xref: /linux/drivers/scsi/wd33c93.c (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
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] & (1 << cmd->device->lun)))
506 			break;
507 		prev = cmd;
508 		cmd = (struct scsi_cmnd *) cmd->host_scribble;
509 	}
510 
511 	/* quit if queue empty or all possible targets are busy */
512 
513 	if (!cmd) {
514 		DB(DB_EXECUTE, printk(")EX-1 "))
515 		return;
516 	}
517 
518 	/*  remove command from queue */
519 
520 	if (prev)
521 		prev->host_scribble = cmd->host_scribble;
522 	else
523 		hostdata->input_Q = (struct scsi_cmnd *) cmd->host_scribble;
524 
525 #ifdef PROC_STATISTICS
526 	hostdata->cmd_cnt[cmd->device->id]++;
527 #endif
528 
529 	/*
530 	 * Start the selection process
531 	 */
532 
533 	if (cmd->sc_data_direction == DMA_TO_DEVICE)
534 		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
535 	else
536 		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id | DSTID_DPD);
537 
538 /* Now we need to figure out whether or not this command is a good
539  * candidate for disconnect/reselect. We guess to the best of our
540  * ability, based on a set of hierarchical rules. When several
541  * devices are operating simultaneously, disconnects are usually
542  * an advantage. In a single device system, or if only 1 device
543  * is being accessed, transfers usually go faster if disconnects
544  * are not allowed:
545  *
546  * + Commands should NEVER disconnect if hostdata->disconnect =
547  *   DIS_NEVER (this holds for tape drives also), and ALWAYS
548  *   disconnect if hostdata->disconnect = DIS_ALWAYS.
549  * + Tape drive commands should always be allowed to disconnect.
550  * + Disconnect should be allowed if disconnected_Q isn't empty.
551  * + Commands should NOT disconnect if input_Q is empty.
552  * + Disconnect should be allowed if there are commands in input_Q
553  *   for a different target/lun. In this case, the other commands
554  *   should be made disconnect-able, if not already.
555  *
556  * I know, I know - this code would flunk me out of any
557  * "C Programming 101" class ever offered. But it's easy
558  * to change around and experiment with for now.
559  */
560 
561 	cmd->SCp.phase = 0;	/* assume no disconnect */
562 	if (hostdata->disconnect == DIS_NEVER)
563 		goto no;
564 	if (hostdata->disconnect == DIS_ALWAYS)
565 		goto yes;
566 	if (cmd->device->type == 1)	/* tape drive? */
567 		goto yes;
568 	if (hostdata->disconnected_Q)	/* other commands disconnected? */
569 		goto yes;
570 	if (!(hostdata->input_Q))	/* input_Q empty? */
571 		goto no;
572 	for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
573 	     prev = (struct scsi_cmnd *) prev->host_scribble) {
574 		if ((prev->device->id != cmd->device->id) ||
575 		    (prev->device->lun != cmd->device->lun)) {
576 			for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
577 			     prev = (struct scsi_cmnd *) prev->host_scribble)
578 				prev->SCp.phase = 1;
579 			goto yes;
580 		}
581 	}
582 
583 	goto no;
584 
585  yes:
586 	cmd->SCp.phase = 1;
587 
588 #ifdef PROC_STATISTICS
589 	hostdata->disc_allowed_cnt[cmd->device->id]++;
590 #endif
591 
592  no:
593 
594 	write_wd33c93(regs, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0));
595 
596 	write_wd33c93(regs, WD_TARGET_LUN, cmd->device->lun);
597 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
598 		      hostdata->sync_xfer[cmd->device->id]);
599 	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
600 
601 	if ((hostdata->level2 == L2_NONE) ||
602 	    (hostdata->sync_stat[cmd->device->id] == SS_UNSET)) {
603 
604 		/*
605 		 * Do a 'Select-With-ATN' command. This will end with
606 		 * one of the following interrupts:
607 		 *    CSR_RESEL_AM:  failure - can try again later.
608 		 *    CSR_TIMEOUT:   failure - give up.
609 		 *    CSR_SELECT:    success - proceed.
610 		 */
611 
612 		hostdata->selecting = cmd;
613 
614 /* Every target has its own synchronous transfer setting, kept in the
615  * sync_xfer array, and a corresponding status byte in sync_stat[].
616  * Each target's sync_stat[] entry is initialized to SX_UNSET, and its
617  * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET
618  * means that the parameters are undetermined as yet, and that we
619  * need to send an SDTR message to this device after selection is
620  * complete: We set SS_FIRST to tell the interrupt routine to do so.
621  * If we've been asked not to try synchronous transfers on this
622  * target (and _all_ luns within it), we'll still send the SDTR message
623  * later, but at that time we'll negotiate for async by specifying a
624  * sync fifo depth of 0.
625  */
626 		if (hostdata->sync_stat[cmd->device->id] == SS_UNSET)
627 			hostdata->sync_stat[cmd->device->id] = SS_FIRST;
628 		hostdata->state = S_SELECTING;
629 		write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
630 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN);
631 	} else {
632 
633 		/*
634 		 * Do a 'Select-With-ATN-Xfer' command. This will end with
635 		 * one of the following interrupts:
636 		 *    CSR_RESEL_AM:  failure - can try again later.
637 		 *    CSR_TIMEOUT:   failure - give up.
638 		 *    anything else: success - proceed.
639 		 */
640 
641 		hostdata->connected = cmd;
642 		write_wd33c93(regs, WD_COMMAND_PHASE, 0);
643 
644 		/* copy command_descriptor_block into WD chip
645 		 * (take advantage of auto-incrementing)
646 		 */
647 
648 		write_wd33c93_cdb(regs, cmd->cmd_len, cmd->cmnd);
649 
650 		/* The wd33c93 only knows about Group 0, 1, and 5 commands when
651 		 * it's doing a 'select-and-transfer'. To be safe, we write the
652 		 * size of the CDB into the OWN_ID register for every case. This
653 		 * way there won't be problems with vendor-unique, audio, etc.
654 		 */
655 
656 		write_wd33c93(regs, WD_OWN_ID, cmd->cmd_len);
657 
658 		/* When doing a non-disconnect command with DMA, we can save
659 		 * ourselves a DATA phase interrupt later by setting everything
660 		 * up ahead of time.
661 		 */
662 
663 		if ((cmd->SCp.phase == 0) && (hostdata->no_dma == 0)) {
664 			if (hostdata->dma_setup(cmd,
665 			    (cmd->sc_data_direction == DMA_TO_DEVICE) ?
666 			     DATA_OUT_DIR : DATA_IN_DIR))
667 				write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
668 			else {
669 				write_wd33c93_count(regs,
670 						    cmd->SCp.this_residual);
671 				write_wd33c93(regs, WD_CONTROL,
672 					      CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
673 				hostdata->dma = D_DMA_RUNNING;
674 			}
675 		} else
676 			write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
677 
678 		hostdata->state = S_RUNNING_LEVEL2;
679 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
680 	}
681 
682 	/*
683 	 * Since the SCSI bus can handle only 1 connection at a time,
684 	 * we get out of here now. If the selection fails, or when
685 	 * the command disconnects, we'll come back to this routine
686 	 * to search the input_Q again...
687 	 */
688 
689 	DB(DB_EXECUTE,
690 	   printk("%s)EX-2 ", (cmd->SCp.phase) ? "d:" : ""))
691 }
692 
693 static void
694 transfer_pio(const wd33c93_regs regs, uchar * buf, int cnt,
695 	     int data_in_dir, struct WD33C93_hostdata *hostdata)
696 {
697 	uchar asr;
698 
699 	DB(DB_TRANSFER,
700 	   printk("(%p,%d,%s:", buf, cnt, data_in_dir ? "in" : "out"))
701 
702 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
703 	write_wd33c93_count(regs, cnt);
704 	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
705 	if (data_in_dir) {
706 		do {
707 			asr = read_aux_stat(regs);
708 			if (asr & ASR_DBR)
709 				*buf++ = read_wd33c93(regs, WD_DATA);
710 		} while (!(asr & ASR_INT));
711 	} else {
712 		do {
713 			asr = read_aux_stat(regs);
714 			if (asr & ASR_DBR)
715 				write_wd33c93(regs, WD_DATA, *buf++);
716 		} while (!(asr & ASR_INT));
717 	}
718 
719 	/* Note: we are returning with the interrupt UN-cleared.
720 	 * Since (presumably) an entire I/O operation has
721 	 * completed, the bus phase is probably different, and
722 	 * the interrupt routine will discover this when it
723 	 * responds to the uncleared int.
724 	 */
725 
726 }
727 
728 static void
729 transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
730 		int data_in_dir)
731 {
732 	struct WD33C93_hostdata *hostdata;
733 	unsigned long length;
734 
735 	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
736 
737 /* Normally, you'd expect 'this_residual' to be non-zero here.
