xref: /openbmc/linux/drivers/scsi/wd33c93.c (revision cfbb9be8)
1 /*
2  * Copyright (c) 1996 John Shifflett, GeoLog Consulting
3  *    john@geolog.com
4  *    jshiffle@netcom.com
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2, or (at your option)
9  * any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 
17 /*
18  * Drew Eckhardt's excellent 'Generic NCR5380' sources from Linux-PC
19  * provided much of the inspiration and some of the code for this
20  * driver. Everything I know about Amiga DMA was gleaned from careful
21  * reading of Hamish Mcdonald's original wd33c93 driver; in fact, I
22  * borrowed shamelessly from all over that source. Thanks Hamish!
23  *
24  * _This_ driver is (I feel) an improvement over the old one in
25  * several respects:
26  *
27  *    -  Target Disconnection/Reconnection  is now supported. Any
28  *          system with more than one device active on the SCSI bus
29  *          will benefit from this. The driver defaults to what I
30  *          call 'adaptive disconnect' - meaning that each command
31  *          is evaluated individually as to whether or not it should
32  *          be run with the option to disconnect/reselect (if the
33  *          device chooses), or as a "SCSI-bus-hog".
34  *
35  *    -  Synchronous data transfers are now supported. Because of
36  *          a few devices that choke after telling the driver that
37  *          they can do sync transfers, we don't automatically use
38  *          this faster protocol - it can be enabled via the command-
39  *          line on a device-by-device basis.
40  *
41  *    -  Runtime operating parameters can now be specified through
42  *       the 'amiboot' or the 'insmod' command line. For amiboot do:
43  *          "amiboot [usual stuff] wd33c93=blah,blah,blah"
44  *       The defaults should be good for most people. See the comment
45  *       for 'setup_strings' below for more details.
46  *
47  *    -  The old driver relied exclusively on what the Western Digital
48  *          docs call "Combination Level 2 Commands", which are a great
49  *          idea in that the CPU is relieved of a lot of interrupt
50  *          overhead. However, by accepting a certain (user-settable)
51  *          amount of additional interrupts, this driver achieves
52  *          better control over the SCSI bus, and data transfers are
53  *          almost as fast while being much easier to define, track,
54  *          and debug.
55  *
56  *
57  * TODO:
58  *       more speed. linked commands.
59  *
60  *
61  * People with bug reports, wish-lists, complaints, comments,
62  * or improvements are asked to pah-leeez email me (John Shifflett)
63  * at john@geolog.com or jshiffle@netcom.com! I'm anxious to get
64  * this thing into as good a shape as possible, and I'm positive
65  * there are lots of lurking bugs and "Stupid Places".
66  *
67  * Updates:
68  *
69  * Added support for pre -A chips, which don't have advanced features
70  * and will generate CSR_RESEL rather than CSR_RESEL_AM.
71  *	Richard Hirst <richard@sleepie.demon.co.uk>  August 2000
72  *
73  * Added support for Burst Mode DMA and Fast SCSI. Enabled the use of
74  * default_sx_per for asynchronous data transfers. Added adjustment
75  * of transfer periods in sx_table to the actual input-clock.
76  *  peter fuerst <post@pfrst.de>  February 2007
77  */
78 
79 #include <linux/module.h>
80 
81 #include <linux/string.h>
82 #include <linux/delay.h>
83 #include <linux/init.h>
84 #include <linux/interrupt.h>
85 #include <linux/blkdev.h>
86 
87 #include <scsi/scsi.h>
88 #include <scsi/scsi_cmnd.h>
89 #include <scsi/scsi_device.h>
90 #include <scsi/scsi_host.h>
91 
92 #include <asm/irq.h>
93 
94 #include "wd33c93.h"
95 
96 #define optimum_sx_per(hostdata) (hostdata)->sx_table[1].period_ns
97 
98 
99 #define WD33C93_VERSION    "1.26++"
100 #define WD33C93_DATE       "10/Feb/2007"
101 
102 MODULE_AUTHOR("John Shifflett");
103 MODULE_DESCRIPTION("Generic WD33C93 SCSI driver");
104 MODULE_LICENSE("GPL");
105 
106 /*
107  * 'setup_strings' is a single string used to pass operating parameters and
108  * settings from the kernel/module command-line to the driver. 'setup_args[]'
109  * is an array of strings that define the compile-time default values for
110  * these settings. If Linux boots with an amiboot or insmod command-line,
111  * those settings are combined with 'setup_args[]'. Note that amiboot
112  * command-lines are prefixed with "wd33c93=" while insmod uses a
113  * "setup_strings=" prefix. The driver recognizes the following keywords
114  * (lower case required) and arguments:
115  *
116  * -  nosync:bitmask -bitmask is a byte where the 1st 7 bits correspond with
117  *                    the 7 possible SCSI devices. Set a bit to negotiate for
118  *                    asynchronous transfers on that device. To maintain
119  *                    backwards compatibility, a command-line such as
120  *                    "wd33c93=255" will be automatically translated to
121  *                    "wd33c93=nosync:0xff".
122  * -  nodma:x        -x = 1 to disable DMA, x = 0 to enable it. Argument is
123  *                    optional - if not present, same as "nodma:1".
124  * -  period:ns      -ns is the minimum # of nanoseconds in a SCSI data transfer
125  *                    period. Default is 500; acceptable values are 250 - 1000.
126  * -  disconnect:x   -x = 0 to never allow disconnects, 2 to always allow them.
127  *                    x = 1 does 'adaptive' disconnects, which is the default
128  *                    and generally the best choice.
129  * -  debug:x        -If 'DEBUGGING_ON' is defined, x is a bit mask that causes
130  *                    various types of debug output to printed - see the DB_xxx
131  *                    defines in wd33c93.h
132  * -  clock:x        -x = clock input in MHz for WD33c93 chip. Normal values
133  *                    would be from 8 through 20. Default is 8.
134  * -  burst:x        -x = 1 to use Burst Mode (or Demand-Mode) DMA, x = 0 to use
135  *                    Single Byte DMA, which is the default. Argument is
136  *                    optional - if not present, same as "burst:1".
137  * -  fast:x         -x = 1 to enable Fast SCSI, which is only effective with
138  *                    input-clock divisor 4 (WD33C93_FS_16_20), x = 0 to disable
139  *                    it, which is the default.  Argument is optional - if not
140  *                    present, same as "fast:1".
141  * -  next           -No argument. Used to separate blocks of keywords when
142  *                    there's more than one host adapter in the system.
143  *
144  * Syntax Notes:
145  * -  Numeric arguments can be decimal or the '0x' form of hex notation. There
146  *    _must_ be a colon between a keyword and its numeric argument, with no
147  *    spaces.
148  * -  Keywords are separated by commas, no spaces, in the standard kernel
149  *    command-line manner.
150  * -  A keyword in the 'nth' comma-separated command-line member will overwrite
151  *    the 'nth' element of setup_args[]. A blank command-line member (in
152  *    other words, a comma with no preceding keyword) will _not_ overwrite
153  *    the corresponding setup_args[] element.
154  * -  If a keyword is used more than once, the first one applies to the first
155  *    SCSI host found, the second to the second card, etc, unless the 'next'
156  *    keyword is used to change the order.
157  *
158  * Some amiboot examples (for insmod, use 'setup_strings' instead of 'wd33c93'):
159  * -  wd33c93=nosync:255
160  * -  wd33c93=nodma
161  * -  wd33c93=nodma:1
162  * -  wd33c93=disconnect:2,nosync:0x08,period:250
163  * -  wd33c93=debug:0x1c
164  */
165 
166 /* Normally, no defaults are specified */
167 static char *setup_args[] = { "", "", "", "", "", "", "", "", "", "" };
168 
169 static char *setup_strings;
170 module_param(setup_strings, charp, 0);
171 
172 static void wd33c93_execute(struct Scsi_Host *instance);
173 
174 #ifdef CONFIG_WD33C93_PIO
175 static inline uchar
176 read_wd33c93(const wd33c93_regs regs, uchar reg_num)
177 {
178 	uchar data;
179 
180 	outb(reg_num, regs.SASR);
181 	data = inb(regs.SCMD);
182 	return data;
183 }
184 
185 static inline unsigned long
186 read_wd33c93_count(const wd33c93_regs regs)
187 {
188 	unsigned long value;
189 
190 	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
191 	value = inb(regs.SCMD) << 16;
192 	value |= inb(regs.SCMD) << 8;
193 	value |= inb(regs.SCMD);
194 	return value;
195 }
196 
197 static inline uchar
198 read_aux_stat(const wd33c93_regs regs)
199 {
200 	return inb(regs.SASR);
201 }
202 
203 static inline void
204 write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
205 {
206       outb(reg_num, regs.SASR);
207       outb(value, regs.SCMD);
208 }
209 
210 static inline void
211 write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
212 {
213 	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
214 	outb((value >> 16) & 0xff, regs.SCMD);
215 	outb((value >> 8) & 0xff, regs.SCMD);
216 	outb( value & 0xff, regs.SCMD);
217 }
218 
219 #define write_wd33c93_cmd(regs, cmd) \
220 	write_wd33c93((regs), WD_COMMAND, (cmd))
221 
222 static inline void
223 write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
224 {
225 	int i;
226 
227 	outb(WD_CDB_1, regs.SASR);
228 	for (i=0; i<len; i++)
229 		outb(cmnd[i], regs.SCMD);
230 }
231 
232 #else /* CONFIG_WD33C93_PIO */
233 static inline uchar
234 read_wd33c93(const wd33c93_regs regs, uchar reg_num)
235 {
236 	*regs.SASR = reg_num;
237 	mb();
238 	return (*regs.SCMD);
239 }
240 
241 static unsigned long
242 read_wd33c93_count(const wd33c93_regs regs)
243 {
244 	unsigned long value;
245 
246 	*regs.SASR = WD_TRANSFER_COUNT_MSB;
247 	mb();
248 	value = *regs.SCMD << 16;
249 	value |= *regs.SCMD << 8;
250 	value |= *regs.SCMD;
251 	mb();
252 	return value;
253 }
254 
255 static inline uchar
256 read_aux_stat(const wd33c93_regs regs)
257 {
258 	return *regs.SASR;
259 }
260 
261 static inline void
262 write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
263 {
264 	*regs.SASR = reg_num;
265 	mb();
266 	*regs.SCMD = value;
267 	mb();
268 }
269 
270 static void
271 write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
272 {
273 	*regs.SASR = WD_TRANSFER_COUNT_MSB;
274 	mb();
275 	*regs.SCMD = value >> 16;
276 	*regs.SCMD = value >> 8;
277 	*regs.SCMD = value;
278 	mb();
279 }
280 
281 static inline void
282 write_wd33c93_cmd(const wd33c93_regs regs, uchar cmd)
283 {
284 	*regs.SASR = WD_COMMAND;
285 	mb();
286 	*regs.SCMD = cmd;
287 	mb();
288 }
289 
290 static inline void
291 write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
292 {
293 	int i;
294 
295 	*regs.SASR = WD_CDB_1;
296 	for (i = 0; i < len; i++)
297 		*regs.SCMD = cmnd[i];
298 }
299 #endif /* CONFIG_WD33C93_PIO */
300 
301 static inline uchar
302 read_1_byte(const wd33c93_regs regs)
303 {
304 	uchar asr;
305 	uchar x = 0;
306 
307 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
308 	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO | 0x80);
309 	do {
310 		asr = read_aux_stat(regs);
311 		if (asr & ASR_DBR)
312 			x = read_wd33c93(regs, WD_DATA);
313 	} while (!(asr & ASR_INT));
314 	return x;
315 }
316 
317 static int
318 round_period(unsigned int period, const struct sx_period *sx_table)
319 {
320 	int x;
321 
322 	for (x = 1; sx_table[x].period_ns; x++) {
323 		if ((period <= sx_table[x - 0].period_ns) &&
324 		    (period > sx_table[x - 1].period_ns)) {
325 			return x;
326 		}
327 	}
328 	return 7;
329 }
330 
331 /*
332  * Calculate Synchronous Transfer Register value from SDTR code.
