xref: /netbsd-src/sys/arch/acorn32/podulebus/esc.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: esc.c,v 1.27 2014/02/22 19:03:06 matt 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  * AMD AM53CF94 scsi adaptor driver
78  *
79  * Functionally compatible with the FAS216
80  *
81  * Apart from a very small patch to set up control register 4
82  */
83 
84 /*
85  * Modified for NetBSD/arm32 by Scott Stevens
86  */
87 
88 #include <sys/cdefs.h>
89 __KERNEL_RCSID(0, "$NetBSD: esc.c,v 1.27 2014/02/22 19:03:06 matt Exp $");
90 
91 #include <sys/param.h>
92 #include <sys/systm.h>
93 #include <sys/device.h>
94 #include <sys/buf.h>
95 #include <sys/proc.h>
96 #include <dev/scsipi/scsi_all.h>
97 #include <dev/scsipi/scsipi_all.h>
98 #include <dev/scsipi/scsiconf.h>
99 
100 #include <uvm/uvm_extern.h>
101 
102 #include <machine/pmap.h>
103 #include <machine/cpu.h>
104 #include <machine/io.h>
105 #include <machine/intr.h>
106 #include <arm/arm32/katelib.h>
107 #include <acorn32/podulebus/podulebus.h>
108 #include <acorn32/podulebus/escreg.h>
109 #include <acorn32/podulebus/escvar.h>
110 
111 void escinitialize(struct esc_softc *);
112 void esc_minphys(struct buf *bp);
113 void esc_scsi_request(struct scsipi_channel *,
114 				scsipi_adapter_req_t, void *);
115 void esc_donextcmd(struct esc_softc *dev, struct esc_pending *pendp);
116 void esc_scsidone(struct esc_softc *dev, struct scsipi_xfer *xs,
117 			 int stat);
118 void escintr(struct esc_softc *dev);
119 void esciwait(struct esc_softc *dev);
120 void escreset(struct esc_softc *dev, int how);
121 int  escselect(struct esc_softc *dev, struct esc_pending *pendp,
122 			 unsigned char *cbuf, int clen,
123 			 unsigned char *buf, int len, int mode);
124 void escicmd(struct esc_softc *dev, struct esc_pending *pendp);
125 int escgo(struct esc_softc *dev, struct esc_pending *pendp);
126 
127 void esc_init_nexus(struct esc_softc *, struct nexus *);
128 void esc_save_pointers(struct esc_softc *);
129 void esc_restore_pointers(struct esc_softc *);
130 void esc_ixfer(struct esc_softc *);
131 void esc_build_sdtrm(struct esc_softc *, int, int);
132 int esc_select_unit(struct esc_softc *,	short);
133 struct nexus *esc_arbitate_target(struct esc_softc *, int);
134 void esc_setup_nexus(struct esc_softc *, struct nexus *, struct esc_pending *,
135     unsigned char *, int, unsigned char *, int, int);
136 int esc_pretests(struct esc_softc *, esc_regmap_p);
137 int esc_midaction(struct esc_softc *, esc_regmap_p, struct nexus *);
138 int esc_postaction(struct esc_softc *, esc_regmap_p, struct nexus *);
139 
140 
141 /*
142  * Initialize these to make 'em patchable. Defaults to enable sync and discon.
143  */
144 u_char	esc_inhibit_sync[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
145 u_char	esc_inhibit_disc[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
146 
147 #undef DEBUG
148 #define DEBUG
149 #ifdef DEBUG
150 #define QPRINTF(a) if (esc_debug > 1) printf a
151 int	esc_debug = 2;
152 #else
153 #define QPRINTF
154 #endif
155 
156 /*
157  * default minphys routine for esc based controllers
158  */
159 void
160 esc_minphys(struct buf *bp)
161 {
162 
163 	/*
164 	 * No max transfer at this level.
165 	 */
166 	minphys(bp);
167 }
168 
169 /*
170  * Initialize the nexus structs.
171  */
172 void
173 esc_init_nexus(struct esc_softc *dev, struct nexus *nexus)
174 {
175 	memset(nexus, 0, sizeof(struct nexus));
176 
177 	nexus->state	= ESC_NS_IDLE;
178 	nexus->period	= 200;
179 	nexus->offset	= 0;
180 	nexus->syncper	= 5;
181 	nexus->syncoff	= 0;
182 	nexus->config3	= dev->sc_config3 & ~ESC_CFG3_FASTSCSI;
183 }
184 
185 void
186 escinitialize(struct esc_softc *dev)
187 {
188 	int		 i;
189 
190 	dev->sc_led_status = 0;
191 
192 	TAILQ_INIT(&dev->sc_xs_pending);
193 	TAILQ_INIT(&dev->sc_xs_free);
194 
195 /*
196  * Initialize the esc_pending structs and link them into the free list. We
197  * have to set vm_link_data.pages to 0 or the vm FIX won't work.
198  */
199 	for(i=0; i<MAXPENDING; i++) {
200 		TAILQ_INSERT_TAIL(&dev->sc_xs_free, &dev->sc_xs_store[i],
201 				  link);
202 	}
203 
204 /*
205  * Calculate the correct clock conversion factor 2 <= factor <= 8, i.e. set
206  * the factor to clock_freq / 5 (int).
207  */
208 	if (dev->sc_clock_freq <= 10)
209 		dev->sc_clock_conv_fact = 2;
210 	if (dev->sc_clock_freq <= 40)
211 		dev->sc_clock_conv_fact = 2+((dev->sc_clock_freq-10)/5);
212 	else
213 		panic("escinitialize: Clock frequence too high");
214 
215 /* Setup and save the basic configuration registers */
216 	dev->sc_config1 = (dev->sc_host_id & ESC_CFG1_BUS_ID_MASK);
217 	dev->sc_config2 = ESC_CFG2_FEATURES_ENABLE;
218 	dev->sc_config3 = (dev->sc_clock_freq > 25 ? ESC_CFG3_FASTCLK : 0);
219 
220 /* Precalculate timeout value and clock period. */
221 /* Ekkk ... floating point in the kernel !!!! */
222 /*	dev->sc_timeout_val  = 1+dev->sc_timeout*dev->sc_clock_freq/
223 				 (7.682*dev->sc_clock_conv_fact);*/
224 	dev->sc_timeout_val  = 1+dev->sc_timeout*dev->sc_clock_freq/
225 				 ((7682*dev->sc_clock_conv_fact)/1000);
226 	dev->sc_clock_period = 1000/dev->sc_clock_freq;
227 
228 	escreset(dev, 1 | 2);	/* Reset Chip and Bus */
229 
230 	dev->sc_units_disconnected = 0;
231 	dev->sc_msg_in_len = 0;
232 	dev->sc_msg_out_len = 0;
233 
234 	dev->sc_flags = 0;
235 
236 	for(i=0; i<8; i++)
237 		esc_init_nexus(dev, &dev->sc_nexus[i]);
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 	pt_entry_t * const ptep = vtopte((vaddr_t) dev->sc_bump_va);
252 	const pt_entry_t opte = *ptep;
253 	const pt_entry_t npte = opte & ~L2_C;
254 	l2pte_set(ptep, npte, opte);
255 	PTE_SYNC(ptep);
256 	cpu_tlb_flushD();
257 	cpu_dcache_wbinv_range((vm_offset_t)dev->sc_bump_va, PAGE_SIZE);
258 
259 	printf(" dmabuf V0x%08x P0x%08x", (u_int)dev->sc_bump_va, (u_int)dev->sc_bump_pa);
260 }
261 
262 
263 /*
264  * used by specific esc controller
265  */
266 void
267 esc_scsi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
268  								void *arg)
269 {
270 	struct scsipi_xfer *xs;
271 	struct esc_softc	*dev = device_private(chan->chan_adapter->adapt_dev);
272 	struct scsipi_periph	*periph;
273 	struct esc_pending	*pendp;
274 	int			 flags, s, target;
275 
276 	switch (req) {
277 	case ADAPTER_REQ_RUN_XFER:
278 		xs = arg;
279 		periph = xs->xs_periph;
280 		flags = xs->xs_control;
281 		target = periph->periph_target;
282 
283 		if (flags & XS_CTL_DATA_UIO)
284 			panic("esc: scsi data uio requested");
285 
286 		if ((flags & XS_CTL_POLL) && (dev->sc_flags & ESC_ACTIVE))
287 			panic("esc_scsicmd: busy");
288 
289 /* Get hold of a esc_pending block. */
290 		s = splbio();
291 		pendp = dev->sc_xs_free.tqh_first;
292 		if (pendp == NULL) {
293 			splx(s);
294 			xs->error = XS_RESOURCE_SHORTAGE;
295 			scsipi_done(xs);
296 			return;
297 		}
298 		TAILQ_REMOVE(&dev->sc_xs_free, pendp, link);
299 		pendp->xs = xs;
300 		splx(s);
301 
302 
303 /* If the chip if busy OR the unit is busy, we have to wait for out turn. */
304 		if ((dev->sc_flags & ESC_ACTIVE) ||
305 		    (dev->sc_nexus[target].flags & ESC_NF_UNIT_BUSY)) {
306 			s = splbio();
307 			TAILQ_INSERT_TAIL(&dev->sc_xs_pending, pendp, link);
308 			splx(s);
309 		} else
310 			esc_donextcmd(dev, pendp);
311 
312 		return;
313 	case ADAPTER_REQ_GROW_RESOURCES:
314 	case ADAPTER_REQ_SET_XFER_MODE:
315 		/* XXX Not supported. */
316 		return;
317 	}
318 
319 }
320 
321 /*
322  * Actually select the unit, whereby the whole scsi-process is started.
