->state = SFAS_NS_MSG_OUT;
1341 
1342 		*rp->sfas_command = SFAS_CMD_FLUSH_FIFO;
1343 
1344 		if (nexus->flags & SFAS_NF_DO_SDTR) {
1345 			/* Send a Synchronous Data Transfer Request. */
1346 
1347 			sfas_build_sdtrm(dev, nexus->period, nexus->offset);
1348 			nexus->flags |= SFAS_NF_SDTR_SENT;
1349 			nexus->flags &= ~SFAS_NF_DO_SDTR;
1350 		} else if (nexus->flags & SFAS_NF_RESET) {
1351 			/* Send a reset scsi unit message. */
1352 
1353 			dev->sc_msg_out[0] = 0x0C;
1354 			dev->sc_msg_out_len = 1;
1355 			nexus->state = SFAS_NS_RESET;
1356 			nexus->flags &= ~SFAS_NF_RESET;
1357 		} else if (dev->sc_msg_out_len == 0) {
1358 			/* Don't know what to send so we send a NOP message. */
1359 
1360 			dev->sc_msg_out[0] = 0x08;
1361 			dev->sc_msg_out_len = 1;
1362 		}
1363 
1364 		cmd = SFAS_CMD_TRANSFER_INFO;
1365 
1366 		for(i=0; i<dev->sc_msg_out_len; i++)
1367 			*rp->sfas_fifo = dev->sc_msg_out[i];
1368 		dev->sc_msg_out_len = 0;
1369 
1370 		break;
1371 
1372 	case SFAS_PHASE_MESSAGE_IN:
1373 		/* Receive a message from the scsi unit. */
1374 		nexus->state = SFAS_NS_MSG_IN;
1375 
1376 		while(!(nexus->flags & SFAS_NF_HAS_MSG)) {
1377 			*rp->sfas_command = SFAS_CMD_TRANSFER_INFO;
1378 			sfasiwait(dev);
1379 
1380 			dev->sc_msg_in[dev->sc_msg_in_len++] = *rp->sfas_fifo;
1381 
1382 			/* Check if we got all the bytes in the message. */
1383 			if (dev->sc_msg_in[0] >= 0x80)       ;
1384 			else if (dev->sc_msg_in[0] >= 0x30)  ;
1385 			else if (((dev->sc_msg_in[0] >= 0x20) &&
1386 				  (dev->sc_msg_in_len == 2)) ||
1387 				 ((dev->sc_msg_in[0] != 0x01) &&
1388 				  (dev->sc_msg_in_len == 1))) {
1389 				nexus->flags |= SFAS_NF_HAS_MSG;
1390 				break;
1391 			} else {
1392 			  if (dev->sc_msg_in_len >= 2)
1393 			    if ((dev->sc_msg_in[1]+2) == dev->sc_msg_in_len) {
1394 				nexus->flags |= SFAS_NF_HAS_MSG;
1395 				break;
1396 			    }
1397 			}
1398 
1399 			*rp->sfas_command = SFAS_CMD_MESSAGE_ACCEPTED;
1400 			sfasiwait(dev);
1401 
1402 			if ((dev->sc_status & SFAS_STAT_PHASE_MASK) !=
1403 			    SFAS_PHASE_MESSAGE_IN)
1404 				break;
1405 		}
1406 
1407 		cmd = SFAS_CMD_MESSAGE_ACCEPTED;
1408 		if (nexus->flags & SFAS_NF_HAS_MSG) {
1409 			/* We have a message. Decode it. */
1410 
1411 			switch(dev->sc_msg_in[0]) {
1412 			case 0x00:	/* COMMAND COMPLETE */
1413 				nexus->state = SFAS_NS_DONE;
1414 				break;
1415 			case 0x04:	/* DISCONNECT */
1416 				nexus->state = SFAS_NS_DISCONNECTING;
1417 				break;
1418 			case 0x02:	/* SAVE DATA POINTER */
1419 				sfas_save_pointers(dev);
1420 				break;
1421 			case 0x03:	/* RESTORE DATA POINTERS */
1422 				sfas_restore_pointers(dev);
1423 				break;
1424 			case 0x07:	/* MESSAGE REJECT */
1425 				/*
1426 				 * If we had sent a SDTR and we got a message
1427 				 * reject, the scsi docs say that we must go
1428 				 * to async transfer.
1429 				 */
1430 				if (nexus->flags & SFAS_NF_SDTR_SENT) {
1431 					nexus->flags &= ~SFAS_NF_SDTR_SENT;
1432 
1433 					nexus->config3 &= ~SFAS_CFG3_FASTSCSI;
1434 					nexus->syncper = 5;
1435 					nexus->syncoff = 0;
1436 
1437 					*rp->sfas_syncper = nexus->syncper;
1438 					*rp->sfas_syncoff = nexus->syncoff;
1439 					*rp->sfas_config3 = nexus->config3;
1440 				} else
1441 				/*
1442 				 * Something was rejected but we don't know
1443 				 * what! PANIC!