738  * In a series of scatter-gather transfers, however, this
739  * routine will usually be called with 'this_residual' equal
740  * to 0 and 'buffers_residual' non-zero. This means that a
741  * previous transfer completed, clearing 'this_residual', and
742  * now we need to setup the next scatter-gather buffer as the
743  * source or destination for THIS transfer.
744  */
745 	if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
746 		++cmd->SCp.buffer;
747 		--cmd->SCp.buffers_residual;
748 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
749 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
750 	}
751 	if (!cmd->SCp.this_residual) /* avoid bogus setups */
752 		return;
753 
754 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
755 		      hostdata->sync_xfer[cmd->device->id]);
756 
757 /* 'hostdata->no_dma' is TRUE if we don't even want to try DMA.
758  * Update 'this_residual' and 'ptr' after 'transfer_pio()' returns.
759  */
760 
761 	if (hostdata->no_dma || hostdata->dma_setup(cmd, data_in_dir)) {
762 #ifdef PROC_STATISTICS
763 		hostdata->pio_cnt++;
764 #endif
765 		transfer_pio(regs, (uchar *) cmd->SCp.ptr,
766 			     cmd->SCp.this_residual, data_in_dir, hostdata);
767 		length = cmd->SCp.this_residual;
768 		cmd->SCp.this_residual = read_wd33c93_count(regs);
769 		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
770 	}
771 
772 /* We are able to do DMA (in fact, the Amiga hardware is
773  * already going!), so start up the wd33c93 in DMA mode.
774  * We set 'hostdata->dma' = D_DMA_RUNNING so that when the
775  * transfer completes and causes an interrupt, we're
776  * reminded to tell the Amiga to shut down its end. We'll
777  * postpone the updating of 'this_residual' and 'ptr'
778  * until then.
779  */
780 
781 	else {
782 #ifdef PROC_STATISTICS
783 		hostdata->dma_cnt++;
784 #endif
785 		write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
786 		write_wd33c93_count(regs, cmd->SCp.this_residual);
787 
788 		if ((hostdata->level2 >= L2_DATA) ||
789 		    (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
790 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
791 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
792 			hostdata->state = S_RUNNING_LEVEL2;
793 		} else
794 			write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
795 
796 		hostdata->dma = D_DMA_RUNNING;
797 	}
798 }
799 
800 void
801 wd33c93_intr(struct Scsi_Host *instance)
802 {
803 	struct WD33C93_hostdata *hostdata =
804 	    (struct WD33C93_hostdata *) instance->hostdata;
805 	const wd33c93_regs regs = hostdata->regs;
806 	struct scsi_cmnd *patch, *cmd;
807 	uchar asr, sr, phs, id, lun, *ucp, msg;
808 	unsigned long length, flags;
809 
810 	asr = read_aux_stat(regs);
811 	if (!(asr & ASR_INT) || (asr & ASR_BSY))
812 		return;
813 
814 	spin_lock_irqsave(&hostdata->lock, flags);
815 
816 #ifdef PROC_STATISTICS
817 	hostdata->int_cnt++;
818 #endif
819 
820 	cmd = (struct scsi_cmnd *) hostdata->connected;	/* assume we're connected */
821 	sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear the interrupt */
822 	phs = read_wd33c93(regs, WD_COMMAND_PHASE);
823 
824 	DB(DB_INTR, printk("{%02x:%02x-", asr, sr))
825 
826 /* After starting a DMA transfer, the next interrupt
827  * is guaranteed to be in response to completion of
828  * the transfer. Since the Amiga DMA hardware runs in
829  * in an open-ended fashion, it needs to be told when
830  * to stop; do that here if D_DMA_RUNNING is true.
831  * Also, we have to update 'this_residual' and 'ptr'
832  * based on the contents of the TRANSFER_COUNT register,
833  * in case the device decided to do an intermediate
834  * disconnect (a device may do this if it has to do a
835  * seek, or just to be nice and let other devices have
836  * some bus time during long transfers). After doing
837  * whatever is needed, we go on and service the WD3393
838  * interrupt normally.
839  */
840 	    if (hostdata->dma == D_DMA_RUNNING) {
841 		DB(DB_TRANSFER,
842 		   printk("[%p/%d:", cmd->SCp.ptr, cmd->SCp.this_residual))
843 		    hostdata->dma_stop(cmd->device->host, cmd, 1);
844 		hostdata->dma = D_DMA_OFF;
845 		length = cmd->SCp.this_residual;
846 		cmd->SCp.this_residual = read_wd33c93_count(regs);
847 		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
848 		DB(DB_TRANSFER,
849 		   printk("%p/%d]", cmd->SCp.ptr, cmd->SCp.this_residual))
850 	}
851 
852 /* Respond to the specific WD3393 interrupt - there are quite a few! */
853 	switch (sr) {
854 	case CSR_TIMEOUT:
855 		DB(DB_INTR, printk("TIMEOUT"))
856 
857 		    if (hostdata->state == S_RUNNING_LEVEL2)
858 			hostdata->connected = NULL;
859 		else {
860 			cmd = (struct scsi_cmnd *) hostdata->selecting;	/* get a valid cmd */
861 			hostdata->selecting = NULL;
862 		}
863 
864 		cmd->result = DID_NO_CONNECT << 16;
865 		hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
866 		hostdata->state = S_UNCONNECTED;
867 		cmd->scsi_done(cmd);
868 
869 		/* From esp.c:
870 		 * There is a window of time within the scsi_done() path
871 		 * of execution where interrupts are turned back on full
872 		 * blast and left that way.  During that time we could
873 		 * reconnect to a disconnected command, then we'd bomb
874 		 * out below.  We could also end up executing two commands
875 		 * at _once_.  ...just so you know why the restore_flags()
876 		 * is here...
877 		 */
878 
879 		spin_unlock_irqrestore(&hostdata->lock, flags);
880 
881 /* We are not connected to a target - check to see if there
882  * are commands waiting to be executed.
883  */
884 
885 		wd33c93_execute(instance);
886 		break;
887 
888 /* Note: this interrupt should not occur in a LEVEL2 command */
889 
890 	case CSR_SELECT:
891 		DB(DB_INTR, printk("SELECT"))
892 		    hostdata->connected = cmd =
893 		    (struct scsi_cmnd *) hostdata->selecting;
894 		hostdata->selecting = NULL;
895 
896 		/* construct an IDENTIFY message with correct disconnect bit */
897 
898 		hostdata->outgoing_msg[0] = (0x80 | 0x00 | cmd->device->lun);
899 		if (cmd->SCp.phase)
900 			hostdata->outgoing_msg[0] |= 0x40;
901 
902 		if (hostdata->sync_stat[cmd->device->id] == SS_FIRST) {
903 
904 			hostdata->sync_stat[cmd->device->id] = SS_WAITING;
905 
906 /* Tack on a 2nd message to ask about synchronous transfers. If we've
907  * been asked to do only asynchronous transfers on this device, we
908  * request a fifo depth of 0, which is equivalent to async - should
909  * solve the problems some people have had with GVP's Guru ROM.
