xref: /linux/drivers/scsi/wd33c93.c (revision fde668244d1d8d490b5b9daf53fe4f92a6751773)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 1996 John Shifflett, GeoLog Consulting
4  *    john@geolog.com
5  *    jshiffle@netcom.com
6  */
7 
8 /*
9  * Drew Eckhardt's excellent 'Generic NCR5380' sources from Linux-PC
10  * provided much of the inspiration and some of the code for this
11  * driver. Everything I know about Amiga DMA was gleaned from careful
12  * reading of Hamish Mcdonald's original wd33c93 driver; in fact, I
13  * borrowed shamelessly from all over that source. Thanks Hamish!
14  *
15  * _This_ driver is (I feel) an improvement over the old one in
16  * several respects:
17  *
18  *    -  Target Disconnection/Reconnection  is now supported. Any
19  *          system with more than one device active on the SCSI bus
20  *          will benefit from this. The driver defaults to what I
21  *          call 'adaptive disconnect' - meaning that each command
22  *          is evaluated individually as to whether or not it should
23  *          be run with the option to disconnect/reselect (if the
24  *          device chooses), or as a "SCSI-bus-hog".
25  *
26  *    -  Synchronous data transfers are now supported. Because of
27  *          a few devices that choke after telling the driver that
28  *          they can do sync transfers, we don't automatically use
29  *          this faster protocol - it can be enabled via the command-
30  *          line on a device-by-device basis.
31  *
32  *    -  Runtime operating parameters can now be specified through
33  *       the 'amiboot' or the 'insmod' command line. For amiboot do:
34  *          "amiboot [usual stuff] wd33c93=blah,blah,blah"
35  *       The defaults should be good for most people. See the comment
36  *       for 'setup_strings' below for more details.
37  *
38  *    -  The old driver relied exclusively on what the Western Digital
39  *          docs call "Combination Level 2 Commands", which are a great
40  *          idea in that the CPU is relieved of a lot of interrupt
41  *          overhead. However, by accepting a certain (user-settable)
42  *          amount of additional interrupts, this driver achieves
43  *          better control over the SCSI bus, and data transfers are
44  *          almost as fast while being much easier to define, track,
45  *          and debug.
46  *
47  *
48  * TODO:
49  *       more speed. linked commands.
50  *
51  *
52  * People with bug reports, wish-lists, complaints, comments,
53  * or improvements are asked to pah-leeez email me (John Shifflett)
54  * at john@geolog.com or jshiffle@netcom.com! I'm anxious to get
55  * this thing into as good a shape as possible, and I'm positive
56  * there are lots of lurking bugs and "Stupid Places".
57  *
58  * Updates:
59  *
60  * Added support for pre -A chips, which don't have advanced features
61  * and will generate CSR_RESEL rather than CSR_RESEL_AM.
62  *	Richard Hirst <richard@sleepie.demon.co.uk>  August 2000
63  *
64  * Added support for Burst Mode DMA and Fast SCSI. Enabled the use of
65  * default_sx_per for asynchronous data transfers. Added adjustment
66  * of transfer periods in sx_table to the actual input-clock.
67  *  peter fuerst <post@pfrst.de>  February 2007
68  */
69 
70 #include <linux/module.h>
71 
72 #include <linux/string.h>
73 #include <linux/delay.h>
74 #include <linux/init.h>
75 #include <linux/interrupt.h>
76 #include <linux/blkdev.h>
77 
78 #include <scsi/scsi.h>
79 #include <scsi/scsi_cmnd.h>
80 #include <scsi/scsi_device.h>
81 #include <scsi/scsi_host.h>
82 
83 #include <asm/irq.h>
84 
85 #include "wd33c93.h"
86 
87 #define optimum_sx_per(hostdata) (hostdata)->sx_table[1].period_ns
88 
89 
90 #define WD33C93_VERSION    "1.26++"
91 #define WD33C93_DATE       "10/Feb/2007"
92 
93 MODULE_AUTHOR("John Shifflett");
94 MODULE_DESCRIPTION("Generic WD33C93 SCSI driver");
95 MODULE_LICENSE("GPL");
96 
97 /*
98  * 'setup_strings' is a single string used to pass operating parameters and
99  * settings from the kernel/module command-line to the driver. 'setup_args[]'
100  * is an array of strings that define the compile-time default values for
101  * these settings. If Linux boots with an amiboot or insmod command-line,
102  * those settings are combined with 'setup_args[]'. Note that amiboot
103  * command-lines are prefixed with "wd33c93=" while insmod uses a
104  * "setup_strings=" prefix. The driver recognizes the following keywords
105  * (lower case required) and arguments:
106  *
107  * -  nosync:bitmask -bitmask is a byte where the 1st 7 bits correspond with
108  *                    the 7 possible SCSI devices. Set a bit to negotiate for
109  *                    asynchronous transfers on that device. To maintain
110  *                    backwards compatibility, a command-line such as
111  *                    "wd33c93=255" will be automatically translated to
112  *                    "wd33c93=nosync:0xff".
113  * -  nodma:x        -x = 1 to disable DMA, x = 0 to enable it. Argument is
114  *                    optional - if not present, same as "nodma:1".
115  * -  period:ns      -ns is the minimum # of nanoseconds in a SCSI data transfer
116  *                    period. Default is 500; acceptable values are 250 - 1000.
117  * -  disconnect:x   -x = 0 to never allow disconnects, 2 to always allow them.
118  *                    x = 1 does 'adaptive' disconnects, which is the default
119  *                    and generally the best choice.
120  * -  debug:x        -If 'DEBUGGING_ON' is defined, x is a bit mask that causes
121  *                    various types of debug output to printed - see the DB_xxx
122  *                    defines in wd33c93.h
123  * -  clock:x        -x = clock input in MHz for WD33c93 chip. Normal values
124  *                    would be from 8 through 20. Default is 8.
125  * -  burst:x        -x = 1 to use Burst Mode (or Demand-Mode) DMA, x = 0 to use
126  *                    Single Byte DMA, which is the default. Argument is
127  *                    optional - if not present, same as "burst:1".
128  * -  fast:x         -x = 1 to enable Fast SCSI, which is only effective with
129  *                    input-clock divisor 4 (WD33C93_FS_16_20), x = 0 to disable
130  *                    it, which is the default.  Argument is optional - if not
131  *                    present, same as "fast:1".
132  * -  next           -No argument. Used to separate blocks of keywords when
133  *                    there's more than one host adapter in the system.
134  *
135  * Syntax Notes:
136  * -  Numeric arguments can be decimal or the '0x' form of hex notation. There
137  *    _must_ be a colon between a keyword and its numeric argument, with no
138  *    spaces.
139  * -  Keywords are separated by commas, no spaces, in the standard kernel
140  *    command-line manner.
141  * -  A keyword in the 'nth' comma-separated command-line member will overwrite
142  *    the 'nth' element of setup_args[]. A blank command-line member (in
143  *    other words, a comma with no preceding keyword) will _not_ overwrite
144  *    the corresponding setup_args[] element.
145  * -  If a keyword is used more than once, the first one applies to the first
146  *    SCSI host found, the second to the second card, etc, unless the 'next'
147  *    keyword is used to change the order.
148  *
149  * Some amiboot examples (for insmod, use 'setup_strings' instead of 'wd33c93'):
150  * -  wd33c93=nosync:255
151  * -  wd33c93=nodma
152  * -  wd33c93=nodma:1
153  * -  wd33c93=disconnect:2,nosync:0x08,period:250
154  * -  wd33c93=debug:0x1c
155  */
156 
157 /* Normally, no defaults are specified */
158 static char *setup_args[] = { "", "", "", "", "", "", "", "", "", "" };
159 
160 static char *setup_strings;
161 module_param(setup_strings, charp, 0);
162 
163 static void wd33c93_execute(struct Scsi_Host *instance);
164 
165 #ifdef CONFIG_WD33C93_PIO
166 static inline uchar
167 read_wd33c93(const wd33c93_regs regs, uchar reg_num)
168 {
169 	uchar data;
170 
171 	outb(reg_num, regs.SASR);
172 	data = inb(regs.SCMD);
173 	return data;
174 }
175 
176 static inline unsigned long
177 read_wd33c93_count(const wd33c93_regs regs)
178 {
179 	unsigned long value;
180 
181 	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
182 	value = inb(regs.SCMD) << 16;
183 	value |= inb(regs.SCMD) << 8;
184 	value |= inb(regs.SCMD);
185 	return value;
186 }
187 
188 static inline uchar
189 read_aux_stat(const wd33c93_regs regs)
190 {
191 	return inb(regs.SASR);
192 }
193 
194 static inline void
195 write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
196 {
197       outb(reg_num, regs.SASR);
198       outb(value, regs.SCMD);
199 }
200 
201 static inline void
202 write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
203 {
204 	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
205 	outb((value >> 16) & 0xff, regs.SCMD);
206 	outb((value >> 8) & 0xff, regs.SCMD);
207 	outb( value & 0xff, regs.SCMD);
208 }
209 
210 #define write_wd33c93_cmd(regs, cmd) \
211 	write_wd33c93((regs), WD_COMMAND, (cmd))
212 
213 static inline void
214 write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
215 {
216 	int i;
217 
218 	outb(WD_CDB_1, regs.SASR);
219 	for (i=0; i<len; i++)
220 		outb(cmnd[i], regs.SCMD);
221 }
222 
223 #else /* CONFIG_WD33C93_PIO */
224 static inline uchar
225 read_wd33c93(const wd33c93_regs regs, uchar reg_num)
226 {
227 	*regs.SASR = reg_num;
228 	mb();
229 	return (*regs.SCMD);
230 }
231 
232 static unsigned long
233 read_wd33c93_count(const wd33c93_regs regs)
234 {
235 	unsigned long value;
236 
237 	*regs.SASR = WD_TRANSFER_COUNT_MSB;
238 	mb();
239 	value = *regs.SCMD << 16;
240 	value |= *regs.SCMD << 8;
241 	value |= *regs.SCMD;
242 	mb();
243 	return value;
244 }
245 
246 static inline uchar
247 read_aux_stat(const wd33c93_regs regs)
248 {
249 	return *regs.SASR;
250 }
251 
252 static inline void
253 write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
254 {
255 	*regs.SASR = reg_num;
256 	mb();
257 	*regs.SCMD = value;
258 	mb();
259 }
260 
261 static void
262 write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
263 {
264 	*regs.SASR = WD_TRANSFER_COUNT_MSB;
265 	mb();
266 	*regs.SCMD = value >> 16;
267 	*regs.SCMD = value >> 8;
268 	*regs.SCMD = value;
269 	mb();
270 }
271 
272 static inline void
273 write_wd33c93_cmd(const wd33c93_regs regs, uchar cmd)
274 {
275 	*regs.SASR = WD_COMMAND;
276 	mb();
277 	*regs.SCMD = cmd;
278 	mb();
279 }
280 
281 static inline void
282 write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
283 {
284 	int i;
285 
286 	*regs.SASR = WD_CDB_1;
287 	for (i = 0; i < len; i++)
288 		*regs.SCMD = cmnd[i];
289 }
290 #endif /* CONFIG_WD33C93_PIO */
291 
292 static inline uchar
293 read_1_byte(const wd33c93_regs regs)
294 {
295 	uchar asr;
296 	uchar x = 0;
297 
298 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
299 	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO | 0x80);
300 	do {
301 		asr = read_aux_stat(regs);
302 		if (asr & ASR_DBR)
303 			x = read_wd33c93(regs, WD_DATA);
304 	} while (!(asr & ASR_INT));
305 	return x;
306 }
307 
308 static int
309 round_period(unsigned int period, const struct sx_period *sx_table)
310 {
311 	int x;
312 
313 	for (x = 1; sx_table[x].period_ns; x++) {
314 		if ((period <= sx_table[x - 0].period_ns) &&
315 		    (period > sx_table[x - 1].period_ns)) {
316 			return x;
317 		}
318 	}
319 	return 7;
320 }
321 
322 /*
323  * Calculate Synchronous Transfer Register value from SDTR code.