1444 				 */
1445 				  panic("sfasintr: Unknown message rejected!");
1446 				break;
1447 			case 0x08:	/* MO OPERATION */
1448 				break;
1449 			case 0x01:	/* EXTENDED MESSAGE */
1450 				switch(dev->sc_msg_in[2]) {
1451 				case 0x01:/* SYNC. DATA TRANSFER REQUEST */
1452 					/* Decode the SDTR message. */
1453 					period = 4*dev->sc_msg_in[3];
1454 					offset = dev->sc_msg_in[4];
1455 
1456 					/*
1457 					 * Make sure that the specs are within
1458 					 * chip limits. Note that if we
1459 					 * initiated the negotiation the specs
1460 					 * WILL be withing chip limits. If it
1461 					 * was the scsi unit that initiated
1462 					 * the negotiation, the specs may be
1463 					 * to high.
1464 					 */
1465 					if (offset > 16)
1466 						offset = 16;
1467 					if ((period < 200) &&
1468 					    (dev->sc_clock_freq <= 25))
1469 						period = 200;
1470 
1471 					if (offset == 0)
1472 					       period = 5*dev->sc_clock_period;
1473 
1474 					nexus->syncper = period/
1475 							  dev->sc_clock_period;
1476 					nexus->syncoff = offset;
1477 
1478 					if (period < 200)
1479 					  nexus->config3 |= SFAS_CFG3_FASTSCSI;
1480 					else
1481 					  nexus->config3 &=~SFAS_CFG3_FASTSCSI;
1482 
1483 					nexus->flags |= SFAS_NF_SYNC_TESTED;
1484 
1485 					*rp->sfas_syncper = nexus->syncper;
1486 					*rp->sfas_syncoff = nexus->syncoff;
1487 					*rp->sfas_config3 = nexus->config3;
1488 
1489 					/*
1490 					 * Hmmm, it seems that the scsi unit
1491 					 * initiated sync negotiation, so lets
1492 					 * reply acording to scsi-2 standard.
1493 					 */
1494 					if (!(nexus->flags& SFAS_NF_SDTR_SENT))
1495 					{
1496 					  if ((dev->sc_config_flags &
1497 					       SFAS_NO_SYNCH) ||
1498 					      (dev->sc_config_flags &
1499 					       SFAS_NO_DMA) ||
1500 					      sfas_inhibit_sync[
1501 							nexus->lun_unit & 7]) {
1502 					          period = 200;
1503 					          offset = 0;
1504 					  }
1505 
1506 					  nexus->offset = offset;
1507 					  nexus->period = period;
1508 					  nexus->flags |= SFAS_NF_DO_SDTR;
1509 					  *rp->sfas_command = SFAS_CMD_SET_ATN;
1510 					}
1511 
1512 					nexus->flags &= ~SFAS_NF_SDTR_SENT;
1513 					break;
1514 
1515 				case 0x00: /* MODIFY DATA POINTERS */
1516 				case 0x02: /* EXTENDED IDENTIFY (SCSI-1) */
1517 				case 0x03: /* WIDE DATA TRANSFER REQUEST */
1518 			        default:
1519 					/* Reject any unhandeled messages. */
1520 
1521 					dev->sc_msg_out[0] = 0x07;
1522 					dev->sc_msg_out_len = 1;
1523 					*rp->sfas_command = SFAS_CMD_SET_ATN;
1524 					cmd = SFAS_CMD_MESSAGE_ACCEPTED;
1525 					break;
1526 				}
1527 				break;
1528 
1529 			default:
1530 				/* Reject any unhandeled messages. */
1531 
1532 				dev->sc_msg_out[0] = 0x07;
1533 				dev->sc_msg_out_len = 1;
1534 				*rp->sfas_command = SFAS_CMD_SET_ATN;
1535 				cmd = SFAS_CMD_MESSAGE_ACCEPTED;
1536 				break;
1537 			}
1538 			nexus->flags &= ~SFAS_NF_HAS_MSG;
1539 			dev->sc_msg_in_len = 0;
1540 		}
1541 		break;
1542 	default:
1543 		printf("SFASINTR: UNKNOWN PHASE! phase: %d\n",
1544 		       dev->sc_status & SFAS_STAT_PHASE_MASK);
1545 		dev->sc_led(dev, 0);
1546 		sfas_scsidone(dev, nexus->xs, -4);
1547 
1548 		return(-1);
1549 	}
1550 
1551 	if (cmd)
1552 		*rp->sfas_command = cmd;
1553 
1554 	return(0);
1555 }
1556 
1557 /*
1558  * Stub for interrupt machine.