910  */
911 
912 			hostdata->outgoing_msg[1] = EXTENDED_MESSAGE;
913 			hostdata->outgoing_msg[2] = 3;
914 			hostdata->outgoing_msg[3] = EXTENDED_SDTR;
915 			if (hostdata->no_sync & (1 << cmd->device->id)) {
916 				calc_sync_msg(hostdata->default_sx_per, 0,
917 						0, hostdata->outgoing_msg + 4);
918 			} else {
919 				calc_sync_msg(optimum_sx_per(hostdata),
920 						OPTIMUM_SX_OFF,
921 						hostdata->fast,
922 						hostdata->outgoing_msg + 4);
923 			}
924 			hostdata->outgoing_len = 6;
925 #ifdef SYNC_DEBUG
926 			ucp = hostdata->outgoing_msg + 1;
927 			printk(" sending SDTR %02x03%02x%02x%02x ",
928 				ucp[0], ucp[2], ucp[3], ucp[4]);
929 #endif
930 		} else
931 			hostdata->outgoing_len = 1;
932 
933 		hostdata->state = S_CONNECTED;
934 		spin_unlock_irqrestore(&hostdata->lock, flags);
935 		break;
936 
937 	case CSR_XFER_DONE | PHS_DATA_IN:
938 	case CSR_UNEXP | PHS_DATA_IN:
939 	case CSR_SRV_REQ | PHS_DATA_IN:
940 		DB(DB_INTR,
941 		   printk("IN-%d.%d", cmd->SCp.this_residual,
942 			  cmd->SCp.buffers_residual))
943 		    transfer_bytes(regs, cmd, DATA_IN_DIR);
944 		if (hostdata->state != S_RUNNING_LEVEL2)
945 			hostdata->state = S_CONNECTED;
946 		spin_unlock_irqrestore(&hostdata->lock, flags);
947 		break;
948 
949 	case CSR_XFER_DONE | PHS_DATA_OUT:
950 	case CSR_UNEXP | PHS_DATA_OUT:
951 	case CSR_SRV_REQ | PHS_DATA_OUT:
952 		DB(DB_INTR,
953 		   printk("OUT-%d.%d", cmd->SCp.this_residual,
954 			  cmd->SCp.buffers_residual))
955 		    transfer_bytes(regs, cmd, DATA_OUT_DIR);
956 		if (hostdata->state != S_RUNNING_LEVEL2)
957 			hostdata->state = S_CONNECTED;
958 		spin_unlock_irqrestore(&hostdata->lock, flags);
959 		break;
960 
961 /* Note: this interrupt should not occur in a LEVEL2 command */
962 
963 	case CSR_XFER_DONE | PHS_COMMAND:
964 	case CSR_UNEXP | PHS_COMMAND:
965 	case CSR_SRV_REQ | PHS_COMMAND:
966 		DB(DB_INTR, printk("CMND-%02x", cmd->cmnd[0]))
967 		    transfer_pio(regs, cmd->cmnd, cmd->cmd_len, DATA_OUT_DIR,
968 				 hostdata);
969 		hostdata->state = S_CONNECTED;
970 		spin_unlock_irqrestore(&hostdata->lock, flags);
971 		break;
972 
973 	case CSR_XFER_DONE | PHS_STATUS:
974 	case CSR_UNEXP | PHS_STATUS:
975 	case CSR_SRV_REQ | PHS_STATUS:
976 		DB(DB_INTR, printk("STATUS="))
977 		cmd->SCp.Status = read_1_byte(regs);
978 		DB(DB_INTR, printk("%02x", cmd->SCp.Status))
979 		    if (hostdata->level2 >= L2_BASIC) {
980 			sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
981 			udelay(7);
982 			hostdata->state = S_RUNNING_LEVEL2;
983 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x50);
984 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
985 		} else {
986 			hostdata->state = S_CONNECTED;
987 		}
988 		spin_unlock_irqrestore(&hostdata->lock, flags);
989 		break;
990 
991 	case CSR_XFER_DONE | PHS_MESS_IN:
992 	case CSR_UNEXP | PHS_MESS_IN:
993 	case CSR_SRV_REQ | PHS_MESS_IN:
994 		DB(DB_INTR, printk("MSG_IN="))
995 
996 		msg = read_1_byte(regs);
997 		sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
998 		udelay(7);
999 
1000 		hostdata->incoming_msg[hostdata->incoming_ptr] = msg;
1001 		if (hostdata->incoming_msg[0] == EXTENDED_MESSAGE)
1002 			msg = EXTENDED_MESSAGE;
1003 		else
1004 			hostdata->incoming_ptr = 0;
1005 
1006 		cmd->SCp.Message = msg;
1007 		switch (msg) {
1008 
1009 		case COMMAND_COMPLETE:
1010 			DB(DB_INTR, printk("CCMP"))
1011 			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1012 			hostdata->state = S_PRE_CMP_DISC;
1013 			break;
1014 
1015 		case SAVE_POINTERS:
1016 			DB(DB_INTR, printk("SDP"))
1017 			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1018 			hostdata->state = S_CONNECTED;
1019 			break;
1020 
1021 		case RESTORE_POINTERS:
1022 			DB(DB_INTR, printk("RDP"))
1023 			    if (hostdata->level2 >= L2_BASIC) {
1024 				write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
1025 				write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1026 				hostdata->state = S_RUNNING_LEVEL2;
1027 			} else {
1028 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1029 				hostdata->state = S_CONNECTED;
1030 			}
1031 			break;
1032 
1033 		case DISCONNECT:
1034 			DB(DB_INTR, printk("DIS"))
1035 			    cmd->device->disconnect = 1;
1036 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1037 			hostdata->state = S_PRE_TMP_DISC;
1038 			break;
1039 
1040 		case MESSAGE_REJECT:
1041 			DB(DB_INTR, printk("REJ"))
1042 #ifdef SYNC_DEBUG
1043 			    printk("-REJ-");
1044 #endif
1045 			if (hostdata->sync_stat[cmd->device->id] == SS_WAITING) {
1046 				hostdata->sync_stat[cmd->device->id] = SS_SET;
1047 				/* we want default_sx_per, not DEFAULT_SX_PER */
1048 				hostdata->sync_xfer[cmd->device->id] =
1049 					calc_sync_xfer(hostdata->default_sx_per
1050 						/ 4, 0, 0, hostdata->sx_table);
1051 			}
1052 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1053 			hostdata->state = S_CONNECTED;
1054 			break;
1055 
1056 		case EXTENDED_MESSAGE:
1057 			DB(DB_INTR, printk("EXT"))
1058 
1059 			    ucp = hostdata->incoming_msg;
1060 
1061 #ifdef SYNC_DEBUG
1062 			printk("%02x", ucp[hostdata->incoming_ptr]);
1063 #endif
1064 			/* Is this the last byte of the extended message? */
1065 
1066 			if ((hostdata->incoming_ptr >= 2) &&
1067 			    (hostdata->incoming_ptr == (ucp[1] + 1))) {
1068 
1069 				switch (ucp[2]) {	/* what's the EXTENDED code? */
1070 				case EXTENDED_SDTR:
1071 					/* default to default async period */
1072 					id = calc_sync_xfer(hostdata->
1073 							default_sx_per / 4, 0,
1074 							0, hostdata->sx_table);
1075 					if (hostdata->sync_stat[cmd->device->id] !=
1076 					    SS_WAITING) {
1077 
1078 /* A device has sent an unsolicited SDTR message; rather than go
1079  * through the effort of decoding it and then figuring out what
1080  * our reply should be, we're just gonna say that we have a
1081  * synchronous fifo depth of 0. This will result in asynchronous
1082  * transfers - not ideal but so much easier.
1083  * Actually, this is OK because it assures us that if we don't
1084  * specifically ask for sync transfers, we won't do any.
1085  */
1086 
1087 						write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1088 						hostdata->outgoing_msg[0] =
1089 						    EXTENDED_MESSAGE;
1090 						hostdata->outgoing_msg[1] = 3;
1091 						hostdata->outgoing_msg[2] =
1092 						    EXTENDED_SDTR;
1093 						calc_sync_msg(hostdata->
1094 							default_sx_per, 0,
1095 							0, hostdata->outgoing_msg + 3);
1096 						hostdata->outgoing_len = 5;
1097 					} else {
1098 						if (ucp[4]) /* well, sync transfer */
1099 							id = calc_sync_xfer(ucp[3], ucp[4],
1100 									hostdata->fast,
1101 									hostdata->sx_table);
1102 						else if (ucp[3]) /* very unlikely... */
1103 							id = calc_sync_xfer(ucp[3], ucp[4],
1104 									0, hostdata->sx_table);
1105 					}
1106 					hostdata->sync_xfer[cmd->device->id] = id;
1107 #ifdef SYNC_DEBUG
1108 					printk(" sync_xfer=%02x\n",
1109 					       hostdata->sync_xfer[cmd->device->id]);
1110 #endif
1111 					hostdata->sync_stat[cmd->device->id] =
1112 					    SS_SET;
1113 					write_wd33c93_cmd(regs,
1114 							  WD_CMD_NEGATE_ACK);
1115 					hostdata->state = S_CONNECTED;
1116 					break;
1117 				case EXTENDED_WDTR:
1118 					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1119 					printk("sending WDTR ");
1120 					hostdata->outgoing_msg[0] =
1121 					    EXTENDED_MESSAGE;
1122 					hostdata->outgoing_msg[1] = 2;
1123 					hostdata->outgoing_msg[2] =
1124 					    EXTENDED_WDTR;
1125 					hostdata->outgoing_msg[3] = 0;	/* 8 bit transfer width */
1126 					hostdata->outgoing_len = 4;
1127 					write_wd33c93_cmd(regs,
1128 							  WD_CMD_NEGATE_ACK);
1129 					hostdata->state = S_CONNECTED;
1130 					break;
1131 				default:
1132 					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1133 					printk
1134 					    ("Rejecting Unknown Extended Message(%02x). ",
1135 					     ucp[2]);
1136 					hostdata->outgoing_msg[0] =
1137 					    MESSAGE_REJECT;
1138 					hostdata->outgoing_len = 1;
1139 					write_wd33c93_cmd(regs,
1140 							  WD_CMD_NEGATE_ACK);
1141 					hostdata->state = S_CONNECTED;
1142 					break;
1143 				}
1144 				hostdata->incoming_ptr = 0;
1145 			}
1146 
1147 			/* We need to read more MESS_IN bytes for the extended message */
1148 
1149 			else {
1150 				hostdata->incoming_ptr++;
1151 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1152 				hostdata->state = S_CONNECTED;
1153 			}
1154 			break;
1155 
1156 		default:
1157 			printk("Rejecting Unknown Message(%02x) ", msg);
1158 			write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1159 			hostdata->outgoing_msg[0] = MESSAGE_REJECT;
1160 			hostdata->outgoing_len = 1;
1161 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1162 			hostdata->state = S_CONNECTED;
1163 		}
1164 		spin_unlock_irqrestore(&hostdata->lock, flags);
1165 		break;
1166 
1167 /* Note: this interrupt will occur only after a LEVEL2 command */
1168 
1169 	case CSR_SEL_XFER_DONE:
1170 
1171 /* Make sure that reselection is enabled at this point - it may
1172  * have been turned off for the command that just completed.
