xref: /netbsd-src/sys/dev/isa/seagate.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*
2  * ST01/02, Future Domain TMC-885, TMC-950 SCSI driver
3  *
4  * Copyright 1994, Charles Hannum (mycroft@ai.mit.edu)
5  * Copyright 1994, Kent Palmkvist (kentp@isy.liu.se)
6  * Copyright 1994, Robert Knier (rknier@qgraph.com)
7  * Copyright 1992, 1994 Drew Eckhardt (drew@colorado.edu)
8  * Copyright 1994, Julian Elischer (julian@tfs.com)
9  *
10  * Others that has contributed by example code is
11  * 		Glen Overby (overby@cray.com)
12  *		Tatu Yllnen
13  *		Brian E Litzinger
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE DEVELOPERS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 /*
38  * kentp  940307 alpha version based on newscsi-03 version of Julians SCSI-code
39  * kentp  940314 Added possibility to not use messages
40  * rknier 940331 Added fast transfer code
41  * rknier 940407 Added assembler coded data transfers
42  */
43 
44 /*
45  * What should really be done:
46  *
47  * Add missing tests for timeouts
48  * Restructure interrupt enable/disable code (runs to long with int disabled)
49  * Find bug? giving problem with tape status
50  * Add code to handle Future Domain 840, 841, 880 and 881
51  * adjust timeouts (startup is very slow)
52  * add code to use tagged commands in SCSI2
53  * Add code to handle slow devices better (sleep if device not disconnecting)
54  * Fix unnecessary interrupts
55  */
56 
57 /*
58  * Note to users trying to share a disk between DOS and unix:
59  * The ST01/02 is a translating host-adapter. It is not giving DOS
60  * the same number of heads/tracks/sectors as specified by the disk.
61  * It is therefore important to look at what numbers DOS thinks the
62  * disk has. Use these to disklabel your disk in an appropriate manner
63  */
64 
65 #include <sys/types.h>
66 #include <sys/param.h>
67 #include <sys/systm.h>
68 #include <sys/kernel.h>
69 #include <sys/errno.h>
70 #include <sys/ioctl.h>
71 #include <sys/device.h>
72 #include <sys/buf.h>
73 #include <sys/proc.h>
74 #include <sys/user.h>
75 #include <sys/queue.h>
76 #include <sys/malloc.h>
77 
78 #include <machine/pio.h>
79 
80 #include <scsi/scsi_all.h>
81 #include <scsi/scsi_message.h>
82 #include <scsi/scsiconf.h>
83 
84 #include <dev/isa/isareg.h>
85 #include <dev/isa/isavar.h>
86 #include <i386/isa/isa_machdep.h>	/* XXX USES ISA HOLE DIRECTLY */
87 
88 #define	SEA_SCB_MAX	32	/* allow maximally 8 scsi control blocks */
89 #define SCB_TABLE_SIZE	8	/* start with 8 scb entries in table */
90 #define BLOCK_SIZE	512	/* size of READ/WRITE areas on SCSI card */
91 
92 /*
93  * defining SEA_BLINDTRANSFER will make DATA IN and DATA OUT to be done with
94  * blind transfers, i.e. no check is done for scsi phase changes. This will
95  * result in data loss if the scsi device does not send its data using
96  * BLOCK_SIZE bytes at a time.
97  * If SEA_BLINDTRANSFER defined and SEA_ASSEMBLER also defined will result in
98  * the use of blind transfers coded in assembler. SEA_ASSEMBLER is no good
99  * without SEA_BLINDTRANSFER defined.
100  */
101 #define	SEA_BLINDTRANSFER	/* do blind transfers */
102 #define	SEA_ASSEMBLER		/* Use assembly code for fast transfers */
103 
104 /*
105  * defining SEA_NOMSGS causes messages not to be used (thereby disabling
106  * disconnects)
107  */
108 #undef	SEA_NOMSGS
109 
110 /*
111  * defining SEA_NODATAOUT makes dataout phase being aborted
112  */
113 #undef	SEA_NODATAOUT
114 
115 /* Debugging definitions. Should not be used unless you want a lot of
116    printouts even under normal conditions */
117 
118 #undef	SEA_DEBUGQUEUE		/* Display info about queue-lengths */
119 
120 /******************************* board definitions **************************/
121 /*
122  * CONTROL defines
123  */
124 #define CMD_RST		0x01		/* scsi reset */
125 #define CMD_SEL		0x02		/* scsi select */
126 #define CMD_BSY		0x04		/* scsi busy */
127 #define	CMD_ATTN	0x08		/* scsi attention */
128 #define CMD_START_ARB	0x10		/* start arbitration bit */
129 #define	CMD_EN_PARITY	0x20		/* enable scsi parity generation */
130 #define CMD_INTR	0x40		/* enable scsi interrupts */
131 #define CMD_DRVR_ENABLE	0x80		/* scsi enable */
132 
133 /*
134  * STATUS
135  */
136 #define STAT_BSY	0x01		/* scsi busy */
137 #define STAT_MSG	0x02		/* scsi msg */
138 #define STAT_IO		0x04		/* scsi I/O */
139 #define STAT_CD		0x08		/* scsi C/D */
140 #define STAT_REQ	0x10		/* scsi req */
141 #define STAT_SEL	0x20		/* scsi select */
142 #define STAT_PARITY	0x40		/* parity error bit */
143 #define STAT_ARB_CMPL	0x80		/* arbitration complete bit */
144 
145 /*
146  * REQUESTS
147  */
148 #define PH_DATAOUT	(0)
149 #define PH_DATAIN	(STAT_IO)
150 #define PH_CMD		(STAT_CD)
151 #define PH_STAT		(STAT_CD | STAT_IO)
152 #define PH_MSGOUT	(STAT_MSG | STAT_CD)
153 #define PH_MSGIN	(STAT_MSG | STAT_CD | STAT_IO)
154 
155 #define PH_MASK		(STAT_MSG | STAT_CD | STAT_IO)
156 
157 #define PH_INVALID	0xff
158 
159 #define SEA_RAMOFFSET	0x00001800
160 
161 #define BASE_CMD	(CMD_INTR | CMD_EN_PARITY)
162 
163 #define	SEAGATE		1	/* Seagate ST0[12] */
164 #define	FDOMAIN		2	/* Future Domain TMC-{885,950} */
165 #define	FDOMAIN840	3	/* Future Domain TMC-{84[01],88[01]} */
166 
167 /******************************************************************************/
168 
169 /* scsi control block used to keep info about a scsi command */
170 struct sea_scb {
171         u_char *data;			/* position in data buffer so far */
172 	int datalen;			/* bytes remaining to transfer */
173 	TAILQ_ENTRY(sea_scb) chain;
174 	struct scsi_xfer *xs;		/* the scsi_xfer for this cmd */
175 	int flags;			/* status of the instruction */
176 #define	SCB_FREE	0
177 #define	SCB_ACTIVE	1
178 #define SCB_ABORTED	2
179 #define SCB_TIMEOUT	4
180 #define SCB_ERROR	8
181 };
182 
183 /*
184  * data structure describing current status of the scsi bus. One for each
185  * controller card.
