xref: /netbsd-src/sys/arch/acorn32/podulebus/sfas.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: sfas.c,v 1.13 2003/11/10 08:51:51 wiz 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 1.13 2003/11/10 08:51:51 wiz 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_zalloc(kernel_map, dev->sc_bump_sz);
243 	(void) pmap_extract(pmap_kernel(), (vaddr_t)dev->sc_bump_va,
244 	    (paddr_t *)&dev->sc_bump_pa);
245 
246 /*
247  * Setup pages to noncachable, that way we don't have to flush the cache
248  * every time we need "bumped" transfer.
249  */
250 	pte = vtopte((vaddr_t) dev->sc_bump_va);
251 	*pte &= ~(L2_C | L2_B);
252 	PTE_SYNC(pte);
253 	cpu_tlb_flushD();
254 	cpu_dcache_wbinv_range((vm_offset_t)dev->sc_bump_va, PAGE_SIZE);
255 
256 	printf(" dmabuf V0x%08x P0x%08x", (u_int)dev->sc_bump_va, (u_int)dev->sc_bump_pa);
257 }
258 
259 
260 /*
261  * used by specific sfas controller
262  */
263 void
264 sfas_scsi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
265 								void *arg)
266 {
267 	struct scsipi_xfer *xs;
268 	struct sfas_softc	*dev = (void *)chan->chan_adapter->adapt_dev;
269 	struct scsipi_periph	*periph;
270 	struct sfas_pending	*pendp;
271 	int			 flags, s, target;
272 
273 	switch (req) {
274 	case ADAPTER_REQ_RUN_XFER:
275 		xs = arg;
276 		periph = xs->xs_periph;
277 		flags = xs->xs_control;
278 		target = periph->periph_target;
279 
280 		if (flags & XS_CTL_DATA_UIO)
281 			panic("sfas: scsi data uio requested");
282 
283 		if ((flags & XS_CTL_POLL) && (dev->sc_flags & SFAS_ACTIVE))
284 			panic("sfas_scsicmd: busy");
285 
286 /* Get hold of a sfas_pending block. */
287 		s = splbio();
288 		pendp = dev->sc_xs_free.tqh_first;
289 		if (pendp == NULL) {
290 			xs->error = XS_RESOURCE_SHORTAGE;
291 			scsipi_done(xs);
292 			splx(s);
293 			return;
294 		}
295 		TAILQ_REMOVE(&dev->sc_xs_free, pendp, link);
296 		pendp->xs = xs;
297 		splx(s);
298 
299 
300 /* If the chip if busy OR the unit is busy, we have to wait for out turn. */
301 		if ((dev->sc_flags & SFAS_ACTIVE) ||
302 		    (dev->sc_nexus[target].flags & SFAS_NF_UNIT_BUSY)) {
303 			s = splbio();
304 			TAILQ_INSERT_TAIL(&dev->sc_xs_pending, pendp, link);
305 			splx(s);
306 		} else
307 			sfas_donextcmd(dev, pendp);
308 
309 		return;
310 
311 	case ADAPTER_REQ_GROW_RESOURCES:
312 	case ADAPTER_REQ_SET_XFER_MODE:
313 		/* XXX Not supported. */
314 		return;
315 	}
316 }
317 
318 /*
319  * Actually select the unit, whereby the whole scsi-process is started.
320  */
321 void
322 sfas_donextcmd(dev, pendp)
323 	struct sfas_softc	*dev;
324 	struct sfas_pending	*pendp;
325 {
326 	int	s;
327 
328 /*
329  * Special case for scsi unit reset. I think this is waterproof. We first
330  * select the unit during splbio. We then cycle through the generated
331  * interrupts until the interrupt routine signals that the unit has
332  * acknowledged the reset. After that we have to wait a reset to select
333  * delay before anything else can happend.
334  */
335 	if (pendp->xs->xs_control & XS_CTL_RESET) {
336 		struct nexus	*nexus;
337 
338 		s = splbio();
339 		while(!sfasselect(dev, pendp, 0, 0, 0, 0, SFAS_SELECT_K)) {
340 			splx(s);
341 			delay(10);
342 			s = splbio();
343 		}
344 
345 		nexus = dev->sc_cur_nexus;
346 		while(nexus->flags & SFAS_NF_UNIT_BUSY) {
347 			sfasiwait(dev);
348 			sfasintr(dev);
349 		}
350 
351 		nexus->flags |= SFAS_NF_UNIT_BUSY;
352 		splx(s);
353 
354 		sfasreset(dev, 0);
355 
356 		s = splbio();
357 		nexus->flags &= ~SFAS_NF_UNIT_BUSY;
358 		splx(s);
359 	}
360 
361 /*
362  * If we are polling, go to splbio and perform the command, else we poke
363  * the scsi-bus via sfasgo to get the interrupt machine going.
364  */
365 	if (pendp->xs->xs_control & XS_CTL_POLL) {
366 		s = splbio();
367 		sfasicmd(dev, pendp);
368 		TAILQ_INSERT_TAIL(&dev->sc_xs_free, pendp, link);
369 		splx(s);
370 	} else {
371 		sfasgo(dev, pendp);
372 	}
373 }
374 
375 void
376 sfas_scsidone(dev, xs, stat)
377 	struct sfas_softc *dev;
378 	struct scsipi_xfer *xs;
379 	int		 stat;
380 {
381 	struct sfas_pending	*pendp;
382 	int			 s;
383 
384 	xs->status = stat;
385 
386 	if (stat == 0)
387 		xs->resid = 0;
388 	else {
389 		switch(stat) {
390 		case SCSI_CHECK:
391 		case SCSI_BUSY:
392 			xs->error = XS_BUSY;
393 			break;
394 		case -1:
395 			xs->error = XS_DRIVER_STUFFUP;
396 			QPRINTF(("sfas_scsicmd() bad %x\n", stat));
397 			break;
398 		default:
399 			xs->error = XS_TIMEOUT;
400 			break;
401 		}
402 	}
403 
404 /* Steal the next command from the queue so that one unit can't hog the bus. */
405 	s = splbio();
406 	pendp = dev->sc_xs_pending.tqh_first;
407 	while(pendp) {
408 		if (!(dev->sc_nexus[pendp->xs->xs_periph->periph_target].flags &
409 		      SFAS_NF_UNIT_BUSY))
410 			break;
411 		pendp = pendp->link.tqe_next;
412 	}
413 
414 	if (pendp != NULL) {
415 		TAILQ_REMOVE(&dev->sc_xs_pending, pendp, link);
416 	}
417 
418 	splx(s);
419 	scsipi_done(xs);
420 
421 	if (pendp)
422 		sfas_donextcmd(dev, pendp);
423 }
424 
425 /*
426  * There are two kinds of reset:
427  *  1) CHIP-bus reset. This also implies a SCSI-bus reset.
428  *  2) SCSI-bus reset.
429  * After the appropriate resets have been performed we wait a reset to select
430  * delay time.