323  */
324 void
325 esc_donextcmd(struct esc_softc *dev, struct esc_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(!escselect(dev, pendp, 0, 0, 0, 0, ESC_SELECT_K)) {
341 			splx(s);
342 			delay(10);
343 			s = splbio();
344 		}
345 
346 		nexus = dev->sc_cur_nexus;
347 		while(nexus->flags & ESC_NF_UNIT_BUSY) {
348 			esciwait(dev);
349 			escintr(dev);
350 		}
351 
352 		nexus->flags |= ESC_NF_UNIT_BUSY;
353 		splx(s);
354 
355 		escreset(dev, 0);
356 
357 		s = splbio();
358 		nexus->flags &= ~ESC_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 escgo to get the interrupt machine going.
365  */
366 	if (pendp->xs->xs_control & XS_CTL_POLL) {
367 		s = splbio();
368 		escicmd(dev, pendp);
369 		TAILQ_INSERT_TAIL(&dev->sc_xs_free, pendp, link);
370 		splx(s);
371 	} else {
372 		escgo(dev, pendp);
373 		return;
374 	}
375 }
376 
377 void
378 esc_scsidone(struct esc_softc *dev, struct scsipi_xfer *xs, int stat)
379 {
380 	struct esc_pending	*pendp;
381 	int			 s;
382 
383 	xs->status = stat;
384 
385 	if (stat == 0)
386 		xs->resid = 0;
387 	else {
388 		switch(stat) {
389 		case SCSI_CHECK:
390 		case SCSI_BUSY:
391 			xs->error = XS_BUSY;
392 			break;
393 		case -1:
394 			xs->error = XS_DRIVER_STUFFUP;
395 			QPRINTF(("esc_scsicmd() bad %x\n", stat));
396 			break;
397 		default:
398 			xs->error = XS_TIMEOUT;
399 			break;
400 		}
401 	}
402 
403 /* Steal the next command from the queue so that one unit can't hog the bus. */
404 	s = splbio();
405 	pendp = dev->sc_xs_pending.tqh_first;
406 	while(pendp) {
407 		if (!(dev->sc_nexus[pendp->xs->xs_periph->periph_target].flags &
408 		      ESC_NF_UNIT_BUSY))
409 			break;
410 		pendp = pendp->link.tqe_next;
411 	}
412 
413 	if (pendp != NULL) {
414 		TAILQ_REMOVE(&dev->sc_xs_pending, pendp, link);
415 	}
416 
417 	splx(s);
418 	scsipi_done(xs);
419 
420 	if (pendp)
421 		esc_donextcmd(dev, pendp);
422 }
423 
424 /*
425  * There are two kinds of reset:
426  *  1) CHIP-bus reset. This also implies a SCSI-bus reset.
427  *  2) SCSI-bus reset.
428  * After the appropriate resets have been performed we wait a reset to select
429  * delay time.
430  */
431 void
432 escreset(struct esc_softc *dev, int how)
433 {
434 	esc_regmap_p	rp;
435 	int		i, s;
436 
437 	rp = dev->sc_esc;
438 
439 	if (how & 1) {
440 		for(i=0; i<8; i++)
441 			esc_init_nexus(dev, &dev->sc_nexus[i]);
442 
443 		*rp->esc_command = ESC_CMD_RESET_CHIP;
444 		delay(1);
445 		*rp->esc_command = ESC_CMD_NOP;
446 
447 		*rp->esc_config1 = dev->sc_config1;
448 		*rp->esc_config2 = dev->sc_config2;
449 		*rp->esc_config3 = dev->sc_config3;
450 		*rp->esc_config4 = dev->sc_config4;
451 		*rp->esc_timeout = dev->sc_timeout_val;
452 		*rp->esc_clkconv = dev->sc_clock_conv_fact &
453 					ESC_CLOCK_CONVERSION_MASK;
454 	}
455 
456 	if (how & 2) {
457 		for(i=0; i<8; i++)
458 			esc_init_nexus(dev, &dev->sc_nexus[i]);
459 
460 		s = splbio();
461 
462 		*rp->esc_command = ESC_CMD_RESET_SCSI_BUS;
463 		delay(100);
464 
465 /* Skip interrupt generated by RESET_SCSI_BUS */
466 		while(*rp->esc_status & ESC_STAT_INTERRUPT_PENDING) {
467 			dev->sc_status = *rp->esc_status;
468 			dev->sc_interrupt = *rp->esc_interrupt;
469 
470 			delay(100);
471 		}
472 
473 		dev->sc_status = *rp->esc_status;
474 		dev->sc_interrupt = *rp->esc_interrupt;
475 
476 		splx(s);
477 	}
478 
479 	if (dev->sc_config_flags & ESC_SLOW_START)
480 		delay(4*250000); /* RESET to SELECT DELAY*4 for slow devices */
481 	else
482 		delay(250000);	 /* RESET to SELECT DELAY */
483 }
484 
485 /*
486  * Save active data pointers to the nexus block currently active.
487  */
488 void
489 esc_save_pointers(struct esc_softc *dev)
490 {
491 	struct nexus	*nx;
492 
493 	nx = dev->sc_cur_nexus;
494 	if (nx) {
495 		nx->cur_link	= dev->sc_cur_link;
496 		nx->max_link	= dev->sc_max_link;
497 		nx->buf		= dev->sc_buf;
498 		nx->len		= dev->sc_len;
499 		nx->dma_len	= dev->sc_dma_len;
500 		nx->dma_buf	= dev->sc_dma_buf;
501 		nx->dma_blk_flg	= dev->sc_dma_blk_flg;
502 		nx->dma_blk_len	= dev->sc_dma_blk_len;
503 		nx->dma_blk_ptr	= dev->sc_dma_blk_ptr;
504 	}
505 }
506 
507 /*
508  * Restore data pointers from the currently active nexus block.