186  */
187 struct sea_softc {
188 	struct device sc_dev;
189 	struct isadev sc_id;
190 	void *sc_ih;
191 
192 	int type;			/* board type */
193 	caddr_t	maddr;			/* Base address for card */
194 	caddr_t	maddr_cr_sr;		/* Address of control and status reg */
195 	caddr_t	maddr_dr;		/* Address of data register */
196 
197 	struct scsi_link sc_link;	/* prototype for subdevs */
198 	TAILQ_HEAD(, sea_scb) free_list, ready_list, nexus_list;
199 	struct sea_scb *nexus;		/* currently connected command */
200 	int numscbs;			/* number of scsi control blocks */
201 	struct sea_scb scb[SCB_TABLE_SIZE];
202 
203 	int our_id;			/* our scsi id */
204 	u_char our_id_mask;
205 	volatile u_char busy[8];	/* index=target, bit=lun, Keep track of
206 					   busy luns at device target */
207 };
208 
209 /* flag showing if main routine is running. */
210 static volatile int main_running = 0;
211 
212 #define	STATUS	(*(volatile u_char *)sea->maddr_cr_sr)
213 #define CONTROL	STATUS
214 #define DATA	(*(volatile u_char *)sea->maddr_dr)
215 
216 /*
217  * These are "special" values for the tag parameter passed to sea_select
218  * Not implemented right now.
219  */
220 #define TAG_NEXT	-1	/* Use next free tag */
221 #define TAG_NONE	-2	/*
222 				 * Establish I_T_L nexus instead of I_T_L_Q
223 				 * even on SCSI-II devices.
224 				 */
225 
226 typedef struct {
227 	char *signature;
228 	int offset, length;
229 	int type;
230 } BiosSignature;
231 
232 /*
233  * Signatures for automatic recognition of board type
234  */
235 static const BiosSignature signatures[] = {
236 {"ST01 v1.7  (C) Copyright 1987 Seagate", 15, 37, SEAGATE},
237 {"SCSI BIOS 2.00  (C) Copyright 1987 Seagate", 15, 40, SEAGATE},
238 
239 /*
240  * The following two lines are NOT mistakes. One detects ROM revision
241  * 3.0.0, the other 3.2. Since seagate has only one type of SCSI adapter,
242  * and this is not going to change, the "SEAGATE" and "SCSI" together
243  * are probably "good enough"
244  */
245 {"SEAGATE SCSI BIOS ", 16, 17, SEAGATE},
246 {"SEAGATE SCSI BIOS ", 17, 17, SEAGATE},
247 
248 /*
249  * However, future domain makes several incompatible SCSI boards, so specific
250  * signatures must be used.
251  */
252 {"FUTURE DOMAIN CORP. (C) 1986-1989 V5.0C2/14/89", 5, 45, FDOMAIN},
253 {"FUTURE DOMAIN CORP. (C) 1986-1989 V6.0A7/28/89", 5, 46, FDOMAIN},
254 {"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0105/31/90",5, 47, FDOMAIN},
255 {"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0209/18/90",5, 47, FDOMAIN},
256 {"FUTURE DOMAIN CORP. (C) 1986-1990 V7.009/18/90", 5, 46, FDOMAIN},
257 {"FUTURE DOMAIN CORP. (C) 1992 V8.00.004/02/92",   5, 44, FDOMAIN},
258 {"FUTURE DOMAIN TMC-950",			   5, 21, FDOMAIN},
259 };
260 
261 #define	nsignatures	(sizeof(signatures) / sizeof(signatures[0]))
262 
263 static const char *bases[] = {
264 	(char *) 0xc8000, (char *) 0xca000, (char *) 0xcc000,
265 	(char *) 0xce000, (char *) 0xdc000, (char *) 0xde000
266 };
267 
268 #define	nbases		(sizeof(bases) / sizeof(bases[0]))
269 
270 int seaintr __P((void *));
271 int sea_scsi_cmd __P((struct scsi_xfer *));
272 void sea_timeout __P((void *));
273 void seaminphys __P((struct buf *));
274 void sea_done __P((struct sea_softc *, struct sea_scb *));
275 struct sea_scb *sea_get_scb __P((struct sea_softc *, int));
276 void sea_free_scb __P((struct sea_softc *, struct sea_scb *, int));
277 static void sea_main __P((void));
278 static void sea_information_transfer __P((struct sea_softc *));
279 int sea_poll __P((struct sea_softc *, struct scsi_xfer *, int));
280 void sea_init __P((struct sea_softc *));
281 void sea_send_scb __P((struct sea_softc *sea, struct sea_scb *scb));
282 void sea_reselect __P((struct sea_softc *sea));
283 int sea_select __P((struct sea_softc *sea, struct sea_scb *scb));
284 int sea_transfer_pio __P((struct sea_softc *sea, u_char *phase,
285     int *count, u_char **data));
286 int sea_abort __P((struct sea_softc *, struct sea_scb *scb));
287 
288 struct scsi_adapter sea_switch = {
289 	sea_scsi_cmd,
290 	seaminphys,
291 	0,
292 	0,
293 };
294 
295 /* the below structure is so we have a default dev struct for our link struct */
296 struct scsi_device sea_dev = {
297 	NULL,		/* use default error handler */
298 	NULL,		/* have a queue, served by this */
299 	NULL,		/* have no async handler */
300 	NULL,		/* Use default 'done' routine */
301 };
302 
303 int seaprobe __P((struct device *, void *, void *));
304 void seaattach __P((struct device *, struct device *, void *));
305 
306 struct cfdriver seacd = {
307 	NULL, "sea", seaprobe, seaattach, DV_DULL, sizeof(struct sea_softc)
308 };
309 
310 #ifdef SEA_DEBUGQUEUE
311 void
312 sea_queue_length(sea)
313 	struct sea_softc *sea;
314 {
315 	struct sea_scb *scb;
316 	int connected, issued, disconnected;
317 
318 	connected = sea->nexus ? 1 : 0;
319 	for (scb = sea->ready_list.tqh_first, issued = 0; scb;
320 	    scb = scb->chain.tqe_next, issued++);
321 	for (scb = sea->nexus_list.tqh_first, disconnected = 0; scb;
322 	    scb = scb->chain.tqe_next, disconnected++);
323 	printf("%s: length: %d/%d/%d\n", sea->sc_dev.dv_xname, connected,
324 	    issued, disconnected);
325 }
326 #endif
327 
328 /*
329  * Check if the device can be found at the port given and if so, detect the
330  * type the type of board.  Set it up ready for further work. Takes the isa_dev
331  * structure from autoconf as an argument.