1173  */
1174 
1175 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1176 		if (phs == 0x60) {
1177 			DB(DB_INTR, printk("SX-DONE"))
1178 			    cmd->SCp.Message = COMMAND_COMPLETE;
1179 			lun = read_wd33c93(regs, WD_TARGET_LUN);
1180 			DB(DB_INTR, printk(":%d.%d", cmd->SCp.Status, lun))
1181 			    hostdata->connected = NULL;
1182 			hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
1183 			hostdata->state = S_UNCONNECTED;
1184 			if (cmd->SCp.Status == ILLEGAL_STATUS_BYTE)
1185 				cmd->SCp.Status = lun;
1186 			if (cmd->cmnd[0] == REQUEST_SENSE
1187 			    && cmd->SCp.Status != GOOD)
1188 				cmd->result =
1189 				    (cmd->
1190 				     result & 0x00ffff) | (DID_ERROR << 16);
1191 			else
1192 				cmd->result =
1193 				    cmd->SCp.Status | (cmd->SCp.Message << 8);
1194 			cmd->scsi_done(cmd);
1195 
1196 /* We are no longer  connected to a target - check to see if
1197  * there are commands waiting to be executed.
1198  */
1199 			spin_unlock_irqrestore(&hostdata->lock, flags);
1200 			wd33c93_execute(instance);
1201 		} else {
1202 			printk
1203 			    ("%02x:%02x:%02x: Unknown SEL_XFER_DONE phase!!---",
1204 			     asr, sr, phs);
1205 			spin_unlock_irqrestore(&hostdata->lock, flags);
1206 		}
1207 		break;
1208 
1209 /* Note: this interrupt will occur only after a LEVEL2 command */
1210 
1211 	case CSR_SDP:
1212 		DB(DB_INTR, printk("SDP"))
1213 		    hostdata->state = S_RUNNING_LEVEL2;
1214 		write_wd33c93(regs, WD_COMMAND_PHASE, 0x41);
1215 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1216 		spin_unlock_irqrestore(&hostdata->lock, flags);
1217 		break;
1218 
1219 	case CSR_XFER_DONE | PHS_MESS_OUT:
1220 	case CSR_UNEXP | PHS_MESS_OUT:
1221 	case CSR_SRV_REQ | PHS_MESS_OUT:
1222 		DB(DB_INTR, printk("MSG_OUT="))
1223 
1224 /* To get here, we've probably requested MESSAGE_OUT and have
1225  * already put the correct bytes in outgoing_msg[] and filled
1226  * in outgoing_len. We simply send them out to the SCSI bus.
1227  * Sometimes we get MESSAGE_OUT phase when we're not expecting
1228  * it - like when our SDTR message is rejected by a target. Some
1229  * targets send the REJECT before receiving all of the extended
1230  * message, and then seem to go back to MESSAGE_OUT for a byte
1231  * or two. Not sure why, or if I'm doing something wrong to
1232  * cause this to happen. Regardless, it seems that sending
1233  * NOP messages in these situations results in no harm and
1234  * makes everyone happy.
1235  */
1236 		    if (hostdata->outgoing_len == 0) {
1237 			hostdata->outgoing_len = 1;
1238 			hostdata->outgoing_msg[0] = NOP;
1239 		}
1240 		transfer_pio(regs, hostdata->outgoing_msg,
1241 			     hostdata->outgoing_len, DATA_OUT_DIR, hostdata);
1242 		DB(DB_INTR, printk("%02x", hostdata->outgoing_msg[0]))
1243 		    hostdata->outgoing_len = 0;
1244 		hostdata->state = S_CONNECTED;
1245 		spin_unlock_irqrestore(&hostdata->lock, flags);
1246 		break;
1247 
1248 	case CSR_UNEXP_DISC:
1249 
1250 /* I think I've seen this after a request-sense that was in response
1251  * to an error condition, but not sure. We certainly need to do
1252  * something when we get this interrupt - the question is 'what?'.
1253  * Let's think positively, and assume some command has finished
1254  * in a legal manner (like a command that provokes a request-sense),
1255  * so we treat it as a normal command-complete-disconnect.
1256  */
1257 
1258 /* Make sure that reselection is enabled at this point - it may
1259  * have been turned off for the command that just completed.
1260  */
1261 
1262 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1263 		if (cmd == NULL) {
1264 			printk(" - Already disconnected! ");
1265 			hostdata->state = S_UNCONNECTED;
1266 			spin_unlock_irqrestore(&hostdata->lock, flags);
1267 			return;
1268 		}
1269 		DB(DB_INTR, printk("UNEXP_DISC"))
1270 		    hostdata->connected = NULL;
1271 		hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
1272 		hostdata->state = S_UNCONNECTED;
1273 		if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
1274 			cmd->result =
1275 			    (cmd->result & 0x00ffff) | (DID_ERROR << 16);
1276 		else
1277 			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
1278 		cmd->scsi_done(cmd);
1279 
1280 /* We are no longer connected to a target - check to see if
1281  * there are commands waiting to be executed.
1282  */
1283 		/* look above for comments on scsi_done() */
1284 		spin_unlock_irqrestore(&hostdata->lock, flags);
1285 		wd33c93_execute(instance);
1286 		break;
1287 
1288 	case CSR_DISC:
1289 
1290 /* Make sure that reselection is enabled at this point - it may
1291  * have been turned off for the command that just completed.
1292  */
1293 
1294 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1295 		DB(DB_INTR, printk("DISC"))
1296 		    if (cmd == NULL) {
1297 			printk(" - Already disconnected! ");
1298 			hostdata->state = S_UNCONNECTED;
1299 		}
1300 		switch (hostdata->state) {
1301 		case S_PRE_CMP_DISC:
1302 			hostdata->connected = NULL;
1303 			hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
1304 			hostdata->state = S_UNCONNECTED;
1305 			DB(DB_INTR, printk(":%d", cmd->SCp.Status))
1306 			    if (cmd->cmnd[0] == REQUEST_SENSE
1307 				&& cmd->SCp.Status != GOOD)
1308 				cmd->result =
1309 				    (cmd->
1310 				     result & 0x00ffff) | (DID_ERROR << 16);
1311 			else
1312 				cmd->result =
1313 				    cmd->SCp.Status | (cmd->SCp.Message << 8);
1314 			cmd->scsi_done(cmd);
1315 			break;
1316 		case S_PRE_TMP_DISC:
1317 		case S_RUNNING_LEVEL2:
1318 			cmd->host_scribble = (uchar *) hostdata->disconnected_Q;
1319 			hostdata->disconnected_Q = cmd;
1320 			hostdata->connected = NULL;
1321 			hostdata->state = S_UNCONNECTED;
1322 
1323 #ifdef PROC_STATISTICS
1324 			hostdata->disc_done_cnt[cmd->device->id]++;
1325 #endif
1326 
1327 			break;
1328 		default:
1329 			printk("*** Unexpected DISCONNECT interrupt! ***");
1330 			hostdata->state = S_UNCONNECTED;
1331 		}
1332 
1333 /* We are no longer connected to a target - check to see if
1334  * there are commands waiting to be executed.
1335  */
1336 		spin_unlock_irqrestore(&hostdata->lock, flags);
1337 		wd33c93_execute(instance);
1338 		break;
1339 
1340 	case CSR_RESEL_AM:
1341 	case CSR_RESEL:
1342 		DB(DB_INTR, printk("RESEL%s", sr == CSR_RESEL_AM ? "_AM" : ""))
1343 
1344 		    /* Old chips (pre -A ???) don't have advanced features and will
1345 		     * generate CSR_RESEL.  In that case we have to extract the LUN the
1346 		     * hard way (see below).
1347 		     * First we have to make sure this reselection didn't
1348 		     * happen during Arbitration/Selection of some other device.
1349 		     * If yes, put losing command back on top of input_Q.