431  */
432 void
433 sfasreset(dev, how)
434 	struct sfas_softc *dev;
435 	int		 how;
436 {
437 	sfas_regmap_p	rp;
438 	int		i, s;
439 
440 	rp = dev->sc_fas;
441 
442 	if (how & 1) {
443 		for(i=0; i<8; i++)
444 			sfas_init_nexus(dev, &dev->sc_nexus[i]);
445 
446 		*rp->sfas_command = SFAS_CMD_RESET_CHIP;
447 		delay(1);
448 		*rp->sfas_command = SFAS_CMD_NOP;
449 
450 		*rp->sfas_config1 = dev->sc_config1;
451 		*rp->sfas_config2 = dev->sc_config2;
452 		*rp->sfas_config3 = dev->sc_config3;
453 		*rp->sfas_timeout = dev->sc_timeout_val;
454 		*rp->sfas_clkconv = dev->sc_clock_conv_fact &
455 					SFAS_CLOCK_CONVERSION_MASK;
456 	}
457 
458 	if (how & 2) {
459 		for(i=0; i<8; i++)
460 			sfas_init_nexus(dev, &dev->sc_nexus[i]);
461 
462 		s = splbio();
463 
464 		*rp->sfas_command = SFAS_CMD_RESET_SCSI_BUS;
465 		delay(100);
466 
467 /* Skip interrupt generated by RESET_SCSI_BUS */
468 		while(*rp->sfas_status & SFAS_STAT_INTERRUPT_PENDING) {
469 			dev->sc_status = *rp->sfas_status;
470 			dev->sc_interrupt = *rp->sfas_interrupt;
471 
472 			delay(100);
473 		}
474 
475 		dev->sc_status = *rp->sfas_status;
476 		dev->sc_interrupt = *rp->sfas_interrupt;
477 
478 		splx(s);
479 	}
480 
481 	if (dev->sc_config_flags & SFAS_SLOW_START)
482 		delay(4*250000); /* RESET to SELECT DELAY*4 for slow devices */
483 	else
484 		delay(250000);	 /* RESET to SELECT DELAY */
485 }
486 
487 /*
488  * Save active data pointers to the nexus block currently active.
489  */
490 void
491 sfas_save_pointers(dev)
492 	struct sfas_softc *dev;
493 {
494 	struct nexus	*nx;
495 
496 	nx = dev->sc_cur_nexus;
497 	if (nx) {
498 		nx->cur_link	= dev->sc_cur_link;
499 		nx->max_link	= dev->sc_max_link;
500 		nx->buf		= dev->sc_buf;
501 		nx->len		= dev->sc_len;
502 		nx->dma_len	= dev->sc_dma_len;
503 		nx->dma_buf	= dev->sc_dma_buf;
504 		nx->dma_blk_flg	= dev->sc_dma_blk_flg;
505 		nx->dma_blk_len	= dev->sc_dma_blk_len;
506 		nx->dma_blk_ptr	= dev->sc_dma_blk_ptr;
507 	}
508 }
509 
510 /*
511  * Restore data pointers from the currently active nexus block.
512  */
513 void
514 sfas_restore_pointers(dev)
515 	struct sfas_softc *dev;
516 {
517 	struct nexus	*nx;
518 
519 	nx = dev->sc_cur_nexus;
520 	if (nx) {
521 		dev->sc_cur_link    = nx->cur_link;
522 		dev->sc_max_link    = nx->max_link;
523 		dev->sc_buf	    = nx->buf;
524 		dev->sc_len	    = nx->len;
525 		dev->sc_dma_len	    = nx->dma_len;
526 		dev->sc_dma_buf	    = nx->dma_buf;
527 		dev->sc_dma_blk_flg = nx->dma_blk_flg;
528 		dev->sc_dma_blk_len = nx->dma_blk_len;
529 		dev->sc_dma_blk_ptr = nx->dma_blk_ptr;
530 		dev->sc_chain	    = nx->dma;
531 		dev->sc_unit	    = (nx->lun_unit & 0x0F);
532 		dev->sc_lun	    = (nx->lun_unit & 0xF0) >> 4;
533 	}
534 }
535 
536 /*
537  * sfasiwait is used during interrupt and polled IO to wait for an event from
538  * the FAS chip. This function MUST NOT BE CALLED without interrupt disabled.
539  */
540 void
541 sfasiwait(dev)
542 	struct sfas_softc *dev;
543 {
544 	sfas_regmap_p	rp;
545 
546 /*
547  * If SFAS_DONT_WAIT is set, we have already grabbed the interrupt info
548  * elsewhere. So we don't have to wait for it.
549  */
550 	if (dev->sc_flags & SFAS_DONT_WAIT) {
551 		dev->sc_flags &= ~SFAS_DONT_WAIT;
552 		return;
553 	}
554 
555 	rp = dev->sc_fas;
556 
557 /* Wait for FAS chip to signal an interrupt. */
558 	while(!(*rp->sfas_status & SFAS_STAT_INTERRUPT_PENDING))
559 		delay(1);
560 
561 /* Grab interrupt info from chip. */
562 	dev->sc_status = *rp->sfas_status;
563 	dev->sc_interrupt = *rp->sfas_interrupt;
564 	if (dev->sc_interrupt & SFAS_INT_RESELECTED) {
565 		dev->sc_resel[0] = *rp->sfas_fifo;
566 		dev->sc_resel[1] = *rp->sfas_fifo;
567 	}
568 }
569 
570 /*
571  * Transfer info to/from device. sfas_ixfer uses polled IO+sfasiwait so the
572  * rules that apply to sfasiwait also applies here.
573  */
574 void
575 sfas_ixfer(v, polling)
576 	void *v;
577 	int polling;
578 {
579 	struct sfas_softc *dev = v;
580 	sfas_regmap_p	 rp;
581 	u_char		*buf;
582 	int		 len, mode, phase;
583 
584 	rp = dev->sc_fas;
585 	buf = dev->sc_buf;
586 	len = dev->sc_len;
587 
588 /*
589  * Decode the scsi phase to determine whether we are reading or writing.
590  * mode == 1 => READ, mode == 0 => WRITE
591  */
592 	phase = dev->sc_status & SFAS_STAT_PHASE_MASK;
593 	mode = (phase == SFAS_PHASE_DATA_IN);
594 
595 	while(len && ((dev->sc_status & SFAS_STAT_PHASE_MASK) == phase))
596 		if (mode) {
597 			*rp->sfas_command = SFAS_CMD_TRANSFER_INFO;
598 
599 			sfasiwait(dev);
600 
601 			*buf++ = *rp->sfas_fifo;
602 			len--;
603 		} else {
604 			len--;
605 			*rp->sfas_fifo = *buf++;
606 			*rp->sfas_command = SFAS_CMD_TRANSFER_INFO;
607 
608 			sfasiwait(dev);
609 		}
610 
611 /* Update buffer pointers to reflect the sent/received data. */
612 	dev->sc_buf = buf;
613 	dev->sc_len = len;
614 
615 /*
616  * Since the last sfasiwait will be a phase-change, we can't wait for it
617  * again later, so we have to signal that.
618  * Since this may be called from an interrupt initiated routine then we
619  * must call sfasintr again to avoid losing an interrupt. Phew!