332  * Returns 1 if card recognized, 0 if errors.
333  */
334 int
335 seaprobe(parent, match, aux)
336 	struct device *parent;
337 	void *match, *aux;
338 {
339 	struct sea_softc *sea = match;
340 	struct isa_attach_args *ia = aux;
341 	int i;
342 
343 	/*
344 	 * Could try to find a board by looking through all possible addresses.
345 	 * This is not done the right way now, because I have not found a way
346 	 * to get a boards virtual memory address given its physical.  There is
347 	 * a function that returns the physical address for a given virtual
348 	 * address, but not the other way around.
349 	 */
350 
351 	if (ia->ia_maddr == MADDRUNK) {
352 		/* XXX */
353 		return 0;
354 	} else
355 		sea->maddr = ISA_HOLE_VADDR(ia->ia_maddr);
356 
357 	/* check board type */	/* No way to define this through config */
358 	for (i = 0; i < nsignatures; i++)
359 		if (!memcmp(sea->maddr + signatures[i].offset,
360 		    signatures[i].signature, signatures[i].length)) {
361 			sea->type = signatures[i].type;
362 			break;
363 		}
364 
365 	/* Find controller and data memory addresses */
366 	switch (sea->type) {
367 	case SEAGATE:
368 	case FDOMAIN840:
369 		sea->maddr_cr_sr =
370 		    (void *) (((u_char *)sea->maddr) + 0x1a00);
371 		sea->maddr_dr =
372 		    (void *) (((u_char *)sea->maddr) + 0x1c00);
373 		break;
374 	case FDOMAIN:
375 		sea->maddr_cr_sr =
376 		    (void *) (((u_char *)sea->maddr) + 0x1c00);
377 		sea->maddr_dr =
378 		    (void *) (((u_char *)sea->maddr) + 0x1e00);
379 		break;
380 	default:
381 		printf("%s: board type unknown at address 0x%lx\n",
382 		    sea->sc_dev.dv_xname, sea->maddr);
383 		return 0;
384 	}
385 
386 	/* Test controller RAM (works the same way on future domain cards?) */
387 	*((u_char *)sea->maddr + SEA_RAMOFFSET) = 0xa5;
388 	*((u_char *)sea->maddr + SEA_RAMOFFSET + 1) = 0x5a;
389 
390 	if ((*((u_char *)sea->maddr + SEA_RAMOFFSET) != 0xa5) ||
391 	    (*((u_char *)sea->maddr + SEA_RAMOFFSET + 1) != 0x5a)) {
392 		printf("%s: board RAM failure\n", sea->sc_dev.dv_xname);
393 		return 0;
394 	}
395 
396 	ia->ia_drq = DRQUNK;
397 	ia->ia_msize = 0x2000;
398 	ia->ia_iosize = 0;
399 	return 1;
400 }
401 
402 seaprint()
403 {
404 
405 }
406 
407 /*
408  * Attach all sub-devices we can find
409  */
410 void
411 seaattach(parent, self, aux)
412 	struct device *parent, *self;
413 	void *aux;
414 {
415 	struct isa_attach_args *ia = aux;
416 	struct sea_softc *sea = (void *)self;
417 
418 	sea_init(sea);
419 
420 	/*
421 	 * fill in the prototype scsi_link.
422 	 */
423 	sea->sc_link.adapter_softc = sea;
424 	sea->sc_link.adapter_target = sea->our_id;
425 	sea->sc_link.adapter = &sea_switch;
426 	sea->sc_link.device = &sea_dev;
427 	sea->sc_link.openings = 1;
428 
429 	printf("\n");
430 
431 #ifdef NEWCONFIG
432 	isa_establish(&sea->sc_id, &sea->sc_deV);
433 #endif
434 	sea->sc_ih = isa_intr_establish(ia->ia_irq, ISA_IST_EDGE, ISA_IPL_BIO,
435 	    seaintr, sea);
436 
437 	/*
438 	 * ask the adapter what subunits are present
439 	 */
440 	config_found(self, &sea->sc_link, seaprint);
441 }
442 
443 /*
444  * Catch an interrupt from the adaptor
445  */
446 int
447 seaintr(arg)
448 	void *arg;
449 {
450 	struct sea_softc *sea = arg;
451 
452 #ifdef DEBUG	/* extra overhead, and only needed for intr debugging */
453 	if ((STATUS & STAT_PARITY) == 0 &&
454 	    (STATUS & (STAT_SEL | STAT_IO)) != (STAT_SEL | STAT_IO))
455 		return 0;
456 #endif
457 
458 loop:
459 	/* dispatch to appropriate routine if found and done=0 */
460 	/* should check to see that this card really caused the interrupt */
461 
462 	if (STATUS & STAT_PARITY) {
463 		/* Parity error interrupt */
464 		printf("%s: parity error\n", sea->sc_dev.dv_xname);
465 		return 1;
466 	}
467 
468 	if ((STATUS & (STAT_SEL | STAT_IO)) == (STAT_SEL | STAT_IO)) {
469 		/* Reselect interrupt */
470 		sea_reselect(sea);
471 		if (!main_running)
472 			sea_main();
473 		goto loop;
474 	}
475 
476 	return 1;
477 }
478 
479 /*
480  * Setup data structures, and reset the board and the SCSI bus.
481  */
482 void
483 sea_init(sea)
484 	struct sea_softc *sea;
485 {
486 	int i;
487 
488 	/* Reset the scsi bus (I don't know if this is needed */
489 	CONTROL = BASE_CMD | CMD_DRVR_ENABLE | CMD_RST;
490 	delay(25);	/* hold reset for at least 25 microseconds */
491 	CONTROL = BASE_CMD;
492 	delay(10); 	/* wait a Bus Clear Delay (800 ns + bus free delay (800 ns) */
493 
494 	/* Set our id (don't know anything about this) */
495 	switch (sea->type) {
496 	case SEAGATE:
497 		sea->our_id = 7;
498 		break;
499 	case FDOMAIN:
500 	case FDOMAIN840:
501 		sea->our_id = 6;
502 		break;
503 	}
504 	sea->our_id_mask = 1 << sea->our_id;
505 
506 	/* init fields used by our routines */
507 	sea->nexus = 0;
508 	TAILQ_INIT(&sea->ready_list);
509 	TAILQ_INIT(&sea->nexus_list);
510 	TAILQ_INIT(&sea->free_list);
511 	for (i = 0; i < 8; i++)
512 		sea->busy[i] = 0x00;
513 
514 	/* link up the free list of scbs */
515 	sea->numscbs = SCB_TABLE_SIZE;
516 	for (i = 0; i < SCB_TABLE_SIZE; i++) {
517 		TAILQ_INSERT_TAIL(&sea->free_list, &sea->scb[i], chain);
518 	}
519 }
520 
521 void
522 seaminphys(bp)
523 	struct buf *bp;
524 {
525 
526 	/* No need for a max since we're doing PIO. */
527 }
528 
529 /*
530  * start a scsi operation given the command and the data address. Also needs
531  * the unit, target and lu.