324  */
325 static uchar
326 calc_sync_xfer(unsigned int period, unsigned int offset, unsigned int fast,
327                const struct sx_period *sx_table)
328 {
329 	/* When doing Fast SCSI synchronous data transfers, the corresponding
330 	 * value in 'sx_table' is two times the actually used transfer period.
331 	 */
332 	uchar result;
333 
334 	if (offset && fast) {
335 		fast = STR_FSS;
336 		period *= 2;
337 	} else {
338 		fast = 0;
339 	}
340 	period *= 4;		/* convert SDTR code to ns */
341 	result = sx_table[round_period(period,sx_table)].reg_value;
342 	result |= (offset < OPTIMUM_SX_OFF) ? offset : OPTIMUM_SX_OFF;
343 	result |= fast;
344 	return result;
345 }
346 
347 /*
348  * Calculate SDTR code bytes [3],[4] from period and offset.
349  */
350 static inline void
351 calc_sync_msg(unsigned int period, unsigned int offset, unsigned int fast,
352                 uchar  msg[2])
353 {
354 	/* 'period' is a "normal"-mode value, like the ones in 'sx_table'. The
355 	 * actually used transfer period for Fast SCSI synchronous data
356 	 * transfers is half that value.
357 	 */
358 	period /= 4;
359 	if (offset && fast)
360 		period /= 2;
361 	msg[0] = period;
362 	msg[1] = offset;
363 }
364 
365 static int
366 wd33c93_queuecommand_lck(struct scsi_cmnd *cmd,
367 		void (*done)(struct scsi_cmnd *))
368 {
369 	struct WD33C93_hostdata *hostdata;
370 	struct scsi_cmnd *tmp;
371 
372 	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
373 
374 	DB(DB_QUEUE_COMMAND,
375 	   printk("Q-%d-%02x( ", cmd->device->id, cmd->cmnd[0]))
376 
377 /* Set up a few fields in the scsi_cmnd structure for our own use:
378  *  - host_scribble is the pointer to the next cmd in the input queue
379  *  - scsi_done points to the routine we call when a cmd is finished
380  *  - result is what you'd expect
381  */
382 	cmd->host_scribble = NULL;
383 	cmd->scsi_done = done;
384 	cmd->result = 0;
385 
386 /* We use the Scsi_Pointer structure that's included with each command
387  * as a scratchpad (as it's intended to be used!). The handy thing about
388  * the SCp.xxx fields is that they're always associated with a given
389  * cmd, and are preserved across disconnect-reselect. This means we
390  * can pretty much ignore SAVE_POINTERS and RESTORE_POINTERS messages
391  * if we keep all the critical pointers and counters in SCp:
392  *  - SCp.ptr is the pointer into the RAM buffer
393  *  - SCp.this_residual is the size of that buffer
394  *  - SCp.buffer points to the current scatter-gather buffer
395  *  - SCp.buffers_residual tells us how many S.G. buffers there are
396  *  - SCp.have_data_in is not used
397  *  - SCp.sent_command is not used
398  *  - SCp.phase records this command's SRCID_ER bit setting
399  */
400 
401 	if (scsi_bufflen(cmd)) {
402 		cmd->SCp.buffer = scsi_sglist(cmd);
403 		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
404 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
405 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
406 	} else {
407 		cmd->SCp.buffer = NULL;
408 		cmd->SCp.buffers_residual = 0;
409 		cmd->SCp.ptr = NULL;
410 		cmd->SCp.this_residual = 0;
411 	}
412 
413 /* WD docs state that at the conclusion of a "LEVEL2" command, the
414  * status byte can be retrieved from the LUN register. Apparently,
415  * this is the case only for *uninterrupted* LEVEL2 commands! If
416  * there are any unexpected phases entered, even if they are 100%
417  * legal (different devices may choose to do things differently),
418  * the LEVEL2 command sequence is exited. This often occurs prior
419  * to receiving the status byte, in which case the driver does a
420  * status phase interrupt and gets the status byte on its own.
421  * While such a command can then be "resumed" (ie restarted to
422  * finish up as a LEVEL2 command), the LUN register will NOT be
423  * a valid status byte at the command's conclusion, and we must
424  * use the byte obtained during the earlier interrupt. Here, we
425  * preset SCp.Status to an illegal value (0xff) so that when
426  * this command finally completes, we can tell where the actual
427  * status byte is stored.
428  */
429 
430 	cmd->SCp.Status = ILLEGAL_STATUS_BYTE;
431 
432 	/*
433 	 * Add the cmd to the end of 'input_Q'. Note that REQUEST SENSE
434 	 * commands are added to the head of the queue so that the desired
435 	 * sense data is not lost before REQUEST_SENSE executes.
436 	 */
437 
438 	spin_lock_irq(&hostdata->lock);
439 
440 	if (!(hostdata->input_Q) || (cmd->cmnd[0] == REQUEST_SENSE)) {
441 		cmd->host_scribble = (uchar *) hostdata->input_Q;
442 		hostdata->input_Q = cmd;
443 	} else {		/* find the end of the queue */
444 		for (tmp = (struct scsi_cmnd *) hostdata->input_Q;
445 		     tmp->host_scribble;
446 		     tmp = (struct scsi_cmnd *) tmp->host_scribble) ;
447 		tmp->host_scribble = (uchar *) cmd;
448 	}
449 
450 /* We know that there's at least one command in 'input_Q' now.
451  * Go see if any of them are runnable!
452  */
453 
454 	wd33c93_execute(cmd->device->host);
455 
456 	DB(DB_QUEUE_COMMAND, printk(")Q "))
457 
458 	spin_unlock_irq(&hostdata->lock);
459 	return 0;
460 }
461 
462 DEF_SCSI_QCMD(wd33c93_queuecommand)
463 
464 /*
465  * This routine attempts to start a scsi command. If the host_card is
466  * already connected, we give up immediately. Otherwise, look through
467  * the input_Q, using the first command we find that's intended
468  * for a currently non-busy target/lun.
469  *
470  * wd33c93_execute() is always called with interrupts disabled or from
471  * the wd33c93_intr itself, which means that a wd33c93 interrupt
472  * cannot occur while we are in here.
473  */
474 static void
475 wd33c93_execute(struct Scsi_Host *instance)
476 {
477 	struct WD33C93_hostdata *hostdata =
478 	    (struct WD33C93_hostdata *) instance->hostdata;
479 	const wd33c93_regs regs = hostdata->regs;
480 	struct scsi_cmnd *cmd, *prev;
481 
482 	DB(DB_EXECUTE, printk("EX("))
483 	if (hostdata->selecting || hostdata->connected) {
484 		DB(DB_EXECUTE, printk(")EX-0 "))
485 		return;
486 	}
487 
488 	/*
489 	 * Search through the input_Q for a command destined
490 	 * for an idle target/lun.
491 	 */
492 
493 	cmd = (struct scsi_cmnd *) hostdata->input_Q;
494 	prev = NULL;
495 	while (cmd) {
496 		if (!(hostdata->busy[cmd->device->id] &
497 		      (1 << (cmd->device->lun & 0xff))))
498 			break;
499 		prev = cmd;
500 		cmd = (struct scsi_cmnd *) cmd->host_scribble;
501 	}
502 
503 	/* quit if queue empty or all possible targets are busy */
504 
505 	if (!cmd) {
506 		DB(DB_EXECUTE, printk(")EX-1 "))
507 		return;
508 	}
509 
510 	/*  remove command from queue */
511 
512 	if (prev)
513 		prev->host_scribble = cmd->host_scribble;
514 	else
515 		hostdata->input_Q = (struct scsi_cmnd *) cmd->host_scribble;
516 
517 #ifdef PROC_STATISTICS
518 	hostdata->cmd_cnt[cmd->device->id]++;
519 #endif
520 
521 	/*
522 	 * Start the selection process
523 	 */
524 
525 	if (cmd->sc_data_direction == DMA_TO_DEVICE)
526 		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
527 	else
528 		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id | DSTID_DPD);
529 
530 /* Now we need to figure out whether or not this command is a good
531  * candidate for disconnect/reselect. We guess to the best of our
532  * ability, based on a set of hierarchical rules. When several
533  * devices are operating simultaneously, disconnects are usually
534  * an advantage. In a single device system, or if only 1 device
535  * is being accessed, transfers usually go faster if disconnects
536  * are not allowed:
537  *
538  * + Commands should NEVER disconnect if hostdata->disconnect =
539  *   DIS_NEVER (this holds for tape drives also), and ALWAYS
540  *   disconnect if hostdata->disconnect = DIS_ALWAYS.
541  * + Tape drive commands should always be allowed to disconnect.
542  * + Disconnect should be allowed if disconnected_Q isn't empty.
543  * + Commands should NOT disconnect if input_Q is empty.
544  * + Disconnect should be allowed if there are commands in input_Q
545  *   for a different target/lun. In this case, the other commands
546  *   should be made disconnect-able, if not already.
547  *
548  * I know, I know - this code would flunk me out of any
549  * "C Programming 101" class ever offered. But it's easy
550  * to change around and experiment with for now.
551  */
552 
553 	cmd->SCp.phase = 0;	/* assume no disconnect */
554 	if (hostdata->disconnect == DIS_NEVER)
555 		goto no;
556 	if (hostdata->disconnect == DIS_ALWAYS)
557 		goto yes;
558 	if (cmd->device->type == 1)	/* tape drive? */
559 		goto yes;
560 	if (hostdata->disconnected_Q)	/* other commands disconnected? */
561 		goto yes;
562 	if (!(hostdata->input_Q))	/* input_Q empty? */
563 		goto no;
564 	for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
565 	     prev = (struct scsi_cmnd *) prev->host_scribble) {
566 		if ((prev->device->id != cmd->device->id) ||
567 		    (prev->device->lun != cmd->device->lun)) {
568 			for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
569 			     prev = (struct scsi_cmnd *) prev->host_scribble)
570 				prev->SCp.phase = 1;
571 			goto yes;
572 		}
573 	}
574 
575 	goto no;
576 
577  yes:
578 	cmd->SCp.phase = 1;
579 
580 #ifdef PROC_STATISTICS
581 	hostdata->disc_allowed_cnt[cmd->device->id]++;
582 #endif
583 
584  no:
585 
586 	write_wd33c93(regs, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0));
587 
588 	write_wd33c93(regs, WD_TARGET_LUN, (u8)cmd->device->lun);
589 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
590 		      hostdata->sync_xfer[cmd->device->id]);
591 	hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
592 
593 	if ((hostdata->level2 == L2_NONE) ||
594 	    (hostdata->sync_stat[cmd->device->id] == SS_UNSET)) {
595 
596 		/*
597 		 * Do a 'Select-With-ATN' command. This will end with
598 		 * one of the following interrupts:
599 		 *    CSR_RESEL_AM:  failure - can try again later.