1350 		     */
1351 		    if (hostdata->level2 <= L2_NONE) {
1352 
1353 			if (hostdata->selecting) {
1354 				cmd = (struct scsi_cmnd *) hostdata->selecting;
1355 				hostdata->selecting = NULL;
1356 				hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
1357 				cmd->host_scribble =
1358 				    (uchar *) hostdata->input_Q;
1359 				hostdata->input_Q = cmd;
1360 			}
1361 		}
1362 
1363 		else {
1364 
1365 			if (cmd) {
1366 				if (phs == 0x00) {
1367 					hostdata->busy[cmd->device->id] &=
1368 					    ~(1 << cmd->device->lun);
1369 					cmd->host_scribble =
1370 					    (uchar *) hostdata->input_Q;
1371 					hostdata->input_Q = cmd;
1372 				} else {
1373 					printk
1374 					    ("---%02x:%02x:%02x-TROUBLE: Intrusive ReSelect!---",
1375 					     asr, sr, phs);
1376 					while (1)
1377 						printk("\r");
1378 				}
1379 			}
1380 
1381 		}
1382 
1383 		/* OK - find out which device reselected us. */
1384 
1385 		id = read_wd33c93(regs, WD_SOURCE_ID);
1386 		id &= SRCID_MASK;
1387 
1388 		/* and extract the lun from the ID message. (Note that we don't
1389 		 * bother to check for a valid message here - I guess this is
1390 		 * not the right way to go, but...)
1391 		 */
1392 
1393 		if (sr == CSR_RESEL_AM) {
1394 			lun = read_wd33c93(regs, WD_DATA);
1395 			if (hostdata->level2 < L2_RESELECT)
1396 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1397 			lun &= 7;
1398 		} else {
1399 			/* Old chip; wait for msgin phase to pick up the LUN. */
1400 			for (lun = 255; lun; lun--) {
1401 				if ((asr = read_aux_stat(regs)) & ASR_INT)
1402 					break;
1403 				udelay(10);
1404 			}
1405 			if (!(asr & ASR_INT)) {
1406 				printk
1407 				    ("wd33c93: Reselected without IDENTIFY\n");
1408 				lun = 0;
1409 			} else {
1410 				/* Verify this is a change to MSG_IN and read the message */
1411 				sr = read_wd33c93(regs, WD_SCSI_STATUS);
1412 				udelay(7);
1413 				if (sr == (CSR_ABORT | PHS_MESS_IN) ||
1414 				    sr == (CSR_UNEXP | PHS_MESS_IN) ||
1415 				    sr == (CSR_SRV_REQ | PHS_MESS_IN)) {
1416 					/* Got MSG_IN, grab target LUN */
1417 					lun = read_1_byte(regs);
1418 					/* Now we expect a 'paused with ACK asserted' int.. */
1419 					asr = read_aux_stat(regs);
1420 					if (!(asr & ASR_INT)) {
1421 						udelay(10);
1422 						asr = read_aux_stat(regs);
1423 						if (!(asr & ASR_INT))
1424 							printk
1425 							    ("wd33c93: No int after LUN on RESEL (%02x)\n",
1426 							     asr);
1427 					}
1428 					sr = read_wd33c93(regs, WD_SCSI_STATUS);
1429 					udelay(7);
1430 					if (sr != CSR_MSGIN)
1431 						printk
1432 						    ("wd33c93: Not paused with ACK on RESEL (%02x)\n",
1433 						     sr);
1434 					lun &= 7;
1435 					write_wd33c93_cmd(regs,
1436 							  WD_CMD_NEGATE_ACK);
1437 				} else {
1438 					printk
1439 					    ("wd33c93: Not MSG_IN on reselect (%02x)\n",
1440 					     sr);
1441 					lun = 0;
1442 				}
1443 			}
1444 		}
1445 
1446 		/* Now we look for the command that's reconnecting. */
1447 
1448 		cmd = (struct scsi_cmnd *) hostdata->disconnected_Q;
1449 		patch = NULL;
1450 		while (cmd) {
1451 			if (id == cmd->device->id && lun == cmd->device->lun)
1452 				break;
1453 			patch = cmd;
1454 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
1455 		}
1456 
1457 		/* Hmm. Couldn't find a valid command.... What to do? */
1458 
1459 		if (!cmd) {
1460 			printk
1461 			    ("---TROUBLE: target %d.%d not in disconnect queue---",
1462 			     id, lun);
1463 			spin_unlock_irqrestore(&hostdata->lock, flags);
1464 			return;
1465 		}
1466 
1467 		/* Ok, found the command - now start it up again. */
1468 
1469 		if (patch)
1470 			patch->host_scribble = cmd->host_scribble;
1471 		else
1472 			hostdata->disconnected_Q =
1473 			    (struct scsi_cmnd *) cmd->host_scribble;
1474 		hostdata->connected = cmd;
1475 
1476 		/* We don't need to worry about 'initialize_SCp()' or 'hostdata->busy[]'
1477 		 * because these things are preserved over a disconnect.
1478 		 * But we DO need to fix the DPD bit so it's correct for this command.
1479 		 */
1480 
1481 		if (cmd->sc_data_direction == DMA_TO_DEVICE)
1482 			write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
1483 		else
1484 			write_wd33c93(regs, WD_DESTINATION_ID,
1485 				      cmd->device->id | DSTID_DPD);
1486 		if (hostdata->level2 >= L2_RESELECT) {
1487 			write_wd33c93_count(regs, 0);	/* we want a DATA_PHASE interrupt */
1488 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
1489 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1490 			hostdata->state = S_RUNNING_LEVEL2;
1491 		} else
1492 			hostdata->state = S_CONNECTED;
1493 
1494 		    spin_unlock_irqrestore(&hostdata->lock, flags);
1495 		break;
1496 
1497 	default:
1498 		printk("--UNKNOWN INTERRUPT:%02x:%02x:%02x--", asr, sr, phs);
1499 		spin_unlock_irqrestore(&hostdata->lock, flags);
1500 	}
1501 
1502 	DB(DB_INTR, printk("} "))
1503 
1504 }
1505 
1506 static void
1507 reset_wd33c93(struct Scsi_Host *instance)
1508 {
1509 	struct WD33C93_hostdata *hostdata =
1510 	    (struct WD33C93_hostdata *) instance->hostdata;
1511 	const wd33c93_regs regs = hostdata->regs;
1512 	uchar sr;
1513 
1514 #ifdef CONFIG_SGI_IP22
1515 	{
1516 		int busycount = 0;
1517 		extern void sgiwd93_reset(unsigned long);
1518 		/* wait 'til the chip gets some time for us */
1519 		while ((read_aux_stat(regs) & ASR_BSY) && busycount++ < 100)
1520 			udelay (10);
1521 	/*
1522  	 * there are scsi devices out there, which manage to lock up
1523 	 * the wd33c93 in a busy condition. In this state it won't
1524 	 * accept the reset command. The only way to solve this is to
1525  	 * give the chip a hardware reset (if possible). The code below
1526 	 * does this for the SGI Indy, where this is possible
1527 	 */
1528 	/* still busy ? */
1529 	if (read_aux_stat(regs) & ASR_BSY)
1530 		sgiwd93_reset(instance->base); /* yeah, give it the hard one */
1531 	}
1532 #endif
1533 
1534 	write_wd33c93(regs, WD_OWN_ID, OWNID_EAF | OWNID_RAF |
1535 		      instance->this_id | hostdata->clock_freq);
1536 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1537 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
1538 		      calc_sync_xfer(hostdata->default_sx_per / 4,
1539 				     DEFAULT_SX_OFF, 0, hostdata->sx_table));
1540 	write_wd33c93(regs, WD_COMMAND, WD_CMD_RESET);
1541 
1542 
1543 #ifdef CONFIG_MVME147_SCSI
1544 	udelay(25);		/* The old wd33c93 on MVME147 needs this, at least */
1545 #endif
1546 
1547 	while (!(read_aux_stat(regs) & ASR_INT))
1548 		;
1549 	sr = read_wd33c93(regs, WD_SCSI_STATUS);
1550 
1551 	hostdata->microcode = read_wd33c93(regs, WD_CDB_1);
1552 	if (sr == 0x00)
1553 		hostdata->chip = C_WD33C93;
1554 	else if (sr == 0x01) {
1555 		write_wd33c93(regs, WD_QUEUE_TAG, 0xa5);	/* any random number */
1556 		sr = read_wd33c93(regs, WD_QUEUE_TAG);
1557 		if (sr == 0xa5) {
1558 			hostdata->chip = C_WD33C93B;
1559 			write_wd33c93(regs, WD_QUEUE_TAG, 0);
1560 		} else
1561 			hostdata->chip = C_WD33C93A;
1562 	} else
1563 		hostdata->chip = C_UNKNOWN_CHIP;
1564 
1565 	if (hostdata->chip != C_WD33C93B)	/* Fast SCSI unavailable */
1566 		hostdata->fast = 0;
1567 
1568 	write_wd33c93(regs, WD_TIMEOUT_PERIOD, TIMEOUT_PERIOD_VALUE);
1569 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1570 }
1571 
1572 int
1573 wd33c93_host_reset(struct scsi_cmnd * SCpnt)
1574 {
1575 	struct Scsi_Host *instance;
1576 	struct WD33C93_hostdata *hostdata;
1577 	int i;
1578 
1579 	instance = SCpnt->device->host;
1580 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1581 
1582 	printk("scsi%d: reset. ", instance->host_no);
1583 	disable_irq(instance->irq);
1584 
1585 	hostdata->dma_stop(instance, NULL, 0);
1586 	for (i = 0; i < 8; i++) {
1587 		hostdata->busy[i] = 0;
1588 		hostdata->sync_xfer[i] =
1589 			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
1590 					0, hostdata->sx_table);
1591 		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
1592 	}
1593 	hostdata->input_Q = NULL;
1594 	hostdata->selecting = NULL;
1595 	hostdata->connected = NULL;
1596 	hostdata->disconnected_Q = NULL;
1597 	hostdata->state = S_UNCONNECTED;
1598 	hostdata->dma = D_DMA_OFF;
1599 	hostdata->incoming_ptr = 0;
1600 	hostdata->outgoing_len = 0;
1601 
1602 	reset_wd33c93(instance);
1603 	SCpnt->result = DID_RESET << 16;
1604 	enable_irq(instance->irq);
1605 	return SUCCESS;
1606 }
1607 
1608 int
1609 wd33c93_abort(struct scsi_cmnd * cmd)
1610 {
1611 	struct Scsi_Host *instance;
1612 	struct WD33C93_hostdata *hostdata;
1613 	wd33c93_regs regs;
1614 	struct scsi_cmnd *tmp, *prev;
1615 
1616 	disable_irq(cmd->device->host->irq);
1617 
1618 	instance = cmd->device->host;
1619 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1620 	regs = hostdata->regs;
1621 
1622 /*
1623  * Case 1 : If the command hasn't been issued yet, we simply remove it
1624  *     from the input_Q.