333  */
334 static uchar
335 calc_sync_xfer(unsigned int period, unsigned int offset, unsigned int fast,
336                const struct sx_period *sx_table)
337 {
338 	/* When doing Fast SCSI synchronous data transfers, the corresponding
339 	 * value in 'sx_table' is two times the actually used transfer period.
340 	 */
341 	uchar result;
342 
343 	if (offset && fast) {
344 		fast = STR_FSS;
345 		period *= 2;
346 	} else {
347 		fast = 0;
348 	}
349 	period *= 4;		/* convert SDTR code to ns */
350 	result = sx_table[round_period(period,sx_table)].reg_value;
351 	result |= (offset < OPTIMUM_SX_OFF) ? offset : OPTIMUM_SX_OFF;
352 	result |= fast;
353 	return result;
354 }
355 
356 /*
357  * Calculate SDTR code bytes [3],[4] from period and offset.
358  */
359 static inline void
360 calc_sync_msg(unsigned int period, unsigned int offset, unsigned int fast,
361                 uchar  msg[2])
362 {
363 	/* 'period' is a "normal"-mode value, like the ones in 'sx_table'. The
364 	 * actually used transfer period for Fast SCSI synchronous data
365 	 * transfers is half that value.
366 	 */
367 	period /= 4;
368 	if (offset && fast)
369 		period /= 2;
370 	msg[0] = period;
371 	msg[1] = offset;
372 }
373 
374 static int
375 wd33c93_queuecommand_lck(struct scsi_cmnd *cmd,
376 		void (*done)(struct scsi_cmnd *))
377 {
378 	struct WD33C93_hostdata *hostdata;
379 	struct scsi_cmnd *tmp;
380 
381 	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
382 
383 	DB(DB_QUEUE_COMMAND,
384 	   printk("Q-%d-%02x( ", cmd->device->id, cmd->cmnd[0]))
385 
386 /* Set up a few fields in the scsi_cmnd structure for our own use:
387  *  - host_scribble is the pointer to the next cmd in the input queue
388  *  - scsi_done points to the routine we call when a cmd is finished
389  *  - result is what you'd expect
390  */
391 	cmd->host_scribble = NULL;
392 	cmd->scsi_done = done;
393 	cmd->result = 0;
394 
395 /* We use the Scsi_Pointer structure that's included with each command
396  * as a scratchpad (as it's intended to be used!). The handy thing about
397  * the SCp.xxx fields is that they're always associated with a given
398  * cmd, and are preserved across disconnect-reselect. This means we
399  * can pretty much ignore SAVE_POINTERS and RESTORE_POINTERS messages
400  * if we keep all the critical pointers and counters in SCp:
401  *  - SCp.ptr is the pointer into the RAM buffer
402  *  - SCp.this_residual is the size of that buffer
403  *  - SCp.buffer points to the current scatter-gather buffer
404  *  - SCp.buffers_residual tells us how many S.G. buffers there are
405  *  - SCp.have_data_in is not used
406  *  - SCp.sent_command is not used
407  *  - SCp.phase records this command's SRCID_ER bit setting
408  */
409 
410 	if (scsi_bufflen(cmd)) {
411 		cmd->SCp.buffer = scsi_sglist(cmd);
412 		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
413 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
414 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
415 	} else {
416 		cmd->SCp.buffer = NULL;
417 		cmd->SCp.buffers_residual = 0;
418 		cmd->SCp.ptr = NULL;
419 		cmd->SCp.this_residual = 0;
420 	}
421 
422 /* WD docs state that at the conclusion of a "LEVEL2" command, the
423  * status byte can be retrieved from the LUN register. Apparently,
424  * this is the case only for *uninterrupted* LEVEL2 commands! If
425  * there are any unexpected phases entered, even if they are 100%
426  * legal (different devices may choose to do things differently),
427  * the LEVEL2 command sequence is exited. This often occurs prior
428  * to receiving the status byte, in which case the driver does a
429  * status phase interrupt and gets the status byte on its own.
430  * While such a command can then be "resumed" (ie restarted to
431  * finish up as a LEVEL2 command), the LUN register will NOT be
432  * a valid status byte at the command's conclusion, and we must
433  * use the byte obtained during the earlier interrupt. Here, we
434  * preset SCp.Status to an illegal value (0xff) so that when
435  * this command finally completes, we can tell where the actual
436  * status byte is stored.
437  */
438 
439 	cmd->SCp.Status = ILLEGAL_STATUS_BYTE;
440 
441 	/*
442 	 * Add the cmd to the end of 'input_Q'. Note that REQUEST SENSE
443 	 * commands are added to the head of the queue so that the desired
444 	 * sense data is not lost before REQUEST_SENSE executes.
445 	 */
446 
447 	spin_lock_irq(&hostdata->lock);
448 
449 	if (!(hostdata->input_Q) || (cmd->cmnd[0] == REQUEST_SENSE)) {
450 		cmd->host_scribble = (uchar *) hostdata->input_Q;
451 		hostdata->input_Q = cmd;
452 	} else {		/* find the end of the queue */
453 		for (tmp = (struct scsi_cmnd *) hostdata->input_Q;
454 		     tmp->host_scribble;
455 		     tmp = (struct scsi_cmnd *) tmp->host_scribble) ;
456 		tmp->host_scribble = (uchar *) cmd;
457 	}
458 
459 /* We know that there's at least one command in 'input_Q' now.
460  * Go see if any of them are runnable!
461  */
462 
463 	wd33c93_execute(cmd->device->host);
464 
465 	DB(DB_QUEUE_COMMAND, printk(")Q "))
466 
467 	spin_unlock_irq(&hostdata->lock);
468 	return 0;
469 }
470 
471 DEF_SCSI_QCMD(wd33c93_queuecommand)
472 
473 /*
474  * This routine attempts to start a scsi command. If the host_card is
475  * already connected, we give up immediately. Otherwise, look through
476  * the input_Q, using the first command we find that's intended
477  * for a currently non-busy target/lun.
478  *
479  * wd33c93_execute() is always called with interrupts disabled or from
480  * the wd33c93_intr itself, which means that a wd33c93 interrupt
481  * cannot occur while we are in here.
482  */
483 static void
484 wd33c93_execute(struct Scsi_Host *instance)
485 {
486 	struct WD33C93_hostdata *hostdata =
487 	    (struct WD33C93_hostdata *) instance->hostdata;
488 	const wd33c93_regs regs = hostdata->regs;
489 	struct scsi_cmnd *cmd, *prev;
490 
491 	DB(DB_EXECUTE, printk("EX("))
492 	if (hostdata->selecting || hostdata->connected) {
493 		DB(DB_EXECUTE, printk(")EX-0 "))
494 		return;
495 	}
496 
497 	/*
498 	 * Search through the input_Q for a command destined
499 	 * for an idle target/lun.
500 	 */
501 
502 	cmd = (struct scsi_cmnd *) hostdata->input_Q;
503 	prev = NULL;
504 	while (cmd) {
505 		if (!(hostdata->busy[cmd->device->id] &
506 		      (1 << (cmd->device->lun & 0xff))))
507 			break;
508 		prev = cmd;
509 		cmd = (struct scsi_cmnd *) cmd->host_scribble;
510 	}
511 
512 	/* quit if queue empty or all possible targets are busy */
513 
514 	if (!cmd) {
515 		DB(DB_EXECUTE, printk(")EX-1 "))
516 		return;
517 	}
518 
519 	/*  remove command from queue */
520 
521 	if (prev)
522 		prev->host_scribble = cmd->host_scribble;
523 	else
524 		hostdata->input_Q = (struct scsi_cmnd *) cmd->host_scribble;
525 
526 #ifdef PROC_STATISTICS
527 	hostdata->cmd_cnt[cmd->device->id]++;
528 #endif
529 
530 	/*
531 	 * Start the selection process
532 	 */
533 
534 	if (cmd->sc_data_direction == DMA_TO_DEVICE)
535 		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
536 	else
537 		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id | DSTID_DPD);
538 
539 /* Now we need to figure out whether or not this command is a good
540  * candidate for disconnect/reselect. We guess to the best of our
541  * ability, based on a set of hierarchical rules. When several
542  * devices are operating simultaneously, disconnects are usually
543  * an advantage. In a single device system, or if only 1 device
544  * is being accessed, transfers usually go faster if disconnects
545  * are not allowed:
546  *
547  * + Commands should NEVER disconnect if hostdata->disconnect =
548  *   DIS_NEVER (this holds for tape drives also), and ALWAYS
549  *   disconnect if hostdata->disconnect = DIS_ALWAYS.
550  * + Tape drive commands should always be allowed to disconnect.
551  * + Disconnect should be allowed if disconnected_Q isn't empty.
552  * + Commands should NOT disconnect if input_Q is empty.
553  * + Disconnect should be allowed if there are commands in input_Q
554  *   for a different target/lun. In this case, the other commands
555  *   should be made disconnect-able, if not already.
556  *
557  * I know, I know - this code would flunk me out of any
558  * "C Programming 101" class ever offered. But it's easy
559  * to change around and experiment with for now.
560  */
561 
562 	cmd->SCp.phase = 0;	/* assume no disconnect */
563 	if (hostdata->disconnect == DIS_NEVER)
564 		goto no;
565 	if (hostdata->disconnect == DIS_ALWAYS)
566 		goto yes;
567 	if (cmd->device->type == 1)	/* tape drive? */
568 		goto yes;
569 	if (hostdata->disconnected_Q)	/* other commands disconnected? */
570 		goto yes;
571 	if (!(hostdata->input_Q))	/* input_Q empty? */
572 		goto no;
573 	for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
574 	     prev = (struct scsi_cmnd *) prev->host_scribble) {
575 		if ((prev->device->id != cmd->device->id) ||
576 		    (prev->device->lun != cmd->device->lun)) {
577 			for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
578 			     prev = (struct scsi_cmnd *) prev->host_scribble)
579 				prev->SCp.phase = 1;
580 			goto yes;
581 		}
582 	}
583 
584 	goto no;
585 
586  yes:
587 	cmd->SCp.phase = 1;
588 
589 #ifdef PROC_STATISTICS
590 	hostdata->disc_allowed_cnt[cmd->device->id]++;
591 #endif
592 
593  no:
594 
595 	write_wd33c93(regs, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0));
596 
597 	write_wd33c93(regs, WD_TARGET_LUN, (u8)cmd->device->lun);
598 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
599 		      hostdata->sync_xfer[cmd->device->id]);
600 	hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
601 
602 	if ((hostdata->level2 == L2_NONE) ||
603 	    (hostdata->sync_stat[cmd->device->id] == SS_UNSET)) {
604 
605 		/*
606 		 * Do a 'Select-With-ATN' command. This will end with
607 		 * one of the following interrupts:
608 		 *    CSR_RESEL_AM:  failure - can try again later.