600 		 *    CSR_TIMEOUT:   failure - give up.
601 		 *    CSR_SELECT:    success - proceed.
602 		 */
603 
604 		hostdata->selecting = cmd;
605 
606 /* Every target has its own synchronous transfer setting, kept in the
607  * sync_xfer array, and a corresponding status byte in sync_stat[].
608  * Each target's sync_stat[] entry is initialized to SX_UNSET, and its
609  * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET
610  * means that the parameters are undetermined as yet, and that we
611  * need to send an SDTR message to this device after selection is
612  * complete: We set SS_FIRST to tell the interrupt routine to do so.
613  * If we've been asked not to try synchronous transfers on this
614  * target (and _all_ luns within it), we'll still send the SDTR message
615  * later, but at that time we'll negotiate for async by specifying a
616  * sync fifo depth of 0.
617  */
618 		if (hostdata->sync_stat[cmd->device->id] == SS_UNSET)
619 			hostdata->sync_stat[cmd->device->id] = SS_FIRST;
620 		hostdata->state = S_SELECTING;
621 		write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
622 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN);
623 	} else {
624 
625 		/*
626 		 * Do a 'Select-With-ATN-Xfer' command. This will end with
627 		 * one of the following interrupts:
628 		 *    CSR_RESEL_AM:  failure - can try again later.
629 		 *    CSR_TIMEOUT:   failure - give up.
630 		 *    anything else: success - proceed.
631 		 */
632 
633 		hostdata->connected = cmd;
634 		write_wd33c93(regs, WD_COMMAND_PHASE, 0);
635 
636 		/* copy command_descriptor_block into WD chip
637 		 * (take advantage of auto-incrementing)
638 		 */
639 
640 		write_wd33c93_cdb(regs, cmd->cmd_len, cmd->cmnd);
641 
642 		/* The wd33c93 only knows about Group 0, 1, and 5 commands when
643 		 * it's doing a 'select-and-transfer'. To be safe, we write the
644 		 * size of the CDB into the OWN_ID register for every case. This
645 		 * way there won't be problems with vendor-unique, audio, etc.
646 		 */
647 
648 		write_wd33c93(regs, WD_OWN_ID, cmd->cmd_len);
649 
650 		/* When doing a non-disconnect command with DMA, we can save
651 		 * ourselves a DATA phase interrupt later by setting everything
652 		 * up ahead of time.
653 		 */
654 
655 		if ((cmd->SCp.phase == 0) && (hostdata->no_dma == 0)) {
656 			if (hostdata->dma_setup(cmd,
657 			    (cmd->sc_data_direction == DMA_TO_DEVICE) ?
658 			     DATA_OUT_DIR : DATA_IN_DIR))
659 				write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
660 			else {
661 				write_wd33c93_count(regs,
662 						    cmd->SCp.this_residual);
663 				write_wd33c93(regs, WD_CONTROL,
664 					      CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
665 				hostdata->dma = D_DMA_RUNNING;
666 			}
667 		} else
668 			write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
669 
670 		hostdata->state = S_RUNNING_LEVEL2;
671 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
672 	}
673 
674 	/*
675 	 * Since the SCSI bus can handle only 1 connection at a time,
676 	 * we get out of here now. If the selection fails, or when
677 	 * the command disconnects, we'll come back to this routine
678 	 * to search the input_Q again...
679 	 */
680 
681 	DB(DB_EXECUTE,
682 	   printk("%s)EX-2 ", (cmd->SCp.phase) ? "d:" : ""))
683 }
684 
685 static void
686 transfer_pio(const wd33c93_regs regs, uchar * buf, int cnt,
687 	     int data_in_dir, struct WD33C93_hostdata *hostdata)
688 {
689 	uchar asr;
690 
691 	DB(DB_TRANSFER,
692 	   printk("(%p,%d,%s:", buf, cnt, data_in_dir ? "in" : "out"))
693 
694 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
695 	write_wd33c93_count(regs, cnt);
696 	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
697 	if (data_in_dir) {
698 		do {
699 			asr = read_aux_stat(regs);
700 			if (asr & ASR_DBR)
701 				*buf++ = read_wd33c93(regs, WD_DATA);
702 		} while (!(asr & ASR_INT));
703 	} else {
704 		do {
705 			asr = read_aux_stat(regs);
706 			if (asr & ASR_DBR)
707 				write_wd33c93(regs, WD_DATA, *buf++);
708 		} while (!(asr & ASR_INT));
709 	}
710 
711 	/* Note: we are returning with the interrupt UN-cleared.
712 	 * Since (presumably) an entire I/O operation has
713 	 * completed, the bus phase is probably different, and
714 	 * the interrupt routine will discover this when it
715 	 * responds to the uncleared int.
716 	 */
717 
718 }
719 
720 static void
721 transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
722 		int data_in_dir)
723 {
724 	struct WD33C93_hostdata *hostdata;
725 	unsigned long length;
726 
727 	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
728 
729 /* Normally, you'd expect 'this_residual' to be non-zero here.
730  * In a series of scatter-gather transfers, however, this
731  * routine will usually be called with 'this_residual' equal
732  * to 0 and 'buffers_residual' non-zero. This means that a
733  * previous transfer completed, clearing 'this_residual', and
734  * now we need to setup the next scatter-gather buffer as the
735  * source or destination for THIS transfer.
736  */
737 	if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
738 		cmd->SCp.buffer = sg_next(cmd->SCp.buffer);
739 		--cmd->SCp.buffers_residual;
740 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
741 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
742 	}
743 	if (!cmd->SCp.this_residual) /* avoid bogus setups */
744 		return;
745 
746 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
747 		      hostdata->sync_xfer[cmd->device->id]);
748 
749 /* 'hostdata->no_dma' is TRUE if we don't even want to try DMA.
750  * Update 'this_residual' and 'ptr' after 'transfer_pio()' returns.
751  */
752 
753 	if (hostdata->no_dma || hostdata->dma_setup(cmd, data_in_dir)) {
754 #ifdef PROC_STATISTICS
755 		hostdata->pio_cnt++;
756 #endif
757 		transfer_pio(regs, (uchar *) cmd->SCp.ptr,
758 			     cmd->SCp.this_residual, data_in_dir, hostdata);
759 		length = cmd->SCp.this_residual;
760 		cmd->SCp.this_residual = read_wd33c93_count(regs);
761 		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
762 	}
763 
764 /* We are able to do DMA (in fact, the Amiga hardware is
765  * already going!), so start up the wd33c93 in DMA mode.
766  * We set 'hostdata->dma' = D_DMA_RUNNING so that when the
767  * transfer completes and causes an interrupt, we're
768  * reminded to tell the Amiga to shut down its end. We'll
769  * postpone the updating of 'this_residual' and 'ptr'
770  * until then.
771  */
772 
773 	else {
774 #ifdef PROC_STATISTICS
775 		hostdata->dma_cnt++;
776 #endif
777 		write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
778 		write_wd33c93_count(regs, cmd->SCp.this_residual);
779 
780 		if ((hostdata->level2 >= L2_DATA) ||
781 		    (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
782 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
783 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
784 			hostdata->state = S_RUNNING_LEVEL2;
785 		} else
786 			write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
787 
788 		hostdata->dma = D_DMA_RUNNING;
789 	}
790 }
791 
792 void
793 wd33c93_intr(struct Scsi_Host *instance)
794 {
795 	struct WD33C93_hostdata *hostdata =
796 	    (struct WD33C93_hostdata *) instance->hostdata;
797 	const wd33c93_regs regs = hostdata->regs;
798 	struct scsi_cmnd *patch, *cmd;
799 	uchar asr, sr, phs, id, lun, *ucp, msg;
800 	unsigned long length, flags;
801 
802 	asr = read_aux_stat(regs);
803 	if (!(asr & ASR_INT) || (asr & ASR_BSY))
804 		return;
805 
806 	spin_lock_irqsave(&hostdata->lock, flags);
807 
808 #ifdef PROC_STATISTICS
809 	hostdata->int_cnt++;
810 #endif
811 
812 	cmd = (struct scsi_cmnd *) hostdata->connected;	/* assume we're connected */
813 	sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear the interrupt */
814 	phs = read_wd33c93(regs, WD_COMMAND_PHASE);
815 
816 	DB(DB_INTR, printk("{%02x:%02x-", asr, sr))
817 
818 /* After starting a DMA transfer, the next interrupt
819  * is guaranteed to be in response to completion of
820  * the transfer. Since the Amiga DMA hardware runs in
821  * in an open-ended fashion, it needs to be told when
822  * to stop; do that here if D_DMA_RUNNING is true.
823  * Also, we have to update 'this_residual' and 'ptr'
824  * based on the contents of the TRANSFER_COUNT register,
825  * in case the device decided to do an intermediate
826  * disconnect (a device may do this if it has to do a
827  * seek, or just to be nice and let other devices have
828  * some bus time during long transfers). After doing
829  * whatever is needed, we go on and service the WD3393
830  * interrupt normally.
831  */
832 	    if (hostdata->dma == D_DMA_RUNNING) {
833 		DB(DB_TRANSFER,
834 		   printk("[%p/%d:", cmd->SCp.ptr, cmd->SCp.this_residual))
835 		    hostdata->dma_stop(cmd->device->host, cmd, 1);
836 		hostdata->dma = D_DMA_OFF;
837 		length = cmd->SCp.this_residual;
838 		cmd->SCp.this_residual = read_wd33c93_count(regs);
839 		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
840 		DB(DB_TRANSFER,
841 		   printk("%p/%d]", cmd->SCp.ptr, cmd->SCp.this_residual))
842 	}
843 
844 /* Respond to the specific WD3393 interrupt - there are quite a few! */
845 	switch (sr) {
846 	case CSR_TIMEOUT:
847 		DB(DB_INTR, printk("TIMEOUT"))
848 
849 		    if (hostdata->state == S_RUNNING_LEVEL2)
850 			hostdata->connected = NULL;
851 		else {
852 			cmd = (struct scsi_cmnd *) hostdata->selecting;	/* get a valid cmd */
853 			hostdata->selecting = NULL;
854 		}
855 
856 		cmd->result = DID_NO_CONNECT << 16;
857 		hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
858 		hostdata->state = S_UNCONNECTED;
859 		cmd->scsi_done(cmd);
860 
861 		/* From esp.c:
862 		 * There is a window of time within the scsi_done() path
863 		 * of execution where interrupts are turned back on full
864 		 * blast and left that way.  During that time we could
865 		 * reconnect to a disconnected command, then we'd bomb
866 		 * out below.  We could also end up executing two commands
867 		 * at _once_.  ...just so you know why the restore_flags()
868 		 * is here...