620  */
621 	if(polling)
622 		dev->sc_flags |= SFAS_DONT_WAIT;
623 	else
624 		sfasintr(dev);
625 }
626 
627 /*
628  * Build a Synchronous Data Transfer Request message
629  */
630 void
631 sfas_build_sdtrm(dev, period, offset)
632 	struct sfas_softc *dev;
633 	int		  period;
634 	int		  offset;
635 {
636 	dev->sc_msg_out[0] = 0x01;
637 	dev->sc_msg_out[1] = 0x03;
638 	dev->sc_msg_out[2] = 0x01;
639 	dev->sc_msg_out[3] = period/4;
640 	dev->sc_msg_out[4] = offset;
641 	dev->sc_msg_out_len= 5;
642 }
643 
644 /*
645  * Arbitate the scsi bus and select the unit
646  */
647 int
648 sfas_select_unit(dev, target)
649 	struct sfas_softc *dev;
650 	short		  target;
651 {
652 	sfas_regmap_p	 rp;
653 	struct nexus	*nexus;
654 	int		 s, retcode, i;
655 	u_char		 cmd;
656 
657 	s = splbio();	/* Do this at splbio so that we won't be disturbed. */
658 
659 	retcode = 0;
660 
661 	nexus = &dev->sc_nexus[target];
662 
663 /*
664  * Check if the chip is busy. If not the we mark it as so and hope that nobody
665  * reselects us until we have grabbed the bus.
666  */
667 	if (!(dev->sc_flags & SFAS_ACTIVE) && !dev->sc_sel_nexus) {
668 		dev->sc_flags |= SFAS_ACTIVE;
669 
670 		rp = dev->sc_fas;
671 
672 		*rp->sfas_syncper = nexus->syncper;
673 		*rp->sfas_syncoff = nexus->syncoff;
674 		*rp->sfas_config3 = nexus->config3;
675 
676 		*rp->sfas_config1 = dev->sc_config1;
677 		*rp->sfas_timeout = dev->sc_timeout_val;
678 		*rp->sfas_dest_id = target;
679 
680 /* If nobody has stolen the bus, we can send a select command to the chip. */
681 		if (!(*rp->sfas_status & SFAS_STAT_INTERRUPT_PENDING)) {
682 			*rp->sfas_fifo = nexus->ID;
683 			if ((nexus->flags & (SFAS_NF_DO_SDTR | SFAS_NF_RESET))
684 			    || (dev->sc_msg_out_len != 0))
685 				cmd = SFAS_CMD_SEL_ATN_STOP;
686 			else {
687 				for(i=0; i<nexus->clen; i++)
688 					*rp->sfas_fifo = nexus->cbuf[i];
689 
690 				cmd = SFAS_CMD_SEL_ATN;
691 			}
692 
693 			dev->sc_sel_nexus = nexus;
694 
695 			*rp->sfas_command = cmd;
696 			retcode = 1;
697 			nexus->flags &= ~SFAS_NF_RETRY_SELECT;
698 		} else
699 			nexus->flags |= SFAS_NF_RETRY_SELECT;
700 	} else
701 		nexus->flags |= SFAS_NF_RETRY_SELECT;
702 
703 	splx(s);
704 	return(retcode);
705 }
706 
707 /*
708  * Grab the nexus if available else return 0.
709  */
710 struct nexus *
711 sfas_arbitate_target(dev, target)
712 	struct sfas_softc *dev;
713 	int		  target;
714 {
715 	struct nexus	*nexus;
716 	int		 s;
717 
718 /*
719  * This is realy simple. Raise interrupt level to splbio. Grab the nexus and
720  * leave.
721  */
722 	nexus = &dev->sc_nexus[target];
723 
724 	s = splbio();
725 
726 	if (nexus->flags & SFAS_NF_UNIT_BUSY)
727 		nexus = 0;
728 	else
729 		nexus->flags |= SFAS_NF_UNIT_BUSY;
730 
731 	splx(s);
732 	return(nexus);
733 }
734 
735 /*
736  * Setup a nexus for use. Initializes command, buffer pointers and DMA chain.
737  */
738 void
739 sfas_setup_nexus(dev, nexus, pendp, cbuf, clen, buf, len, mode)
740 	struct sfas_softc	*dev;
741 	struct nexus		*nexus;
742 	struct sfas_pending	*pendp;
743 	unsigned char		*cbuf;
744 	int			 clen;
745 	unsigned char		*buf;
746 	int			 len;
747 	int			 mode;
748 {
749 	char	sync, target, lun;
750 
751 	target = pendp->xs->xs_periph->periph_target;
752 	lun    = pendp->xs->xs_periph->periph_lun;
753 
754 /*
755  * Adopt mode to reflect the config flags.
756  * If we can't use DMA we can't use synch transfer. Also check the
757  * sfas_inhibit_xxx[target] flags.
758  */
759 	if ((dev->sc_config_flags & (SFAS_NO_SYNCH | SFAS_NO_DMA)) ||
760 	    sfas_inhibit_sync[(int)target])
761 		mode &= ~SFAS_SELECT_S;
762 
763 	if ((dev->sc_config_flags & SFAS_NO_RESELECT) ||
764 	    sfas_inhibit_disc[(int)target])
765 		mode &= ~SFAS_SELECT_R;
766 
767 	nexus->xs		= pendp->xs;
768 
769 /* Setup the nexus struct. */
770 	nexus->ID	   = ((mode & SFAS_SELECT_R) ? 0xC0 : 0x80) | lun;
771 	nexus->clen	   = clen;
772 	bcopy(cbuf, nexus->cbuf, nexus->clen);
773 	nexus->cbuf[1] |= lun << 5;		/* Fix the lun bits */
774 	nexus->cur_link	   = 0;
775 	nexus->dma_len	   = 0;
776 	nexus->dma_buf	   = 0;
777 	nexus->dma_blk_len = 0;
778 	nexus->dma_blk_ptr = 0;
779 	nexus->len	   = len;
780 	nexus->buf	   = buf;
781 	nexus->lun_unit	   = (lun << 4) | target;
782 	nexus->state	   = SFAS_NS_SELECTED;
783 
784 /* We must keep these flags. All else must be zero. */
785 	nexus->flags	  &= SFAS_NF_UNIT_BUSY
786 			   | SFAS_NF_SYNC_TESTED | SFAS_NF_SELECT_ME;
787 
788 	if (mode & SFAS_SELECT_I)
789 		nexus->flags |= SFAS_NF_IMMEDIATE;
790 	if (mode & SFAS_SELECT_K)
791 		nexus->flags |= SFAS_NF_RESET;
792 
793 	sync  = ((mode & SFAS_SELECT_S) ? 1 : 0);
794 
795 /* We can't use sync during polled IO. */
796 	if (sync && (mode & SFAS_SELECT_I))
797 		sync = 0;
798 
799 	if (!sync &&
800 	    ((nexus->flags & SFAS_NF_SYNC_TESTED) && (nexus->offset != 0))) {
801 		/*
802 		 * If the scsi unit is set to synch transfer and we don't want
803 		 * that, we have to renegotiate.