1625  */
1626 
1627 	tmp = (struct scsi_cmnd *) hostdata->input_Q;
1628 	prev = NULL;
1629 	while (tmp) {
1630 		if (tmp == cmd) {
1631 			if (prev)
1632 				prev->host_scribble = cmd->host_scribble;
1633 			else
1634 				hostdata->input_Q =
1635 				    (struct scsi_cmnd *) cmd->host_scribble;
1636 			cmd->host_scribble = NULL;
1637 			cmd->result = DID_ABORT << 16;
1638 			printk
1639 			    ("scsi%d: Abort - removing command from input_Q. ",
1640 			     instance->host_no);
1641 			enable_irq(cmd->device->host->irq);
1642 			cmd->scsi_done(cmd);
1643 			return SUCCESS;
1644 		}
1645 		prev = tmp;
1646 		tmp = (struct scsi_cmnd *) tmp->host_scribble;
1647 	}
1648 
1649 /*
1650  * Case 2 : If the command is connected, we're going to fail the abort
1651  *     and let the high level SCSI driver retry at a later time or
1652  *     issue a reset.
1653  *
1654  *     Timeouts, and therefore aborted commands, will be highly unlikely
1655  *     and handling them cleanly in this situation would make the common
1656  *     case of noresets less efficient, and would pollute our code.  So,
1657  *     we fail.
1658  */
1659 
1660 	if (hostdata->connected == cmd) {
1661 		uchar sr, asr;
1662 		unsigned long timeout;
1663 
1664 		printk("scsi%d: Aborting connected command - ",
1665 		       instance->host_no);
1666 
1667 		printk("stopping DMA - ");
1668 		if (hostdata->dma == D_DMA_RUNNING) {
1669 			hostdata->dma_stop(instance, cmd, 0);
1670 			hostdata->dma = D_DMA_OFF;
1671 		}
1672 
1673 		printk("sending wd33c93 ABORT command - ");
1674 		write_wd33c93(regs, WD_CONTROL,
1675 			      CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1676 		write_wd33c93_cmd(regs, WD_CMD_ABORT);
1677 
1678 /* Now we have to attempt to flush out the FIFO... */
1679 
1680 		printk("flushing fifo - ");
1681 		timeout = 1000000;
1682 		do {
1683 			asr = read_aux_stat(regs);
1684 			if (asr & ASR_DBR)
1685 				read_wd33c93(regs, WD_DATA);
1686 		} while (!(asr & ASR_INT) && timeout-- > 0);
1687 		sr = read_wd33c93(regs, WD_SCSI_STATUS);
1688 		printk
1689 		    ("asr=%02x, sr=%02x, %ld bytes un-transferred (timeout=%ld) - ",
1690 		     asr, sr, read_wd33c93_count(regs), timeout);
1691 
1692 		/*
1693 		 * Abort command processed.
1694 		 * Still connected.
1695 		 * We must disconnect.
1696 		 */
1697 
1698 		printk("sending wd33c93 DISCONNECT command - ");
1699 		write_wd33c93_cmd(regs, WD_CMD_DISCONNECT);
1700 
1701 		timeout = 1000000;
1702 		asr = read_aux_stat(regs);
1703 		while ((asr & ASR_CIP) && timeout-- > 0)
1704 			asr = read_aux_stat(regs);
1705 		sr = read_wd33c93(regs, WD_SCSI_STATUS);
1706 		printk("asr=%02x, sr=%02x.", asr, sr);
1707 
1708 		hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
1709 		hostdata->connected = NULL;
1710 		hostdata->state = S_UNCONNECTED;
1711 		cmd->result = DID_ABORT << 16;
1712 
1713 /*      sti();*/
1714 		wd33c93_execute(instance);
1715 
1716 		enable_irq(cmd->device->host->irq);
1717 		cmd->scsi_done(cmd);
1718 		return SUCCESS;
1719 	}
1720 
1721 /*
1722  * Case 3: If the command is currently disconnected from the bus,
1723  * we're not going to expend much effort here: Let's just return
1724  * an ABORT_SNOOZE and hope for the best...
1725  */
1726 
1727 	tmp = (struct scsi_cmnd *) hostdata->disconnected_Q;
1728 	while (tmp) {
1729 		if (tmp == cmd) {
1730 			printk
1731 			    ("scsi%d: Abort - command found on disconnected_Q - ",
1732 			     instance->host_no);
1733 			printk("Abort SNOOZE. ");
1734 			enable_irq(cmd->device->host->irq);
1735 			return FAILED;
1736 		}
1737 		tmp = (struct scsi_cmnd *) tmp->host_scribble;
1738 	}
1739 
1740 /*
1741  * Case 4 : If we reached this point, the command was not found in any of
1742  *     the queues.
1743  *
1744  * We probably reached this point because of an unlikely race condition
1745  * between the command completing successfully and the abortion code,
1746  * so we won't panic, but we will notify the user in case something really
1747  * broke.
1748  */
1749 
1750 /*   sti();*/
1751 	wd33c93_execute(instance);
1752 
1753 	enable_irq(cmd->device->host->irq);
1754 	printk("scsi%d: warning : SCSI command probably completed successfully"
1755 	       "         before abortion. ", instance->host_no);
1756 	return FAILED;
1757 }
1758 
1759 #define MAX_WD33C93_HOSTS 4
1760 #define MAX_SETUP_ARGS ARRAY_SIZE(setup_args)
1761 #define SETUP_BUFFER_SIZE 200
1762 static char setup_buffer[SETUP_BUFFER_SIZE];
1763 static char setup_used[MAX_SETUP_ARGS];
1764 static int done_setup = 0;
1765 
1766 static int
1767 wd33c93_setup(char *str)
1768 {
1769 	int i;
1770 	char *p1, *p2;
1771 
1772 	/* The kernel does some processing of the command-line before calling
1773 	 * this function: If it begins with any decimal or hex number arguments,
1774 	 * ints[0] = how many numbers found and ints[1] through [n] are the values
1775 	 * themselves. str points to where the non-numeric arguments (if any)
1776 	 * start: We do our own parsing of those. We construct synthetic 'nosync'
1777 	 * keywords out of numeric args (to maintain compatibility with older
1778 	 * versions) and then add the rest of the arguments.