609 		 *    CSR_TIMEOUT:   failure - give up.
610 		 *    CSR_SELECT:    success - proceed.
611 		 */
612 
613 		hostdata->selecting = cmd;
614 
615 /* Every target has its own synchronous transfer setting, kept in the
616  * sync_xfer array, and a corresponding status byte in sync_stat[].
617  * Each target's sync_stat[] entry is initialized to SX_UNSET, and its
618  * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET
619  * means that the parameters are undetermined as yet, and that we
620  * need to send an SDTR message to this device after selection is
621  * complete: We set SS_FIRST to tell the interrupt routine to do so.
622  * If we've been asked not to try synchronous transfers on this
623  * target (and _all_ luns within it), we'll still send the SDTR message
624  * later, but at that time we'll negotiate for async by specifying a
625  * sync fifo depth of 0.
626  */
627 		if (hostdata->sync_stat[cmd->device->id] == SS_UNSET)
628 			hostdata->sync_stat[cmd->device->id] = SS_FIRST;
629 		hostdata->state = S_SELECTING;
630 		write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
631 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN);
632 	} else {
633 
634 		/*
635 		 * Do a 'Select-With-ATN-Xfer' command. This will end with
636 		 * one of the following interrupts:
637 		 *    CSR_RESEL_AM:  failure - can try again later.
638 		 *    CSR_TIMEOUT:   failure - give up.
639 		 *    anything else: success - proceed.
640 		 */
641 
642 		hostdata->connected = cmd;
643 		write_wd33c93(regs, WD_COMMAND_PHASE, 0);
644 
645 		/* copy command_descriptor_block into WD chip
646 		 * (take advantage of auto-incrementing)
647 		 */
648 
649 		write_wd33c93_cdb(regs, cmd->cmd_len, cmd->cmnd);
650 
651 		/* The wd33c93 only knows about Group 0, 1, and 5 commands when
652 		 * it's doing a 'select-and-transfer'. To be safe, we write the
653 		 * size of the CDB into the OWN_ID register for every case. This
654 		 * way there won't be problems with vendor-unique, audio, etc.
655 		 */
656 
657 		write_wd33c93(regs, WD_OWN_ID, cmd->cmd_len);
658 
659 		/* When doing a non-disconnect command with DMA, we can save
660 		 * ourselves a DATA phase interrupt later by setting everything
661 		 * up ahead of time.
662 		 */
663 
664 		if ((cmd->SCp.phase == 0) && (hostdata->no_dma == 0)) {
665 			if (hostdata->dma_setup(cmd,
666 			    (cmd->sc_data_direction == DMA_TO_DEVICE) ?
667 			     DATA_OUT_DIR : DATA_IN_DIR))
668 				write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
669 			else {
670 				write_wd33c93_count(regs,
671 						    cmd->SCp.this_residual);
672 				write_wd33c93(regs, WD_CONTROL,
673 					      CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
674 				hostdata->dma = D_DMA_RUNNING;
675 			}
676 		} else
677 			write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
678 
679 		hostdata->state = S_RUNNING_LEVEL2;
680 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
681 	}
682 
683 	/*
684 	 * Since the SCSI bus can handle only 1 connection at a time,
685 	 * we get out of here now. If the selection fails, or when
686 	 * the command disconnects, we'll come back to this routine
687 	 * to search the input_Q again...
688 	 */
689 
690 	DB(DB_EXECUTE,
691 	   printk("%s)EX-2 ", (cmd->SCp.phase) ? "d:" : ""))
692 }
693 
694 static void
695 transfer_pio(const wd33c93_regs regs, uchar * buf, int cnt,
696 	     int data_in_dir, struct WD33C93_hostdata *hostdata)
697 {
698 	uchar asr;
699 
700 	DB(DB_TRANSFER,
701 	   printk("(%p,%d,%s:", buf, cnt, data_in_dir ? "in" : "out"))
702 
703 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
704 	write_wd33c93_count(regs, cnt);
705 	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
706 	if (data_in_dir) {
707 		do {
708 			asr = read_aux_stat(regs);
709 			if (asr & ASR_DBR)
710 				*buf++ = read_wd33c93(regs, WD_DATA);
711 		} while (!(asr & ASR_INT));
712 	} else {
713 		do {
714 			asr = read_aux_stat(regs);
715 			if (asr & ASR_DBR)
716 				write_wd33c93(regs, WD_DATA, *buf++);
717 		} while (!(asr & ASR_INT));
718 	}
719 
720 	/* Note: we are returning with the interrupt UN-cleared.
721 	 * Since (presumably) an entire I/O operation has
722 	 * completed, the bus phase is probably different, and
723 	 * the interrupt routine will discover this when it
724 	 * responds to the uncleared int.
725 	 */
726 
727 }
728 
729 static void
730 transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
731 		int data_in_dir)
732 {
733 	struct WD33C93_hostdata *hostdata;
734 	unsigned long length;
735 
736 	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
737 
738 /* Normally, you'd expect 'this_residual' to be non-zero here.
739  * In a series of scatter-gather transfers, however, this
740  * routine will usually be called with 'this_residual' equal
741  * to 0 and 'buffers_residual' non-zero. This means that a
742  * previous transfer completed, clearing 'this_residual', and
743  * now we need to setup the next scatter-gather buffer as the
744  * source or destination for THIS transfer.
745  */
746 	if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
747 		++cmd->SCp.buffer;
748 		--cmd->SCp.buffers_residual;
749 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
750 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
751 	}
752 	if (!cmd->SCp.this_residual) /* avoid bogus setups */
753 		return;
754 
755 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
756 		      hostdata->sync_xfer[cmd->device->id]);
757 
758 /* 'hostdata->no_dma' is TRUE if we don't even want to try DMA.
759  * Update 'this_residual' and 'ptr' after 'transfer_pio()' returns.
760  */
761 
762 	if (hostdata->no_dma || hostdata->dma_setup(cmd, data_in_dir)) {
763 #ifdef PROC_STATISTICS
764 		hostdata->pio_cnt++;
765 #endif
766 		transfer_pio(regs, (uchar *) cmd->SCp.ptr,
767 			     cmd->SCp.this_residual, data_in_dir, hostdata);
768 		length = cmd->SCp.this_residual;
769 		cmd->SCp.this_residual = read_wd33c93_count(regs);
770 		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
771 	}
772 
773 /* We are able to do DMA (in fact, the Amiga hardware is
774  * already going!), so start up the wd33c93 in DMA mode.
775  * We set 'hostdata->dma' = D_DMA_RUNNING so that when the
776  * transfer completes and causes an interrupt, we're
777  * reminded to tell the Amiga to shut down its end. We'll
778  * postpone the updating of 'this_residual' and 'ptr'
779  * until then.
780  */
781 
782 	else {
783 #ifdef PROC_STATISTICS
784 		hostdata->dma_cnt++;
785 #endif
786 		write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
787 		write_wd33c93_count(regs, cmd->SCp.this_residual);
788 
789 		if ((hostdata->level2 >= L2_DATA) ||
790 		    (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
791 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
792 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
793 			hostdata->state = S_RUNNING_LEVEL2;
794 		} else
795 			write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
796 
797 		hostdata->dma = D_DMA_RUNNING;
798 	}
799 }
800 
801 void
802 wd33c93_intr(struct Scsi_Host *instance)
803 {
804 	struct WD33C93_hostdata *hostdata =
805 	    (struct WD33C93_hostdata *) instance->hostdata;
806 	const wd33c93_regs regs = hostdata->regs;
807 	struct scsi_cmnd *patch, *cmd;
808 	uchar asr, sr, phs, id, lun, *ucp, msg;
809 	unsigned long length, flags;
810 
811 	asr = read_aux_stat(regs);
812 	if (!(asr & ASR_INT) || (asr & ASR_BSY))
813 		return;
814 
815 	spin_lock_irqsave(&hostdata->lock, flags);
816 
817 #ifdef PROC_STATISTICS
818 	hostdata->int_cnt++;
819 #endif
820 
821 	cmd = (struct scsi_cmnd *) hostdata->connected;	/* assume we're connected */
822 	sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear the interrupt */
823 	phs = read_wd33c93(regs, WD_COMMAND_PHASE);
824 
825 	DB(DB_INTR, printk("{%02x:%02x-", asr, sr))
826 
827 /* After starting a DMA transfer, the next interrupt
828  * is guaranteed to be in response to completion of
829  * the transfer. Since the Amiga DMA hardware runs in
830  * in an open-ended fashion, it needs to be told when
831  * to stop; do that here if D_DMA_RUNNING is true.
832  * Also, we have to update 'this_residual' and 'ptr'
833  * based on the contents of the TRANSFER_COUNT register,
834  * in case the device decided to do an intermediate
835  * disconnect (a device may do this if it has to do a
836  * seek, or just to be nice and let other devices have
837  * some bus time during long transfers). After doing
838  * whatever is needed, we go on and service the WD3393
839  * interrupt normally.
840  */
841 	    if (hostdata->dma == D_DMA_RUNNING) {
842 		DB(DB_TRANSFER,
843 		   printk("[%p/%d:", cmd->SCp.ptr, cmd->SCp.this_residual))
844 		    hostdata->dma_stop(cmd->device->host, cmd, 1);
845 		hostdata->dma = D_DMA_OFF;
846 		length = cmd->SCp.this_residual;
847 		cmd->SCp.this_residual = read_wd33c93_count(regs);
848 		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
849 		DB(DB_TRANSFER,
850 		   printk("%p/%d]", cmd->SCp.ptr, cmd->SCp.this_residual))
851 	}
852 
853 /* Respond to the specific WD3393 interrupt - there are quite a few! */
854 	switch (sr) {
855 	case CSR_TIMEOUT:
856 		DB(DB_INTR, printk("TIMEOUT"))
857 
858 		    if (hostdata->state == S_RUNNING_LEVEL2)
859 			hostdata->connected = NULL;
860 		else {
861 			cmd = (struct scsi_cmnd *) hostdata->selecting;	/* get a valid cmd */
862 			hostdata->selecting = NULL;
863 		}
864 
865 		cmd->result = DID_NO_CONNECT << 16;
866 		hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
867 		hostdata->state = S_UNCONNECTED;
868 		cmd->scsi_done(cmd);
869 
870 		/* From esp.c:
871 		 * There is a window of time within the scsi_done() path
872 		 * of execution where interrupts are turned back on full
873 		 * blast and left that way.  During that time we could
874 		 * reconnect to a disconnected command, then we'd bomb
875 		 * out below.  We could also end up executing two commands
876 		 * at _once_.  ...just so you know why the restore_flags()
877 		 * is here...
878 		 */
879 
880 		spin_unlock_irqrestore(&hostdata->lock, flags);
881 
882 /* We are not connected to a target - check to see if there
883  * are commands waiting to be executed.