509  */
510 void
511 esc_restore_pointers(struct esc_softc *dev)
512 {
513 	struct nexus	*nx;
514 
515 	nx = dev->sc_cur_nexus;
516 	if (nx) {
517 		dev->sc_cur_link    = nx->cur_link;
518 		dev->sc_max_link    = nx->max_link;
519 		dev->sc_buf	    = nx->buf;
520 		dev->sc_len	    = nx->len;
521 		dev->sc_dma_len	    = nx->dma_len;
522 		dev->sc_dma_buf	    = nx->dma_buf;
523 		dev->sc_dma_blk_flg = nx->dma_blk_flg;
524 		dev->sc_dma_blk_len = nx->dma_blk_len;
525 		dev->sc_dma_blk_ptr = nx->dma_blk_ptr;
526 		dev->sc_chain	    = nx->dma;
527 		dev->sc_unit	    = (nx->lun_unit & 0x0F);
528 		dev->sc_lun	    = (nx->lun_unit & 0xF0) >> 4;
529 	}
530 }
531 
532 /*
533  * esciwait is used during interrupt and polled IO to wait for an event from
534  * the FAS chip. This function MUST NOT BE CALLED without interrupt disabled.
535  */
536 void
537 esciwait(struct esc_softc *dev)
538 {
539 	esc_regmap_p	rp;
540 
541 /*
542  * If ESC_DONT_WAIT is set, we have already grabbed the interrupt info
543  * elsewhere. So we don't have to wait for it.
544  */
545 	if (dev->sc_flags & ESC_DONT_WAIT) {
546 		dev->sc_flags &= ~ESC_DONT_WAIT;
547 		return;
548 	}
549 
550 	rp = dev->sc_esc;
551 
552 /* Wait for FAS chip to signal an interrupt. */
553 	while(!(*rp->esc_status & ESC_STAT_INTERRUPT_PENDING));
554 /*		delay(1);*/
555 
556 /* Grab interrupt info from chip. */
557 	dev->sc_status = *rp->esc_status;
558 	dev->sc_interrupt = *rp->esc_interrupt;
559 	if (dev->sc_interrupt & ESC_INT_RESELECTED) {
560 		dev->sc_resel[0] = *rp->esc_fifo;
561 		dev->sc_resel[1] = *rp->esc_fifo;
562 	}
563 }
564 
565 #if 0
566 /*
567  * Transfer info to/from device. esc_ixfer uses polled IO+esciwait so the
568  * rules that apply to esciwait also applies here.
569  */
570 void
571 esc_ixfer(struct esc_softc *dev)
572 {
573 	esc_regmap_p	 rp;
574 	u_char		*buf;
575 	int		 len, mode, phase;
576 
577 	rp = dev->sc_esc;
578 	buf = dev->sc_buf;
579 	len = dev->sc_len;
580 
581 /*
582  * Decode the scsi phase to determine whether we are reading or writing.
583  * mode == 1 => READ, mode == 0 => WRITE
584  */
585 	phase = dev->sc_status & ESC_STAT_PHASE_MASK;
586 	mode = (phase == ESC_PHASE_DATA_IN);
587 
588 	while(len && ((dev->sc_status & ESC_STAT_PHASE_MASK) == phase))
589 		if (mode) {
590 			*rp->esc_command = ESC_CMD_TRANSFER_INFO;
591 
592 			esciwait(dev);
593 
594 			*buf++ = *rp->esc_fifo;
595 			len--;
596 		} else {
597 			len--;
598 			*rp->esc_fifo = *buf++;
599 			*rp->esc_command = ESC_CMD_TRANSFER_INFO;
600 
601 			esciwait(dev);
602 		}
603 
604 /* Update buffer pointers to reflect the sent/received data. */
605 	dev->sc_buf = buf;
606 	dev->sc_len = len;
607 
608 /*
609  * Since the last esciwait will be a phase-change, we can't wait for it
610  * again later, so we have to signal that.
611  */
612 
613 	dev->sc_flags |= ESC_DONT_WAIT;
614 }
615 #else
616 /*
617  * Transfer info to/from device. esc_ixfer uses polled IO+esciwait so the
618  * rules that apply to esciwait also applies here.
619  */
620 void
621 esc_ixfer(struct esc_softc *dev)
622 {
623 	esc_regmap_p	 rp;
624 	vu_char		*esc_status;
625 	vu_char		*esc_command;
626 	vu_char		*esc_interrupt;
627 	vu_char		*esc_fifo;
628 	u_char		*buf;
629 	int		 len, mode, phase;
630 
631 	rp = dev->sc_esc;
632 	buf = dev->sc_buf;
633 	len = dev->sc_len;
634 
635 	/* Use discrete variables for better optimisation */
636 
637 	esc_status = rp->esc_status;
638 	esc_command = rp->esc_command;
639 	esc_interrupt = rp->esc_interrupt;
640 	esc_fifo = rp->esc_fifo;
641 
642 /*
643  * Decode the scsi phase to determine whether we are reading or writing.
644  * mode == 1 => READ, mode == 0 => WRITE
645  */
646 	phase = dev->sc_status & ESC_STAT_PHASE_MASK;
647 	mode = (phase == ESC_PHASE_DATA_IN);
648 
649 	if (mode) {
650 		while(len && ((dev->sc_status & ESC_STAT_PHASE_MASK) == phase)) {
651 			*esc_command = ESC_CMD_TRANSFER_INFO;
652 
653 			/* Wait for FAS chip to signal an interrupt. */
654 			while(!(*esc_status & ESC_STAT_INTERRUPT_PENDING));
655 /*				delay(1);*/
656 
657 			/* Grab interrupt info from chip. */
658 			dev->sc_status = *esc_status;
659 			dev->sc_interrupt = *esc_interrupt;
660 
661 			*buf++ = *esc_fifo;
662 			len--;
663 		}
664 	} else {
665 		while(len && ((dev->sc_status & ESC_STAT_PHASE_MASK) == phase)) {
666 			len--;
667 			*esc_fifo = *buf++;
668 			*esc_command = ESC_CMD_TRANSFER_INFO;
669 
670 			/* Wait for FAS chip to signal an interrupt. */
671 			while(!(*esc_status & ESC_STAT_INTERRUPT_PENDING));
672 /*				delay(1);*/
673 
674 			/* Grab interrupt info from chip. */
675 			dev->sc_status = *esc_status;
676 			dev->sc_interrupt = *esc_interrupt;
677 		}
678 	}
679 
680 /* Update buffer pointers to reflect the sent/received data. */
681 	dev->sc_buf = buf;
682 	dev->sc_len = len;
683 
684 /*
685  * Since the last esciwait will be a phase-change, we can't wait for it
686  * again later, so we have to signal that.