869 		 */
870 
871 		spin_unlock_irqrestore(&hostdata->lock, flags);
872 
873 /* We are not connected to a target - check to see if there
874  * are commands waiting to be executed.
875  */
876 
877 		wd33c93_execute(instance);
878 		break;
879 
880 /* Note: this interrupt should not occur in a LEVEL2 command */
881 
882 	case CSR_SELECT:
883 		DB(DB_INTR, printk("SELECT"))
884 		    hostdata->connected = cmd =
885 		    (struct scsi_cmnd *) hostdata->selecting;
886 		hostdata->selecting = NULL;
887 
888 		/* construct an IDENTIFY message with correct disconnect bit */
889 
890 		hostdata->outgoing_msg[0] = IDENTIFY(0, cmd->device->lun);
891 		if (cmd->SCp.phase)
892 			hostdata->outgoing_msg[0] |= 0x40;
893 
894 		if (hostdata->sync_stat[cmd->device->id] == SS_FIRST) {
895 
896 			hostdata->sync_stat[cmd->device->id] = SS_WAITING;
897 
898 /* Tack on a 2nd message to ask about synchronous transfers. If we've
899  * been asked to do only asynchronous transfers on this device, we
900  * request a fifo depth of 0, which is equivalent to async - should
901  * solve the problems some people have had with GVP's Guru ROM.
902  */
903 
904 			hostdata->outgoing_msg[1] = EXTENDED_MESSAGE;
905 			hostdata->outgoing_msg[2] = 3;
906 			hostdata->outgoing_msg[3] = EXTENDED_SDTR;
907 			if (hostdata->no_sync & (1 << cmd->device->id)) {
908 				calc_sync_msg(hostdata->default_sx_per, 0,
909 						0, hostdata->outgoing_msg + 4);
910 			} else {
911 				calc_sync_msg(optimum_sx_per(hostdata),
912 						OPTIMUM_SX_OFF,
913 						hostdata->fast,
914 						hostdata->outgoing_msg + 4);
915 			}
916 			hostdata->outgoing_len = 6;
917 #ifdef SYNC_DEBUG
918 			ucp = hostdata->outgoing_msg + 1;
919 			printk(" sending SDTR %02x03%02x%02x%02x ",
920 				ucp[0], ucp[2], ucp[3], ucp[4]);
921 #endif
922 		} else
923 			hostdata->outgoing_len = 1;
924 
925 		hostdata->state = S_CONNECTED;
926 		spin_unlock_irqrestore(&hostdata->lock, flags);
927 		break;
928 
929 	case CSR_XFER_DONE | PHS_DATA_IN:
930 	case CSR_UNEXP | PHS_DATA_IN:
931 	case CSR_SRV_REQ | PHS_DATA_IN:
932 		DB(DB_INTR,
933 		   printk("IN-%d.%d", cmd->SCp.this_residual,
934 			  cmd->SCp.buffers_residual))
935 		    transfer_bytes(regs, cmd, DATA_IN_DIR);
936 		if (hostdata->state != S_RUNNING_LEVEL2)
937 			hostdata->state = S_CONNECTED;
938 		spin_unlock_irqrestore(&hostdata->lock, flags);
939 		break;
940 
941 	case CSR_XFER_DONE | PHS_DATA_OUT:
942 	case CSR_UNEXP | PHS_DATA_OUT:
943 	case CSR_SRV_REQ | PHS_DATA_OUT:
944 		DB(DB_INTR,
945 		   printk("OUT-%d.%d", cmd->SCp.this_residual,
946 			  cmd->SCp.buffers_residual))
947 		    transfer_bytes(regs, cmd, DATA_OUT_DIR);
948 		if (hostdata->state != S_RUNNING_LEVEL2)
949 			hostdata->state = S_CONNECTED;
950 		spin_unlock_irqrestore(&hostdata->lock, flags);
951 		break;
952 
953 /* Note: this interrupt should not occur in a LEVEL2 command */
954 
955 	case CSR_XFER_DONE | PHS_COMMAND:
956 	case CSR_UNEXP | PHS_COMMAND:
957 	case CSR_SRV_REQ | PHS_COMMAND:
958 		DB(DB_INTR, printk("CMND-%02x", cmd->cmnd[0]))
959 		    transfer_pio(regs, cmd->cmnd, cmd->cmd_len, DATA_OUT_DIR,
960 				 hostdata);
961 		hostdata->state = S_CONNECTED;
962 		spin_unlock_irqrestore(&hostdata->lock, flags);
963 		break;
964 
965 	case CSR_XFER_DONE | PHS_STATUS:
966 	case CSR_UNEXP | PHS_STATUS:
967 	case CSR_SRV_REQ | PHS_STATUS:
968 		DB(DB_INTR, printk("STATUS="))
969 		cmd->SCp.Status = read_1_byte(regs);
970 		DB(DB_INTR, printk("%02x", cmd->SCp.Status))
971 		    if (hostdata->level2 >= L2_BASIC) {
972 			sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
973 			udelay(7);
974 			hostdata->state = S_RUNNING_LEVEL2;
975 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x50);
976 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
977 		} else {
978 			hostdata->state = S_CONNECTED;
979 		}
980 		spin_unlock_irqrestore(&hostdata->lock, flags);
981 		break;
982 
983 	case CSR_XFER_DONE | PHS_MESS_IN:
984 	case CSR_UNEXP | PHS_MESS_IN:
985 	case CSR_SRV_REQ | PHS_MESS_IN:
986 		DB(DB_INTR, printk("MSG_IN="))
987 
988 		msg = read_1_byte(regs);
989 		sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
990 		udelay(7);
991 
992 		hostdata->incoming_msg[hostdata->incoming_ptr] = msg;
993 		if (hostdata->incoming_msg[0] == EXTENDED_MESSAGE)
994 			msg = EXTENDED_MESSAGE;
995 		else
996 			hostdata->incoming_ptr = 0;
997 
998 		cmd->SCp.Message = msg;
999 		switch (msg) {
1000 
1001 		case COMMAND_COMPLETE:
1002 			DB(DB_INTR, printk("CCMP"))
1003 			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1004 			hostdata->state = S_PRE_CMP_DISC;
1005 			break;
1006 
1007 		case SAVE_POINTERS:
1008 			DB(DB_INTR, printk("SDP"))
1009 			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1010 			hostdata->state = S_CONNECTED;
1011 			break;
1012 
1013 		case RESTORE_POINTERS:
1014 			DB(DB_INTR, printk("RDP"))
1015 			    if (hostdata->level2 >= L2_BASIC) {
1016 				write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
1017 				write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1018 				hostdata->state = S_RUNNING_LEVEL2;
1019 			} else {
1020 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1021 				hostdata->state = S_CONNECTED;
1022 			}
1023 			break;
1024 
1025 		case DISCONNECT:
1026 			DB(DB_INTR, printk("DIS"))
1027 			    cmd->device->disconnect = 1;
1028 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1029 			hostdata->state = S_PRE_TMP_DISC;
1030 			break;
1031 
1032 		case MESSAGE_REJECT:
1033 			DB(DB_INTR, printk("REJ"))
1034 #ifdef SYNC_DEBUG
1035 			    printk("-REJ-");
1036 #endif
1037 			if (hostdata->sync_stat[cmd->device->id] == SS_WAITING) {
1038 				hostdata->sync_stat[cmd->device->id] = SS_SET;
1039 				/* we want default_sx_per, not DEFAULT_SX_PER */
1040 				hostdata->sync_xfer[cmd->device->id] =
1041 					calc_sync_xfer(hostdata->default_sx_per
1042 						/ 4, 0, 0, hostdata->sx_table);
1043 			}
1044 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1045 			hostdata->state = S_CONNECTED;
1046 			break;
1047 
1048 		case EXTENDED_MESSAGE:
1049 			DB(DB_INTR, printk("EXT"))
1050 
1051 			    ucp = hostdata->incoming_msg;
1052 
1053 #ifdef SYNC_DEBUG
1054 			printk("%02x", ucp[hostdata->incoming_ptr]);
1055 #endif
1056 			/* Is this the last byte of the extended message? */
1057 
1058 			if ((hostdata->incoming_ptr >= 2) &&
1059 			    (hostdata->incoming_ptr == (ucp[1] + 1))) {
1060 
1061 				switch (ucp[2]) {	/* what's the EXTENDED code? */
1062 				case EXTENDED_SDTR:
1063 					/* default to default async period */
1064 					id = calc_sync_xfer(hostdata->
1065 							default_sx_per / 4, 0,
1066 							0, hostdata->sx_table);
1067 					if (hostdata->sync_stat[cmd->device->id] !=
1068 					    SS_WAITING) {
1069 
1070 /* A device has sent an unsolicited SDTR message; rather than go
1071  * through the effort of decoding it and then figuring out what
1072  * our reply should be, we're just gonna say that we have a
1073  * synchronous fifo depth of 0. This will result in asynchronous
1074  * transfers - not ideal but so much easier.
1075  * Actually, this is OK because it assures us that if we don't
1076  * specifically ask for sync transfers, we won't do any.