804 		 */
805 
806 		nexus->flags |= SFAS_NF_DO_SDTR;
807 		nexus->period = 200;
808 		nexus->offset = 0;
809 	} else if (sync && !(nexus->flags & SFAS_NF_SYNC_TESTED)) {
810 		/*
811 		 * If the scsi unit is not set to synch transfer and we want
812 		 * that, we have to negotiate. This should realy base the
813 		 * period on the clock frequence rather than just check if
814 		 * >25Mhz
815 		 */
816 
817 		nexus->flags |= SFAS_NF_DO_SDTR;
818 		nexus->period = ((dev->sc_clock_freq>25) ? 100 : 200);
819 		nexus->offset = 8;
820 
821 		/* If the user has a long cable, we want to limit the period */
822 		if ((nexus->period == 100) &&
823 		    (dev->sc_config_flags & SFAS_SLOW_CABLE))
824 			nexus->period = 200;
825 	}
826 
827 /*
828  * Fake a DMA-block for polled IO. This way we can use the same code to handle
829  * reselection. Much nicer this way.
830  */
831 	if ((mode & SFAS_SELECT_I) || (dev->sc_config_flags & SFAS_NO_DMA)) {
832 		nexus->dma[0].ptr = buf;
833 		nexus->dma[0].len = len;
834 		nexus->dma[0].flg = SFAS_CHAIN_PRG;
835 		nexus->max_link   = 1;
836 	} else {
837 		nexus->max_link = dev->sc_build_dma_chain(dev, nexus->dma,
838 							  buf, len);
839 	}
840 
841 /* Flush the caches. */
842 
843 	if (len && !(mode & SFAS_SELECT_I))
844 		cpu_dcache_wbinv_range((vm_offset_t)buf, len);
845 }
846 
847 int
848 sfasselect(dev, pendp, cbuf, clen, buf, len, mode)
849 	struct sfas_softc	*dev;
850 	struct sfas_pending	*pendp;
851 	unsigned char		*cbuf;
852 	int			 clen;
853 	unsigned char		*buf;
854 	int			 len;
855 	int			 mode;
856 {
857 	struct nexus	*nexus;
858 
859 /* Get the nexus struct. */
860 	nexus = sfas_arbitate_target(dev, pendp->xs->xs_periph->periph_target);
861 	if (nexus == NULL)
862 		return(0);
863 
864 /* Setup the nexus struct. */
865 	sfas_setup_nexus(dev, nexus, pendp, cbuf, clen, buf, len, mode);
866 
867 /* Post it to the interrupt machine. */
868 	sfas_select_unit(dev, pendp->xs->xs_periph->periph_target);
869 
870 	return(1);
871 }
872 
873 void
874 sfasgo(dev, pendp)
875 	struct sfas_softc   *dev;
876 	struct sfas_pending *pendp;
877 {
878 	int	 s;
879 	char	*buf;
880 
881 	buf    = pendp->xs->data;
882 
883 	if (sfasselect(dev, pendp, (char *)pendp->xs->cmd, pendp->xs->cmdlen,
884 		      buf, pendp->xs->datalen, SFAS_SELECT_RS)) {
885 		/*
886 		 * We got the command going so the sfas_pending struct is now
887 		 * free to reuse.
888 		 */
889 
890 		s = splbio();
891 		TAILQ_INSERT_TAIL(&dev->sc_xs_free, pendp, link);
892 		splx(s);
893 	} else {
894 		/*
895 		 * We couldn't make the command fly so we have to wait. The
896 		 * struct MUST be inserted at the head to keep the order of
897 		 * the commands.
898 		 */
899 
900 		s = splbio();
901 		TAILQ_INSERT_HEAD(&dev->sc_xs_pending, pendp, link);
902 		splx(s);
903 	}
904 
905 	return;
906 }
907 
908 /*
909  * Part one of the interrupt machine. Error checks and reselection test.
910  * We don't know if we have an active nexus here!
911  */
912 int
913 sfas_pretests(dev, rp)
914 	struct sfas_softc *dev;
915 	sfas_regmap_p	  rp;
916 {
917 	struct nexus	*nexus;
918 	int		 i, s;
919 
920 	if (dev->sc_interrupt & SFAS_INT_SCSI_RESET_DETECTED) {
921 		/*
922 		 * Cleanup and notify user. Lets hope that this is all we
923 		 * have to do
924 		 */
925 
926 		for(i=0; i<8; i++) {
927 			if (dev->sc_nexus[i].xs)
928 				sfas_scsidone(dev, dev->sc_nexus[i].xs, -2);
929 
930 			sfas_init_nexus(dev, &dev->sc_nexus[i]);
931 		}
932 		printf("sfasintr: SCSI-RESET detected!");
933 		return(-1);
934 	}
935 
936 	if (dev->sc_interrupt & SFAS_INT_ILLEGAL_COMMAND) {
937 		/* Something went terrible wrong! Dump some data and panic! */
938 
939 		printf("FIFO:");
940 		while(*rp->sfas_fifo_flags & SFAS_FIFO_COUNT_MASK)
941 			printf(" %x", *rp->sfas_fifo);
942 		printf("\n");
943 
944 		printf("CMD: %x\n", *rp->sfas_command);
945 		panic("sfasintr: ILLEGAL COMMAND!");
946 	}
947 
948 	if (dev->sc_interrupt & SFAS_INT_RESELECTED) {
949 		/* We were reselected. Set the chip as busy */
950 
951 		s = splbio();
952 		dev->sc_flags |= SFAS_ACTIVE;
953 		if (dev->sc_sel_nexus) {
954 			dev->sc_sel_nexus->flags |= SFAS_NF_SELECT_ME;
955 			dev->sc_sel_nexus = 0;
956 		}
957 		splx(s);
958 
959 		if (dev->sc_units_disconnected) {
960 			/* Find out who reselected us. */
961 
962 			dev->sc_resel[0] &= ~(1<<dev->sc_host_id);
963 
964 			for(i=0; i<8; i++)
965 				if (dev->sc_resel[0] & (1<<i))
966 					break;
967 
968 			if (i == 8)
969 				panic("Illegal reselection!");
970 
971 			if (dev->sc_nexus[i].state == SFAS_NS_DISCONNECTED) {
972 				/*
973 				 * This unit had disconnected, so we reconnect
974 				 * it.
975 				 */
976 
977 				dev->sc_cur_nexus = &dev->sc_nexus[i];
978 				nexus = dev->sc_cur_nexus;
979 
980 				*rp->sfas_syncper = nexus->syncper;
981 				*rp->sfas_syncoff = nexus->syncoff;
982 				*rp->sfas_config3 = nexus->config3;
983 
984 				*rp->sfas_dest_id = i & 7;
985 
986 				dev->sc_units_disconnected--;
987 				dev->sc_msg_in_len= 0;
988 
989 				/* Restore active pointers. */
990 				sfas_restore_pointers(dev);
991 
992 				nexus->state = SFAS_NS_RESELECTED;
993 
994 				*rp->sfas_command = SFAS_CMD_MESSAGE_ACCEPTED;
995 
996 				return(1);
997 			}
998 		}
999 
1000 		/* Somehow we got an illegal reselection. Dump and panic. */
1001 		printf("sfasintr: resel[0] %x resel[1] %x disconnected %d\n",
1002 		       dev->sc_resel[0], dev->sc_resel[1],
1003 		       dev->sc_units_disconnected);
1004 		panic("sfasintr: Unexpected reselection!");
1005 	}
1006 
1007 	return(0);
1008 }
1009 
1010 /*
1011  * Part two of the interrupt machine. Handle disconnection and post command
1012  * processing. We know that we have an active nexus here.