1779 	 */
1780 
1781 	p1 = setup_buffer;
1782 	*p1 = '\0';
1783 	if (str)
1784 		strncpy(p1, str, SETUP_BUFFER_SIZE - strlen(setup_buffer));
1785 	setup_buffer[SETUP_BUFFER_SIZE - 1] = '\0';
1786 	p1 = setup_buffer;
1787 	i = 0;
1788 	while (*p1 && (i < MAX_SETUP_ARGS)) {
1789 		p2 = strchr(p1, ',');
1790 		if (p2) {
1791 			*p2 = '\0';
1792 			if (p1 != p2)
1793 				setup_args[i] = p1;
1794 			p1 = p2 + 1;
1795 			i++;
1796 		} else {
1797 			setup_args[i] = p1;
1798 			break;
1799 		}
1800 	}
1801 	for (i = 0; i < MAX_SETUP_ARGS; i++)
1802 		setup_used[i] = 0;
1803 	done_setup = 1;
1804 
1805 	return 1;
1806 }
1807 __setup("wd33c93=", wd33c93_setup);
1808 
1809 /* check_setup_args() returns index if key found, 0 if not
1810  */
1811 static int
1812 check_setup_args(char *key, int *flags, int *val, char *buf)
1813 {
1814 	int x;
1815 	char *cp;
1816 
1817 	for (x = 0; x < MAX_SETUP_ARGS; x++) {
1818 		if (setup_used[x])
1819 			continue;
1820 		if (!strncmp(setup_args[x], key, strlen(key)))
1821 			break;
1822 		if (!strncmp(setup_args[x], "next", strlen("next")))
1823 			return 0;
1824 	}
1825 	if (x == MAX_SETUP_ARGS)
1826 		return 0;
1827 	setup_used[x] = 1;
1828 	cp = setup_args[x] + strlen(key);
1829 	*val = -1;
1830 	if (*cp != ':')
1831 		return ++x;
1832 	cp++;
1833 	if ((*cp >= '0') && (*cp <= '9')) {
1834 		*val = simple_strtoul(cp, NULL, 0);
1835 	}
1836 	return ++x;
1837 }
1838 
1839 /*
1840  * Calculate internal data-transfer-clock cycle from input-clock
1841  * frequency (/MHz) and fill 'sx_table'.
1842  *
1843  * The original driver used to rely on a fixed sx_table, containing periods
1844  * for (only) the lower limits of the respective input-clock-frequency ranges
1845  * (8-10/12-15/16-20 MHz). Although it seems, that no problems occurred with
1846  * this setting so far, it might be desirable to adjust the transfer periods
1847  * closer to the really attached, possibly 25% higher, input-clock, since
1848  * - the wd33c93 may really use a significant shorter period, than it has
1849  *   negotiated (eg. thrashing the target, which expects 4/8MHz, with 5/10MHz
1850  *   instead).
1851  * - the wd33c93 may ask the target for a lower transfer rate, than the target
1852  *   is capable of (eg. negotiating for an assumed minimum of 252ns instead of
1853  *   possible 200ns, which indeed shows up in tests as an approx. 10% lower
1854  *   transfer rate).
1855  */
1856 static inline unsigned int
1857 round_4(unsigned int x)
1858 {
1859 	switch (x & 3) {
1860 		case 1: --x;
1861 			break;
1862 		case 2: ++x;
1863 		case 3: ++x;
1864 	}
1865 	return x;
1866 }
1867 
1868 static void
1869 calc_sx_table(unsigned int mhz, struct sx_period sx_table[9])
1870 {
1871 	unsigned int d, i;
1872 	if (mhz < 11)
1873 		d = 2;	/* divisor for  8-10 MHz input-clock */
1874 	else if (mhz < 16)
1875 		d = 3;	/* divisor for 12-15 MHz input-clock */
1876 	else
1877 		d = 4;	/* divisor for 16-20 MHz input-clock */
1878 
1879 	d = (100000 * d) / 2 / mhz; /* 100 x DTCC / nanosec */
1880 
1881 	sx_table[0].period_ns = 1;
1882 	sx_table[0].reg_value = 0x20;
1883 	for (i = 1; i < 8; i++) {
1884 		sx_table[i].period_ns = round_4((i+1)*d / 100);
1885 		sx_table[i].reg_value = (i+1)*0x10;
1886 	}
1887 	sx_table[7].reg_value = 0;
1888 	sx_table[8].period_ns = 0;
1889 	sx_table[8].reg_value = 0;
1890 }
1891 
1892 /*
1893  * check and, maybe, map an init- or "clock:"- argument.
1894  */
1895 static uchar
1896 set_clk_freq(int freq, int *mhz)
1897 {
1898 	int x = freq;
1899 	if (WD33C93_FS_8_10 == freq)
1900 		freq = 8;
1901 	else if (WD33C93_FS_12_15 == freq)
1902 		freq = 12;
1903 	else if (WD33C93_FS_16_20 == freq)
1904 		freq = 16;
1905 	else if (freq > 7 && freq < 11)
1906 		x = WD33C93_FS_8_10;
1907 		else if (freq > 11 && freq < 16)
1908 		x = WD33C93_FS_12_15;
1909 		else if (freq > 15 && freq < 21)
1910 		x = WD33C93_FS_16_20;
1911 	else {
1912 			/* Hmm, wouldn't it be safer to assume highest freq here? */
1913 		x = WD33C93_FS_8_10;
1914 		freq = 8;
1915 	}
1916 	*mhz = freq;
1917 	return x;
1918 }
1919 
1920 /*
1921  * to be used with the resync: fast: ... options
1922  */
1923 static inline void set_resync ( struct WD33C93_hostdata *hd, int mask )
1924 {
1925 	int i;
1926 	for (i = 0; i < 8; i++)
1927 		if (mask & (1 << i))
1928 			hd->sync_stat[i] = SS_UNSET;
1929 }
1930 
1931 void
1932 wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
1933 	     dma_setup_t setup, dma_stop_t stop, int clock_freq)
1934 {
1935 	struct WD33C93_hostdata *hostdata;
1936 	int i;
1937 	int flags;
1938 	int val;
1939 	char buf[32];
1940 
1941 	if (!done_setup && setup_strings)
1942 		wd33c93_setup(setup_strings);
1943 
1944 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1945 
1946 	hostdata->regs = regs;
1947 	hostdata->clock_freq = set_clk_freq(clock_freq, &i);
1948 	calc_sx_table(i, hostdata->sx_table);
1949 	hostdata->dma_setup = setup;
1950 	hostdata->dma_stop = stop;
1951 	hostdata->dma_bounce_buffer = NULL;
1952 	hostdata->dma_bounce_len = 0;
1953 	for (i = 0; i < 8; i++) {
1954 		hostdata->busy[i] = 0;
1955 		hostdata->sync_xfer[i] =
1956 			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
1957 					0, hostdata->sx_table);
1958 		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
1959 #ifdef PROC_STATISTICS
1960 		hostdata->cmd_cnt[i] = 0;
1961 		hostdata->disc_allowed_cnt[i] = 0;
1962 		hostdata->disc_done_cnt[i] = 0;
1963 #endif
1964 	}
1965 	hostdata->input_Q = NULL;
1966 	hostdata->selecting = NULL;
1967 	hostdata->connected = NULL;
1968 	hostdata->disconnected_Q = NULL;
1969 	hostdata->state = S_UNCONNECTED;
1970 	hostdata->dma = D_DMA_OFF;
1971 	hostdata->level2 = L2_BASIC;
1972 	hostdata->disconnect = DIS_ADAPTIVE;
1973 	hostdata->args = DEBUG_DEFAULTS;
1974 	hostdata->incoming_ptr = 0;
1975 	hostdata->outgoing_len = 0;
1976 	hostdata->default_sx_per = DEFAULT_SX_PER;
1977 	hostdata->no_dma = 0;	/* default is DMA enabled */
1978 
1979 #ifdef PROC_INTERFACE
1980 	hostdata->proc = PR_VERSION | PR_INFO | PR_STATISTICS |
1981 	    PR_CONNECTED | PR_INPUTQ | PR_DISCQ | PR_STOP;
1982 #ifdef PROC_STATISTICS
1983 	hostdata->dma_cnt = 0;
1984 	hostdata->pio_cnt = 0;
1985 	hostdata->int_cnt = 0;
1986 #endif
1987 #endif
1988 
1989 	if (check_setup_args("clock", &flags, &val, buf)) {
1990 		hostdata->clock_freq = set_clk_freq(val, &val);
1991 		calc_sx_table(val, hostdata->sx_table);
1992 	}
1993 
1994 	if (check_setup_args("nosync", &flags, &val, buf))
1995 		hostdata->no_sync = val;
1996 
1997 	if (check_setup_args("nodma", &flags, &val, buf))
1998 		hostdata->no_dma = (val == -1) ? 1 : val;
1999 
2000 	if (check_setup_args("period", &flags, &val, buf))
2001 		hostdata->default_sx_per =
2002 		    hostdata->sx_table[round_period((unsigned int) val,
2003 		                                    hostdata->sx_table)].period_ns;
2004 
2005 	if (check_setup_args("disconnect", &flags, &val, buf)) {
2006 		if ((val >= DIS_NEVER) && (val <= DIS_ALWAYS))
2007 			hostdata->disconnect = val;
2008 		else
2009 			hostdata->disconnect = DIS_ADAPTIVE;
2010 	}
2011 
2012 	if (check_setup_args("level2", &flags, &val, buf))
2013 		hostdata->level2 = val;
2014 
2015 	if (check_setup_args("debug", &flags, &val, buf))
2016 		hostdata->args = val & DB_MASK;
2017 
2018 	if (check_setup_args("burst", &flags, &val, buf))
2019 		hostdata->dma_mode = val ? CTRL_BURST:CTRL_DMA;
2020 
2021 	if (WD33C93_FS_16_20 == hostdata->clock_freq /* divisor 4 */
2022 		&& check_setup_args("fast", &flags, &val, buf))
2023 		hostdata->fast = !!val;
2024 
2025 	if ((i = check_setup_args("next", &flags, &val, buf))) {
2026 		while (i)
2027 			setup_used[--i] = 1;
2028 	}
2029 #ifdef PROC_INTERFACE
2030 	if (check_setup_args("proc", &flags, &val, buf))
2031 		hostdata->proc = val;
2032 #endif
2033 
2034 	spin_lock_irq(&hostdata->lock);
2035 	reset_wd33c93(instance);
2036 	spin_unlock_irq(&hostdata->lock);