1077  */
1078 
1079 						write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1080 						hostdata->outgoing_msg[0] =
1081 						    EXTENDED_MESSAGE;
1082 						hostdata->outgoing_msg[1] = 3;
1083 						hostdata->outgoing_msg[2] =
1084 						    EXTENDED_SDTR;
1085 						calc_sync_msg(hostdata->
1086 							default_sx_per, 0,
1087 							0, hostdata->outgoing_msg + 3);
1088 						hostdata->outgoing_len = 5;
1089 					} else {
1090 						if (ucp[4]) /* well, sync transfer */
1091 							id = calc_sync_xfer(ucp[3], ucp[4],
1092 									hostdata->fast,
1093 									hostdata->sx_table);
1094 						else if (ucp[3]) /* very unlikely... */
1095 							id = calc_sync_xfer(ucp[3], ucp[4],
1096 									0, hostdata->sx_table);
1097 					}
1098 					hostdata->sync_xfer[cmd->device->id] = id;
1099 #ifdef SYNC_DEBUG
1100 					printk(" sync_xfer=%02x\n",
1101 					       hostdata->sync_xfer[cmd->device->id]);
1102 #endif
1103 					hostdata->sync_stat[cmd->device->id] =
1104 					    SS_SET;
1105 					write_wd33c93_cmd(regs,
1106 							  WD_CMD_NEGATE_ACK);
1107 					hostdata->state = S_CONNECTED;
1108 					break;
1109 				case EXTENDED_WDTR:
1110 					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1111 					printk("sending WDTR ");
1112 					hostdata->outgoing_msg[0] =
1113 					    EXTENDED_MESSAGE;
1114 					hostdata->outgoing_msg[1] = 2;
1115 					hostdata->outgoing_msg[2] =
1116 					    EXTENDED_WDTR;
1117 					hostdata->outgoing_msg[3] = 0;	/* 8 bit transfer width */
1118 					hostdata->outgoing_len = 4;
1119 					write_wd33c93_cmd(regs,
1120 							  WD_CMD_NEGATE_ACK);
1121 					hostdata->state = S_CONNECTED;
1122 					break;
1123 				default:
1124 					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1125 					printk
1126 					    ("Rejecting Unknown Extended Message(%02x). ",
1127 					     ucp[2]);
1128 					hostdata->outgoing_msg[0] =
1129 					    MESSAGE_REJECT;
1130 					hostdata->outgoing_len = 1;
1131 					write_wd33c93_cmd(regs,
1132 							  WD_CMD_NEGATE_ACK);
1133 					hostdata->state = S_CONNECTED;
1134 					break;
1135 				}
1136 				hostdata->incoming_ptr = 0;
1137 			}
1138 
1139 			/* We need to read more MESS_IN bytes for the extended message */
1140 
1141 			else {
1142 				hostdata->incoming_ptr++;
1143 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1144 				hostdata->state = S_CONNECTED;
1145 			}
1146 			break;
1147 
1148 		default:
1149 			printk("Rejecting Unknown Message(%02x) ", msg);
1150 			write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1151 			hostdata->outgoing_msg[0] = MESSAGE_REJECT;
1152 			hostdata->outgoing_len = 1;
1153 			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1154 			hostdata->state = S_CONNECTED;
1155 		}
1156 		spin_unlock_irqrestore(&hostdata->lock, flags);
1157 		break;
1158 
1159 /* Note: this interrupt will occur only after a LEVEL2 command */
1160 
1161 	case CSR_SEL_XFER_DONE:
1162 
1163 /* Make sure that reselection is enabled at this point - it may
1164  * have been turned off for the command that just completed.
1165  */
1166 
1167 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1168 		if (phs == 0x60) {
1169 			DB(DB_INTR, printk("SX-DONE"))
1170 			    cmd->SCp.Message = COMMAND_COMPLETE;
1171 			lun = read_wd33c93(regs, WD_TARGET_LUN);
1172 			DB(DB_INTR, printk(":%d.%d", cmd->SCp.Status, lun))
1173 			    hostdata->connected = NULL;
1174 			hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1175 			hostdata->state = S_UNCONNECTED;
1176 			if (cmd->SCp.Status == ILLEGAL_STATUS_BYTE)
1177 				cmd->SCp.Status = lun;
1178 			if (cmd->cmnd[0] == REQUEST_SENSE
1179 			    && cmd->SCp.Status != GOOD)
1180 				cmd->result =
1181 				    (cmd->
1182 				     result & 0x00ffff) | (DID_ERROR << 16);
1183 			else
1184 				cmd->result =
1185 				    cmd->SCp.Status | (cmd->SCp.Message << 8);
1186 			cmd->scsi_done(cmd);
1187 
1188 /* We are no longer  connected to a target - check to see if
1189  * there are commands waiting to be executed.
1190  */
1191 			spin_unlock_irqrestore(&hostdata->lock, flags);
1192 			wd33c93_execute(instance);
1193 		} else {
1194 			printk
1195 			    ("%02x:%02x:%02x: Unknown SEL_XFER_DONE phase!!---",
1196 			     asr, sr, phs);
1197 			spin_unlock_irqrestore(&hostdata->lock, flags);
1198 		}
1199 		break;
1200 
1201 /* Note: this interrupt will occur only after a LEVEL2 command */
1202 
1203 	case CSR_SDP:
1204 		DB(DB_INTR, printk("SDP"))
1205 		    hostdata->state = S_RUNNING_LEVEL2;
1206 		write_wd33c93(regs, WD_COMMAND_PHASE, 0x41);
1207 		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1208 		spin_unlock_irqrestore(&hostdata->lock, flags);
1209 		break;
1210 
1211 	case CSR_XFER_DONE | PHS_MESS_OUT:
1212 	case CSR_UNEXP | PHS_MESS_OUT:
1213 	case CSR_SRV_REQ | PHS_MESS_OUT:
1214 		DB(DB_INTR, printk("MSG_OUT="))
1215 
1216 /* To get here, we've probably requested MESSAGE_OUT and have
1217  * already put the correct bytes in outgoing_msg[] and filled
1218  * in outgoing_len. We simply send them out to the SCSI bus.
1219  * Sometimes we get MESSAGE_OUT phase when we're not expecting
1220  * it - like when our SDTR message is rejected by a target. Some
1221  * targets send the REJECT before receiving all of the extended
1222  * message, and then seem to go back to MESSAGE_OUT for a byte
1223  * or two. Not sure why, or if I'm doing something wrong to
1224  * cause this to happen. Regardless, it seems that sending
1225  * NOP messages in these situations results in no harm and
1226  * makes everyone happy.
1227  */
1228 		    if (hostdata->outgoing_len == 0) {
1229 			hostdata->outgoing_len = 1;
1230 			hostdata->outgoing_msg[0] = NOP;
1231 		}
1232 		transfer_pio(regs, hostdata->outgoing_msg,
1233 			     hostdata->outgoing_len, DATA_OUT_DIR, hostdata);
1234 		DB(DB_INTR, printk("%02x", hostdata->outgoing_msg[0]))
1235 		    hostdata->outgoing_len = 0;
1236 		hostdata->state = S_CONNECTED;
1237 		spin_unlock_irqrestore(&hostdata->lock, flags);
1238 		break;
1239 
1240 	case CSR_UNEXP_DISC:
1241 
1242 /* I think I've seen this after a request-sense that was in response
1243  * to an error condition, but not sure. We certainly need to do
1244  * something when we get this interrupt - the question is 'what?'.
1245  * Let's think positively, and assume some command has finished
1246  * in a legal manner (like a command that provokes a request-sense),
1247  * so we treat it as a normal command-complete-disconnect.
1248  */
1249 
1250 /* Make sure that reselection is enabled at this point - it may
1251  * have been turned off for the command that just completed.
1252  */
1253 
1254 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1255 		if (cmd == NULL) {
1256 			printk(" - Already disconnected! ");
1257 			hostdata->state = S_UNCONNECTED;
1258 			spin_unlock_irqrestore(&hostdata->lock, flags);
1259 			return;
1260 		}
1261 		DB(DB_INTR, printk("UNEXP_DISC"))
1262 		    hostdata->connected = NULL;
1263 		hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1264 		hostdata->state = S_UNCONNECTED;
1265 		if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
1266 			cmd->result =
1267 			    (cmd->result & 0x00ffff) | (DID_ERROR << 16);
1268 		else
1269 			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
1270 		cmd->scsi_done(cmd);
1271 
1272 /* We are no longer connected to a target - check to see if
1273  * there are commands waiting to be executed.
1274  */
1275 		/* look above for comments on scsi_done() */
1276 		spin_unlock_irqrestore(&hostdata->lock, flags);
1277 		wd33c93_execute(instance);
1278 		break;
1279 
1280 	case CSR_DISC:
1281 
1282 /* Make sure that reselection is enabled at this point - it may
1283  * have been turned off for the command that just completed.
1284  */
1285 
1286 		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1287 		DB(DB_INTR, printk("DISC"))
1288 		    if (cmd == NULL) {
1289 			printk(" - Already disconnected! ");
1290 			hostdata->state = S_UNCONNECTED;
1291 		}
1292 		switch (hostdata->state) {
1293 		case S_PRE_CMP_DISC:
1294 			hostdata->connected = NULL;
1295 			hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1296 			hostdata->state = S_UNCONNECTED;
1297 			DB(DB_INTR, printk(":%d", cmd->SCp.Status))
1298 			    if (cmd->cmnd[0] == REQUEST_SENSE
1299 				&& cmd->SCp.Status != GOOD)
1300 				cmd->result =
1301 				    (cmd->
1302 				     result & 0x00ffff) | (DID_ERROR << 16);
1303 			else
1304 				cmd->result =
1305 				    cmd->SCp.Status | (cmd->SCp.Message << 8);
1306 			cmd->scsi_done(cmd);
1307 			break;
1308 		case S_PRE_TMP_DISC:
1309 		case S_RUNNING_LEVEL2:
1310 			cmd->host_scribble = (uchar *) hostdata->disconnected_Q;
1311 			hostdata->disconnected_Q = cmd;
1312 			hostdata->connected = NULL;
1313 			hostdata->state = S_UNCONNECTED;
1314 
1315 #ifdef PROC_STATISTICS
1316 			hostdata->disc_done_cnt[cmd->device->id]++;
1317 #endif
1318 
1319 			break;
1320 		default:
1321 			printk("*** Unexpected DISCONNECT interrupt! ***");
1322 			hostdata->state = S_UNCONNECTED;
1323 		}
1324 
1325 /* We are no longer connected to a target - check to see if
1326  * there are commands waiting to be executed.
1327  */
1328 		spin_unlock_irqrestore(&hostdata->lock, flags);
1329 		wd33c93_execute(instance);
1330 		break;
1331 
1332 	case CSR_RESEL_AM:
1333 	case CSR_RESEL:
1334 		DB(DB_INTR, printk("RESEL%s", sr == CSR_RESEL_AM ? "_AM" : ""))
1335 
1336 		    /* Old chips (pre -A ???) don't have advanced features and will
1337 		     * generate CSR_RESEL.  In that case we have to extract the LUN the
1338 		     * hard way (see below).
1339 		     * First we have to make sure this reselection didn't
1340 		     * happen during Arbitration/Selection of some other device.
1341 		     * If yes, put losing command back on top of input_Q.
1342 		     */
1343 		    if (hostdata->level2 <= L2_NONE) {
1344 
1345 			if (hostdata->selecting) {
1346 				cmd = (struct scsi_cmnd *) hostdata->selecting;
1347 				hostdata->selecting = NULL;
1348 				hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1349 				cmd->host_scribble =
1350 				    (uchar *) hostdata->input_Q;
1351 				hostdata->input_Q = cmd;
1352 			}
1353 		}
1354 
1355 		else {
1356 
1357 			if (cmd) {
1358 				if (phs == 0x00) {
1359 					hostdata->busy[cmd->device->id] &=
1360 						~(1 << (cmd->device->lun & 0xff));
1361 					cmd->host_scribble =
1362 					    (uchar *) hostdata->input_Q;
1363 					hostdata->input_Q = cmd;
1364 				} else {
1365 					printk
1366 					    ("---%02x:%02x:%02x-TROUBLE: Intrusive ReSelect!---",
1367 					     asr, sr, phs);
1368 					while (1)
1369 						printk("\r");
1370 				}
1371 			}
1372 
1373 		}
1374 
1375 		/* OK - find out which device reselected us. */
1376 
1377 		id = read_wd33c93(regs, WD_SOURCE_ID);
1378 		id &= SRCID_MASK;
1379 
1380 		/* and extract the lun from the ID message. (Note that we don't
1381 		 * bother to check for a valid message here - I guess this is
1382 		 * not the right way to go, but...)