1013  */
1014 int
1015 sfas_midaction(dev, rp, nexus)
1016 	struct sfas_softc *dev;
1017 	sfas_regmap_p	  rp;
1018 	struct nexus	 *nexus;
1019 {
1020 	int	i, left, len, s;
1021 	u_char	status, msg;
1022 
1023 	if (dev->sc_interrupt & SFAS_INT_DISCONNECT) {
1024 		s = splbio();
1025 		dev->sc_cur_nexus = 0;
1026 
1027 		/* Mark chip as busy and clean up the chip FIFO. */
1028 		dev->sc_flags &= ~SFAS_ACTIVE;
1029 		*rp->sfas_command = SFAS_CMD_FLUSH_FIFO;
1030 
1031 		/* Let the nexus state reflect what we have to do. */
1032 		switch(nexus->state) {
1033 		case SFAS_NS_SELECTED:
1034 			dev->sc_sel_nexus = 0;
1035 			nexus->flags &= ~SFAS_NF_SELECT_ME;
1036 
1037 			/*
1038 			 * We were trying to select the unit. Probably no unit
1039 			 * at this ID.
1040 			 */
1041 			nexus->xs->resid = dev->sc_len;
1042 
1043 			nexus->status = -2;
1044 			nexus->flags &= ~SFAS_NF_UNIT_BUSY;
1045 			nexus->state = SFAS_NS_FINISHED;
1046 			break;
1047 
1048 		case SFAS_NS_DONE:
1049 			/* All done. */
1050 			nexus->xs->resid = dev->sc_len;
1051 
1052 			nexus->flags &= ~SFAS_NF_UNIT_BUSY;
1053 			nexus->state  = SFAS_NS_FINISHED;
1054 			dev->sc_led(dev, 0);
1055 			break;
1056 
1057 		case SFAS_NS_DISCONNECTING:
1058 			/*
1059 			 * We have received a DISCONNECT message, so we are
1060 			 * doing a normal disconnection.
1061 			 */
1062 			nexus->state = SFAS_NS_DISCONNECTED;
1063 
1064 			dev->sc_units_disconnected++;
1065 			break;
1066 
1067 		case SFAS_NS_RESET:
1068 			/*
1069 			 * We were reseting this SCSI-unit. Clean up the
1070 			 * nexus struct.
1071 			 */
1072 			dev->sc_led(dev, 0);
1073 			sfas_init_nexus(dev, nexus);
1074 			break;
1075 
1076 		default:
1077 			/*
1078 			 * Unexpected disconnection! Cleanup and exit. This
1079 			 * shouldn't cause any problems.
1080 			 */
1081 			printf("sfasintr: Unexpected disconnection\n");
1082 			printf("sfasintr: u %x s %d p %d f %x c %x\n",
1083 			       nexus->lun_unit, nexus->state,
1084 			       dev->sc_status & SFAS_STAT_PHASE_MASK,
1085 			       nexus->flags, nexus->cbuf[0]);
1086 
1087 			nexus->xs->resid = dev->sc_len;
1088 
1089 			nexus->flags &= ~SFAS_NF_UNIT_BUSY;
1090 			nexus->state = SFAS_NS_FINISHED;
1091 			nexus->status = -3;
1092 
1093 			dev->sc_led(dev, 0);
1094 			break;
1095 		}
1096 
1097 		/*
1098 		 * If we have disconnected units, we MUST enable reselection
1099 		 * within 250ms.
1100 		 */
1101 		if (dev->sc_units_disconnected &&
1102 		    !(dev->sc_flags & SFAS_ACTIVE))
1103 			*rp->sfas_command = SFAS_CMD_ENABLE_RESEL;
1104 
1105 		splx(s);
1106 
1107 		/* Select the first pre-initialized nexus we find. */
1108 		for(i=0; i<8; i++)
1109 			if (dev->sc_nexus[i].flags & (SFAS_NF_SELECT_ME | SFAS_NF_RETRY_SELECT))
1110 				if (sfas_select_unit(dev, i) == 2)
1111 					break;
1112 
1113 		/* We are done with this nexus! */
1114 		if (nexus->state == SFAS_NS_FINISHED)
1115 			sfas_scsidone(dev, nexus->xs, nexus->status);
1116 
1117 		return(1);
1118 	}
1119 
1120 	switch(nexus->state) {
1121 	case SFAS_NS_SELECTED:
1122 		dev->sc_cur_nexus = nexus;
1123 		dev->sc_sel_nexus = 0;
1124 
1125 		nexus->flags &= ~SFAS_NF_SELECT_ME;
1126 
1127 		/*
1128 		 * We have selected a unit. Setup chip, restore pointers and
1129 		 * light the led.
1130 		 */
1131 		*rp->sfas_syncper = nexus->syncper;
1132 		*rp->sfas_syncoff = nexus->syncoff;
1133 		*rp->sfas_config3 = nexus->config3;
1134 
1135 		sfas_restore_pointers(dev);
1136 
1137 		nexus->status	= 0xFF;
1138 		dev->sc_msg_in[0] = 0xFF;
1139 		dev->sc_msg_in_len= 0;
1140 
1141 		dev->sc_led(dev, 1);
1142 
1143 		break;
1144 
1145 	case SFAS_NS_DATA_IN:
1146 	case SFAS_NS_DATA_OUT:
1147 		/* We have transfered data. */
1148 		if (dev->sc_dma_len)
1149 			if (dev->sc_cur_link < dev->sc_max_link) {
1150 				/*
1151 				 * Clean up DMA and at the same time get how
1152 				 * many bytes that were NOT transfered.
1153 				 */
1154 			  left = dev->sc_setup_dma(dev, 0, 0, SFAS_DMA_CLEAR);
1155 			  len  = dev->sc_dma_len;
1156 
1157 			  if (nexus->state == SFAS_NS_DATA_IN) {
1158 			    /*
1159 			     * If we were bumping we may have had an odd length
1160 			     * which means that there may be bytes left in the
1161 			     * fifo. We also need to move the data from the
1162 			     * bump buffer to the actual memory.
1163 			     */
1164 			    if (dev->sc_dma_buf == dev->sc_bump_pa)
1165 			    {
1166 			      while((*rp->sfas_fifo_flags&SFAS_FIFO_COUNT_MASK)
1167 				    && left)
1168 				dev->sc_bump_va[len-(left--)] = *rp->sfas_fifo;
1169 
1170 			      bcopy(dev->sc_bump_va, dev->sc_buf, len-left);
1171 			    }
1172 			  } else {
1173 			    /* Count any unsent bytes and flush them. */
1174 			    left+= *rp->sfas_fifo_flags & SFAS_FIFO_COUNT_MASK;
1175 			    *rp->sfas_command = SFAS_CMD_FLUSH_FIFO;
1176 			  }
1177 
1178 			  /*
1179 			   * Update pointers/length to reflect the transfered
1180 			   * data.