532  */
533 int
534 sea_scsi_cmd(xs)
535 	struct scsi_xfer *xs;
536 {
537 	struct scsi_link *sc_link = xs->sc_link;
538 	struct sea_softc *sea = sc_link->adapter_softc;
539 	struct sea_scb *scb;
540 	int flags;
541 	int s;
542 
543 	SC_DEBUG(sc_link, SDEV_DB2, ("sea_scsi_cmd\n"));
544 
545 	flags = xs->flags;
546 	if ((flags & (ITSDONE|INUSE)) != INUSE) {
547 		printf("%s: done or not in use?\n", sea->sc_dev.dv_xname);
548 		xs->flags &= ~ITSDONE;
549 		xs->flags |= INUSE;
550 	}
551 	if ((scb = sea_get_scb(sea, flags)) == NULL) {
552 		xs->error = XS_DRIVER_STUFFUP;
553 		return TRY_AGAIN_LATER;
554 	}
555 	scb->flags = SCB_ACTIVE;
556 	scb->xs = xs;
557 
558 	if (flags & SCSI_RESET) {
559 		/*
560 		 * Try to send a reset command to the card.
561 		 * XXX Not implemented.
562 		 */
563 		printf("%s: resetting\n", sea->sc_dev.dv_xname);
564 		xs->error = XS_DRIVER_STUFFUP;
565 		return COMPLETE;
566 	}
567 
568 	/*
569 	 * Put all the arguments for the xfer in the scb
570 	 */
571 	scb->datalen = xs->datalen;
572 	scb->data = xs->data;
573 
574 #ifdef SEA_DEBUGQUEUE
575 	sea_queue_length(sea);
576 #endif
577 
578 	s = splbio();
579 
580 	sea_send_scb(sea, scb);
581 
582 	/*
583 	 * Usually return SUCCESSFULLY QUEUED
584 	 */
585 	if ((flags & SCSI_POLL) == 0) {
586 		timeout(sea_timeout, scb, (xs->timeout * hz) / 1000);
587 		splx(s);
588 		return SUCCESSFULLY_QUEUED;
589 	}
590 
591 	splx(s);
592 
593 	/*
594 	 * If we can't use interrupts, poll on completion
595 	 */
596 	if (sea_poll(sea, xs, xs->timeout)) {
597 		sea_timeout(scb);
598 		if (sea_poll(sea, xs, 2000))
599 			sea_timeout(scb);
600 	}
601 	return COMPLETE;
602 }
603 
604 /*
605  * Get a free scb. If there are none, see if we can allocate a new one.  If so,
606  * put it in the hash table too; otherwise return an error or sleep.
607  */
608 struct sea_scb *
609 sea_get_scb(sea, flags)
610 	struct sea_softc *sea;
611 	int flags;
612 {
613 	int s;
614 	struct sea_scb *scb;
615 
616 	s = splbio();
617 
618 	/*
619 	 * If we can and have to, sleep waiting for one to come free
620 	 * but only if we can't allocate a new one.
621 	 */
622 	for (;;) {
623 		scb = sea->free_list.tqh_first;
624 		if (scb) {
625 			TAILQ_REMOVE(&sea->free_list, scb, chain);
626 			break;
627 		}
628 		if (sea->numscbs < SEA_SCB_MAX) {
629 			if (scb = (struct sea_scb *) malloc(sizeof(struct sea_scb),
630 			    M_TEMP, M_NOWAIT)) {
631 				bzero(scb, sizeof(struct sea_scb));
632 				sea->numscbs++;
633 			} else
634 				printf("%s: can't malloc scb\n",
635 				    sea->sc_dev.dv_xname);
636 			break;
637 		} else {
638 			if ((flags & SCSI_NOSLEEP) == 0)
639 				tsleep(&sea->free_list, PRIBIO, "seascb", 0);
640 		}
641 	}
642 
643 	splx(s);
644 	return scb;
645 }
646 
647 /*
648  * Try to send this command to the board. Because this board does not use any
649  * mailboxes, this routine simply adds the command to the queue held by the
650  * sea_softc structure.
651  * A check is done to see if the command contains a REQUEST_SENSE command, and
652  * if so the command is put first in the queue, otherwise the command is added
653  * to the end of the queue. ?? Not correct ??
654  */
655 void
656 sea_send_scb(sea, scb)
657 	struct sea_softc *sea;
658 	struct sea_scb *scb;
659 {
660 
661 	TAILQ_INSERT_TAIL(&sea->ready_list, scb, chain);
662 	/* Try to do some work on the card. */
663 	if (!main_running)
664 		sea_main();
665 }
666 
667 /*
668  * Coroutine that runs as long as more work can be done on the seagate host
669  * adapter in a system.  Both sea_scsi_cmd and sea_intr will try to start it in
670  * case it is not running.
671  */
672 void
673 sea_main()
674 {
675 	struct sea_softc *sea;
676 	struct sea_scb *scb;
677 	int done;
678 	int unit;
679 	int s;
680 
681 	main_running = 1;
682 
683 	/*
684 	 * This should not be run with interrupts disabled, but use the splx
685 	 * code instead.
686 	 */
687 loop:
688 	done = 1;
689 	for (unit = 0; unit < seacd.cd_ndevs; unit++) {
690 		sea = seacd.cd_devs[unit];
691 		if (!sea)
692 			continue;
693 		s = splbio();
694 		if (!sea->nexus) {
695 			/*
696 			 * Search through the ready_list for a command
697 			 * destined for a target that's not busy.
698 			 */
699 			for (scb = sea->ready_list.tqh_first; scb;
700 			    scb = scb->chain.tqe_next) {
701 				if (!(sea->busy[scb->xs->sc_link->target] &
702 				    (1 << scb->xs->sc_link->lun))) {
703 					TAILQ_REMOVE(&sea->ready_list, scb,
704 					    chain);
705 
706 					/* Re-enable interrupts. */
707 					splx(s);
708 
709 					/*
710 					 * Attempt to establish an I_T_L nexus.
711 					 * On success, sea->nexus is set.
712 					 * On failure, we must add the command
713 					 * back to the issue queue so we can
714 					 * keep trying.