884  */
885 
886 		wd33c93_execute(instance);
887 		break;
888 
889 /* Note: this interrupt should not occur in a LEVEL2 command */
890 
891 	case CSR_SELECT:
892 		DB(DB_INTR, printk("SELECT"))
893 		    hostdata->connected = cmd =
894 		    (struct scsi_cmnd *) hostdata->selecting;
895 		hostdata->selecting = NULL;
896 
897 		/* construct an IDENTIFY message with correct disconnect bit */
898 
899 		hostdata->outgoing_msg[0] = IDENTIFY(0, cmd->device->lun);
900 		if (cmd->SCp.phase)
901 			hostdata->outgoing_msg[0] |= 0x40;
902 
903 		if (hostdata->sync_stat[cmd->device->id] == SS_FIRST) {
904 
905 			hostdata->sync_stat[cmd->device->id] = SS_WAITING;
906 
907 /* Tack on a 2nd message to ask about synchronous transfers. If we've
908  * been asked to do only asynchronous transfers on this device, we
909  * request a fifo depth of 0, which is equivalent to async - should
910  * solve the problems some people have had with GVP's Guru ROM.
911  */
912 
913 			hostdata->outgoing_msg[1] = EXTENDED_MESSAGE;
914 			hostdata->outgoing_msg[2] = 3;
915 			hostdata->outgoing_msg[3] = EXTENDED_SDTR;
916 			if (hostdata->no_sync & (1 << cmd->device->id)) {
917 				calc_sync_msg(hostdata->default_sx_per, 0,
918 						0, hostdata->outgoing_msg + 4);
919 			} else {
920 				calc_sync_msg(optimum_sx_per(hostdata),
921 						OPTIMUM_SX_OFF,
922 						hostdata->fast,
923 						hostdata->outgoing_msg + 4);
924 			}
925 			hostdata->outgoing_len = 6;
926 #ifdef SYNC_DEBUG
927 			ucp = hostdata->outgoing_msg + 1;
928 			printk(" sending SDTR %02x03%02x%02x%02x ",
929 				ucp[0], ucp[2], ucp[3], ucp[4]);
930 #endif
931 		} else
932 			hostdata->outgoing_len = 1;
933 
934 		hostdata->state = S_CONNECTED;
935 		spin_unlock_irqrestore(&hostdata->lock, flags);
936 		break;
937 
938 	case CSR_XFER_DONE | PHS_DATA_IN:
939 	case CSR_UNEXP | PHS_DATA_IN:
940 	case CSR_SRV_REQ | PHS_DATA_IN:
941 		DB(DB_INTR,
942 		   printk("IN-%d.%d", cmd->SCp.this_residual,
943 			  cmd->SCp.buffers_residual))
944 		    transfer_bytes(regs, cmd, DATA_IN_DIR);
945 		if (hostdata->state != S_RUNNING_LEVEL2)
946 			hostdata->state = S_CONNECTED;
947 		spin_unlock_irqrestore(&hostdata->lock, flags);
948 		break;
949 
950 	case CSR_XFER_DONE | PHS_DATA_OUT:
951 	case CSR_UNEXP | PHS_DATA_OUT:
952 	case CSR_SRV_REQ | PHS_DATA_OUT:
953 		DB(DB_INTR,
954 		   printk("OUT-%d.%d", cmd->SCp.this_residual,
955 			  cmd->SCp.buffers_residual))
956 		    transfer_bytes(regs, cmd, DATA_OUT_DIR);
957 		if (hostdata->state != S_RUNNING_LEVEL2)
958 			hostdata->state = S_CONNECTED;
959 		spin_unlock_irqrestore(&hostdata->lock, flags);
960 		break;
961 
962 /* Note: this interrupt should not occur in a LEVEL2 command */
963 
964 	case CSR_XFER_DONE | PHS_COMMAND:
965 	case CSR_UNEXP | PHS_COMMAND:
966 	case CSR_SRV_REQ | PHS_COMMAND:
967 		DB(DB_INTR, printk("CMND-%02x", cmd->cmnd[0]))
968 		    transfer_pio(regs, cmd->cmnd, cmd->cmd_len, DATA_OUT_DIR,
969 				 hostdata);
970 		hostdata->state = S_CONNECTED;
971 		spin_unlock_irqrestore(&hostdata->lock, flags);
972 		break;
973 
974 	case CSR_XFER_DONE | PHS_STATUS:
975 	case CSR_UNEXP | PHS_STATUS:
976 	case CSR_SRV_REQ | PHS_STATUS:
977 		DB(DB_INTR, printk("STATUS="))
978 		cmd->SCp.Status = read_1_byte(regs);
979 		DB(DB_INTR, printk("%02x", cmd->SCp.Status))
980 		    if (hostdata->level2 >= L2_BASIC) {
981 			sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
982 			udelay(7);
983 			hostdata->state = S_RUNNING_LEVEL2;
984 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x50);
985 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
986 		} else {
987 			hostdata->state = S_CONNECTED;
988 		}
989 		spin_unlock_irqrestore(&hostdata->lock, flags);
990 		break;
991 
992 	case CSR_XFER_DONE | PHS_MESS_IN:
993 	case CSR_UNEXP | PHS_MESS_IN:
994 	case CSR_SRV_REQ | PHS_MESS_IN:
995 		DB(DB_INTR, printk("MSG_IN="))
996 
997 		msg = read_1_byte(regs);
998 		sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
999 		udelay(7);
1000 
1001 		hostdata->incoming_msg[hostdata->incoming_ptr] = msg;
1002 		if (hostdata->incoming_msg[0] == EXTENDED_MESSAGE)
1003 			msg = EXTENDED_MESSAGE;
1004 		else
1005 			hostdata->incoming_ptr = 0;
1006 
1007 		cmd->SCp.Message = msg;
1008 		switch (msg) {
1009 
1010 		case COMMAND_COMPLETE:
1011 			DB(DB_INTR, printk("CCMP"))
1012 			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1013 			hostdata->state = S_PRE_CMP_DISC;
1014 			break;
1015 
1016 		case SAVE_POINTERS:
1017 			DB(DB_INTR, printk("SDP"))
1018 			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1019 			hostdata->state = S_CONNECTED;
1020 			break;
1021 
1022 		case RESTORE_POINTERS:
1023 			DB(DB_INTR, printk("RDP"))
1024 			    if (hostdata->level2 >= L2_BASIC) {
1025 				write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
1026 				write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1027 				hostdata->state = S_RUNNING_LEVEL2;
1028 			} else {
1029 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1030 				hostdata->state = S_CONNECTED;
1031 			}
1032 			break;
1033 
1034 		case DISCONNECT:
1035 			DB(DB_INTR, printk("DIS"))
1036 			    cmd->device->disconnect = 1;
1037 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1038 			hostdata->state = S_PRE_TMP_DISC;
1039 			break;
1040 
1041 		case MESSAGE_REJECT:
1042 			DB(DB_INTR, printk("REJ"))
1043 #ifdef SYNC_DEBUG
1044 			    printk("-REJ-");
1045 #endif
1046 			if (hostdata->sync_stat[cmd->device->id] == SS_WAITING) {
1047 				hostdata->sync_stat[cmd->device->id] = SS_SET;
1048 				/* we want default_sx_per, not DEFAULT_SX_PER */
1049 				hostdata->sync_xfer[cmd->device->id] =
1050 					calc_sync_xfer(hostdata->default_sx_per
1051 						/ 4, 0, 0, hostdata->sx_table);
1052 			}
1053 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1054 			hostdata->state = S_CONNECTED;
1055 			break;
1056 
1057 		case EXTENDED_MESSAGE:
1058 			DB(DB_INTR, printk("EXT"))
1059 
1060 			    ucp = hostdata->incoming_msg;
1061 
1062 #ifdef SYNC_DEBUG
1063 			printk("%02x", ucp[hostdata->incoming_ptr]);
1064 #endif
1065 			/* Is this the last byte of the extended message? */
1066 
1067 			if ((hostdata->incoming_ptr >= 2) &&
1068 			    (hostdata->incoming_ptr == (ucp[1] + 1))) {
1069 
1070 				switch (ucp[2]) {	/* what's the EXTENDED code? */
1071 				case EXTENDED_SDTR:
1072 					/* default to default async period */
1073 					id = calc_sync_xfer(hostdata->
1074 							default_sx_per / 4, 0,
1075 							0, hostdata->sx_table);
1076 					if (hostdata->sync_stat[cmd->device->id] !=
1077 					    SS_WAITING) {
1078 
1079 /* A device has sent an unsolicited SDTR message; rather than go
1080  * through the effort of decoding it and then figuring out what
1081  * our reply should be, we're just gonna say that we have a
1082  * synchronous fifo depth of 0. This will result in asynchronous
1083  * transfers - not ideal but so much easier.
1084  * Actually, this is OK because it assures us that if we don't
1085  * specifically ask for sync transfers, we won't do any.
1086  */
1087 
1088 						write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1089 						hostdata->outgoing_msg[0] =
1090 						    EXTENDED_MESSAGE;
1091 						hostdata->outgoing_msg[1] = 3;
1092 						hostdata->outgoing_msg[2] =
1093 						    EXTENDED_SDTR;
1094 						calc_sync_msg(hostdata->
1095 							default_sx_per, 0,
1096 							0, hostdata->outgoing_msg + 3);
1097 						hostdata->outgoing_len = 5;
1098 					} else {
1099 						if (ucp[4]) /* well, sync transfer */
1100 							id = calc_sync_xfer(ucp[3], ucp[4],
1101 									hostdata->fast,
1102 									hostdata->sx_table);
1103 						else if (ucp[3]) /* very unlikely... */
1104 							id = calc_sync_xfer(ucp[3], ucp[4],
1105 									0, hostdata->sx_table);
1106 					}
1107 					hostdata->sync_xfer[cmd->device->id] = id;
1108 #ifdef SYNC_DEBUG
1109 					printk(" sync_xfer=%02x\n",
1110 					       hostdata->sync_xfer[cmd->device->id]);
1111 #endif
1112 					hostdata->sync_stat[cmd->device->id] =
1113 					    SS_SET;
1114 					write_wd33c93_cmd(regs,
1115 							  WD_CMD_NEGATE_ACK);
1116 					hostdata->state = S_CONNECTED;
1117 					break;
1118 				case EXTENDED_WDTR:
1119 					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1120 					printk("sending WDTR ");
1121 					hostdata->outgoing_msg[0] =
1122 					    EXTENDED_MESSAGE;
1123 					hostdata->outgoing_msg[1] = 2;
1124 					hostdata->outgoing_msg[2] =
1125 					    EXTENDED_WDTR;
1126 					hostdata->outgoing_msg[3] = 0;	/* 8 bit transfer width */
1127 					hostdata->outgoing_len = 4;
1128 					write_wd33c93_cmd(regs,
1129 							  WD_CMD_NEGATE_ACK);
1130 					hostdata->state = S_CONNECTED;
1131 					break;
1132 				default:
1133 					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1134 					printk
1135 					    ("Rejecting Unknown Extended Message(%02x). ",
1136 					     ucp[2]);
1137 					hostdata->outgoing_msg[0] =
1138 					    MESSAGE_REJECT;
1139 					hostdata->outgoing_len = 1;
1140 					write_wd33c93_cmd(regs,
1141 							  WD_CMD_NEGATE_ACK);
1142 					hostdata->state = S_CONNECTED;
1143 					break;
1144 				}
1145 				hostdata->incoming_ptr = 0;
1146 			}
1147 
1148 			/* We need to read more MESS_IN bytes for the extended message */
1149 
1150 			else {
1151 				hostdata->incoming_ptr++;
1152 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1153 				hostdata->state = S_CONNECTED;
1154 			}
1155 			break;
1156 
1157 		default:
1158 			printk("Rejecting Unknown Message(%02x) ", msg);
1159 			write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1160 			hostdata->outgoing_msg[0] = MESSAGE_REJECT;
1161 			hostdata->outgoing_len = 1;
1162 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1163 			hostdata->state = S_CONNECTED;
1164 		}
1165 		spin_unlock_irqrestore(&hostdata->lock, flags);
1166 		break;
1167 
1168 /* Note: this interrupt will occur only after a LEVEL2 command */
1169 
1170 	case CSR_SEL_XFER_DONE:
1171 
1172 /* Make sure that reselection is enabled at this point - it may
1173  * have been turned off for the command that just completed.