1181 			   */
1182 			  dev->sc_len -= len-left;
1183 			  dev->sc_buf += len-left;
1184 
1185 			  dev->sc_dma_buf = (char *)dev->sc_dma_buf + len-left;
1186 			  dev->sc_dma_len = left;
1187 
1188 			  dev->sc_dma_blk_ptr = (char *)dev->sc_dma_blk_ptr +
1189 				  len-left;
1190 			  dev->sc_dma_blk_len -= len-left;
1191 
1192 			  /*
1193 			   * If it was the end of a DMA block, we select the
1194 			   * next to begin with.
1195 			   */
1196 			  if (!dev->sc_dma_blk_len)
1197 			    dev->sc_cur_link++;
1198 			}
1199 		break;
1200 
1201 	case SFAS_NS_STATUS:
1202 		/*
1203 		 * If we were not sensing, grab the status byte. If we were
1204 		 * sensing and we got a bad status, let the user know.
1205 		 */
1206 
1207 		status = *rp->sfas_fifo;
1208 		msg = *rp->sfas_fifo;
1209 
1210 		nexus->status = status;
1211 		if (status != 0)
1212 			nexus->status = -1;
1213 
1214 		/*
1215 		 * Preload the command complete message. Handeled in
1216 		 * sfas_postaction.
1217 		 */
1218 		dev->sc_msg_in[0] = msg;
1219 		dev->sc_msg_in_len = 1;
1220 		nexus->flags |= SFAS_NF_HAS_MSG;
1221 		break;
1222 
1223 	default:
1224 		break;
1225 	}
1226 
1227 	return(0);
1228 }
1229 
1230 /*
1231  * Part three of the interrupt machine. Handle phase changes (and repeated
1232  * phase passes). We know that we have an active nexus here.
1233  */
1234 int
1235 sfas_postaction(dev, rp, nexus)
1236 	struct sfas_softc *dev;
1237 	sfas_regmap_p	  rp;
1238 	struct nexus	 *nexus;
1239 {
1240 	int	i, len;
1241 	u_char	cmd;
1242 	short	offset, period;
1243 
1244 	cmd = 0;
1245 
1246 	switch(dev->sc_status & SFAS_STAT_PHASE_MASK) {
1247 	case SFAS_PHASE_DATA_OUT:
1248 	case SFAS_PHASE_DATA_IN:
1249 		if ((dev->sc_status & SFAS_STAT_PHASE_MASK) ==
1250 		    SFAS_PHASE_DATA_OUT)
1251 			nexus->state = SFAS_NS_DATA_OUT;
1252 		else
1253 			nexus->state = SFAS_NS_DATA_IN;
1254 
1255 		/* Make DMA ready to accept new data. Load active pointers
1256 		 * from the DMA block. */
1257 		dev->sc_setup_dma(dev, 0, 0, SFAS_DMA_CLEAR);
1258 		if (dev->sc_cur_link < dev->sc_max_link) {
1259 		  if (!dev->sc_dma_blk_len) {
1260 		    dev->sc_dma_blk_ptr = dev->sc_chain[dev->sc_cur_link].ptr;
1261 		    dev->sc_dma_blk_len = dev->sc_chain[dev->sc_cur_link].len;
1262 		    dev->sc_dma_blk_flg = dev->sc_chain[dev->sc_cur_link].flg;
1263 		  }
1264 
1265 		  /* We should use polled IO here. */
1266 		  if (dev->sc_dma_blk_flg == SFAS_CHAIN_PRG) {
1267 			dev->sc_ixfer(dev, nexus->xs->xs_control & XS_CTL_POLL);
1268 			dev->sc_cur_link++;
1269 			dev->sc_dma_len = 0;
1270 			break;
1271 		  }
1272 		  else if (dev->sc_dma_blk_flg == SFAS_CHAIN_BUMP)
1273 			len = dev->sc_dma_blk_len;
1274 		  else
1275 			len = dev->sc_need_bump(dev, dev->sc_dma_blk_ptr,
1276 						dev->sc_dma_blk_len);
1277 
1278 		  /*
1279 		   * If len != 0 we must bump the data, else we just DMA it
1280 		   * straight into memory.
1281 		   */
1282 		  if (len) {
1283 			dev->sc_dma_buf = dev->sc_bump_pa;
1284 			dev->sc_dma_len = len;
1285 
1286 			if (nexus->state == SFAS_NS_DATA_OUT)
1287 			  bcopy(dev->sc_buf, dev->sc_bump_va, dev->sc_dma_len);
1288 		  } else {
1289 			dev->sc_dma_buf = dev->sc_dma_blk_ptr;
1290 			dev->sc_dma_len = dev->sc_dma_blk_len;
1291 		  }
1292 
1293 		  /* Load DMA with address and length of transfer. */
1294 		  dev->sc_setup_dma(dev, dev->sc_dma_buf, dev->sc_dma_len,
1295 				    ((nexus->state == SFAS_NS_DATA_OUT) ?
1296 				     SFAS_DMA_WRITE : SFAS_DMA_READ));
1297 
1298 /*		  printf("Using DMA !!!!\n");*/
1299 		  cmd = SFAS_CMD_TRANSFER_INFO | SFAS_CMD_DMA;
1300 		} else {
1301 			/*
1302 			 * Hmmm, the unit wants more info than we have or has
1303 			 * more than we want. Let the chip handle that.
1304 			 */
1305 
1306 			*rp->sfas_tc_low = 0; /* was 256 but this does not make sense */
1307 			*rp->sfas_tc_mid = 1;
1308 			*rp->sfas_tc_high = 0;
1309 			cmd = SFAS_CMD_TRANSFER_PAD;
1310 		}
1311 		break;
1312 
1313 	case SFAS_PHASE_COMMAND:
1314 		/* The scsi unit wants the command, send it. */
1315 		nexus->state = SFAS_NS_SVC;
1316 
1317 		*rp->sfas_command = SFAS_CMD_FLUSH_FIFO;
1318 		for(i=0; i<5; i++);
1319 
1320 		for(i=0; i<nexus->clen; i++)
1321 			*rp->sfas_fifo = nexus->cbuf[i];
1322 		cmd = SFAS_CMD_TRANSFER_INFO;
1323 		break;
1324 
1325 	case SFAS_PHASE_STATUS:
1326 		/*
1327 		 * We've got status phase. Request status and command
1328 		 * complete message.
1329 		 */
1330 		nexus->state = SFAS_NS_STATUS;
1331 		cmd = SFAS_CMD_COMMAND_COMPLETE;
1332 		break;
1333 
1334 	case SFAS_PHASE_MESSAGE_OUT:
1335 		/*
1336 		 * Either the scsi unit wants us to send a message or we have
1337 		 * asked for it by seting the ATN bit.