687  */
688 
689 	dev->sc_flags |= ESC_DONT_WAIT;
690 }
691 #endif
692 
693 /*
694  * Build a Synchronous Data Transfer Request message
695  */
696 void
697 esc_build_sdtrm(struct esc_softc *dev, int period, int offset)
698 {
699 	dev->sc_msg_out[0] = 0x01;
700 	dev->sc_msg_out[1] = 0x03;
701 	dev->sc_msg_out[2] = 0x01;
702 	dev->sc_msg_out[3] = period/4;
703 	dev->sc_msg_out[4] = offset;
704 	dev->sc_msg_out_len= 5;
705 }
706 
707 /*
708  * Arbitate the scsi bus and select the unit
709  */
710 int
711 esc_select_unit(struct esc_softc *dev, short target)
712 {
713 	esc_regmap_p	 rp;
714 	struct nexus	*nexus;
715 	int		 s, retcode, i;
716 	u_char		 cmd;
717 
718 	s = splbio();	/* Do this at splbio so that we won't be disturbed. */
719 
720 	retcode = 0;
721 
722 	nexus = &dev->sc_nexus[target];
723 
724 /*
725  * Check if the chip is busy. If not the we mark it as so and hope that nobody
726  * reselects us until we have grabbed the bus.
727  */
728 	if (!(dev->sc_flags & ESC_ACTIVE) && !dev->sc_sel_nexus) {
729 		dev->sc_flags |= ESC_ACTIVE;
730 
731 		rp = dev->sc_esc;
732 
733 		*rp->esc_syncper = nexus->syncper;
734 		*rp->esc_syncoff = nexus->syncoff;
735 		*rp->esc_config3 = nexus->config3;
736 
737 		*rp->esc_config1 = dev->sc_config1;
738 		*rp->esc_timeout = dev->sc_timeout_val;
739 		*rp->esc_dest_id = target;
740 
741 /* If nobody has stolen the bus, we can send a select command to the chip. */
742 		if (!(*rp->esc_status & ESC_STAT_INTERRUPT_PENDING)) {
743 			*rp->esc_fifo = nexus->ID;
744 			if ((nexus->flags & (ESC_NF_DO_SDTR | ESC_NF_RESET))
745 			    || (dev->sc_msg_out_len != 0))
746 				cmd = ESC_CMD_SEL_ATN_STOP;
747 			else {
748 				for(i=0; i<nexus->clen; i++)
749 					*rp->esc_fifo = nexus->cbuf[i];
750 
751 				cmd = ESC_CMD_SEL_ATN;
752 			}
753 
754 			dev->sc_sel_nexus = nexus;
755 
756 			*rp->esc_command = cmd;
757 			retcode = 1;
758 			nexus->flags &= ~ESC_NF_RETRY_SELECT;
759 		} else
760 			nexus->flags |= ESC_NF_RETRY_SELECT;
761 	} else
762 		nexus->flags |= ESC_NF_RETRY_SELECT;
763 
764 	splx(s);
765 	return(retcode);
766 }
767 
768 /*
769  * Grab the nexus if available else return 0.
770  */
771 struct nexus *
772 esc_arbitate_target(struct esc_softc *dev, int target)
773 {
774 	struct nexus	*nexus;
775 	int		 s;
776 
777 /*
778  * This is realy simple. Raise interrupt level to splbio. Grab the nexus and
779  * leave.
780  */
781 	nexus = &dev->sc_nexus[target];
782 
783 	s = splbio();
784 
785 	if (nexus->flags & ESC_NF_UNIT_BUSY)
786 		nexus = 0;
787 	else
788 		nexus->flags |= ESC_NF_UNIT_BUSY;
789 
790 	splx(s);
791 	return(nexus);
792 }
793 
794 /*
795  * Setup a nexus for use. Initializes command, buffer pointers and DMA chain.
796  */
797 void
798 esc_setup_nexus(struct esc_softc *dev, struct nexus *nexus, struct esc_pending *pendp, unsigned char *cbuf, int clen, unsigned char *buf, int len, int mode)
799 {
800 	int	sync, target, lun;
801 
802 	target = pendp->xs->xs_periph->periph_target;
803 	lun    = pendp->xs->xs_periph->periph_lun;
804 
805 /*
806  * Adopt mode to reflect the config flags.
807  * If we can't use DMA we can't use synch transfer. Also check the
808  * esc_inhibit_xxx[target] flags.
809  */
810 	if ((dev->sc_config_flags & (ESC_NO_SYNCH | ESC_NO_DMA)) ||
811 	    esc_inhibit_sync[(int)target])
812 		mode &= ~ESC_SELECT_S;
813 
814 	if ((dev->sc_config_flags & ESC_NO_RESELECT) ||
815 	    esc_inhibit_disc[(int)target])
816 		mode &= ~ESC_SELECT_R;
817 
818 	nexus->xs		= pendp->xs;
819 
820 /* Setup the nexus struct. */
821 	nexus->ID	   = ((mode & ESC_SELECT_R) ? 0xC0 : 0x80) | lun;
822 	nexus->clen	   = clen;
823 	memcpy(nexus->cbuf, cbuf, nexus->clen);
824 	nexus->cbuf[1] |= lun << 5;		/* Fix the lun bits */
825 	nexus->cur_link	   = 0;
826 	nexus->dma_len	   = 0;
827 	nexus->dma_buf	   = 0;
828 	nexus->dma_blk_len = 0;
829 	nexus->dma_blk_ptr = 0;
830 	nexus->len	   = len;
831 	nexus->buf	   = buf;
832 	nexus->lun_unit	   = (lun << 4) | target;
833 	nexus->state	   = ESC_NS_SELECTED;
834 
835 /* We must keep these flags. All else must be zero. */
836 	nexus->flags	  &= ESC_NF_UNIT_BUSY
837 			   | ESC_NF_SYNC_TESTED | ESC_NF_SELECT_ME;
838 
839 	if (mode & ESC_SELECT_I)
840 		nexus->flags |= ESC_NF_IMMEDIATE;
841 	if (mode & ESC_SELECT_K)
842 		nexus->flags |= ESC_NF_RESET;
843 
844 	sync  = ((mode & ESC_SELECT_S) ? 1 : 0);
845 
846 /* We can't use sync during polled IO. */
847 	if (sync && (mode & ESC_SELECT_I))
848 		sync = 0;
849 
850 	if (!sync &&
851 	    ((nexus->flags & ESC_NF_SYNC_TESTED) && (nexus->offset != 0))) {
852 		/*
853 		 * If the scsi unit is set to synch transfer and we don't want
854 		 * that, we have to renegotiate.
855 		 */
856 
857 		nexus->flags |= ESC_NF_DO_SDTR;
858 		nexus->period = 200;
859 		nexus->offset = 0;
860 	} else if (sync && !(nexus->flags & ESC_NF_SYNC_TESTED)) {
861 		/*
862 		 * If the scsi unit is not set to synch transfer and we want
863 		 * that, we have to negotiate. This should realy base the
864 		 * period on the clock frequence rather than just check if
865 		 * >25 MHz
866 		 */
867 
868 		nexus->flags |= ESC_NF_DO_SDTR;
869 		nexus->period = ((dev->sc_clock_freq>25) ? 100 : 200);
870 		nexus->offset = 8;
871 
872 		/* If the user has a long cable, we want to limit the period */
873 		if ((nexus->period == 100) &&
874 		    (dev->sc_config_flags & ESC_SLOW_CABLE))
875 			nexus->period = 200;
876 	}
877 
878 /*
879  * Fake a DMA-block for polled IO. This way we can use the same code to handle
880  * reselection. Much nicer this way.