1174  */
1175 
1176 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1177 		if (phs == 0x60) {
1178 			DB(DB_INTR, printk("SX-DONE"))
1179 			    cmd->SCp.Message = COMMAND_COMPLETE;
1180 			lun = read_wd33c93(regs, WD_TARGET_LUN);
1181 			DB(DB_INTR, printk(":%d.%d", cmd->SCp.Status, lun))
1182 			    hostdata->connected = NULL;
1183 			hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1184 			hostdata->state = S_UNCONNECTED;
1185 			if (cmd->SCp.Status == ILLEGAL_STATUS_BYTE)
1186 				cmd->SCp.Status = lun;
1187 			if (cmd->cmnd[0] == REQUEST_SENSE
1188 			    && cmd->SCp.Status != GOOD)
1189 				cmd->result =
1190 				    (cmd->
1191 				     result & 0x00ffff) | (DID_ERROR << 16);
1192 			else
1193 				cmd->result =
1194 				    cmd->SCp.Status | (cmd->SCp.Message << 8);
1195 			cmd->scsi_done(cmd);
1196 
1197 /* We are no longer  connected to a target - check to see if
1198  * there are commands waiting to be executed.
1199  */
1200 			spin_unlock_irqrestore(&hostdata->lock, flags);
1201 			wd33c93_execute(instance);
1202 		} else {
1203 			printk
1204 			    ("%02x:%02x:%02x: Unknown SEL_XFER_DONE phase!!---",
1205 			     asr, sr, phs);
1206 			spin_unlock_irqrestore(&hostdata->lock, flags);
1207 		}
1208 		break;
1209 
1210 /* Note: this interrupt will occur only after a LEVEL2 command */
1211 
1212 	case CSR_SDP:
1213 		DB(DB_INTR, printk("SDP"))
1214 		    hostdata->state = S_RUNNING_LEVEL2;
1215 		write_wd33c93(regs, WD_COMMAND_PHASE, 0x41);
1216 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1217 		spin_unlock_irqrestore(&hostdata->lock, flags);
1218 		break;
1219 
1220 	case CSR_XFER_DONE | PHS_MESS_OUT:
1221 	case CSR_UNEXP | PHS_MESS_OUT:
1222 	case CSR_SRV_REQ | PHS_MESS_OUT:
1223 		DB(DB_INTR, printk("MSG_OUT="))
1224 
1225 /* To get here, we've probably requested MESSAGE_OUT and have
1226  * already put the correct bytes in outgoing_msg[] and filled
1227  * in outgoing_len. We simply send them out to the SCSI bus.
1228  * Sometimes we get MESSAGE_OUT phase when we're not expecting
1229  * it - like when our SDTR message is rejected by a target. Some
1230  * targets send the REJECT before receiving all of the extended
1231  * message, and then seem to go back to MESSAGE_OUT for a byte
1232  * or two. Not sure why, or if I'm doing something wrong to
1233  * cause this to happen. Regardless, it seems that sending
1234  * NOP messages in these situations results in no harm and
1235  * makes everyone happy.
1236  */
1237 		    if (hostdata->outgoing_len == 0) {
1238 			hostdata->outgoing_len = 1;
1239 			hostdata->outgoing_msg[0] = NOP;
1240 		}
1241 		transfer_pio(regs, hostdata->outgoing_msg,
1242 			     hostdata->outgoing_len, DATA_OUT_DIR, hostdata);
1243 		DB(DB_INTR, printk("%02x", hostdata->outgoing_msg[0]))
1244 		    hostdata->outgoing_len = 0;
1245 		hostdata->state = S_CONNECTED;
1246 		spin_unlock_irqrestore(&hostdata->lock, flags);
1247 		break;
1248 
1249 	case CSR_UNEXP_DISC:
1250 
1251 /* I think I've seen this after a request-sense that was in response
1252  * to an error condition, but not sure. We certainly need to do
1253  * something when we get this interrupt - the question is 'what?'.
1254  * Let's think positively, and assume some command has finished
1255  * in a legal manner (like a command that provokes a request-sense),
1256  * so we treat it as a normal command-complete-disconnect.
1257  */
1258 
1259 /* Make sure that reselection is enabled at this point - it may
1260  * have been turned off for the command that just completed.
1261  */
1262 
1263 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1264 		if (cmd == NULL) {
1265 			printk(" - Already disconnected! ");
1266 			hostdata->state = S_UNCONNECTED;
1267 			spin_unlock_irqrestore(&hostdata->lock, flags);
1268 			return;
1269 		}
1270 		DB(DB_INTR, printk("UNEXP_DISC"))
1271 		    hostdata->connected = NULL;
1272 		hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1273 		hostdata->state = S_UNCONNECTED;
1274 		if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
1275 			cmd->result =
1276 			    (cmd->result & 0x00ffff) | (DID_ERROR << 16);
1277 		else
1278 			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
1279 		cmd->scsi_done(cmd);
1280 
1281 /* We are no longer connected to a target - check to see if
1282  * there are commands waiting to be executed.
1283  */
1284 		/* look above for comments on scsi_done() */
1285 		spin_unlock_irqrestore(&hostdata->lock, flags);
1286 		wd33c93_execute(instance);
1287 		break;
1288 
1289 	case CSR_DISC:
1290 
1291 /* Make sure that reselection is enabled at this point - it may
1292  * have been turned off for the command that just completed.
1293  */
1294 
1295 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1296 		DB(DB_INTR, printk("DISC"))
1297 		    if (cmd == NULL) {
1298 			printk(" - Already disconnected! ");
1299 			hostdata->state = S_UNCONNECTED;
1300 		}
1301 		switch (hostdata->state) {
1302 		case S_PRE_CMP_DISC:
1303 			hostdata->connected = NULL;
1304 			hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1305 			hostdata->state = S_UNCONNECTED;
1306 			DB(DB_INTR, printk(":%d", cmd->SCp.Status))
1307 			    if (cmd->cmnd[0] == REQUEST_SENSE
1308 				&& cmd->SCp.Status != GOOD)
1309 				cmd->result =
1310 				    (cmd->
1311 				     result & 0x00ffff) | (DID_ERROR << 16);
1312 			else
1313 				cmd->result =
1314 				    cmd->SCp.Status | (cmd->SCp.Message << 8);
1315 			cmd->scsi_done(cmd);
1316 			break;
1317 		case S_PRE_TMP_DISC:
1318 		case S_RUNNING_LEVEL2:
1319 			cmd->host_scribble = (uchar *) hostdata->disconnected_Q;
1320 			hostdata->disconnected_Q = cmd;
1321 			hostdata->connected = NULL;
1322 			hostdata->state = S_UNCONNECTED;
1323 
1324 #ifdef PROC_STATISTICS
1325 			hostdata->disc_done_cnt[cmd->device->id]++;
1326 #endif
1327 
1328 			break;
1329 		default:
1330 			printk("*** Unexpected DISCONNECT interrupt! ***");
1331 			hostdata->state = S_UNCONNECTED;
1332 		}
1333 
1334 /* We are no longer connected to a target - check to see if
1335  * there are commands waiting to be executed.
1336  */
1337 		spin_unlock_irqrestore(&hostdata->lock, flags);
1338 		wd33c93_execute(instance);
1339 		break;
1340 
1341 	case CSR_RESEL_AM:
1342 	case CSR_RESEL:
1343 		DB(DB_INTR, printk("RESEL%s", sr == CSR_RESEL_AM ? "_AM" : ""))
1344 
1345 		    /* Old chips (pre -A ???) don't have advanced features and will
1346 		     * generate CSR_RESEL.  In that case we have to extract the LUN the
1347 		     * hard way (see below).
1348 		     * First we have to make sure this reselection didn't
1349 		     * happen during Arbitration/Selection of some other device.
1350 		     * If yes, put losing command back on top of input_Q.
1351 		     */
1352 		    if (hostdata->level2 <= L2_NONE) {
1353 
1354 			if (hostdata->selecting) {
1355 				cmd = (struct scsi_cmnd *) hostdata->selecting;
1356 				hostdata->selecting = NULL;
1357 				hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1358 				cmd->host_scribble =
1359 				    (uchar *) hostdata->input_Q;
1360 				hostdata->input_Q = cmd;
1361 			}
1362 		}
1363 
1364 		else {
1365 
1366 			if (cmd) {
1367 				if (phs == 0x00) {
1368 					hostdata->busy[cmd->device->id] &=
1369 						~(1 << (cmd->device->lun & 0xff));
1370 					cmd->host_scribble =
1371 					    (uchar *) hostdata->input_Q;
1372 					hostdata->input_Q = cmd;
1373 				} else {
1374 					printk
1375 					    ("---%02x:%02x:%02x-TROUBLE: Intrusive ReSelect!---",
1376 					     asr, sr, phs);
1377 					while (1)
1378 						printk("\r");
1379 				}
1380 			}
1381 
1382 		}
1383 
1384 		/* OK - find out which device reselected us. */
1385 
1386 		id = read_wd33c93(regs, WD_SOURCE_ID);
1387 		id &= SRCID_MASK;
1388 
1389 		/* and extract the lun from the ID message. (Note that we don't
1390 		 * bother to check for a valid message here - I guess this is
1391 		 * not the right way to go, but...)