1383 		 */
1384 
1385 		if (sr == CSR_RESEL_AM) {
1386 			lun = read_wd33c93(regs, WD_DATA);
1387 			if (hostdata->level2 < L2_RESELECT)
1388 				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1389 			lun &= 7;
1390 		} else {
1391 			/* Old chip; wait for msgin phase to pick up the LUN. */
1392 			for (lun = 255; lun; lun--) {
1393 				if ((asr = read_aux_stat(regs)) & ASR_INT)
1394 					break;
1395 				udelay(10);
1396 			}
1397 			if (!(asr & ASR_INT)) {
1398 				printk
1399 				    ("wd33c93: Reselected without IDENTIFY\n");
1400 				lun = 0;
1401 			} else {
1402 				/* Verify this is a change to MSG_IN and read the message */
1403 				sr = read_wd33c93(regs, WD_SCSI_STATUS);
1404 				udelay(7);
1405 				if (sr == (CSR_ABORT | PHS_MESS_IN) ||
1406 				    sr == (CSR_UNEXP | PHS_MESS_IN) ||
1407 				    sr == (CSR_SRV_REQ | PHS_MESS_IN)) {
1408 					/* Got MSG_IN, grab target LUN */
1409 					lun = read_1_byte(regs);
1410 					/* Now we expect a 'paused with ACK asserted' int.. */
1411 					asr = read_aux_stat(regs);
1412 					if (!(asr & ASR_INT)) {
1413 						udelay(10);
1414 						asr = read_aux_stat(regs);
1415 						if (!(asr & ASR_INT))
1416 							printk
1417 							    ("wd33c93: No int after LUN on RESEL (%02x)\n",
1418 							     asr);
1419 					}
1420 					sr = read_wd33c93(regs, WD_SCSI_STATUS);
1421 					udelay(7);
1422 					if (sr != CSR_MSGIN)
1423 						printk
1424 						    ("wd33c93: Not paused with ACK on RESEL (%02x)\n",
1425 						     sr);
1426 					lun &= 7;
1427 					write_wd33c93_cmd(regs,
1428 							  WD_CMD_NEGATE_ACK);
1429 				} else {
1430 					printk
1431 					    ("wd33c93: Not MSG_IN on reselect (%02x)\n",
1432 					     sr);
1433 					lun = 0;
1434 				}
1435 			}
1436 		}
1437 
1438 		/* Now we look for the command that's reconnecting. */
1439 
1440 		cmd = (struct scsi_cmnd *) hostdata->disconnected_Q;
1441 		patch = NULL;
1442 		while (cmd) {
1443 			if (id == cmd->device->id && lun == (u8)cmd->device->lun)
1444 				break;
1445 			patch = cmd;
1446 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
1447 		}
1448 
1449 		/* Hmm. Couldn't find a valid command.... What to do? */
1450 
1451 		if (!cmd) {
1452 			printk
1453 			    ("---TROUBLE: target %d.%d not in disconnect queue---",
1454 			     id, (u8)lun);
1455 			spin_unlock_irqrestore(&hostdata->lock, flags);
1456 			return;
1457 		}
1458 
1459 		/* Ok, found the command - now start it up again. */
1460 
1461 		if (patch)
1462 			patch->host_scribble = cmd->host_scribble;
1463 		else
1464 			hostdata->disconnected_Q =
1465 			    (struct scsi_cmnd *) cmd->host_scribble;
1466 		hostdata->connected = cmd;
1467 
1468 		/* We don't need to worry about 'initialize_SCp()' or 'hostdata->busy[]'
1469 		 * because these things are preserved over a disconnect.
1470 		 * But we DO need to fix the DPD bit so it's correct for this command.
1471 		 */
1472 
1473 		if (cmd->sc_data_direction == DMA_TO_DEVICE)
1474 			write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
1475 		else
1476 			write_wd33c93(regs, WD_DESTINATION_ID,
1477 				      cmd->device->id | DSTID_DPD);
1478 		if (hostdata->level2 >= L2_RESELECT) {
1479 			write_wd33c93_count(regs, 0);	/* we want a DATA_PHASE interrupt */
1480 			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
1481 			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1482 			hostdata->state = S_RUNNING_LEVEL2;
1483 		} else
1484 			hostdata->state = S_CONNECTED;
1485 
1486 		    spin_unlock_irqrestore(&hostdata->lock, flags);
1487 		break;
1488 
1489 	default:
1490 		printk("--UNKNOWN INTERRUPT:%02x:%02x:%02x--", asr, sr, phs);
1491 		spin_unlock_irqrestore(&hostdata->lock, flags);
1492 	}
1493 
1494 	DB(DB_INTR, printk("} "))
1495 
1496 }
1497 
1498 static void
1499 reset_wd33c93(struct Scsi_Host *instance)
1500 {
1501 	struct WD33C93_hostdata *hostdata =
1502 	    (struct WD33C93_hostdata *) instance->hostdata;
1503 	const wd33c93_regs regs = hostdata->regs;
1504 	uchar sr;
1505 
1506 #ifdef CONFIG_SGI_IP22
1507 	{
1508 		int busycount = 0;
1509 		extern void sgiwd93_reset(unsigned long);
1510 		/* wait 'til the chip gets some time for us */
1511 		while ((read_aux_stat(regs) & ASR_BSY) && busycount++ < 100)
1512 			udelay (10);
1513 	/*
1514  	 * there are scsi devices out there, which manage to lock up
1515 	 * the wd33c93 in a busy condition. In this state it won't
1516 	 * accept the reset command. The only way to solve this is to
1517  	 * give the chip a hardware reset (if possible). The code below
1518 	 * does this for the SGI Indy, where this is possible
1519 	 */
1520 	/* still busy ? */
1521 	if (read_aux_stat(regs) & ASR_BSY)
1522 		sgiwd93_reset(instance->base); /* yeah, give it the hard one */
1523 	}
1524 #endif
1525 
1526 	write_wd33c93(regs, WD_OWN_ID, OWNID_EAF | OWNID_RAF |
1527 		      instance->this_id | hostdata->clock_freq);
1528 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1529 	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
1530 		      calc_sync_xfer(hostdata->default_sx_per / 4,
1531 				     DEFAULT_SX_OFF, 0, hostdata->sx_table));
1532 	write_wd33c93(regs, WD_COMMAND, WD_CMD_RESET);
1533 
1534 
1535 #ifdef CONFIG_MVME147_SCSI
1536 	udelay(25);		/* The old wd33c93 on MVME147 needs this, at least */
1537 #endif
1538 
1539 	while (!(read_aux_stat(regs) & ASR_INT))
1540 		;
1541 	sr = read_wd33c93(regs, WD_SCSI_STATUS);
1542 
1543 	hostdata->microcode = read_wd33c93(regs, WD_CDB_1);
1544 	if (sr == 0x00)
1545 		hostdata->chip = C_WD33C93;
1546 	else if (sr == 0x01) {
1547 		write_wd33c93(regs, WD_QUEUE_TAG, 0xa5);	/* any random number */
1548 		sr = read_wd33c93(regs, WD_QUEUE_TAG);
1549 		if (sr == 0xa5) {
1550 			hostdata->chip = C_WD33C93B;
1551 			write_wd33c93(regs, WD_QUEUE_TAG, 0);
1552 		} else
1553 			hostdata->chip = C_WD33C93A;
1554 	} else
1555 		hostdata->chip = C_UNKNOWN_CHIP;
1556 
1557 	if (hostdata->chip != C_WD33C93B)	/* Fast SCSI unavailable */
1558 		hostdata->fast = 0;
1559 
1560 	write_wd33c93(regs, WD_TIMEOUT_PERIOD, TIMEOUT_PERIOD_VALUE);
1561 	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1562 }
1563 
1564 int
1565 wd33c93_host_reset(struct scsi_cmnd * SCpnt)
1566 {
1567 	struct Scsi_Host *instance;
1568 	struct WD33C93_hostdata *hostdata;
1569 	int i;
1570 
1571 	instance = SCpnt->device->host;
1572 	spin_lock_irq(instance->host_lock);
1573 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1574 
1575 	printk("scsi%d: reset. ", instance->host_no);
1576 	disable_irq(instance->irq);
1577 
1578 	hostdata->dma_stop(instance, NULL, 0);
1579 	for (i = 0; i < 8; i++) {
1580 		hostdata->busy[i] = 0;
1581 		hostdata->sync_xfer[i] =
1582 			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
1583 					0, hostdata->sx_table);
1584 		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
1585 	}
1586 	hostdata->input_Q = NULL;
1587 	hostdata->selecting = NULL;
1588 	hostdata->connected = NULL;
1589 	hostdata->disconnected_Q = NULL;
1590 	hostdata->state = S_UNCONNECTED;
1591 	hostdata->dma = D_DMA_OFF;
1592 	hostdata->incoming_ptr = 0;
1593 	hostdata->outgoing_len = 0;
1594 
1595 	reset_wd33c93(instance);
1596 	SCpnt->result = DID_RESET << 16;
1597 	enable_irq(instance->irq);
1598 	spin_unlock_irq(instance->host_lock);
1599 	return SUCCESS;
1600 }
1601 
1602 int
1603 wd33c93_abort(struct scsi_cmnd * cmd)
1604 {
1605 	struct Scsi_Host *instance;
1606 	struct WD33C93_hostdata *hostdata;
1607 	wd33c93_regs regs;
1608 	struct scsi_cmnd *tmp, *prev;
1609 
1610 	disable_irq(cmd->device->host->irq);
1611 
1612 	instance = cmd->device->host;
1613 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1614 	regs = hostdata->regs;
1615 
1616 /*
1617  * Case 1 : If the command hasn't been issued yet, we simply remove it
1618  *     from the input_Q.
1619  */
1620 
1621 	tmp = (struct scsi_cmnd *) hostdata->input_Q;
1622 	prev = NULL;
1623 	while (tmp) {
1624 		if (tmp == cmd) {
1625 			if (prev)
1626 				prev->host_scribble = cmd->host_scribble;
1627 			else
1628 				hostdata->input_Q =
1629 				    (struct scsi_cmnd *) cmd->host_scribble;
1630 			cmd->host_scribble = NULL;
1631 			cmd->result = DID_ABORT << 16;
1632 			printk
1633 			    ("scsi%d: Abort - removing command from input_Q. ",
1634 			     instance->host_no);
1635 			enable_irq(cmd->device->host->irq);
1636 			cmd->scsi_done(cmd);
1637 			return SUCCESS;
1638 		}
1639 		prev = tmp;
1640 		tmp = (struct scsi_cmnd *) tmp->host_scribble;
1641 	}
1642 
1643 /*
1644  * Case 2 : If the command is connected, we're going to fail the abort
1645  *     and let the high level SCSI driver retry at a later time or
1646  *     issue a reset.
1647  *
1648  *     Timeouts, and therefore aborted commands, will be highly unlikely
1649  *     and handling them cleanly in this situation would make the common
1650  *     case of noresets less efficient, and would pollute our code.  So,
1651  *     we fail.