881  */
882 	if ((mode & ESC_SELECT_I) || (dev->sc_config_flags & ESC_NO_DMA)) {
883 		nexus->dma[0].ptr = buf;
884 		nexus->dma[0].len = len;
885 		nexus->dma[0].flg = ESC_CHAIN_PRG;
886 		nexus->max_link   = 1;
887 	} else {
888 		nexus->max_link = dev->sc_build_dma_chain(dev, nexus->dma,
889 							  buf, len);
890 	}
891 
892 /* Flush the caches. */
893 
894 	if (len && !(mode & ESC_SELECT_I))
895 		cpu_dcache_wbinv_range((vm_offset_t)buf, len);
896 }
897 
898 int
899 escselect(struct esc_softc *dev, struct esc_pending *pendp, unsigned char *cbuf, int clen, unsigned char *buf, int len, int mode)
900 {
901 	struct nexus	*nexus;
902 
903 /* Get the nexus struct. */
904 	nexus = esc_arbitate_target(dev, pendp->xs->xs_periph->periph_target);
905 	if (nexus == NULL)
906 		return(0);
907 
908 /* Setup the nexus struct. */
909 	esc_setup_nexus(dev, nexus, pendp, cbuf, clen, buf, len, mode);
910 
911 /* Post it to the interrupt machine. */
912 	esc_select_unit(dev, pendp->xs->xs_periph->periph_target);
913 
914 	return(1);
915 }
916 
917 int
918 escgo(struct esc_softc *dev, struct esc_pending *pendp)
919 {
920 	int	 s;
921 	char	*buf;
922 
923 	buf    = pendp->xs->data;
924 
925 	if (escselect(dev, pendp, (char *)pendp->xs->cmd, pendp->xs->cmdlen,
926 		      buf, pendp->xs->datalen, ESC_SELECT_RS)) {
927 		/*
928 		 * We got the command going so the esc_pending struct is now
929 		 * free to reuse.
930 		 */
931 
932 		s = splbio();
933 		TAILQ_INSERT_TAIL(&dev->sc_xs_free, pendp, link);
934 		splx(s);
935 	} else {
936 		/*
937 		 * We couldn't make the command fly so we have to wait. The
938 		 * struct MUST be inserted at the head to keep the order of
939 		 * the commands.
940 		 */
941 
942 		s = splbio();
943 		TAILQ_INSERT_HEAD(&dev->sc_xs_pending, pendp, link);
944 		splx(s);
945 	}
946 
947 	return(0);
948 }
949 
950 /*
951  * Part one of the interrupt machine. Error checks and reselection test.
952  * We don't know if we have an active nexus here!
953  */
954 int
955 esc_pretests(struct esc_softc *dev, esc_regmap_p rp)
956 {
957 	struct nexus	*nexus;
958 	int		 i, s;
959 
960 	if (dev->sc_interrupt & ESC_INT_SCSI_RESET_DETECTED) {
961 		/*
962 		 * Cleanup and notify user. Lets hope that this is all we
963 		 * have to do
964 		 */
965 
966 		for(i=0; i<8; i++) {
967 			if (dev->sc_nexus[i].xs)
968 				esc_scsidone(dev, dev->sc_nexus[i].xs, -2);
969 
970 			esc_init_nexus(dev, &dev->sc_nexus[i]);
971 		}
972 		printf("escintr: SCSI-RESET detected!");
973 		return(-1);
974 	}
975 
976 	if (dev->sc_interrupt & ESC_INT_ILLEGAL_COMMAND) {
977 		/* Something went terrible wrong! Dump some data and panic! */
978 
979 		printf("FIFO:");
980 		while(*rp->esc_fifo_flags & ESC_FIFO_COUNT_MASK)
981 			printf(" %x", *rp->esc_fifo);
982 		printf("\n");
983 
984 		printf("CMD: %x\n", *rp->esc_command);
985 		panic("escintr: ILLEGAL COMMAND!");
986 	}
987 
988 	if (dev->sc_interrupt & ESC_INT_RESELECTED) {
989 		/* We were reselected. Set the chip as busy */
990 
991 		s = splbio();
992 		dev->sc_flags |= ESC_ACTIVE;
993 		if (dev->sc_sel_nexus) {
994 			dev->sc_sel_nexus->flags |= ESC_NF_SELECT_ME;
995 			dev->sc_sel_nexus = 0;
996 		}
997 		splx(s);
998 
999 		if (dev->sc_units_disconnected) {
1000 			/* Find out who reselected us. */
1001 
1002 			dev->sc_resel[0] &= ~(1<<dev->sc_host_id);
1003 
1004 			for(i=0; i<8; i++)
1005 				if (dev->sc_resel[0] & (1<<i))
1006 					break;
1007 
1008 			if (i == 8)
1009 				panic("Illegal reselection!");
1010 
1011 			if (dev->sc_nexus[i].state == ESC_NS_DISCONNECTED) {
1012 				/*
1013 				 * This unit had disconnected, so we reconnect
1014 				 * it.
1015 				 */
1016 
1017 				dev->sc_cur_nexus = &dev->sc_nexus[i];
1018 				nexus = dev->sc_cur_nexus;
1019 
1020 				*rp->esc_syncper = nexus->syncper;
1021 				*rp->esc_syncoff = nexus->syncoff;
1022 				*rp->esc_config3 = nexus->config3;
1023 
1024 				*rp->esc_dest_id = i & 7;
1025 
1026 				dev->sc_units_disconnected--;
1027 				dev->sc_msg_in_len= 0;
1028 
1029 				/* Restore active pointers. */
1030 				esc_restore_pointers(dev);
1031 
1032 				nexus->state = ESC_NS_RESELECTED;
1033 
1034 				*rp->esc_command = ESC_CMD_MESSAGE_ACCEPTED;
1035 
1036 				return(1);
1037 			}
1038 		}
1039 
1040 		/* Somehow we got an illegal reselection. Dump and panic. */
1041 		printf("escintr: resel[0] %x resel[1] %x disconnected %d\n",
1042 		       dev->sc_resel[0], dev->sc_resel[1],
1043 		       dev->sc_units_disconnected);
1044 		panic("escintr: Unexpected reselection!");
1045 	}
1046 
1047 	return(0);
1048 }
1049 
1050 /*
1051  * Part two of the interrupt machine. Handle disconnection and post command
1052  * processing. We know that we have an active nexus here.
1053  */
1054 int
1055 esc_midaction(struct esc_softc *dev, esc_regmap_p rp, struct nexus *nexus)
1056 {
1057 	int	i, left, len, s;
1058 	u_char	status, msg;
1059 
1060 	if (dev->sc_interrupt & ESC_INT_DISCONNECT) {
1061 		s = splbio();
1062 		dev->sc_cur_nexus = 0;
1063 
1064 		/* Mark chip as busy and clean up the chip FIFO. */
1065 		dev->sc_flags &= ~ESC_ACTIVE;
1066 		*rp->esc_command = ESC_CMD_FLUSH_FIFO;
1067 
1068 		/* Let the nexus state reflect what we have to do. */
1069 		switch(nexus->state) {
1070 		case ESC_NS_SELECTED:
1071 			dev->sc_sel_nexus = 0;
1072 			nexus->flags &= ~ESC_NF_SELECT_ME;
1073 
1074 			/*
1075 			 * We were trying to select the unit. Probably no unit
1076 			 * at this ID.
1077 			 */
1078 			nexus->xs->resid = dev->sc_len;
1079 
1080 			nexus->status = -2;
1081 			nexus->flags &= ~ESC_NF_UNIT_BUSY;
1082 			nexus->state = ESC_NS_FINISHED;
1083 			break;
1084 
1085 		case ESC_NS_DONE:
1086 			/* All done. */
1087 			nexus->xs->resid = dev->sc_len;
1088 
1089 			nexus->flags &= ~ESC_NF_UNIT_BUSY;
1090 			nexus->state  = ESC_NS_FINISHED;
1091 			dev->sc_led(dev, 0);
1092 			break;
1093 
1094 		case ESC_NS_DISCONNECTING:
1095 			/*
1096 			 * We have received a DISCONNECT message, so we are
1097 			 * doing a normal disconnection.