715 					 */
716 
717 					/*
718 					 * REQUEST_SENSE commands are issued
719 					 * without tagged queueing, even on
720 					 * SCSI-II devices because the
721 					 * contingent alligence condition
722 					 * exists for the entire unit.
723 					 */
724 
725 					/*
726 					 * First check that if any device has
727 					 * tried a reconnect while we have done
728 					 * other things with interrupts
729 					 * disabled.
730 					 */
731 
732 					if ((STATUS & (STAT_SEL | STAT_IO)) ==
733 					    (STAT_SEL | STAT_IO)) {
734 						sea_reselect(sea);
735 						break;
736 					}
737 					if (sea_select(sea, scb)) {
738 						s = splbio();
739 						TAILQ_INSERT_HEAD(&sea->ready_list,
740 						    scb, chain);
741 						splx(s);
742 					} else
743 						break;
744 				} /* if target/lun is not busy */
745 			} /* for scb */
746 			if (!sea->nexus) {
747 				/* check for reselection phase */
748 				if ((STATUS & (STAT_SEL | STAT_IO)) ==
749 				    (STAT_SEL | STAT_IO)) {
750 					sea_reselect(sea);
751 				}
752 			}
753 		} /* if (!sea->nexus) */
754 
755 		splx(s);
756 		if (sea->nexus) {	/* we are connected. Do the task */
757 			sea_information_transfer(sea);
758 			done = 0;
759 		} else
760 			break;
761 	} /* for instance */
762 
763 	if (!done)
764 		goto loop;
765 
766 	main_running = 0;
767 }
768 
769 void
770 sea_free_scb(sea, scb, flags)
771 	struct sea_softc *sea;
772 	struct sea_scb *scb;
773 	int flags;
774 {
775 	int s;
776 
777 	s = splbio();
778 
779 	scb->flags = SCB_FREE;
780 	TAILQ_INSERT_HEAD(&sea->free_list, scb, chain);
781 
782 	/*
783 	 * If there were none, wake anybody waiting for one to come free,
784 	 * starting with queued entries.
785 	 */
786 	if (!scb->chain.tqe_next)
787 		wakeup((caddr_t)&sea->free_list);
788 
789 	splx(s);
790 }
791 
792 void
793 sea_timeout(arg)
794 	void *arg;
795 {
796 	struct sea_scb *scb = arg;
797 	struct scsi_xfer *xs = scb->xs;
798 	struct scsi_link *sc_link = xs->sc_link;
799 	struct sea_softc *sea = sc_link->adapter_softc;
800 	int s;
801 
802 	sc_print_addr(sc_link);
803 	printf("timed out");
804 
805 	s = splbio();
806 
807 	/*
808 	 * If it has been through before, then
809 	 * a previous abort has failed, don't
810 	 * try abort again
811 	 */
812 	if (scb->flags & SCB_ABORTED) {
813 		/* abort timed out */
814 		printf(" AGAIN\n");
815 	 	scb->xs->retries = 0;
816 		scb->flags |= SCB_ABORTED;
817 		sea_done(sea, scb);
818 	} else {
819 		/* abort the operation that has timed out */
820 		printf("\n");
821 		scb->flags |= SCB_ABORTED;
822 		sea_abort(sea, scb);
823 		/* 2 secs for the abort */
824 		if ((xs->flags & SCSI_POLL) == 0)
825 			timeout(sea_timeout, scb, 2 * hz);
826 	}
827 
828 	splx(s);
829 }
830 
831 void
832 sea_reselect(sea)
833 	struct sea_softc *sea;
834 {
835 	u_char target_mask;
836 	int i;
837 	u_char lun, phase;
838 	u_char msg[3];
839 	int len;
840 	u_char *data;
841 	struct sea_scb *scb;
842 	int abort = 0;
843 
844 	if (!((target_mask = STATUS) & STAT_SEL)) {
845 		printf("%s: wrong state 0x%x\n", sea->sc_dev.dv_xname,
846 		    target_mask);
847 		return;
848 	}
849 
850 	/* wait for a device to win the reselection phase */
851 	/* signals this by asserting the I/O signal */
852 	for (i = 10; i && (STATUS & (STAT_SEL | STAT_IO | STAT_BSY)) !=
853 	    (STAT_SEL | STAT_IO | 0); i--);
854 	/* !! Check for timeout here */
855 	/* the data bus contains original initiator id ORed with target id */
856 	target_mask = DATA;
857 	/* see that we really are the initiator */
858 	if (!(target_mask & sea->our_id_mask)) {
859 		printf("%s: polled reselection was not for me: 0x%x\n",
860 		    sea->sc_dev.dv_xname, target_mask);
861 		return;
862 	}
863 	/* find target who won */
864 	target_mask &= ~sea->our_id_mask;
865 	/* host responds by asserting the BSY signal */
866 	CONTROL = BASE_CMD | CMD_DRVR_ENABLE | CMD_BSY;
867 	/* target should respond by deasserting the SEL signal */
868 	for (i = 50000; i && (STATUS & STAT_SEL); i++);
869 	/* remove the busy status */
870 	CONTROL = BASE_CMD | CMD_DRVR_ENABLE;
871 	/* we are connected. Now we wait for the MSGIN condition */
872 	for (i = 50000; i && !(STATUS & STAT_REQ); i--);
873 	/* !! Add timeout check here */
874 	/* hope we get an IDENTIFY message */
875 	len = 3;
876 	data = msg;
877 	phase = PH_MSGIN;
878 	sea_transfer_pio(sea, &phase, &len, &data);
879 
880 	if (MSG_ISIDENTIFY(msg[0])) {
881 		printf("%s: expecting IDENTIFY message, got 0x%x\n",
882 		    sea->sc_dev.dv_xname, msg[0]);
883 		abort = 1;
884 	} else {
885 		lun = msg[0] & 0x07;
886 
887 		/*
888 		 * Find the command corresponding to the I_T_L or I_T_L_Q nexus
889 		 * we just reestablished, and remove it from the disconnected
890 		 * queue.
891 		 */
892 		for (scb = sea->nexus_list.tqh_first; scb;
893 		    scb = scb->chain.tqe_next)
894 			if (target_mask == (1 << scb->xs->sc_link->target) &&
895 			    lun == scb->xs->sc_link->lun) {
896 				TAILQ_REMOVE(&sea->nexus_list, scb,
897 				    chain);
898 				break;
899 			}
900 		if (!scb) {
901 			printf("%s: target %02x lun %d not disconnected\n",
902 			    sea->sc_dev.dv_xname, target_mask, lun);
903 			/*
904 			 * Since we have an established nexus that we can't do
905 			 * anything with, we must abort it.