1392 		 */
1393 
1394 		if (sr == CSR_RESEL_AM) {
1395 			lun = read_wd33c93(regs, WD_DATA);
1396 			if (hostdata->level2 < L2_RESELECT)
1397 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1398 			lun &= 7;
1399 		} else {
1400 			/* Old chip; wait for msgin phase to pick up the LUN. */
1401 			for (lun = 255; lun; lun--) {
1402 				if ((asr = read_aux_stat(regs)) & ASR_INT)
1403 					break;
1404 				udelay(10);
1405 			}
1406 			if (!(asr & ASR_INT)) {
1407 				printk
1408 				    ("wd33c93: Reselected without IDENTIFY\n");
1409 				lun = 0;
1410 			} else {
1411 				/* Verify this is a change to MSG_IN and read the message */
1412 				sr = read_wd33c93(regs, WD_SCSI_STATUS);
1413 				udelay(7);
1414 				if (sr == (CSR_ABORT | PHS_MESS_IN) ||
1415 				    sr == (CSR_UNEXP | PHS_MESS_IN) ||
1416 				    sr == (CSR_SRV_REQ | PHS_MESS_IN)) {
1417 					/* Got MSG_IN, grab target LUN */
1418 					lun = read_1_byte(regs);
1419 					/* Now we expect a 'paused with ACK asserted' int.. */
1420 					asr = read_aux_stat(regs);
1421 					if (!(asr & ASR_INT)) {
1422 						udelay(10);
1423 						asr = read_aux_stat(regs);
1424 						if (!(asr & ASR_INT))
1425 							printk
1426 							    ("wd33c93: No int after LUN on RESEL (%02x)\n",
1427 							     asr);
1428 					}
1429 					sr = read_wd33c93(regs, WD_SCSI_STATUS);
1430 					udelay(7);
1431 					if (sr != CSR_MSGIN)
1432 						printk
1433 						    ("wd33c93: Not paused with ACK on RESEL (%02x)\n",
1434 						     sr);
1435 					lun &= 7;
1436 					write_wd33c93_cmd(regs,
1437 							  WD_CMD_NEGATE_ACK);
1438 				} else {
1439 					printk
1440 					    ("wd33c93: Not MSG_IN on reselect (%02x)\n",
1441 					     sr);
1442 					lun = 0;
1443 				}
1444 			}
1445 		}
1446 
1447 		/* Now we look for the command that's reconnecting. */
1448 
1449 		cmd = (struct scsi_cmnd *) hostdata->disconnected_Q;
1450 		patch = NULL;
1451 		while (cmd) {
1452 			if (id == cmd->device->id && lun == (u8)cmd->device->lun)
1453 				break;
1454 			patch = cmd;
1455 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
1456 		}
1457 
1458 		/* Hmm. Couldn't find a valid command.... What to do? */
1459 
1460 		if (!cmd) {
1461 			printk
1462 			    ("---TROUBLE: target %d.%d not in disconnect queue---",
1463 			     id, (u8)lun);
1464 			spin_unlock_irqrestore(&hostdata->lock, flags);
1465 			return;
1466 		}
1467 
1468 		/* Ok, found the command - now start it up again. */
1469 
1470 		if (patch)
1471 			patch->host_scribble = cmd->host_scribble;
1472 		else
1473 			hostdata->disconnected_Q =
1474 			    (struct scsi_cmnd *) cmd->host_scribble;
1475 		hostdata->connected = cmd;
1476 
1477 		/* We don't need to worry about 'initialize_SCp()' or 'hostdata->busy[]'
1478 		 * because these things are preserved over a disconnect.
1479 		 * But we DO need to fix the DPD bit so it's correct for this command.
1480 		 */
1481 
1482 		if (cmd->sc_data_direction == DMA_TO_DEVICE)
1483 			write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
1484 		else
1485 			write_wd33c93(regs, WD_DESTINATION_ID,
1486 				      cmd->device->id | DSTID_DPD);
1487 		if (hostdata->level2 >= L2_RESELECT) {
1488 			write_wd33c93_count(regs, 0);	/* we want a DATA_PHASE interrupt */
1489 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
1490 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1491 			hostdata->state = S_RUNNING_LEVEL2;
1492 		} else
1493 			hostdata->state = S_CONNECTED;
1494 
1495 		    spin_unlock_irqrestore(&hostdata->lock, flags);
1496 		break;
1497 
1498 	default:
1499 		printk("--UNKNOWN INTERRUPT:%02x:%02x:%02x--", asr, sr, phs);
1500 		spin_unlock_irqrestore(&hostdata->lock, flags);
1501 	}
1502 
1503 	DB(DB_INTR, printk("} "))
1504 
1505 }
1506 
1507 static void
1508 reset_wd33c93(struct Scsi_Host *instance)
1509 {
1510 	struct WD33C93_hostdata *hostdata =
1511 	    (struct WD33C93_hostdata *) instance->hostdata;
1512 	const wd33c93_regs regs = hostdata->regs;
1513 	uchar sr;
1514 
1515 #ifdef CONFIG_SGI_IP22
1516 	{
1517 		int busycount = 0;
1518 		extern void sgiwd93_reset(unsigned long);
1519 		/* wait 'til the chip gets some time for us */
1520 		while ((read_aux_stat(regs) & ASR_BSY) && busycount++ < 100)
1521 			udelay (10);
1522 	/*
1523  	 * there are scsi devices out there, which manage to lock up
1524 	 * the wd33c93 in a busy condition. In this state it won't
1525 	 * accept the reset command. The only way to solve this is to
1526  	 * give the chip a hardware reset (if possible). The code below
1527 	 * does this for the SGI Indy, where this is possible
1528 	 */
1529 	/* still busy ? */
1530 	if (read_aux_stat(regs) & ASR_BSY)
1531 		sgiwd93_reset(instance->base); /* yeah, give it the hard one */
1532 	}
1533 #endif
1534 
1535 	write_wd33c93(regs, WD_OWN_ID, OWNID_EAF | OWNID_RAF |
1536 		      instance->this_id | hostdata->clock_freq);
1537 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1538 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
1539 		      calc_sync_xfer(hostdata->default_sx_per / 4,
1540 				     DEFAULT_SX_OFF, 0, hostdata->sx_table));
1541 	write_wd33c93(regs, WD_COMMAND, WD_CMD_RESET);
1542 
1543 
1544 #ifdef CONFIG_MVME147_SCSI
1545 	udelay(25);		/* The old wd33c93 on MVME147 needs this, at least */
1546 #endif
1547 
1548 	while (!(read_aux_stat(regs) & ASR_INT))
1549 		;
1550 	sr = read_wd33c93(regs, WD_SCSI_STATUS);
1551 
1552 	hostdata->microcode = read_wd33c93(regs, WD_CDB_1);
1553 	if (sr == 0x00)
1554 		hostdata->chip = C_WD33C93;
1555 	else if (sr == 0x01) {
1556 		write_wd33c93(regs, WD_QUEUE_TAG, 0xa5);	/* any random number */
1557 		sr = read_wd33c93(regs, WD_QUEUE_TAG);
1558 		if (sr == 0xa5) {
1559 			hostdata->chip = C_WD33C93B;
1560 			write_wd33c93(regs, WD_QUEUE_TAG, 0);
1561 		} else
1562 			hostdata->chip = C_WD33C93A;
1563 	} else
1564 		hostdata->chip = C_UNKNOWN_CHIP;
1565 
1566 	if (hostdata->chip != C_WD33C93B)	/* Fast SCSI unavailable */
1567 		hostdata->fast = 0;
1568 
1569 	write_wd33c93(regs, WD_TIMEOUT_PERIOD, TIMEOUT_PERIOD_VALUE);
1570 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1571 }
1572 
1573 int
1574 wd33c93_host_reset(struct scsi_cmnd * SCpnt)
1575 {
1576 	struct Scsi_Host *instance;
1577 	struct WD33C93_hostdata *hostdata;
1578 	int i;
1579 
1580 	instance = SCpnt->device->host;
1581 	spin_lock_irq(instance->host_lock);
1582 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1583 
1584 	printk("scsi%d: reset. ", instance->host_no);
1585 	disable_irq(instance->irq);
1586 
1587 	hostdata->dma_stop(instance, NULL, 0);
1588 	for (i = 0; i < 8; i++) {
1589 		hostdata->busy[i] = 0;
1590 		hostdata->sync_xfer[i] =
1591 			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
1592 					0, hostdata->sx_table);
1593 		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
1594 	}
1595 	hostdata->input_Q = NULL;
1596 	hostdata->selecting = NULL;
1597 	hostdata->connected = NULL;
1598 	hostdata->disconnected_Q = NULL;
1599 	hostdata->state = S_UNCONNECTED;
1600 	hostdata->dma = D_DMA_OFF;
1601 	hostdata->incoming_ptr = 0;
1602 	hostdata->outgoing_len = 0;
1603 
1604 	reset_wd33c93(instance);
1605 	SCpnt->result = DID_RESET << 16;
1606 	enable_irq(instance->irq);
1607 	spin_unlock_irq(instance->host_lock);
1608 	return SUCCESS;
1609 }
1610 
1611 int
1612 wd33c93_abort(struct scsi_cmnd * cmd)
1613 {
1614 	struct Scsi_Host *instance;
1615 	struct WD33C93_hostdata *hostdata;
1616 	wd33c93_regs regs;
1617 	struct scsi_cmnd *tmp, *prev;
1618 
1619 	disable_irq(cmd->device->host->irq);
1620 
1621 	instance = cmd->device->host;
1622 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1623 	regs = hostdata->regs;
1624 
1625 /*
1626  * Case 1 : If the command hasn't been issued yet, we simply remove it
1627  *     from the input_Q.
1628  */
1629 
1630 	tmp = (struct scsi_cmnd *) hostdata->input_Q;
1631 	prev = NULL;
1632 	while (tmp) {
1633 		if (tmp == cmd) {
1634 			if (prev)
1635 				prev->host_scribble = cmd->host_scribble;
1636 			else
1637 				hostdata->input_Q =
1638 				    (struct scsi_cmnd *) cmd->host_scribble;
1639 			cmd->host_scribble = NULL;
1640 			cmd->result = DID_ABORT << 16;
1641 			printk
1642 			    ("scsi%d: Abort - removing command from input_Q. ",
1643 			     instance->host_no);
1644 			enable_irq(cmd->device->host->irq);
1645 			cmd->scsi_done(cmd);
1646 			return SUCCESS;
1647 		}
1648 		prev = tmp;
1649 		tmp = (struct scsi_cmnd *) tmp->host_scribble;
1650 	}
1651 
1652 /*
1653  * Case 2 : If the command is connected, we're going to fail the abort
1654  *     and let the high level SCSI driver retry at a later time or
1655  *     issue a reset.
1656  *
1657  *     Timeouts, and therefore aborted commands, will be highly unlikely
1658  *     and handling them cleanly in this situation would make the common
1659  *     case of noresets less efficient, and would pollute our code.  So,
1660  *     we fail.
1661  */
1662 
1663 	if (hostdata->connected == cmd) {
1664 		uchar sr, asr;
1665 		unsigned long timeout;
1666 
1667 		printk("scsi%d: Aborting connected command - ",
1668 		       instance->host_no);
1669 
1670 		printk("stopping DMA - ");
1671 		if (hostdata->dma == D_DMA_RUNNING) {
1672 			hostdata->dma_stop(instance, cmd, 0);
1673 			hostdata->dma = D_DMA_OFF;
1674 		}
1675 
1676 		printk("sending wd33c93 ABORT command - ");
1677 		write_wd33c93(regs, WD_CONTROL,
1678 			      CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1679 		write_wd33c93_cmd(regs, WD_CMD_ABORT);
1680 
1681 /* Now we have to attempt to flush out the FIFO... */
1682 
1683 		printk("flushing fifo - ");
1684 		timeout = 1000000;
1685 		do {
1686 			asr = read_aux_stat(regs);
1687 			if (asr & ASR_DBR)
1688 				read_wd33c93(regs, WD_DATA);
1689 		} while (!(asr & ASR_INT) && timeout-- > 0);
1690 		sr = read_wd33c93(regs, WD_SCSI_STATUS);
1691 		printk
1692 		    ("asr=%02x, sr=%02x, %ld bytes un-transferred (timeout=%ld) - ",
1693 		     asr, sr, read_wd33c93_count(regs), timeout);
1694 
1695 		/*
1696 		 * Abort command processed.