1098 			 */
1099 			nexus->state = ESC_NS_DISCONNECTED;
1100 
1101 			dev->sc_units_disconnected++;
1102 			break;
1103 
1104 		case ESC_NS_RESET:
1105 			/*
1106 			 * We were reseting this SCSI-unit. Clean up the
1107 			 * nexus struct.
1108 			 */
1109 			dev->sc_led(dev, 0);
1110 			esc_init_nexus(dev, nexus);
1111 			break;
1112 
1113 		default:
1114 			/*
1115 			 * Unexpected disconnection! Cleanup and exit. This
1116 			 * shouldn't cause any problems.
1117 			 */
1118 			printf("escintr: Unexpected disconnection\n");
1119 			printf("escintr: u %x s %d p %d f %x c %x\n",
1120 			       nexus->lun_unit, nexus->state,
1121 			       dev->sc_status & ESC_STAT_PHASE_MASK,
1122 			       nexus->flags, nexus->cbuf[0]);
1123 
1124 			nexus->xs->resid = dev->sc_len;
1125 
1126 			nexus->flags &= ~ESC_NF_UNIT_BUSY;
1127 			nexus->state = ESC_NS_FINISHED;
1128 			nexus->status = -3;
1129 
1130 			dev->sc_led(dev, 0);
1131 			break;
1132 		}
1133 
1134 		/*
1135 		 * If we have disconnected units, we MUST enable reselection
1136 		 * within 250ms.
1137 		 */
1138 		if (dev->sc_units_disconnected &&
1139 		    !(dev->sc_flags & ESC_ACTIVE))
1140 			*rp->esc_command = ESC_CMD_ENABLE_RESEL;
1141 
1142 		splx(s);
1143 
1144 		/* Select the first pre-initialized nexus we find. */
1145 		for(i=0; i<8; i++)
1146 			if (dev->sc_nexus[i].flags & (ESC_NF_SELECT_ME | ESC_NF_RETRY_SELECT))
1147 				if (esc_select_unit(dev, i) == 2)
1148 					break;
1149 
1150 		/* We are done with this nexus! */
1151 		if (nexus->state == ESC_NS_FINISHED)
1152 			esc_scsidone(dev, nexus->xs, nexus->status);
1153 
1154 		return(1);
1155 	}
1156 
1157 	switch(nexus->state) {
1158 	case ESC_NS_SELECTED:
1159 		dev->sc_cur_nexus = nexus;
1160 		dev->sc_sel_nexus = 0;
1161 
1162 		nexus->flags &= ~ESC_NF_SELECT_ME;
1163 
1164 		/*
1165 		 * We have selected a unit. Setup chip, restore pointers and
1166 		 * light the led.
1167 		 */
1168 		*rp->esc_syncper = nexus->syncper;
1169 		*rp->esc_syncoff = nexus->syncoff;
1170 		*rp->esc_config3 = nexus->config3;
1171 
1172 		esc_restore_pointers(dev);
1173 
1174 		nexus->status	= 0xFF;
1175 		dev->sc_msg_in[0] = 0xFF;
1176 		dev->sc_msg_in_len= 0;
1177 
1178 		dev->sc_led(dev, 1);
1179 
1180 		break;
1181 
1182 	case ESC_NS_DATA_IN:
1183 	case ESC_NS_DATA_OUT:
1184 		/* We have transfered data. */
1185 		if (dev->sc_dma_len)
1186 			if (dev->sc_cur_link < dev->sc_max_link) {
1187 				/*
1188 				 * Clean up DMA and at the same time get how
1189 				 * many bytes that were NOT transfered.
1190 				 */
1191 			  left = dev->sc_setup_dma(dev, 0, 0, ESC_DMA_CLEAR);
1192 			  len  = dev->sc_dma_len;
1193 
1194 			  if (nexus->state == ESC_NS_DATA_IN) {
1195 			    /*
1196 			     * If we were bumping we may have had an odd length
1197 			     * which means that there may be bytes left in the
1198 			     * fifo. We also need to move the data from the
1199 			     * bump buffer to the actual memory.
1200 			     */
1201 			    if (dev->sc_dma_buf == dev->sc_bump_pa)
1202 			    {
1203 			      while((*rp->esc_fifo_flags&ESC_FIFO_COUNT_MASK)
1204 				    && left)
1205 				dev->sc_bump_va[len-(left--)] = *rp->esc_fifo;
1206 
1207 			      memcpy(dev->sc_buf, dev->sc_bump_va, len-left);
1208 			    }
1209 			  } else {
1210 			    /* Count any unsent bytes and flush them. */
1211 			    left+= *rp->esc_fifo_flags & ESC_FIFO_COUNT_MASK;
1212 			    *rp->esc_command = ESC_CMD_FLUSH_FIFO;
1213 			  }
1214 
1215 			  /*
1216 			   * Update pointers/length to reflect the transfered
1217 			   * data.
1218 			   */
1219 			  dev->sc_len -= len-left;
1220 			  dev->sc_buf += len-left;
1221 
1222 			  dev->sc_dma_buf = (char *)dev->sc_dma_buf + len-left;
1223 			  dev->sc_dma_len = left;
1224 
1225 			  dev->sc_dma_blk_ptr = (char *)dev->sc_dma_blk_ptr +
1226 				  len-left;
1227 			  dev->sc_dma_blk_len -= len-left;
1228 
1229 			  /*
1230 			   * If it was the end of a DMA block, we select the
1231 			   * next to begin with.
1232 			   */
1233 			  if (!dev->sc_dma_blk_len)
1234 			    dev->sc_cur_link++;
1235 			}
1236 		break;
1237 
1238 	case ESC_NS_STATUS:
1239 		/*
1240 		 * If we were not sensing, grab the status byte. If we were
1241 		 * sensing and we got a bad status, let the user know.
1242 		 */
1243 
1244 		status = *rp->esc_fifo;
1245 		msg = *rp->esc_fifo;
1246 
1247 		nexus->status = status;
1248 		if (status != 0)
1249 			nexus->status = -1;
1250 
1251 		/*
1252 		 * Preload the command complete message. Handeled in
1253 		 * esc_postaction.
1254 		 */
1255 		dev->sc_msg_in[0] = msg;
1256 		dev->sc_msg_in_len = 1;
1257 		nexus->flags |= ESC_NF_HAS_MSG;
1258 		break;
1259 
1260 	default:
1261 		break;
1262 	}
1263 
1264 	return(0);
1265 }
1266 
1267 /*
1268  * Part three of the interrupt machine. Handle phase changes (and repeated
1269  * phase passes). We know that we have an active nexus here.