906 			 */
907 			abort = 1;
908 		}
909 	}
910 
911 	if (abort) {
912 		msg[0] = MSG_ABORT;
913 		len = 1;
914 		data = msg;
915 		phase = PH_MSGOUT;
916 		CONTROL = BASE_CMD | CMD_ATTN;
917 		sea_transfer_pio(sea, &phase, &len, &data);
918 	} else
919 		sea->nexus = scb;
920 
921 	return;
922 }
923 
924 /*
925  * Transfer data in given phase using polled I/O.
926  */
927 int
928 sea_transfer_pio(sea, phase, count, data)
929 	struct sea_softc *sea;
930 	u_char *phase;
931 	int *count;
932 	u_char **data;
933 {
934 	register u_char p = *phase, tmp;
935 	register int c = *count;
936 	register u_char *d = *data;
937 	int timeout;
938 
939 	do {
940 		/*
941 		 * Wait for assertion of REQ, after which the phase bits will
942 		 * be valid.
943 		 */
944 		for (timeout = 0; timeout < 50000; timeout++)
945 			if ((tmp = STATUS) & STAT_REQ)
946 				break;
947 		if (!(tmp & STAT_REQ)) {
948 			printf("%s: timeout waiting for STAT_REQ\n",
949 			    sea->sc_dev.dv_xname);
950 			break;
951 		}
952 
953 		/*
954 		 * Check for phase mismatch.  Reached if the target decides
955 		 * that it has finished the transfer.
956 		 */
957 		if (sea->type == FDOMAIN840)
958 			tmp = ((tmp & 0x08) >> 2) |
959 			      ((tmp & 0x02) << 2) |
960 			       (tmp & 0xf5);
961 		if ((tmp & PH_MASK) != p)
962 			break;
963 
964 		/* Do actual transfer from SCSI bus to/from memory. */
965 		if (!(p & STAT_IO))
966 			DATA = *d;
967 		else
968 			*d = DATA;
969 		++d;
970 
971 		/*
972 		 * The SCSI standard suggests that in MSGOUT phase, the
973 		 * initiator should drop ATN on the last byte of the message
974 		 * phase after REQ has been asserted for the handshake but
975 		 * before the initiator raises ACK.
976 		 * Don't know how to accomplish this on the ST01/02.
977 		 */
978 
979 #if 0
980 		/*
981 		 * XXX
982 		 * The st01 code doesn't wait for STAT_REQ to be deasserted.
983 		 * Is this ok?
984 		 */
985 		for (timeout = 0; timeout < 200000L; timeout++)
986 			if (!(STATUS & STAT_REQ))
987 				break;
988 		if (STATUS & STAT_REQ)
989 			printf("%s: timeout on wait for !STAT_REQ",
990 			    sea->sc_dev.dv_xname);
991 #endif
992 	} while (--c);
993 
994 	*count = c;
995 	*data = d;
996 	tmp = STATUS;
997 	if (tmp & STAT_REQ)
998 		*phase = tmp & PH_MASK;
999 	else
1000 		*phase = PH_INVALID;
1001 
1002 	if (c && (*phase != p))
1003 		return -1;
1004 	return 0;
1005 }
1006 
1007 /*
1008  * Establish I_T_L or I_T_L_Q nexus for new or existing command including
1009  * ARBITRATION, SELECTION, and initial message out for IDENTIFY and queue
1010  * messages.  Return -1 if selection could not execute for some reason, 0 if
1011  * selection succeded or failed because the target did not respond.
1012  */
1013 int
1014 sea_select(sea, scb)
1015 	struct sea_softc *sea;
1016 	struct sea_scb *scb;
1017 {
1018 	u_char msg[3], phase;
1019 	u_char *data;
1020 	int len;
1021 	int timeout;
1022 
1023 	CONTROL = BASE_CMD;
1024 	DATA = sea->our_id_mask;
1025 	CONTROL = (BASE_CMD & ~CMD_INTR) | CMD_START_ARB;
1026 
1027 	/* wait for arbitration to complete */
1028 	for (timeout = 0; timeout < 3000000L; timeout++)
1029 		if (STATUS & STAT_ARB_CMPL)
1030 			break;
1031 	if (!(STATUS & STAT_ARB_CMPL)) {
1032 		if (STATUS & STAT_SEL) {
1033 			printf("%s: arbitration lost\n", sea->sc_dev.dv_xname);
1034 			scb->flags |= SCB_ERROR;
1035 		} else {
1036 			printf("%s: arbitration timeout\n",
1037 			    sea->sc_dev.dv_xname);
1038 			scb->flags |= SCB_TIMEOUT;
1039 		}
1040 		CONTROL = BASE_CMD;
1041 		return -1;
1042 	}
1043 
1044 	delay(2);
1045 	DATA = (u_char)((1 << scb->xs->sc_link->target) | sea->our_id_mask);
1046 	CONTROL =
1047 #ifdef SEA_NOMSGS
1048 	    (BASE_CMD & ~CMD_INTR) | CMD_DRVR_ENABLE | CMD_SEL;
1049 #else
1050 	    (BASE_CMD & ~CMD_INTR) | CMD_DRVR_ENABLE | CMD_SEL | CMD_ATTN;
1051 #endif
1052 	delay(1);
1053 
1054 	/* wait for a bsy from target */
1055 	for (timeout = 0; timeout < 2000000L; timeout++)
1056 		if (STATUS & STAT_BSY)
1057 			break;
1058 	if (!(STATUS & STAT_BSY)) {
1059 		/* should return some error to the higher level driver */
1060 		CONTROL = BASE_CMD;
1061 		scb->flags |= SCB_TIMEOUT;
1062 		return 0;
1063 	}
1064 
1065 	/* Try to make the target to take a message from us */
1066 #ifdef SEA_NOMSGS
1067 	CONTROL = (BASE_CMD & ~CMD_INTR) | CMD_DRVR_ENABLE;
1068 #else
1069 	CONTROL = (BASE_CMD & ~CMD_INTR) | CMD_DRVR_ENABLE | CMD_ATTN;
1070 #endif
1071 	delay(1);
1072 
1073 	/* should start a msg_out phase */
1074 	for (timeout = 0; timeout < 2000000L; timeout++)
1075 		if (STATUS & STAT_REQ)
1076 			break;
1077 	/* Remove ATN. */
1078 	CONTROL = BASE_CMD | CMD_DRVR_ENABLE;
1079 	if (!(STATUS & STAT_REQ)) {
1080 		/*
1081 		 * This should not be taken as an error, but more like an
1082 		 * unsupported feature!  Should set a flag indicating that the
1083 		 * target don't support messages, and continue without failure.
1084 		 * (THIS IS NOT AN ERROR!)