1697 		 * Still connected.
1698 		 * We must disconnect.
1699 		 */
1700 
1701 		printk("sending wd33c93 DISCONNECT command - ");
1702 		write_wd33c93_cmd(regs, WD_CMD_DISCONNECT);
1703 
1704 		timeout = 1000000;
1705 		asr = read_aux_stat(regs);
1706 		while ((asr & ASR_CIP) && timeout-- > 0)
1707 			asr = read_aux_stat(regs);
1708 		sr = read_wd33c93(regs, WD_SCSI_STATUS);
1709 		printk("asr=%02x, sr=%02x.", asr, sr);
1710 
1711 		hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1712 		hostdata->connected = NULL;
1713 		hostdata->state = S_UNCONNECTED;
1714 		cmd->result = DID_ABORT << 16;
1715 
1716 /*      sti();*/
1717 		wd33c93_execute(instance);
1718 
1719 		enable_irq(cmd->device->host->irq);
1720 		cmd->scsi_done(cmd);
1721 		return SUCCESS;
1722 	}
1723 
1724 /*
1725  * Case 3: If the command is currently disconnected from the bus,
1726  * we're not going to expend much effort here: Let's just return
1727  * an ABORT_SNOOZE and hope for the best...
1728  */
1729 
1730 	tmp = (struct scsi_cmnd *) hostdata->disconnected_Q;
1731 	while (tmp) {
1732 		if (tmp == cmd) {
1733 			printk
1734 			    ("scsi%d: Abort - command found on disconnected_Q - ",
1735 			     instance->host_no);
1736 			printk("Abort SNOOZE. ");
1737 			enable_irq(cmd->device->host->irq);
1738 			return FAILED;
1739 		}
1740 		tmp = (struct scsi_cmnd *) tmp->host_scribble;
1741 	}
1742 
1743 /*
1744  * Case 4 : If we reached this point, the command was not found in any of
1745  *     the queues.
1746  *
1747  * We probably reached this point because of an unlikely race condition
1748  * between the command completing successfully and the abortion code,
1749  * so we won't panic, but we will notify the user in case something really
1750  * broke.
1751  */
1752 
1753 /*   sti();*/
1754 	wd33c93_execute(instance);
1755 
1756 	enable_irq(cmd->device->host->irq);
1757 	printk("scsi%d: warning : SCSI command probably completed successfully"
1758 	       "         before abortion. ", instance->host_no);
1759 	return FAILED;
1760 }
1761 
1762 #define MAX_WD33C93_HOSTS 4
1763 #define MAX_SETUP_ARGS ARRAY_SIZE(setup_args)
1764 #define SETUP_BUFFER_SIZE 200
1765 static char setup_buffer[SETUP_BUFFER_SIZE];
1766 static char setup_used[MAX_SETUP_ARGS];
1767 static int done_setup = 0;
1768 
1769 static int
1770 wd33c93_setup(char *str)
1771 {
1772 	int i;
1773 	char *p1, *p2;
1774 
1775 	/* The kernel does some processing of the command-line before calling
1776 	 * this function: If it begins with any decimal or hex number arguments,
1777 	 * ints[0] = how many numbers found and ints[1] through [n] are the values
1778 	 * themselves. str points to where the non-numeric arguments (if any)
1779 	 * start: We do our own parsing of those. We construct synthetic 'nosync'
1780 	 * keywords out of numeric args (to maintain compatibility with older
1781 	 * versions) and then add the rest of the arguments.
1782 	 */
1783 
1784 	p1 = setup_buffer;
1785 	*p1 = '\0';
1786 	if (str)
1787 		strncpy(p1, str, SETUP_BUFFER_SIZE - strlen(setup_buffer));
1788 	setup_buffer[SETUP_BUFFER_SIZE - 1] = '\0';
1789 	p1 = setup_buffer;
1790 	i = 0;
1791 	while (*p1 && (i < MAX_SETUP_ARGS)) {
1792 		p2 = strchr(p1, ',');
1793 		if (p2) {
1794 			*p2 = '\0';
1795 			if (p1 != p2)
1796 				setup_args[i] = p1;
1797 			p1 = p2 + 1;
1798 			i++;
1799 		} else {
1800 			setup_args[i] = p1;
1801 			break;
1802 		}
1803 	}
1804 	for (i = 0; i < MAX_SETUP_ARGS; i++)
1805 		setup_used[i] = 0;
1806 	done_setup = 1;
1807 
1808 	return 1;
1809 }
1810 __setup("wd33c93=", wd33c93_setup);
1811 
1812 /* check_setup_args() returns index if key found, 0 if not
1813  */
1814 static int
1815 check_setup_args(char *key, int *flags, int *val, char *buf)
1816 {
1817 	int x;
1818 	char *cp;
1819 
1820 	for (x = 0; x < MAX_SETUP_ARGS; x++) {
1821 		if (setup_used[x])
1822 			continue;
1823 		if (!strncmp(setup_args[x], key, strlen(key)))
1824 			break;
1825 		if (!strncmp(setup_args[x], "next", strlen("next")))
1826 			return 0;
1827 	}
1828 	if (x == MAX_SETUP_ARGS)
1829 		return 0;
1830 	setup_used[x] = 1;
1831 	cp = setup_args[x] + strlen(key);
1832 	*val = -1;
1833 	if (*cp != ':')
1834 		return ++x;
1835 	cp++;
1836 	if ((*cp >= '0') && (*cp <= '9')) {
1837 		*val = simple_strtoul(cp, NULL, 0);
1838 	}
1839 	return ++x;
1840 }
1841 
1842 /*
1843  * Calculate internal data-transfer-clock cycle from input-clock
1844  * frequency (/MHz) and fill 'sx_table'.
1845  *
1846  * The original driver used to rely on a fixed sx_table, containing periods
1847  * for (only) the lower limits of the respective input-clock-frequency ranges
1848  * (8-10/12-15/16-20 MHz). Although it seems, that no problems occurred with
1849  * this setting so far, it might be desirable to adjust the transfer periods
1850  * closer to the really attached, possibly 25% higher, input-clock, since
1851  * - the wd33c93 may really use a significant shorter period, than it has
1852  *   negotiated (eg. thrashing the target, which expects 4/8MHz, with 5/10MHz
1853  *   instead).
1854  * - the wd33c93 may ask the target for a lower transfer rate, than the target
1855  *   is capable of (eg. negotiating for an assumed minimum of 252ns instead of
1856  *   possible 200ns, which indeed shows up in tests as an approx. 10% lower
1857  *   transfer rate).
1858  */
1859 static inline unsigned int
1860 round_4(unsigned int x)
1861 {
1862 	switch (x & 3) {
1863 		case 1: --x;
1864 			break;
1865 		case 2: ++x;
1866 		case 3: ++x;
1867 	}
1868 	return x;
1869 }
1870 
1871 static void
1872 calc_sx_table(unsigned int mhz, struct sx_period sx_table[9])
1873 {
1874 	unsigned int d, i;
1875 	if (mhz < 11)
1876 		d = 2;	/* divisor for  8-10 MHz input-clock */
1877 	else if (mhz < 16)
1878 		d = 3;	/* divisor for 12-15 MHz input-clock */
1879 	else
1880 		d = 4;	/* divisor for 16-20 MHz input-clock */
1881 
1882 	d = (100000 * d) / 2 / mhz; /* 100 x DTCC / nanosec */
1883 
1884 	sx_table[0].period_ns = 1;
1885 	sx_table[0].reg_value = 0x20;
1886 	for (i = 1; i < 8; i++) {
1887 		sx_table[i].period_ns = round_4((i+1)*d / 100);
1888 		sx_table[i].reg_value = (i+1)*0x10;
1889 	}
1890 	sx_table[7].reg_value = 0;
1891 	sx_table[8].period_ns = 0;
1892 	sx_table[8].reg_value = 0;
1893 }
1894 
1895 /*
1896  * check and, maybe, map an init- or "clock:"- argument.