1652  */
1653 
1654 	if (hostdata->connected == cmd) {
1655 		uchar sr, asr;
1656 		unsigned long timeout;
1657 
1658 		printk("scsi%d: Aborting connected command - ",
1659 		       instance->host_no);
1660 
1661 		printk("stopping DMA - ");
1662 		if (hostdata->dma == D_DMA_RUNNING) {
1663 			hostdata->dma_stop(instance, cmd, 0);
1664 			hostdata->dma = D_DMA_OFF;
1665 		}
1666 
1667 		printk("sending wd33c93 ABORT command - ");
1668 		write_wd33c93(regs, WD_CONTROL,
1669 			      CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1670 		write_wd33c93_cmd(regs, WD_CMD_ABORT);
1671 
1672 /* Now we have to attempt to flush out the FIFO... */
1673 
1674 		printk("flushing fifo - ");
1675 		timeout = 1000000;
1676 		do {
1677 			asr = read_aux_stat(regs);
1678 			if (asr & ASR_DBR)
1679 				read_wd33c93(regs, WD_DATA);
1680 		} while (!(asr & ASR_INT) && timeout-- > 0);
1681 		sr = read_wd33c93(regs, WD_SCSI_STATUS);
1682 		printk
1683 		    ("asr=%02x, sr=%02x, %ld bytes un-transferred (timeout=%ld) - ",
1684 		     asr, sr, read_wd33c93_count(regs), timeout);
1685 
1686 		/*
1687 		 * Abort command processed.
1688 		 * Still connected.
1689 		 * We must disconnect.
1690 		 */
1691 
1692 		printk("sending wd33c93 DISCONNECT command - ");
1693 		write_wd33c93_cmd(regs, WD_CMD_DISCONNECT);
1694 
1695 		timeout = 1000000;
1696 		asr = read_aux_stat(regs);
1697 		while ((asr & ASR_CIP) && timeout-- > 0)
1698 			asr = read_aux_stat(regs);
1699 		sr = read_wd33c93(regs, WD_SCSI_STATUS);
1700 		printk("asr=%02x, sr=%02x.", asr, sr);
1701 
1702 		hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1703 		hostdata->connected = NULL;
1704 		hostdata->state = S_UNCONNECTED;
1705 		cmd->result = DID_ABORT << 16;
1706 
1707 /*      sti();*/
1708 		wd33c93_execute(instance);
1709 
1710 		enable_irq(cmd->device->host->irq);
1711 		cmd->scsi_done(cmd);
1712 		return SUCCESS;
1713 	}
1714 
1715 /*
1716  * Case 3: If the command is currently disconnected from the bus,
1717  * we're not going to expend much effort here: Let's just return
1718  * an ABORT_SNOOZE and hope for the best...
1719  */
1720 
1721 	tmp = (struct scsi_cmnd *) hostdata->disconnected_Q;
1722 	while (tmp) {
1723 		if (tmp == cmd) {
1724 			printk
1725 			    ("scsi%d: Abort - command found on disconnected_Q - ",
1726 			     instance->host_no);
1727 			printk("Abort SNOOZE. ");
1728 			enable_irq(cmd->device->host->irq);
1729 			return FAILED;
1730 		}
1731 		tmp = (struct scsi_cmnd *) tmp->host_scribble;
1732 	}
1733 
1734 /*
1735  * Case 4 : If we reached this point, the command was not found in any of
1736  *     the queues.
1737  *
1738  * We probably reached this point because of an unlikely race condition
1739  * between the command completing successfully and the abortion code,
1740  * so we won't panic, but we will notify the user in case something really
1741  * broke.
1742  */
1743 
1744 /*   sti();*/
1745 	wd33c93_execute(instance);
1746 
1747 	enable_irq(cmd->device->host->irq);
1748 	printk("scsi%d: warning : SCSI command probably completed successfully"
1749 	       "         before abortion. ", instance->host_no);
1750 	return FAILED;
1751 }
1752 
1753 #define MAX_WD33C93_HOSTS 4
1754 #define MAX_SETUP_ARGS ARRAY_SIZE(setup_args)
1755 #define SETUP_BUFFER_SIZE 200
1756 static char setup_buffer[SETUP_BUFFER_SIZE];
1757 static char setup_used[MAX_SETUP_ARGS];
1758 static int done_setup = 0;
1759 
1760 static int
1761 wd33c93_setup(char *str)
1762 {
1763 	int i;
1764 	char *p1, *p2;
1765 
1766 	/* The kernel does some processing of the command-line before calling
1767 	 * this function: If it begins with any decimal or hex number arguments,
1768 	 * ints[0] = how many numbers found and ints[1] through [n] are the values
1769 	 * themselves. str points to where the non-numeric arguments (if any)
1770 	 * start: We do our own parsing of those. We construct synthetic 'nosync'
1771 	 * keywords out of numeric args (to maintain compatibility with older
1772 	 * versions) and then add the rest of the arguments.
1773 	 */
1774 
1775 	p1 = setup_buffer;
1776 	*p1 = '\0';
1777 	if (str)
1778 		strncpy(p1, str, SETUP_BUFFER_SIZE - strlen(setup_buffer));
1779 	setup_buffer[SETUP_BUFFER_SIZE - 1] = '\0';
1780 	p1 = setup_buffer;
1781 	i = 0;
1782 	while (*p1 && (i < MAX_SETUP_ARGS)) {
1783 		p2 = strchr(p1, ',');
1784 		if (p2) {
1785 			*p2 = '\0';
1786 			if (p1 != p2)
1787 				setup_args[i] = p1;
1788 			p1 = p2 + 1;
1789 			i++;
1790 		} else {
1791 			setup_args[i] = p1;
1792 			break;
1793 		}
1794 	}
1795 	for (i = 0; i < MAX_SETUP_ARGS; i++)
1796 		setup_used[i] = 0;
1797 	done_setup = 1;
1798 
1799 	return 1;
1800 }
1801 __setup("wd33c93=", wd33c93_setup);
1802 
1803 /* check_setup_args() returns index if key found, 0 if not
1804  */
1805 static int
1806 check_setup_args(char *key, int *flags, int *val, char *buf)
1807 {
1808 	int x;
1809 	char *cp;
1810 
1811 	for (x = 0; x < MAX_SETUP_ARGS; x++) {
1812 		if (setup_used[x])
1813 			continue;
1814 		if (!strncmp(setup_args[x], key, strlen(key)))
1815 			break;
1816 		if (!strncmp(setup_args[x], "next", strlen("next")))
1817 			return 0;
1818 	}
1819 	if (x == MAX_SETUP_ARGS)
1820 		return 0;
1821 	setup_used[x] = 1;
1822 	cp = setup_args[x] + strlen(key);
1823 	*val = -1;
1824 	if (*cp != ':')
1825 		return ++x;
1826 	cp++;
1827 	if ((*cp >= '0') && (*cp <= '9')) {
1828 		*val = simple_strtoul(cp, NULL, 0);
1829 	}
1830 	return ++x;
1831 }
1832 
1833 /*
1834  * Calculate internal data-transfer-clock cycle from input-clock
1835  * frequency (/MHz) and fill 'sx_table'.
1836  *
1837  * The original driver used to rely on a fixed sx_table, containing periods
1838  * for (only) the lower limits of the respective input-clock-frequency ranges
1839  * (8-10/12-15/16-20 MHz). Although it seems, that no problems occurred with
1840  * this setting so far, it might be desirable to adjust the transfer periods
1841  * closer to the really attached, possibly 25% higher, input-clock, since
1842  * - the wd33c93 may really use a significant shorter period, than it has
1843  *   negotiated (eg. thrashing the target, which expects 4/8MHz, with 5/10MHz
1844  *   instead).
1845  * - the wd33c93 may ask the target for a lower transfer rate, than the target
1846  *   is capable of (eg. negotiating for an assumed minimum of 252ns instead of
1847  *   possible 200ns, which indeed shows up in tests as an approx. 10% lower
1848  *   transfer rate).
1849  */
1850 static inline unsigned int
1851 round_4(unsigned int x)
1852 {
1853 	switch (x & 3) {
1854 		case 1: --x;
1855 			break;
1856 		case 2: ++x;
1857 			fallthrough;
1858 		case 3: ++x;
1859 	}
1860 	return x;
1861 }
1862 
1863 static void
1864 calc_sx_table(unsigned int mhz, struct sx_period sx_table[9])
1865 {
1866 	unsigned int d, i;
1867 	if (mhz < 11)
1868 		d = 2;	/* divisor for  8-10 MHz input-clock */
1869 	else if (mhz < 16)
1870 		d = 3;	/* divisor for 12-15 MHz input-clock */
1871 	else
1872 		d = 4;	/* divisor for 16-20 MHz input-clock */
1873 
1874 	d = (100000 * d) / 2 / mhz; /* 100 x DTCC / nanosec */
1875 
1876 	sx_table[0].period_ns = 1;
1877 	sx_table[0].reg_value = 0x20;
1878 	for (i = 1; i < 8; i++) {
1879 		sx_table[i].period_ns = round_4((i+1)*d / 100);
1880 		sx_table[i].reg_value = (i+1)*0x10;
1881 	}
1882 	sx_table[7].reg_value = 0;
1883 	sx_table[8].period_ns = 0;
1884 	sx_table[8].reg_value = 0;
1885 }
1886 
1887 /*
1888  * check and, maybe, map an init- or "clock:"- argument.