1270  */
1271 int
1272 esc_postaction(struct esc_softc *dev, esc_regmap_p rp, struct nexus *nexus)
1273 {
1274 	int	i, len;
1275 	u_char	cmd;
1276 	short	offset, period;
1277 
1278 	cmd = 0;
1279 
1280 	switch(dev->sc_status & ESC_STAT_PHASE_MASK) {
1281 	case ESC_PHASE_DATA_OUT:
1282 	case ESC_PHASE_DATA_IN:
1283 		if ((dev->sc_status & ESC_STAT_PHASE_MASK) ==
1284 		    ESC_PHASE_DATA_OUT)
1285 			nexus->state = ESC_NS_DATA_OUT;
1286 		else
1287 			nexus->state = ESC_NS_DATA_IN;
1288 
1289 		/* Make DMA ready to accept new data. Load active pointers
1290 		 * from the DMA block. */
1291 		dev->sc_setup_dma(dev, 0, 0, ESC_DMA_CLEAR);
1292 		if (dev->sc_cur_link < dev->sc_max_link) {
1293 		  if (!dev->sc_dma_blk_len) {
1294 		    dev->sc_dma_blk_ptr = dev->sc_chain[dev->sc_cur_link].ptr;
1295 		    dev->sc_dma_blk_len = dev->sc_chain[dev->sc_cur_link].len;
1296 		    dev->sc_dma_blk_flg = dev->sc_chain[dev->sc_cur_link].flg;
1297 		  }
1298 
1299 		  /* We should use polled IO here. */
1300 		  if (dev->sc_dma_blk_flg == ESC_CHAIN_PRG) {
1301 			esc_ixfer(dev/*, nexus->xs->xs_control & XS_CTL_POLL*/);
1302 			dev->sc_cur_link++;
1303 			dev->sc_dma_len = 0;
1304 			break;
1305 		  }
1306 		  else if (dev->sc_dma_blk_flg == ESC_CHAIN_BUMP)
1307 			len = dev->sc_dma_blk_len;
1308 		  else
1309 			len = dev->sc_need_bump(dev,
1310 						(void *)dev->sc_dma_blk_ptr,
1311 						dev->sc_dma_blk_len);
1312 
1313 		  /*
1314 		   * If len != 0 we must bump the data, else we just DMA it
1315 		   * straight into memory.
1316 		   */
1317 		  if (len) {
1318 			dev->sc_dma_buf = dev->sc_bump_pa;
1319 			dev->sc_dma_len = len;
1320 
1321 			if (nexus->state == ESC_NS_DATA_OUT)
1322 			  memcpy(dev->sc_bump_va, dev->sc_buf, dev->sc_dma_len);
1323 		  } else {
1324 			dev->sc_dma_buf = dev->sc_dma_blk_ptr;
1325 			dev->sc_dma_len = dev->sc_dma_blk_len;
1326 		  }
1327 
1328 		  /* Load DMA with address and length of transfer. */
1329 		  dev->sc_setup_dma(dev, (void *)dev->sc_dma_buf,
1330 		  		    dev->sc_dma_len,
1331 				    ((nexus->state == ESC_NS_DATA_OUT) ?
1332 				     ESC_DMA_WRITE : ESC_DMA_READ));
1333 
1334 		  printf("Using DMA !!!!\n");
1335 		  cmd = ESC_CMD_TRANSFER_INFO | ESC_CMD_DMA;
1336 		} else {
1337 			/*
1338 			 * Hmmm, the unit wants more info than we have or has
1339 			 * more than we want. Let the chip handle that.
1340 			 */
1341 
1342 			*rp->esc_tc_low = 0;
1343 			*rp->esc_tc_mid = 1;
1344 			*rp->esc_tc_high = 0;
1345 			cmd = ESC_CMD_TRANSFER_PAD;
1346 		}
1347 		break;
1348 
1349 	case ESC_PHASE_COMMAND:
1350 		/* The scsi unit wants the command, send it. */
1351 		nexus->state = ESC_NS_SVC;
1352 
1353 		*rp->esc_command = ESC_CMD_FLUSH_FIFO;
1354 		for(i=0; i<5; i++);
1355 
1356 		for(i=0; i<nexus->clen; i++)
1357 			*rp->esc_fifo = nexus->cbuf[i];
1358 		cmd = ESC_CMD_TRANSFER_INFO;
1359 		break;
1360 
1361 	case ESC_PHASE_STATUS:
1362 		/*
1363 		 * We've got status phase. Request status and command
1364 		 * complete message.
1365 		 */
1366 		nexus->state = ESC_NS_STATUS;
1367 		cmd = ESC_CMD_COMMAND_COMPLETE;
1368 		break;
1369 
1370 	case ESC_PHASE_MESSAGE_OUT:
1371 		/*
1372 		 * Either the scsi unit wants us to send a message or we have
1373 		 * asked for it by seting the ATN bit.
1374 		 */
1375 		nexus->state = ESC_NS_MSG_OUT;
1376 
1377 		*rp->esc_command = ESC_CMD_FLUSH_FIFO;
1378 
1379 		if (nexus->flags & ESC_NF_DO_SDTR) {
1380 			/* Send a Synchronous Data Transfer Request. */
1381 
1382 			esc_build_sdtrm(dev, nexus->period, nexus->offset);
1383 			nexus->flags |= ESC_NF_SDTR_SENT;
1384 			nexus->flags &= ~ESC_NF_DO_SDTR;
1385 		} else if (nexus->flags & ESC_NF_RESET) {
1386 			/* Send a reset scsi unit message. */
1387 
1388 			dev->sc_msg_out[0] = 0x0C;
1389 			dev->sc_msg_out_len = 1;
1390 			nexus->state = ESC_NS_RESET;
1391 			nexus->flags &= ~ESC_NF_RESET;
1392 		} else if (dev->sc_msg_out_len == 0) {
1393 			/* Don't know what to send so we send a NOP message. */
1394 
1395 			dev->sc_msg_out[0] = 0x08;
1396 			dev->sc_msg_out_len = 1;
1397 		}
1398 
1399 		cmd = ESC_CMD_TRANSFER_INFO;
1400 
1401 		for(i=0; i<dev->sc_msg_out_len; i++)
1402 			*rp->esc_fifo = dev->sc_msg_out[i];
1403 		dev->sc_msg_out_len = 0;
1404 
1405 		break;
1406 
1407 	case ESC_PHASE_MESSAGE_IN:
1408 		/* Receive a message from the scsi unit. */
1409 		nexus->state = ESC_NS_MSG_IN;
1410 
1411 		while(!(nexus->flags & ESC_NF_HAS_MSG)) {
1412 			*rp->esc_command = ESC_CMD_TRANSFER_INFO;
1413 			esciwait(dev);
1414 
1415 			dev->sc_msg_in[dev->sc_msg_in_len++] = *rp->esc_fifo;
1416 
1417 			/* Check if we got all the bytes in the message. */
1418 			if (dev->sc_msg_in[0] >= 0x80)       ;
1419 			else if (dev->sc_msg_in[0] >= 0x30)  ;
1420 			else if (((dev->sc_msg_in[0] >= 0x20) &&
1421 				  (dev->sc_msg_in_len == 2)) ||
1422 				 ((dev->sc_msg_in[0] != 0x01) &&
1423 				  (dev->sc_msg_in_len == 1))) {
1424 				nexus->flags |= ESC_NF_HAS_MSG;
1425 				break;
1426 			} else {
1427 			  if (dev->sc_msg_in_len >= 2)
1428 			    if ((dev->sc_msg_in[1]+2) == dev->sc_msg_in_len) {
1429 				nexus->flags |= ESC_NF_HAS_MSG;
1430 				break;
1431 			    }
1432 			}
1433 
1434 			*rp->esc_command = ESC_CMD_MESSAGE_ACCEPTED;
1435 			esciwait(dev);
1436 
1437 			if ((dev->sc_status & ESC_STAT_PHASE_MASK) !=
1438 			    ESC_PHASE_MESSAGE_IN)
1439 				break;
1440 		}
1441 
1442 		cmd = ESC_CMD_MESSAGE_ACCEPTED;
1443 		if (nexus->flags & ESC_NF_HAS_MSG) {
1444 			/* We have a message. Decode it. */
1445 
1446 			switch(dev->sc_msg_in[0]) {
1447 			case 0x00:	/* COMMAND COMPLETE */
1448 				nexus->state = ESC_NS_DONE;
1449 			case 0x04:	/* DISCONNECT */
1450 				nexus->state = ESC_NS_DISCONNECTING;
1451 				break;
1452 			case 0x02:	/* SAVE DATA POINTER */
1453 				esc_save_pointers(dev);
1454 				break;
1455 			case 0x03:	/* RESTORE DATA POINTERS */
1456 				esc_restore_pointers(dev);
1457 				break;
1458 			case 0x07:	/* MESSAGE REJECT */
1459 				/*
1460 				 * If we had sent a SDTR and we got a message
1461 				 * reject, the scsi docs say that we must go
1462 				 * to async transfer.