1897  */
1898 static uchar
1899 set_clk_freq(int freq, int *mhz)
1900 {
1901 	int x = freq;
1902 	if (WD33C93_FS_8_10 == freq)
1903 		freq = 8;
1904 	else if (WD33C93_FS_12_15 == freq)
1905 		freq = 12;
1906 	else if (WD33C93_FS_16_20 == freq)
1907 		freq = 16;
1908 	else if (freq > 7 && freq < 11)
1909 		x = WD33C93_FS_8_10;
1910 		else if (freq > 11 && freq < 16)
1911 		x = WD33C93_FS_12_15;
1912 		else if (freq > 15 && freq < 21)
1913 		x = WD33C93_FS_16_20;
1914 	else {
1915 			/* Hmm, wouldn't it be safer to assume highest freq here? */
1916 		x = WD33C93_FS_8_10;
1917 		freq = 8;
1918 	}
1919 	*mhz = freq;
1920 	return x;
1921 }
1922 
1923 /*
1924  * to be used with the resync: fast: ... options
1925  */
1926 static inline void set_resync ( struct WD33C93_hostdata *hd, int mask )
1927 {
1928 	int i;
1929 	for (i = 0; i < 8; i++)
1930 		if (mask & (1 << i))
1931 			hd->sync_stat[i] = SS_UNSET;
1932 }
1933 
1934 void
1935 wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
1936 	     dma_setup_t setup, dma_stop_t stop, int clock_freq)
1937 {
1938 	struct WD33C93_hostdata *hostdata;
1939 	int i;
1940 	int flags;
1941 	int val;
1942 	char buf[32];
1943 
1944 	if (!done_setup && setup_strings)
1945 		wd33c93_setup(setup_strings);
1946 
1947 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1948 
1949 	hostdata->regs = regs;
1950 	hostdata->clock_freq = set_clk_freq(clock_freq, &i);
1951 	calc_sx_table(i, hostdata->sx_table);
1952 	hostdata->dma_setup = setup;
1953 	hostdata->dma_stop = stop;
1954 	hostdata->dma_bounce_buffer = NULL;
1955 	hostdata->dma_bounce_len = 0;
1956 	for (i = 0; i < 8; i++) {
1957 		hostdata->busy[i] = 0;
1958 		hostdata->sync_xfer[i] =
1959 			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
1960 					0, hostdata->sx_table);
1961 		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
1962 #ifdef PROC_STATISTICS
1963 		hostdata->cmd_cnt[i] = 0;
1964 		hostdata->disc_allowed_cnt[i] = 0;
1965 		hostdata->disc_done_cnt[i] = 0;
1966 #endif
1967 	}
1968 	hostdata->input_Q = NULL;
1969 	hostdata->selecting = NULL;
1970 	hostdata->connected = NULL;
1971 	hostdata->disconnected_Q = NULL;
1972 	hostdata->state = S_UNCONNECTED;
1973 	hostdata->dma = D_DMA_OFF;
1974 	hostdata->level2 = L2_BASIC;
1975 	hostdata->disconnect = DIS_ADAPTIVE;
1976 	hostdata->args = DEBUG_DEFAULTS;
1977 	hostdata->incoming_ptr = 0;
1978 	hostdata->outgoing_len = 0;
1979 	hostdata->default_sx_per = DEFAULT_SX_PER;
1980 	hostdata->no_dma = 0;	/* default is DMA enabled */
1981 
1982 #ifdef PROC_INTERFACE
1983 	hostdata->proc = PR_VERSION | PR_INFO | PR_STATISTICS |
1984 	    PR_CONNECTED | PR_INPUTQ | PR_DISCQ | PR_STOP;
1985 #ifdef PROC_STATISTICS
1986 	hostdata->dma_cnt = 0;
1987 	hostdata->pio_cnt = 0;
1988 	hostdata->int_cnt = 0;
1989 #endif
1990 #endif
1991 
1992 	if (check_setup_args("clock", &flags, &val, buf)) {
1993 		hostdata->clock_freq = set_clk_freq(val, &val);
1994 		calc_sx_table(val, hostdata->sx_table);
1995 	}
1996 
1997 	if (check_setup_args("nosync", &flags, &val, buf))
1998 		hostdata->no_sync = val;
1999 
2000 	if (check_setup_args("nodma", &flags, &val, buf))
2001 		hostdata->no_dma = (val == -1) ? 1 : val;
2002 
2003 	if (check_setup_args("period", &flags, &val, buf))
2004 		hostdata->default_sx_per =
2005 		    hostdata->sx_table[round_period((unsigned int) val,
2006 		                                    hostdata->sx_table)].period_ns;
2007 
2008 	if (check_setup_args("disconnect", &flags, &val, buf)) {
2009 		if ((val >= DIS_NEVER) && (val <= DIS_ALWAYS))
2010 			hostdata->disconnect = val;
2011 		else
2012 			hostdata->disconnect = DIS_ADAPTIVE;
2013 	}
2014 
2015 	if (check_setup_args("level2", &flags, &val, buf))
2016 		hostdata->level2 = val;
2017 
2018 	if (check_setup_args("debug", &flags, &val, buf))
2019 		hostdata->args = val & DB_MASK;
2020 
2021 	if (check_setup_args("burst", &flags, &val, buf))
2022 		hostdata->dma_mode = val ? CTRL_BURST:CTRL_DMA;
2023 
2024 	if (WD33C93_FS_16_20 == hostdata->clock_freq /* divisor 4 */
2025 		&& check_setup_args("fast", &flags, &val, buf))
2026 		hostdata->fast = !!val;
2027 
2028 	if ((i = check_setup_args("next", &flags, &val, buf))) {
2029 		while (i)
2030 			setup_used[--i] = 1;
2031 	}
2032 #ifdef PROC_INTERFACE
2033 	if (check_setup_args("proc", &flags, &val, buf))
2034 		hostdata->proc = val;
2035 #endif
2036 
2037 	spin_lock_irq(&hostdata->lock);
2038 	reset_wd33c93(instance);
2039 	spin_unlock_irq(&hostdata->lock);
2040 
2041 	printk("wd33c93-%d: chip=%s/%d no_sync=0x%x no_dma=%d",
2042 	       instance->host_no,
2043 	       (hostdata->chip == C_WD33C93) ? "WD33c93" : (hostdata->chip ==
2044 							    C_WD33C93A) ?
2045 	       "WD33c93A" : (hostdata->chip ==
2046 			     C_WD33C93B) ? "WD33c93B" : "unknown",
2047 	       hostdata->microcode, hostdata->no_sync, hostdata->no_dma);
2048 #ifdef DEBUGGING_ON
2049 	printk(" debug_flags=0x%02x\n", hostdata->args);
2050 #else
2051 	printk(" debugging=OFF\n");
2052 #endif
2053 	printk("           setup_args=");
2054 	for (i = 0; i < MAX_SETUP_ARGS; i++)
2055 		printk("%s,", setup_args[i]);
2056 	printk("\n");
2057 	printk("           Version %s - %s\n", WD33C93_VERSION, WD33C93_DATE);
2058 }
2059 
2060 int wd33c93_write_info(struct Scsi_Host *instance, char *buf, int len)
2061 {
2062 #ifdef PROC_INTERFACE
2063 	char *bp;
2064 	struct WD33C93_hostdata *hd;
2065 	int x;
2066 
2067 	hd = (struct WD33C93_hostdata *) instance->hostdata;
2068 
2069 /* We accept the following
2070  * keywords (same format as command-line, but arguments are not optional):
2071  *    debug
2072  *    disconnect
2073  *    period
2074  *    resync
2075  *    proc
2076  *    nodma
2077  *    level2
2078  *    burst
2079  *    fast
2080  *    nosync
2081  */
2082 
2083 	buf[len] = '\0';
2084 	for (bp = buf; *bp; ) {
2085 		while (',' == *bp || ' ' == *bp)
2086 			++bp;
2087 	if (!strncmp(bp, "debug:", 6)) {
2088 			hd->args = simple_strtoul(bp+6, &bp, 0) & DB_MASK;
2089 	} else if (!strncmp(bp, "disconnect:", 11)) {
2090 			x = simple_strtoul(bp+11, &bp, 0);
2091 		if (x < DIS_NEVER || x > DIS_ALWAYS)
2092 			x = DIS_ADAPTIVE;
2093 		hd->disconnect = x;
2094 	} else if (!strncmp(bp, "period:", 7)) {
2095 		x = simple_strtoul(bp+7, &bp, 0);
2096 		hd->default_sx_per =
2097 			hd->sx_table[round_period((unsigned int) x,
2098 						  hd->sx_table)].period_ns;
2099 	} else if (!strncmp(bp, "resync:", 7)) {
2100 			set_resync(hd, (int)simple_strtoul(bp+7, &bp, 0));
2101 	} else if (!strncmp(bp, "proc:", 5)) {
2102 			hd->proc = simple_strtoul(bp+5, &bp, 0);
2103 	} else if (!strncmp(bp, "nodma:", 6)) {
2104 			hd->no_dma = simple_strtoul(bp+6, &bp, 0);
2105 	} else if (!strncmp(bp, "level2:", 7)) {
2106 			hd->level2 = simple_strtoul(bp+7, &bp, 0);
2107 		} else if (!strncmp(bp, "burst:", 6)) {
2108 			hd->dma_mode =
2109 				simple_strtol(bp+6, &bp, 0) ? CTRL_BURST:CTRL_DMA;
2110 		} else if (!strncmp(bp, "fast:", 5)) {
2111 			x = !!simple_strtol(bp+5, &bp, 0);
2112 			if (x != hd->fast)
2113 				set_resync(hd, 0xff);
2114 			hd->fast = x;
2115 		} else if (!strncmp(bp, "nosync:", 7)) {
2116 			x = simple_strtoul(bp+7, &bp, 0);
2117 			set_resync(hd, x ^ hd->no_sync);
2118 			hd->no_sync = x;
2119 		} else {
2120 			break; /* unknown keyword,syntax-error,... */
2121 		}
2122 	}
2123 	return len;
2124 #else
2125 	return 0;
2126 #endif
2127 }
2128 
2129 int
2130 wd33c93_show_info(struct seq_file *m, struct Scsi_Host *instance)
2131 {
2132 #ifdef PROC_INTERFACE
2133 	struct WD33C93_hostdata *hd;
2134 	struct scsi_cmnd *cmd;
2135 	int x;
2136 
2137 	hd = (struct WD33C93_hostdata *) instance->hostdata;
2138 
2139 	spin_lock_irq(&hd->lock);
2140 	if (hd->proc & PR_VERSION)
2141 		seq_printf(m, "\nVersion %s - %s.",
2142 			WD33C93_VERSION, WD33C93_DATE);
2143 
2144 	if (hd->proc & PR_INFO) {
2145 		seq_printf(m, "\nclock_freq=%02x no_sync=%02x no_dma=%d"
2146 			" dma_mode=%02x fast=%d",
2147 			hd->clock_freq, hd->no_sync, hd->no_dma, hd->dma_mode, hd->fast);
2148 		seq_puts(m, "\nsync_xfer[] =       ");
2149 		for (x = 0; x < 7; x++)
2150 			seq_printf(m, "\t%02x", hd->sync_xfer[x]);
2151 		seq_puts(m, "\nsync_stat[] =       ");
2152 		for (x = 0; x < 7; x++)
2153 			seq_printf(m, "\t%02x", hd->sync_stat[x]);
2154 	}
2155 #ifdef PROC_STATISTICS
2156 	if (hd->proc & PR_STATISTICS) {
2157 		seq_puts(m, "\ncommands issued:    ");
2158 		for (x = 0; x < 7; x++)
2159 			seq_printf(m, "\t%ld", hd->cmd_cnt[x]);
2160 		seq_puts(m, "\ndisconnects allowed:");
2161 		for (x = 0; x < 7; x++)
2162 			seq_printf(m, "\t%ld", hd->disc_allowed_cnt[x]);
2163 		seq_puts(m, "\ndisconnects done:   ");
2164 		for (x = 0; x < 7; x++)
2165 			seq_printf(m, "\t%ld", hd->disc_done_cnt[x]);
2166 		seq_printf(m,
2167 			"\ninterrupts: %ld, DATA_PHASE ints: %ld DMA, %ld PIO",
2168 			hd->int_cnt, hd->dma_cnt, hd->pio_cnt);
2169 	}
2170 #endif
2171 	if (hd->proc & PR_CONNECTED) {
2172 		seq_puts(m, "\nconnected:     ");
2173 		if (hd->connected) {
2174 			cmd = (struct scsi_cmnd *) hd->connected;
2175 			seq_printf(m, " %d:%llu(%02x)",
2176 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2177 		}
2178 	}
2179 	if (hd->proc & PR_INPUTQ) {
2180 		seq_puts(m, "\ninput_Q:       ");
2181 		cmd = (struct scsi_cmnd *) hd->input_Q;
2182 		while (cmd) {
2183 			seq_printf(m, " %d:%llu(%02x)",
2184 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2185 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
2186 		}
2187 	}
2188 	if (hd->proc & PR_DISCQ) {
2189 		seq_puts(m, "\ndisconnected_Q:");
2190 		cmd = (struct scsi_cmnd *) hd->disconnected_Q;
2191 		while (cmd) {
2192 			seq_printf(m, " %d:%llu(%02x)",
2193 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2194 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
2195 		}
2196 	}
2197 	seq_putc(m, '\n');
2198 	spin_unlock_irq(&hd->lock);
2199 #endif				/* PROC_INTERFACE */
2200 	return 0;
2201 }
2202 
2203 EXPORT_SYMBOL(wd33c93_host_reset);
2204 EXPORT_SYMBOL(wd33c93_init);
2205 EXPORT_SYMBOL(wd33c93_abort);
2206 EXPORT_SYMBOL(wd33c93_queuecommand);
2207 EXPORT_SYMBOL(wd33c93_intr);
2208 EXPORT_SYMBOL(wd33c93_show_info);
2209 EXPORT_SYMBOL(wd33c93_write_info);
2210