2037 
2038 	printk("wd33c93-%d: chip=%s/%d no_sync=0x%x no_dma=%d",
2039 	       instance->host_no,
2040 	       (hostdata->chip == C_WD33C93) ? "WD33c93" : (hostdata->chip ==
2041 							    C_WD33C93A) ?
2042 	       "WD33c93A" : (hostdata->chip ==
2043 			     C_WD33C93B) ? "WD33c93B" : "unknown",
2044 	       hostdata->microcode, hostdata->no_sync, hostdata->no_dma);
2045 #ifdef DEBUGGING_ON
2046 	printk(" debug_flags=0x%02x\n", hostdata->args);
2047 #else
2048 	printk(" debugging=OFF\n");
2049 #endif
2050 	printk("           setup_args=");
2051 	for (i = 0; i < MAX_SETUP_ARGS; i++)
2052 		printk("%s,", setup_args[i]);
2053 	printk("\n");
2054 	printk("           Version %s - %s\n", WD33C93_VERSION, WD33C93_DATE);
2055 }
2056 
2057 int wd33c93_write_info(struct Scsi_Host *instance, char *buf, int len)
2058 {
2059 #ifdef PROC_INTERFACE
2060 	char *bp;
2061 	struct WD33C93_hostdata *hd;
2062 	int x;
2063 
2064 	hd = (struct WD33C93_hostdata *) instance->hostdata;
2065 
2066 /* We accept the following
2067  * keywords (same format as command-line, but arguments are not optional):
2068  *    debug
2069  *    disconnect
2070  *    period
2071  *    resync
2072  *    proc
2073  *    nodma
2074  *    level2
2075  *    burst
2076  *    fast
2077  *    nosync
2078  */
2079 
2080 	buf[len] = '\0';
2081 	for (bp = buf; *bp; ) {
2082 		while (',' == *bp || ' ' == *bp)
2083 			++bp;
2084 	if (!strncmp(bp, "debug:", 6)) {
2085 			hd->args = simple_strtoul(bp+6, &bp, 0) & DB_MASK;
2086 	} else if (!strncmp(bp, "disconnect:", 11)) {
2087 			x = simple_strtoul(bp+11, &bp, 0);
2088 		if (x < DIS_NEVER || x > DIS_ALWAYS)
2089 			x = DIS_ADAPTIVE;
2090 		hd->disconnect = x;
2091 	} else if (!strncmp(bp, "period:", 7)) {
2092 		x = simple_strtoul(bp+7, &bp, 0);
2093 		hd->default_sx_per =
2094 			hd->sx_table[round_period((unsigned int) x,
2095 						  hd->sx_table)].period_ns;
2096 	} else if (!strncmp(bp, "resync:", 7)) {
2097 			set_resync(hd, (int)simple_strtoul(bp+7, &bp, 0));
2098 	} else if (!strncmp(bp, "proc:", 5)) {
2099 			hd->proc = simple_strtoul(bp+5, &bp, 0);
2100 	} else if (!strncmp(bp, "nodma:", 6)) {
2101 			hd->no_dma = simple_strtoul(bp+6, &bp, 0);
2102 	} else if (!strncmp(bp, "level2:", 7)) {
2103 			hd->level2 = simple_strtoul(bp+7, &bp, 0);
2104 		} else if (!strncmp(bp, "burst:", 6)) {
2105 			hd->dma_mode =
2106 				simple_strtol(bp+6, &bp, 0) ? CTRL_BURST:CTRL_DMA;
2107 		} else if (!strncmp(bp, "fast:", 5)) {
2108 			x = !!simple_strtol(bp+5, &bp, 0);
2109 			if (x != hd->fast)
2110 				set_resync(hd, 0xff);
2111 			hd->fast = x;
2112 		} else if (!strncmp(bp, "nosync:", 7)) {
2113 			x = simple_strtoul(bp+7, &bp, 0);
2114 			set_resync(hd, x ^ hd->no_sync);
2115 			hd->no_sync = x;
2116 		} else {
2117 			break; /* unknown keyword,syntax-error,... */
2118 		}
2119 	}
2120 	return len;
2121 #else
2122 	return 0;
2123 #endif
2124 }
2125 
2126 int
2127 wd33c93_show_info(struct seq_file *m, struct Scsi_Host *instance)
2128 {
2129 #ifdef PROC_INTERFACE
2130 	struct WD33C93_hostdata *hd;
2131 	struct scsi_cmnd *cmd;
2132 	int x;
2133 
2134 	hd = (struct WD33C93_hostdata *) instance->hostdata;
2135 
2136 	spin_lock_irq(&hd->lock);
2137 	if (hd->proc & PR_VERSION)
2138 		seq_printf(m, "\nVersion %s - %s.",
2139 			WD33C93_VERSION, WD33C93_DATE);
2140 
2141 	if (hd->proc & PR_INFO) {
2142 		seq_printf(m, "\nclock_freq=%02x no_sync=%02x no_dma=%d"
2143 			" dma_mode=%02x fast=%d",
2144 			hd->clock_freq, hd->no_sync, hd->no_dma, hd->dma_mode, hd->fast);
2145 		seq_printf(m, "\nsync_xfer[] =       ");
2146 		for (x = 0; x < 7; x++)
2147 			seq_printf(m, "\t%02x", hd->sync_xfer[x]);
2148 		seq_printf(m, "\nsync_stat[] =       ");
2149 		for (x = 0; x < 7; x++)
2150 			seq_printf(m, "\t%02x", hd->sync_stat[x]);
2151 	}
2152 #ifdef PROC_STATISTICS
2153 	if (hd->proc & PR_STATISTICS) {
2154 		seq_printf(m, "\ncommands issued:    ");
2155 		for (x = 0; x < 7; x++)
2156 			seq_printf(m, "\t%ld", hd->cmd_cnt[x]);
2157 		seq_printf(m, "\ndisconnects allowed:");
2158 		for (x = 0; x < 7; x++)
2159 			seq_printf(m, "\t%ld", hd->disc_allowed_cnt[x]);
2160 		seq_printf(m, "\ndisconnects done:   ");
2161 		for (x = 0; x < 7; x++)
2162 			seq_printf(m, "\t%ld", hd->disc_done_cnt[x]);
2163 		seq_printf(m,
2164 			"\ninterrupts: %ld, DATA_PHASE ints: %ld DMA, %ld PIO",
2165 			hd->int_cnt, hd->dma_cnt, hd->pio_cnt);
2166 	}
2167 #endif
2168 	if (hd->proc & PR_CONNECTED) {
2169 		seq_printf(m, "\nconnected:     ");
2170 		if (hd->connected) {
2171 			cmd = (struct scsi_cmnd *) hd->connected;
2172 			seq_printf(m, " %d:%d(%02x)",
2173 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2174 		}
2175 	}
2176 	if (hd->proc & PR_INPUTQ) {
2177 		seq_printf(m, "\ninput_Q:       ");
2178 		cmd = (struct scsi_cmnd *) hd->input_Q;
2179 		while (cmd) {
2180 			seq_printf(m, " %d:%d(%02x)",
2181 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2182 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
2183 		}
2184 	}
2185 	if (hd->proc & PR_DISCQ) {
2186 		seq_printf(m, "\ndisconnected_Q:");
2187 		cmd = (struct scsi_cmnd *) hd->disconnected_Q;
2188 		while (cmd) {
2189 			seq_printf(m, " %d:%d(%02x)",
2190 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2191 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
2192 		}
2193 	}
2194 	seq_printf(m, "\n");
2195 	spin_unlock_irq(&hd->lock);
2196 #endif				/* PROC_INTERFACE */
2197 	return 0;
2198 }
2199 
2200 EXPORT_SYMBOL(wd33c93_host_reset);
2201 EXPORT_SYMBOL(wd33c93_init);
2202 EXPORT_SYMBOL(wd33c93_abort);
2203 EXPORT_SYMBOL(wd33c93_queuecommand);
2204 EXPORT_SYMBOL(wd33c93_intr);
2205 EXPORT_SYMBOL(wd33c93_show_info);
2206 EXPORT_SYMBOL(wd33c93_write_info);
2207