1085 		 */
1086 	} else {
1087 		msg[0] = MSG_IDENTIFY(scb->xs->sc_link->lun, 1);
1088 		len = 1;
1089 		data = msg;
1090 		phase = PH_MSGOUT;
1091 		/* Should do test on result of sea_transfer_pio(). */
1092 		sea_transfer_pio(sea, &phase, &len, &data);
1093 	}
1094 	if (!(STATUS & STAT_BSY))
1095 		printf("%s: after successful arbitrate: no STAT_BSY!\n",
1096 		    sea->sc_dev.dv_xname);
1097 
1098 	sea->nexus = scb;
1099 	sea->busy[scb->xs->sc_link->target] |= 1 << scb->xs->sc_link->lun;
1100 	/* This assignment should depend on possibility to send a message to target. */
1101 	CONTROL = BASE_CMD | CMD_DRVR_ENABLE;
1102 	/* XXX Reset pointer in command? */
1103 	return 0;
1104 }
1105 
1106 /*
1107  * Send an abort to the target.  Return 1 success, 0 on failure.
1108  */
1109 int
1110 sea_abort(sea, scb)
1111 	struct sea_softc *sea;
1112 	struct sea_scb *scb;
1113 {
1114 	struct sea_scb *tmp;
1115 	u_char msg, phase, *msgptr;
1116 	int len;
1117 
1118 	/*
1119 	 * If the command hasn't been issued yet, we simply remove it from the
1120 	 * issue queue
1121 	 * XXX Could avoid this loop.
1122 	 */
1123 	for (tmp = sea->ready_list.tqh_first; tmp; tmp = tmp->chain.tqe_next)
1124 		if (scb == tmp) {
1125 			TAILQ_REMOVE(&sea->ready_list, scb, chain);
1126 			/* XXX Set some type of error result for operation. */
1127 			return 1;
1128 		}
1129 
1130 	/*
1131 	 * If any commands are connected, we're going to fail the abort and let
1132 	 * the high level SCSI driver retry at a later time or issue a reset.
1133 	 */
1134 	if (sea->nexus)
1135 		return 0;
1136 
1137 	/*
1138 	 * If the command is currently disconnected from the bus, and there are
1139 	 * no connected commands, we reconnect the I_T_L or I_T_L_Q nexus
1140 	 * associated with it, go into message out, and send an abort message.
1141 	 */
1142 	for (tmp = sea->nexus_list.tqh_first; tmp;
1143 	    tmp = tmp->chain.tqe_next)
1144 		if (scb == tmp) {
1145 			if (sea_select(sea, scb))
1146 				return 0;
1147 
1148 			msg = MSG_ABORT;
1149 			msgptr = &msg;
1150 			len = 1;
1151 			phase = PH_MSGOUT;
1152 			CONTROL = BASE_CMD | CMD_ATTN;
1153 			sea_transfer_pio(sea, &phase, &len, &msgptr);
1154 
1155 			for (tmp = sea->nexus_list.tqh_first; tmp;
1156 			    tmp = tmp->chain.tqe_next)
1157 				if (scb == tmp) {
1158 					TAILQ_REMOVE(&sea->nexus_list,
1159 					    scb, chain);
1160 					/* XXX Set some type of error result
1161 					   for the operation. */
1162 					return 1;
1163 				}
1164 		}
1165 
1166 	/* Command not found in any queue; race condition? */
1167 	return 1;
1168 }
1169 
1170 void
1171 sea_done(sea, scb)
1172 	struct sea_softc *sea;
1173 	struct sea_scb *scb;
1174 {
1175 	struct scsi_xfer *xs = scb->xs;
1176 
1177 	untimeout(sea_timeout, scb);
1178 
1179 	xs->resid = scb->datalen;
1180 
1181 	/* XXXX need to get status */
1182 	if (scb->flags == SCB_ACTIVE) {
1183 		xs->resid = 0;
1184 	} else {
1185 		if (scb->flags & (SCB_TIMEOUT | SCB_ABORTED))
1186 			xs->error = XS_TIMEOUT;
1187 		if (scb->flags & SCB_ERROR)
1188 			xs->error = XS_DRIVER_STUFFUP;
1189 	}
1190 	xs->flags |= ITSDONE;
1191 	sea_free_scb(sea, scb, xs->flags);
1192 	scsi_done(xs);
1193 }
1194 
1195 /*
1196  * Wait for completion of command in polled mode.
1197  */
1198 int
1199 sea_poll(sea, xs, count)
1200 	struct sea_softc *sea;
1201 	struct scsi_xfer *xs;
1202 	int count;
1203 {
1204 	int s;
1205 
1206 	while (count) {
1207 		/* try to do something */
1208 		s = splbio();
1209 		if (!main_running)
1210 			sea_main();
1211 		splx(s);
1212 		if (xs->flags & ITSDONE)
1213 			return 0;
1214 		delay(1000);
1215 		count--;
1216 	}
1217 	return 1;
1218 }
1219 
1220 /*
1221  * Do the transfer.  We know we are connected.  Update the flags, and call
1222  * sea_done() when task accomplished.  Dialog controlled by the target.