1338 		 */
1339 		nexus->state = SFAS_NS_MSG_OUT;
1340 
1341 		*rp->sfas_command = SFAS_CMD_FLUSH_FIFO;
1342 
1343 		if (nexus->flags & SFAS_NF_DO_SDTR) {
1344 			/* Send a Synchronous Data Transfer Request. */
1345 
1346 			sfas_build_sdtrm(dev, nexus->period, nexus->offset);
1347 			nexus->flags |= SFAS_NF_SDTR_SENT;
1348 			nexus->flags &= ~SFAS_NF_DO_SDTR;
1349 		} else if (nexus->flags & SFAS_NF_RESET) {
1350 			/* Send a reset scsi unit message. */
1351 
1352 			dev->sc_msg_out[0] = 0x0C;
1353 			dev->sc_msg_out_len = 1;
1354 			nexus->state = SFAS_NS_RESET;
1355 			nexus->flags &= ~SFAS_NF_RESET;
1356 		} else if (dev->sc_msg_out_len == 0) {
1357 			/* Don't know what to send so we send a NOP message. */
1358 
1359 			dev->sc_msg_out[0] = 0x08;
1360 			dev->sc_msg_out_len = 1;
1361 		}
1362 
1363 		cmd = SFAS_CMD_TRANSFER_INFO;
1364 
1365 		for(i=0; i<dev->sc_msg_out_len; i++)
1366 			*rp->sfas_fifo = dev->sc_msg_out[i];
1367 		dev->sc_msg_out_len = 0;
1368 
1369 		break;
1370 
1371 	case SFAS_PHASE_MESSAGE_IN:
1372 		/* Receive a message from the scsi unit. */
1373 		nexus->state = SFAS_NS_MSG_IN;
1374 
1375 		while(!(nexus->flags & SFAS_NF_HAS_MSG)) {
1376 			*rp->sfas_command = SFAS_CMD_TRANSFER_INFO;
1377 			sfasiwait(dev);
1378 
1379 			dev->sc_msg_in[dev->sc_msg_in_len++] = *rp->sfas_fifo;
1380 
1381 			/* Check if we got all the bytes in the message. */
1382 			if (dev->sc_msg_in[0] >= 0x80)       ;
1383 			else if (dev->sc_msg_in[0] >= 0x30)  ;
1384 			else if (((dev->sc_msg_in[0] >= 0x20) &&
1385 				  (dev->sc_msg_in_len == 2)) ||
1386 				 ((dev->sc_msg_in[0] != 0x01) &&
1387 				  (dev->sc_msg_in_len == 1))) {
1388 				nexus->flags |= SFAS_NF_HAS_MSG;
1389 				break;
1390 			} else {
1391 			  if (dev->sc_msg_in_len >= 2)
1392 			    if ((dev->sc_msg_in[1]+2) == dev->sc_msg_in_len) {
1393 				nexus->flags |= SFAS_NF_HAS_MSG;
1394 				break;
1395 			    }
1396 			}
1397 
1398 			*rp->sfas_command = SFAS_CMD_MESSAGE_ACCEPTED;
1399 			sfasiwait(dev);
1400 
1401 			if ((dev->sc_status & SFAS_STAT_PHASE_MASK) !=
1402 			    SFAS_PHASE_MESSAGE_IN)
1403 				break;
1404 		}
1405 
1406 		cmd = SFAS_CMD_MESSAGE_ACCEPTED;
1407 		if (nexus->flags & SFAS_NF_HAS_MSG) {
1408 			/* We have a message. Decode it. */
1409 
1410 			switch(dev->sc_msg_in[0]) {
1411 			case 0x00:	/* COMMAND COMPLETE */
1412 				nexus->state = SFAS_NS_DONE;
1413 				break;
1414 			case 0x04:	/* DISCONNECT */
1415 				nexus->state = SFAS_NS_DISCONNECTING;
1416 				break;
1417 			case 0x02:	/* SAVE DATA POINTER */
1418 				sfas_save_pointers(dev);
1419 				break;
1420 			case 0x03:	/* RESTORE DATA POINTERS */
1421 				sfas_restore_pointers(dev);
1422 				break;
1423 			case 0x07:	/* MESSAGE REJECT */
1424 				/*
1425 				 * If we had sent a SDTR and we got a message
1426 				 * reject, the scsi docs say that we must go
1427 				 * to async transfer.
1428 				 */
1429 				if (nexus->flags & SFAS_NF_SDTR_SENT) {
1430 					nexus->flags &= ~SFAS_NF_SDTR_SENT;
1431 
1432 					nexus->config3 &= ~SFAS_CFG3_FASTSCSI;
1433 					nexus->syncper = 5;
1434 					nexus->syncoff = 0;
1435 
1436 					*rp->sfas_syncper = nexus->syncper;
1437 					*rp->sfas_syncoff = nexus->syncoff;
1438 					*rp->sfas_config3 = nexus->config3;
1439 				} else
1440 				/*
1441 				 * Something was rejected but we don't know
1442 				 * what! PANIC!
1443 				 */
1444 				  panic("sfasintr: Unknown message rejected!");
1445 				break;
1446 			case 0x08:	/* MO OPERATION */
1447 				break;
1448 			case 0x01:	/* EXTENDED MESSAGE */
1449 				switch(dev->sc_msg_in[2]) {
1450 				case 0x01:/* SYNC. DATA TRANSFER REQUEST */
1451 					/* Decode the SDTR message. */
1452 					period = 4*dev->sc_msg_in[3];
1453 					offset = dev->sc_msg_in[4];
1454 
1455 					/*
1456 					 * Make sure that the specs are within
1457 					 * chip limits. Note that if we
1458 					 * initiated the negotiation the specs
1459 					 * WILL be withing chip limits. If it
1460 					 * was the scsi unit that initiated
1461 					 * the negotiation, the specs may be
1462 					 * to high.
1463 					 */
1464 					if (offset > 16)
1465 						offset = 16;
1466 					if ((period < 200) &&
1467 					    (dev->sc_clock_freq <= 25))
1468 						period = 200;
1469 
1470 					if (offset == 0)
1471 					       period = 5*dev->sc_clock_period;
1472 
1473 					nexus->syncper = period/
1474 							  dev->sc_clock_period;
1475 					nexus->syncoff = offset;
1476 
1477 					if (period < 200)
1478 					  nexus->config3 |= SFAS_CFG3_FASTSCSI;
1479 					else
1480 					  nexus->config3 &=~SFAS_CFG3_FASTSCSI;
1481 
1482 					nexus->flags |= SFAS_NF_SYNC_TESTED;
1483 
1484 					*rp->sfas_syncper = nexus->syncper;
1485 					*rp->sfas_syncoff = nexus->syncoff;
1486 					*rp->sfas_config3 = nexus->config3;
1487 
1488 					/*
1489 					 * Hmmm, it seems that the scsi unit
1490 					 * initiated sync negotiation, so lets
1491 					 * reply acording to scsi-2 standard.