1559  */
1560 void
1561 sfasintr(dev)
1562 	struct sfas_softc *dev;
1563 {
1564 	sfas_regmap_p	 rp;
1565 	struct nexus	*nexus;
1566 
1567 	rp = dev->sc_fas;
1568 
1569 	if (!sfas_pretests(dev, rp)) {
1570 
1571 		nexus = dev->sc_cur_nexus;
1572 		if (nexus == NULL)
1573 			nexus = dev->sc_sel_nexus;
1574 
1575 		if (nexus)
1576 			if (!sfas_midaction(dev, rp, nexus))
1577 				sfas_postaction(dev, rp, nexus);
1578 	}
1579 }
1580 
1581 /*
1582  * sfasicmd is used to perform IO when we can't use interrupts. sfasicmd
1583  * emulates the normal environment by waiting for the chip and calling
1584  * sfasintr.
1585  */
1586 void
1587 sfasicmd(dev, pendp)
1588 	struct sfas_softc   *dev;
1589 	struct sfas_pending *pendp;
1590 {
1591 	sfas_regmap_p	 rp;
1592 	struct nexus	*nexus;
1593 
1594 	nexus = &dev->sc_nexus[pendp->xs->xs_periph->periph_target];
1595 	rp = dev->sc_fas;
1596 
1597 	if (!sfasselect(dev, pendp, (char *)pendp->xs->cmd, pendp->xs->cmdlen,
1598 			(char *)pendp->xs->data, pendp->xs->datalen,
1599 			SFAS_SELECT_I))
1600 		panic("sfasicmd: Couldn't select unit");
1601 
1602 	while(nexus->state != SFAS_NS_FINISHED) {
1603 		sfasiwait(dev);
1604 		sfasintr(dev);
1605 	}
1606 
1607 	nexus->flags &= ~SFAS_NF_SYNC_TESTED;
1608 }
1609 
1610 
1611 #ifdef SFAS_DEBUG
1612 
1613 void
1614 dump_nexus(nexus)
1615 	struct nexus *nexus;
1616 {
1617 	int loop;
1618 
1619 	printf("nexus=%08x\n", (u_int)nexus);
1620 	printf("scsi_fer=%08x\n", (u_int)nexus->xs);
1621 	printf("ID=%02x\n", nexus->ID);
1622 	printf("clen=%02x\n", nexus->clen);
1623 	printf("cbuf=");
1624 	for (loop = 0; loop< 14; ++loop)
1625 		printf(" %02x\n", nexus->cbuf[loop]);
1626 	printf("\n");
1627 	printf("DMA:\n");
1628 	for (loop = 0; loop < MAXCHAIN; ++loop)
1629 		printf("dma_chain: %08x %04x %04x\n", nexus->dma[loop].ptr,
1630 		    nexus->dma[loop].len, nexus->dma[loop].flg);
1631 	printf("\n");
1632 
1633 	printf("max_link=%d\n", nexus->max_link);
1634 	printf("cur_link=%d\n", nexus->cur_link);
1635 
1636 	printf("buf=%08x\n", (u_int)nexus->buf);
1637 	printf("len=%08x\n", nexus->len);
1638 	printf("dma_buf=%08x\n", (u_int)nexus->dma_buf);
1639 	printf("dma_len=%08x\n", nexus->dma_len);
1640 	printf("dma_blk_ptr=%08x\n", (u_int)nexus->dma_blk_ptr);
1641 	printf("dma_blk_len=%08x\n", nexus->dma_blk_len);
1642 	printf("dma_blk_flag=%08x\n", nexus->dma_blk_flg);
1643 	printf("state=%02x\n", nexus->state);
1644 	printf("flags=%04x\n", nexus->flags);
1645 	printf("period=%d\n", nexus->period);
1646 	printf("offset=%d\n", nexus->offset);
1647 	printf("syncper=%d\n", nexus->syncper);
1648 	printf("syncoff=%d\n", nexus->syncoff);
1649 	printf("config3=%02x\n", nexus->config3);
1650 	printf("lun_unit=%d\n", nexus->lun_unit);
1651 	printf("status=%02x\n", nexus->status);
1652 	printf("\n");
1653 }
1654 
1655 void
1656 dump_nexii(sc)
1657 	struct sfas_softc *sc;
1658 {
1659 	int loop;
1660 
1661 	for (loop = 0; loop < 8; ++loop) {
1662 		dump_nexus(&sc->sc_nexus[loop]);
1663 	}
1664 }
1665 
1666 void
1667 dump_sfassoftc(sc)
1668 	struct sfas_softc *sc;
1669 {
1670 	printf("sfassoftc @ 0x%08x\n", (u_int)sc);
1671 	printf("clock_freq = %d\n", sc->sc_clock_freq);
1672 	printf("timeout = %d\n", sc->sc_timeout);
1673 	printf("host_id = %d\n", sc->sc_host_id);
1674 	printf("config_flags = 0x%08x\n", sc->sc_config_flags);
1675 	printf("led_status = %d\n", sc->sc_led_status);
1676 
1677 	dump_nexii(sc);
1678 	printf("cur_nexus = 0x%08x\n", (u_int)sc->sc_cur_nexus);
1679 	printf("sel_nexus = 0x%08x\n", (u_int)sc->sc_sel_nexus);
1680 	printf("\n");
1681 }
1682 
1683 #endif	/* SFAS_DEBUG */
1684