1223  */
1224 void
1225 sea_information_transfer(sea)
1226 	struct sea_softc *sea;
1227 {
1228 	int timeout;
1229 	u_char msgout = MSG_NOOP;
1230 	int len;
1231 	int s;
1232 	u_char *data;
1233 	u_char phase, tmp, old_phase = PH_INVALID;
1234 	struct sea_scb *scb = sea->nexus;
1235 	int loop;
1236 
1237 	for (timeout = 0; timeout < 10000000L; timeout++) {
1238 		tmp = STATUS;
1239 		if (tmp & STAT_PARITY)
1240 			printf("%s: parity error detected\n",
1241 			    sea->sc_dev.dv_xname);
1242 		if (!(tmp & STAT_BSY)) {
1243 			for (loop = 0; loop < 20; loop++)
1244 				if ((tmp = STATUS) & STAT_BSY)
1245 					break;
1246 			if (!(tmp & STAT_BSY)) {
1247 				printf("%s: !STAT_BSY unit in data transfer!\n",
1248 				    sea->sc_dev.dv_xname);
1249 				s = splbio();
1250 				sea->nexus = NULL;
1251 				scb->flags = SCB_ERROR;
1252 				splx(s);
1253 				sea_done(sea, scb);
1254 				return;
1255 			}
1256 		}
1257 
1258 		/* we only have a valid SCSI phase when REQ is asserted */
1259 		if (!(tmp & STAT_REQ))
1260 			continue;
1261 
1262 		if (sea->type == FDOMAIN840)
1263 			tmp = ((tmp & 0x08) >> 2) |
1264 			      ((tmp & 0x02) << 2) |
1265 			       (tmp & 0xf5);
1266 		phase = tmp & PH_MASK;
1267 		if (phase != old_phase)
1268 			old_phase = phase;
1269 
1270 		switch (phase) {
1271 		case PH_DATAOUT:
1272 #ifdef SEA_NODATAOUT
1273 			printf("%s: SEA_NODATAOUT set, attempted DATAOUT aborted\n",
1274 			    sea->sc_dev.dv_xname);
1275 			msgout = MSG_ABORT;
1276 			CONTROL = BASE_CMD | CMD_ATTN;
1277 			break;
1278 #endif
1279 		case PH_DATAIN:
1280 			if (!scb->data)
1281 				printf("no data address!\n");
1282 #ifdef SEA_BLINDTRANSFER
1283 			if (scb->datalen && !(scb->datalen % BLOCK_SIZE)) {
1284 				while (scb->datalen) {
1285 					for (loop = 0; loop < 50000; loop++)
1286 						if ((tmp = STATUS) & STAT_REQ)
1287 							break;
1288 					if (!(tmp & STAT_REQ)) {
1289 						printf("%s: timeout waiting for STAT_REQ\n",
1290 						    sea->sc_dev.dv_xname);
1291 						/* XXX Do something? */
1292 					}
1293 					if (sea->type == FDOMAIN840)
1294 						tmp = ((tmp & 0x08) >> 2) |
1295 						      ((tmp & 0x02) << 2) |
1296 						       (tmp & 0xf5);
1297 					if ((tmp & PH_MASK) != phase)
1298 						break;
1299 					if (!(phase & STAT_IO)) {
1300 #ifdef SEA_ASSEMBLER
1301 						asm("shr $2, %%ecx\n\t\
1302 						    cld\n\t\
1303 						    rep\n\t\
1304 						    movsl" :
1305 						    "=S" (scb->data) :
1306 						    "0" (scb->data),
1307 						    "D" (sea->maddr_dr),
1308 						    "c" (BLOCK_SIZE) :
1309 						    "%ecx", "%edi");
1310 #else
1311 						for (count = 0;
1312 						    count < BLOCK_SIZE;
1313 						    count++)
1314 							DATA = *(scb->data++);
1315 #endif
1316 					} else {
1317 #ifdef SEA_ASSEMBLER
1318 						asm("shr $2, %%ecx\n\t\
1319 						    cld\n\t\
1320 						    rep\n\t\
1321 						    movsl" :
1322 						    "=D" (scb->data) :
1323 						    "S" (sea->maddr_dr),
1324 						    "0" (scb->data),
1325 						    "c" (BLOCK_SIZE) :
1326 						    "%ecx", "%esi");
1327 #else
1328 					        for (count = 0;
1329 						    count < BLOCK_SIZE;
1330 						    count++)
1331 							*(scb->data++) = DATA;
1332 #endif
1333 					}
1334 					scb->datalen -= BLOCK_SIZE;
1335 				}
1336 			}
1337 #endif
1338 			if (scb->datalen)
1339 				sea_transfer_pio(sea, &phase, &scb->datalen,
1340 				    &scb->data);
1341 			break;
1342 		case PH_MSGIN:
1343 			/* Multibyte messages should not be present here. */
1344 			len = 1;
1345 			data = &tmp;
1346 			sea_transfer_pio(sea, &phase, &len, &data);
1347 			/* scb->MessageIn = tmp; */
1348 
1349 			switch (tmp) {
1350 			case MSG_ABORT:
1351 				scb->flags = SCB_ABORTED;
1352 				printf("sea: command aborted by target\n");
1353 				CONTROL = BASE_CMD;
1354 				sea_done(sea, scb);
1355 				return;
1356 			case MSG_CMDCOMPLETE:
1357 				s = splbio();
1358 				sea->nexus = NULL;
1359 				splx(s);
1360 				sea->busy[scb->xs->sc_link->target] &=
1361 				    ~(1 << scb->xs->sc_link->lun);
1362 				CONTROL = BASE_CMD;
1363 				sea_done(sea, scb);
1364 				return;
1365 			case MSG_MESSAGE_REJECT:
1366 				printf("%s: message_reject recieved\n",
1367 				    sea->sc_dev.dv_xname);
1368 				break;
1369 			case MSG_DISCONNECT:
1370 				s = splbio();
1371 				TAILQ_INSERT_TAIL(&sea->nexus_list,
1372 				    scb, chain);
1373 				sea->nexus = NULL;
1374 				CONTROL = BASE_CMD;
1375 				splx(s);
1376 				return;
1377 			case MSG_SAVEDATAPOINTER:
1378 			case MSG_RESTOREPOINTERS:
1379 				/* save/restore of pointers are ignored */
1380 				break;
1381 			default:
1382 				/*
1383 				 * This should be handled in the pio data
1384 				 * transfer phase, as the ATN should be raised
1385 				 * before ACK goes false when rejecting a
1386 				 * message.
1387 				 */
1388 				printf("%s: unknown message in: %x\n",
1389 				    sea->sc_dev.dv_xname, tmp);
1390 				break;
1391 			} /* switch (tmp) */
1392 			break;
1393 		case PH_MSGOUT:
1394 			len = 1;
1395 			data = &msgout;
1396 			/* sea->last_message = msgout; */
1397 			sea_transfer_pio(sea, &phase, &len, &data);
1398 			if (msgout == MSG_ABORT) {
1399 				printf("%s: sent message abort to target\n",
1400 				    sea->sc_dev.dv_xname);
1401 				s = splbio();
1402 				sea->busy[scb->xs->sc_link->target] &=
1403 				    ~(1 << scb->xs->sc_link->lun);
1404 				sea->nexus = NULL;
1405 				scb->flags = SCB_ABORTED;
1406 				splx(s);
1407 				/* enable interrupt from scsi */
1408 				sea_done(sea, scb);
1409 				return;
1410 			}
1411 			msgout = MSG_NOOP;
1412 			break;
1413 		case PH_CMD:
1414 			len = scb->xs->cmdlen;
1415 			data = (char *) scb->xs->cmd;
1416 			sea_transfer_pio(sea, &phase, &len, &data);
1417 			break;
1418 		case PH_STAT:
1419 			len = 1;
1420 			data = &tmp;
1421 			sea_transfer_pio(sea, &phase, &len, &data);
1422 			scb->xs->status = tmp;
1423 			break;
1424 		default:
1425 			printf("sea: unknown phase\n");
1426 		} /* switch (phase) */
1427 	} /* for (...) */
1428 
1429 	/* If we get here we have got a timeout! */
1430 	printf("%s: timeout in data transfer\n", sea->sc_dev.dv_xname);
1431 	scb->flags = SCB_TIMEOUT;
1432 	/* XXX Should I clear scsi-bus state? */
1433 	sea_done(sea, scb);
1434 }
1435