1492 					 */
1493 					if (!(nexus->flags& SFAS_NF_SDTR_SENT))
1494 					{
1495 					  if ((dev->sc_config_flags &
1496 					       SFAS_NO_SYNCH) ||
1497 					      (dev->sc_config_flags &
1498 					       SFAS_NO_DMA) ||
1499 					      sfas_inhibit_sync[
1500 							nexus->lun_unit & 7]) {
1501 					          period = 200;
1502 					          offset = 0;
1503 					  }
1504 
1505 					  nexus->offset = offset;
1506 					  nexus->period = period;
1507 					  nexus->flags |= SFAS_NF_DO_SDTR;
1508 					  *rp->sfas_command = SFAS_CMD_SET_ATN;
1509 					}
1510 
1511 					nexus->flags &= ~SFAS_NF_SDTR_SENT;
1512 					break;
1513 
1514 				case 0x00: /* MODIFY DATA POINTERS */
1515 				case 0x02: /* EXTENDED IDENTIFY (SCSI-1) */
1516 				case 0x03: /* WIDE DATA TRANSFER REQUEST */
1517 			        default:
1518 					/* Reject any unhandeled messages. */
1519 
1520 					dev->sc_msg_out[0] = 0x07;
1521 					dev->sc_msg_out_len = 1;
1522 					*rp->sfas_command = SFAS_CMD_SET_ATN;
1523 					cmd = SFAS_CMD_MESSAGE_ACCEPTED;
1524 					break;
1525 				}
1526 				break;
1527 
1528 			default:
1529 				/* Reject any unhandeled messages. */
1530 
1531 				dev->sc_msg_out[0] = 0x07;
1532 				dev->sc_msg_out_len = 1;
1533 				*rp->sfas_command = SFAS_CMD_SET_ATN;
1534 				cmd = SFAS_CMD_MESSAGE_ACCEPTED;
1535 				break;
1536 			}
1537 			nexus->flags &= ~SFAS_NF_HAS_MSG;
1538 			dev->sc_msg_in_len = 0;
1539 		}
1540 		break;
1541 	default:
1542 		printf("SFASINTR: UNKNOWN PHASE! phase: %d\n",
1543 		       dev->sc_status & SFAS_STAT_PHASE_MASK);
1544 		dev->sc_led(dev, 0);
1545 		sfas_scsidone(dev, nexus->xs, -4);
1546 
1547 		return(-1);
1548 	}
1549 
1550 	if (cmd)
1551 		*rp->sfas_command = cmd;
1552 
1553 	return(0);
1554 }
1555 
1556 /*
1557  * Stub for interrupt machine.
1558  */
1559 void
1560 sfasintr(dev)
1561 	struct sfas_softc *dev;
1562 {
1563 	sfas_regmap_p	 rp;
1564 	struct nexus	*nexus;
1565 
1566 	rp = dev->sc_fas;
1567 
1568 	if (!sfas_pretests(dev, rp)) {
1569 
1570 		nexus = dev->sc_cur_nexus;
1571 		if (nexus == NULL)
1572 			nexus = dev->sc_sel_nexus;
1573 
1574 		if (nexus)
1575 			if (!sfas_midaction(dev, rp, nexus))
1576 				sfas_postaction(dev, rp, nexus);
1577 	}
1578 }
1579 
1580 /*
1581  * sfasicmd is used to perform IO when we can't use interrupts. sfasicmd
1582  * emulates the normal environment by waiting for the chip and calling
1583  * sfasintr.
1584  */
1585 void
1586 sfasicmd(dev, pendp)
1587 	struct sfas_softc   *dev;
1588 	struct sfas_pending *pendp;
1589 {
1590 	sfas_regmap_p	 rp;
1591 	struct nexus	*nexus;
1592 
1593 	nexus = &dev->sc_nexus[pendp->xs->xs_periph->periph_target];
1594 	rp = dev->sc_fas;
1595 
1596 	if (!sfasselect(dev, pendp, (char *)pendp->xs->cmd, pendp->xs->cmdlen,
1597 			(char *)pendp->xs->data, pendp->xs->datalen,
1598 			SFAS_SELECT_I))
1599 		panic("sfasicmd: Couldn't select unit");
1600 
1601 	while(nexus->state != SFAS_NS_FINISHED) {
1602 		sfasiwait(dev);
1603 		sfasintr(dev);
1604 	}
1605 
1606 	nexus->flags &= ~SFAS_NF_SYNC_TESTED;
1607 }
1608 
1609 
1610 #ifdef SFAS_DEBUG
1611 
1612 void
1613 dump_nexus(nexus)
1614 	struct nexus *nexus;
1615 {
1616 	int loop;
1617 
1618 	printf("nexus=%08x\n", (u_int)nexus);
1619 	printf("scsi_fer=%08x\n", (u_int)nexus->xs);
1620 	printf("ID=%02x\n", nexus->ID);
1621 	printf("clen=%02x\n", nexus->clen);
1622 	printf("cbuf=");
1623 	for (loop = 0; loop< 14; ++loop)
1624 		printf(" %02x\n", nexus->cbuf[loop]);
1625 	printf("\n");
1626 	printf("DMA:\n");
1627 	for (loop = 0; loop < MAXCHAIN; ++loop)
1628 		printf("dma_chain: %08x %04x %04x\n", nexus->dma[loop].ptr,
1629 		    nexus->dma[loop].len, nexus->dma[loop].flg);
1630 	printf("\n");
1631 
1632 	printf("max_link=%d\n", nexus->max_link);
1633 	printf("cur_link=%d\n", nexus->cur_link);
1634 
1635 	printf("buf=%08x\n", (u_int)nexus->buf);
1636 	printf("len=%08x\n", nexus->len);
1637 	printf("dma_buf=%08x\n", (u_int)nexus->dma_buf);
1638 	printf("dma_len=%08x\n", nexus->dma_len);
1639 	printf("dma_blk_ptr=%08x\n", (u_int)nexus->dma_blk_ptr);
1640 	printf("dma_blk_len=%08x\n", nexus->dma_blk_len);
1641 	printf("dma_blk_flag=%08x\n", nexus->dma_blk_flg);
1642 	printf("state=%02x\n", nexus->state);
1643 	printf("flags=%04x\n", nexus->flags);
1644 	printf("period=%d\n", nexus->period);
1645 	printf("offset=%d\n", nexus->offset);
1646 	printf("syncper=%d\n", nexus->syncper);
1647 	printf("syncoff=%d\n", nexus->syncoff);
1648 	printf("config3=%02x\n", nexus->config3);
1649 	printf("lun_unit=%d\n", nexus->lun_unit);
1650 	printf("status=%02x\n", nexus->status);
1651 	printf("\n");
1652 }
1653 
1654 void
1655 dump_nexii(sc)
1656 	struct sfas_softc *sc;
1657 {
1658 	int loop;
1659 
1660 	for (loop = 0; loop < 8; ++loop) {
1661 		dump_nexus(&sc->sc_nexus[loop]);
1662 	}
1663 }
1664 
1665 void
1666 dump_sfassoftc(sc)
1667 	struct sfas_softc *sc;
1668 {
1669 	printf("sfassoftc @ 0x%08x\n", (u_int)sc);
1670 	printf("clock_freq = %d\n", sc->sc_clock_freq);
1671 	printf("timeout = %d\n", sc->sc_timeout);
1672 	printf("host_id = %d\n", sc->sc_host_id);
1673 	printf("config_flags = 0x%08x\n", sc->sc_config_flags);
1674 	printf("led_status = %d\n", sc->sc_led_status);
1675 
1676 	dump_nexii(sc);
1677 	printf("cur_nexus = 0x%08x\n", (u_int)sc->sc_cur_nexus);
1678 	printf("sel_nexus = 0x%08x\n", (u_int)sc->sc_sel_nexus);
1679 	printf("\n");
1680 }
1681 
1682 #endif	/* SFAS_DEBUG */
1683