1463 				 */
1464 				if (nexus->flags & ESC_NF_SDTR_SENT) {
1465 					nexus->flags &= ~ESC_NF_SDTR_SENT;
1466 
1467 					nexus->config3 &= ~ESC_CFG3_FASTSCSI;
1468 					nexus->syncper = 5;
1469 					nexus->syncoff = 0;
1470 
1471 					*rp->esc_syncper = nexus->syncper;
1472 					*rp->esc_syncoff = nexus->syncoff;
1473 					*rp->esc_config3 = nexus->config3;
1474 				} else
1475 				/*
1476 				 * Something was rejected but we don't know
1477 				 * what! PANIC!
1478 				 */
1479 				  panic("escintr: Unknown message rejected!");
1480 				break;
1481 			case 0x08:	/* MO OPERATION */
1482 				break;
1483 			case 0x01:	/* EXTENDED MESSAGE */
1484 				switch(dev->sc_msg_in[2]) {
1485 				case 0x01:/* SYNC. DATA TRANSFER REQUEST */
1486 					/* Decode the SDTR message. */
1487 					period = 4*dev->sc_msg_in[3];
1488 					offset = dev->sc_msg_in[4];
1489 
1490 					/*
1491 					 * Make sure that the specs are within
1492 					 * chip limits. Note that if we
1493 					 * initiated the negotiation the specs
1494 					 * WILL be withing chip limits. If it
1495 					 * was the scsi unit that initiated
1496 					 * the negotiation, the specs may be
1497 					 * to high.
1498 					 */
1499 					if (offset > 16)
1500 						offset = 16;
1501 					if ((period < 200) &&
1502 					    (dev->sc_clock_freq <= 25))
1503 						period = 200;
1504 
1505 					if (offset == 0)
1506 					       period = 5*dev->sc_clock_period;
1507 
1508 					nexus->syncper = period/
1509 							  dev->sc_clock_period;
1510 					nexus->syncoff = offset;
1511 
1512 					if (period < 200)
1513 					  nexus->config3 |= ESC_CFG3_FASTSCSI;
1514 					else
1515 					  nexus->config3 &=~ESC_CFG3_FASTSCSI;
1516 
1517 					nexus->flags |= ESC_NF_SYNC_TESTED;
1518 
1519 					*rp->esc_syncper = nexus->syncper;
1520 					*rp->esc_syncoff = nexus->syncoff;
1521 					*rp->esc_config3 = nexus->config3;
1522 
1523 					/*
1524 					 * Hmmm, it seems that the scsi unit
1525 					 * initiated sync negotiation, so lets
1526 					 * reply acording to scsi-2 standard.
1527 					 */
1528 					if (!(nexus->flags& ESC_NF_SDTR_SENT))
1529 					{
1530 					  if ((dev->sc_config_flags &
1531 					       ESC_NO_SYNCH) ||
1532 					      (dev->sc_config_flags &
1533 					       ESC_NO_DMA) ||
1534 					      esc_inhibit_sync[
1535 							nexus->lun_unit & 7]) {
1536 					          period = 200;
1537 					          offset = 0;
1538 					  }
1539 
1540 					  nexus->offset = offset;
1541 					  nexus->period = period;
1542 					  nexus->flags |= ESC_NF_DO_SDTR;
1543 					  *rp->esc_command = ESC_CMD_SET_ATN;
1544 					}
1545 
1546 					nexus->flags &= ~ESC_NF_SDTR_SENT;
1547 					break;
1548 
1549 				case 0x00: /* MODIFY DATA POINTERS */
1550 				case 0x02: /* EXTENDED IDENTIFY (SCSI-1) */
1551 				case 0x03: /* WIDE DATA TRANSFER REQUEST */
1552 			        default:
1553 					/* Reject any unhandeled messages. */
1554 
1555 					dev->sc_msg_out[0] = 0x07;
1556 					dev->sc_msg_out_len = 1;
1557 					*rp->esc_command = ESC_CMD_SET_ATN;
1558 					cmd = ESC_CMD_MESSAGE_ACCEPTED;
1559 					break;
1560 				}
1561 				break;
1562 
1563 			default:
1564 				/* Reject any unhandeled messages. */
1565 
1566 				dev->sc_msg_out[0] = 0x07;
1567 				dev->sc_msg_out_len = 1;
1568 				*rp->esc_command = ESC_CMD_SET_ATN;
1569 				cmd = ESC_CMD_MESSAGE_ACCEPTED;
1570 				break;
1571 			}
1572 			nexus->flags &= ~ESC_NF_HAS_MSG;
1573 			dev->sc_msg_in_len = 0;
1574 		}
1575 		break;
1576 	default:
1577 		printf("ESCINTR: UNKNOWN PHASE! phase: %d\n",
1578 		       dev->sc_status & ESC_STAT_PHASE_MASK);
1579 		dev->sc_led(dev, 0);
1580 		esc_scsidone(dev, nexus->xs, -4);
1581 
1582 		return(-1);
1583 	}
1584 
1585 	if (cmd)
1586 		*rp->esc_command = cmd;
1587 
1588 	return(0);
1589 }
1590 
1591 /*
1592  * Stub for interrupt machine.
1593  */
1594 void
1595 escintr(struct esc_softc *dev)
1596 {
1597 	esc_regmap_p	 rp;
1598 	struct nexus	*nexus;
1599 
1600 	rp = dev->sc_esc;
1601 
1602 	if (!esc_pretests(dev, rp)) {
1603 
1604 		nexus = dev->sc_cur_nexus;
1605 		if (nexus == NULL)
1606 			nexus = dev->sc_sel_nexus;
1607 
1608 		if (nexus)
1609 			if (!esc_midaction(dev, rp, nexus))
1610 				esc_postaction(dev, rp, nexus);
1611 	}
1612 }
1613 
1614 /*
1615  * escicmd is used to perform IO when we can't use interrupts. escicmd
1616  * emulates the normal environment by waiting for the chip and calling
1617  * escintr.
1618  */
1619 void
1620 escicmd(struct esc_softc *dev, struct esc_pending *pendp)
1621 {
1622 	struct nexus	*nexus;
1623 
1624 	nexus = &dev->sc_nexus[pendp->xs->xs_periph->periph_target];
1625 
1626 	if (!escselect(dev, pendp, (char *)pendp->xs->cmd, pendp->xs->cmdlen,
1627 			(char *)pendp->xs->data, pendp->xs->datalen,
1628 			ESC_SELECT_I))
1629 		panic("escicmd: Couldn't select unit");
1630 
1631 	while(nexus->state != ESC_NS_FINISHED) {
1632 		esciwait(dev);
1633 		escintr(dev);
1634 	}
1635 
1636 	nexus->flags &= ~ESC_NF_SYNC_TESTED;
1637 }
1638