1889  */
1890 static uchar
1891 set_clk_freq(int freq, int *mhz)
1892 {
1893 	int x = freq;
1894 	if (WD33C93_FS_8_10 == freq)
1895 		freq = 8;
1896 	else if (WD33C93_FS_12_15 == freq)
1897 		freq = 12;
1898 	else if (WD33C93_FS_16_20 == freq)
1899 		freq = 16;
1900 	else if (freq > 7 && freq < 11)
1901 		x = WD33C93_FS_8_10;
1902 		else if (freq > 11 && freq < 16)
1903 		x = WD33C93_FS_12_15;
1904 		else if (freq > 15 && freq < 21)
1905 		x = WD33C93_FS_16_20;
1906 	else {
1907 			/* Hmm, wouldn't it be safer to assume highest freq here? */
1908 		x = WD33C93_FS_8_10;
1909 		freq = 8;
1910 	}
1911 	*mhz = freq;
1912 	return x;
1913 }
1914 
1915 /*
1916  * to be used with the resync: fast: ... options
1917  */
1918 static inline void set_resync ( struct WD33C93_hostdata *hd, int mask )
1919 {
1920 	int i;
1921 	for (i = 0; i < 8; i++)
1922 		if (mask & (1 << i))
1923 			hd->sync_stat[i] = SS_UNSET;
1924 }
1925 
1926 void
1927 wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
1928 	     dma_setup_t setup, dma_stop_t stop, int clock_freq)
1929 {
1930 	struct WD33C93_hostdata *hostdata;
1931 	int i;
1932 	int flags;
1933 	int val;
1934 	char buf[32];
1935 
1936 	if (!done_setup && setup_strings)
1937 		wd33c93_setup(setup_strings);
1938 
1939 	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1940 
1941 	hostdata->regs = regs;
1942 	hostdata->clock_freq = set_clk_freq(clock_freq, &i);
1943 	calc_sx_table(i, hostdata->sx_table);
1944 	hostdata->dma_setup = setup;
1945 	hostdata->dma_stop = stop;
1946 	hostdata->dma_bounce_buffer = NULL;
1947 	hostdata->dma_bounce_len = 0;
1948 	for (i = 0; i < 8; i++) {
1949 		hostdata->busy[i] = 0;
1950 		hostdata->sync_xfer[i] =
1951 			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
1952 					0, hostdata->sx_table);
1953 		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
1954 #ifdef PROC_STATISTICS
1955 		hostdata->cmd_cnt[i] = 0;
1956 		hostdata->disc_allowed_cnt[i] = 0;
1957 		hostdata->disc_done_cnt[i] = 0;
1958 #endif
1959 	}
1960 	hostdata->input_Q = NULL;
1961 	hostdata->selecting = NULL;
1962 	hostdata->connected = NULL;
1963 	hostdata->disconnected_Q = NULL;
1964 	hostdata->state = S_UNCONNECTED;
1965 	hostdata->dma = D_DMA_OFF;
1966 	hostdata->level2 = L2_BASIC;
1967 	hostdata->disconnect = DIS_ADAPTIVE;
1968 	hostdata->args = DEBUG_DEFAULTS;
1969 	hostdata->incoming_ptr = 0;
1970 	hostdata->outgoing_len = 0;
1971 	hostdata->default_sx_per = DEFAULT_SX_PER;
1972 	hostdata->no_dma = 0;	/* default is DMA enabled */
1973 
1974 #ifdef PROC_INTERFACE
1975 	hostdata->proc = PR_VERSION | PR_INFO | PR_STATISTICS |
1976 	    PR_CONNECTED | PR_INPUTQ | PR_DISCQ | PR_STOP;
1977 #ifdef PROC_STATISTICS
1978 	hostdata->dma_cnt = 0;
1979 	hostdata->pio_cnt = 0;
1980 	hostdata->int_cnt = 0;
1981 #endif
1982 #endif
1983 
1984 	if (check_setup_args("clock", &flags, &val, buf)) {
1985 		hostdata->clock_freq = set_clk_freq(val, &val);
1986 		calc_sx_table(val, hostdata->sx_table);
1987 	}
1988 
1989 	if (check_setup_args("nosync", &flags, &val, buf))
1990 		hostdata->no_sync = val;
1991 
1992 	if (check_setup_args("nodma", &flags, &val, buf))
1993 		hostdata->no_dma = (val == -1) ? 1 : val;
1994 
1995 	if (check_setup_args("period", &flags, &val, buf))
1996 		hostdata->default_sx_per =
1997 		    hostdata->sx_table[round_period((unsigned int) val,
1998 		                                    hostdata->sx_table)].period_ns;
1999 
2000 	if (check_setup_args("disconnect", &flags, &val, buf)) {
2001 		if ((val >= DIS_NEVER) && (val <= DIS_ALWAYS))
2002 			hostdata->disconnect = val;
2003 		else
2004 			hostdata->disconnect = DIS_ADAPTIVE;
2005 	}
2006 
2007 	if (check_setup_args("level2", &flags, &val, buf))
2008 		hostdata->level2 = val;
2009 
2010 	if (check_setup_args("debug", &flags, &val, buf))
2011 		hostdata->args = val & DB_MASK;
2012 
2013 	if (check_setup_args("burst", &flags, &val, buf))
2014 		hostdata->dma_mode = val ? CTRL_BURST:CTRL_DMA;
2015 
2016 	if (WD33C93_FS_16_20 == hostdata->clock_freq /* divisor 4 */
2017 		&& check_setup_args("fast", &flags, &val, buf))
2018 		hostdata->fast = !!val;
2019 
2020 	if ((i = check_setup_args("next", &flags, &val, buf))) {
2021 		while (i)
2022 			setup_used[--i] = 1;
2023 	}
2024 #ifdef PROC_INTERFACE
2025 	if (check_setup_args("proc", &flags, &val, buf))
2026 		hostdata->proc = val;
2027 #endif
2028 
2029 	spin_lock_irq(&hostdata->lock);
2030 	reset_wd33c93(instance);
2031 	spin_unlock_irq(&hostdata->lock);
2032 
2033 	printk("wd33c93-%d: chip=%s/%d no_sync=0x%x no_dma=%d",
2034 	       instance->host_no,
2035 	       (hostdata->chip == C_WD33C93) ? "WD33c93" : (hostdata->chip ==
2036 							    C_WD33C93A) ?
2037 	       "WD33c93A" : (hostdata->chip ==
2038 			     C_WD33C93B) ? "WD33c93B" : "unknown",
2039 	       hostdata->microcode, hostdata->no_sync, hostdata->no_dma);
2040 #ifdef DEBUGGING_ON
2041 	printk(" debug_flags=0x%02x\n", hostdata->args);
2042 #else
2043 	printk(" debugging=OFF\n");
2044 #endif
2045 	printk("           setup_args=");
2046 	for (i = 0; i < MAX_SETUP_ARGS; i++)
2047 		printk("%s,", setup_args[i]);
2048 	printk("\n");
2049 	printk("           Version %s - %s\n", WD33C93_VERSION, WD33C93_DATE);
2050 }
2051 
2052 int wd33c93_write_info(struct Scsi_Host *instance, char *buf, int len)
2053 {
2054 #ifdef PROC_INTERFACE
2055 	char *bp;
2056 	struct WD33C93_hostdata *hd;
2057 	int x;
2058 
2059 	hd = (struct WD33C93_hostdata *) instance->hostdata;
2060 
2061 /* We accept the following
2062  * keywords (same format as command-line, but arguments are not optional):
2063  *    debug
2064  *    disconnect
2065  *    period
2066  *    resync
2067  *    proc
2068  *    nodma
2069  *    level2
2070  *    burst
2071  *    fast
2072  *    nosync
2073  */
2074 
2075 	buf[len] = '\0';
2076 	for (bp = buf; *bp; ) {
2077 		while (',' == *bp || ' ' == *bp)
2078 			++bp;
2079 	if (!strncmp(bp, "debug:", 6)) {
2080 			hd->args = simple_strtoul(bp+6, &bp, 0) & DB_MASK;
2081 	} else if (!strncmp(bp, "disconnect:", 11)) {
2082 			x = simple_strtoul(bp+11, &bp, 0);
2083 		if (x < DIS_NEVER || x > DIS_ALWAYS)
2084 			x = DIS_ADAPTIVE;
2085 		hd->disconnect = x;
2086 	} else if (!strncmp(bp, "period:", 7)) {
2087 		x = simple_strtoul(bp+7, &bp, 0);
2088 		hd->default_sx_per =
2089 			hd->sx_table[round_period((unsigned int) x,
2090 						  hd->sx_table)].period_ns;
2091 	} else if (!strncmp(bp, "resync:", 7)) {
2092 			set_resync(hd, (int)simple_strtoul(bp+7, &bp, 0));
2093 	} else if (!strncmp(bp, "proc:", 5)) {
2094 			hd->proc = simple_strtoul(bp+5, &bp, 0);
2095 	} else if (!strncmp(bp, "nodma:", 6)) {
2096 			hd->no_dma = simple_strtoul(bp+6, &bp, 0);
2097 	} else if (!strncmp(bp, "level2:", 7)) {
2098 			hd->level2 = simple_strtoul(bp+7, &bp, 0);
2099 		} else if (!strncmp(bp, "burst:", 6)) {
2100 			hd->dma_mode =
2101 				simple_strtol(bp+6, &bp, 0) ? CTRL_BURST:CTRL_DMA;
2102 		} else if (!strncmp(bp, "fast:", 5)) {
2103 			x = !!simple_strtol(bp+5, &bp, 0);
2104 			if (x != hd->fast)
2105 				set_resync(hd, 0xff);
2106 			hd->fast = x;
2107 		} else if (!strncmp(bp, "nosync:", 7)) {
2108 			x = simple_strtoul(bp+7, &bp, 0);
2109 			set_resync(hd, x ^ hd->no_sync);
2110 			hd->no_sync = x;
2111 		} else {
2112 			break; /* unknown keyword,syntax-error,... */
2113 		}
2114 	}
2115 	return len;
2116 #else
2117 	return 0;
2118 #endif
2119 }
2120 
2121 int
2122 wd33c93_show_info(struct seq_file *m, struct Scsi_Host *instance)
2123 {
2124 #ifdef PROC_INTERFACE
2125 	struct WD33C93_hostdata *hd;
2126 	struct scsi_cmnd *cmd;
2127 	int x;
2128 
2129 	hd = (struct WD33C93_hostdata *) instance->hostdata;
2130 
2131 	spin_lock_irq(&hd->lock);
2132 	if (hd->proc & PR_VERSION)
2133 		seq_printf(m, "\nVersion %s - %s.",
2134 			WD33C93_VERSION, WD33C93_DATE);
2135 
2136 	if (hd->proc & PR_INFO) {
2137 		seq_printf(m, "\nclock_freq=%02x no_sync=%02x no_dma=%d"
2138 			" dma_mode=%02x fast=%d",
2139 			hd->clock_freq, hd->no_sync, hd->no_dma, hd->dma_mode, hd->fast);
2140 		seq_puts(m, "\nsync_xfer[] =       ");
2141 		for (x = 0; x < 7; x++)
2142 			seq_printf(m, "\t%02x", hd->sync_xfer[x]);
2143 		seq_puts(m, "\nsync_stat[] =       ");
2144 		for (x = 0; x < 7; x++)
2145 			seq_printf(m, "\t%02x", hd->sync_stat[x]);
2146 	}
2147 #ifdef PROC_STATISTICS
2148 	if (hd->proc & PR_STATISTICS) {
2149 		seq_puts(m, "\ncommands issued:    ");
2150 		for (x = 0; x < 7; x++)
2151 			seq_printf(m, "\t%ld", hd->cmd_cnt[x]);
2152 		seq_puts(m, "\ndisconnects allowed:");
2153 		for (x = 0; x < 7; x++)
2154 			seq_printf(m, "\t%ld", hd->disc_allowed_cnt[x]);
2155 		seq_puts(m, "\ndisconnects done:   ");
2156 		for (x = 0; x < 7; x++)
2157 			seq_printf(m, "\t%ld", hd->disc_done_cnt[x]);
2158 		seq_printf(m,
2159 			"\ninterrupts: %ld, DATA_PHASE ints: %ld DMA, %ld PIO",
2160 			hd->int_cnt, hd->dma_cnt, hd->pio_cnt);
2161 	}
2162 #endif
2163 	if (hd->proc & PR_CONNECTED) {
2164 		seq_puts(m, "\nconnected:     ");
2165 		if (hd->connected) {
2166 			cmd = (struct scsi_cmnd *) hd->connected;
2167 			seq_printf(m, " %d:%llu(%02x)",
2168 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2169 		}
2170 	}
2171 	if (hd->proc & PR_INPUTQ) {
2172 		seq_puts(m, "\ninput_Q:       ");
2173 		cmd = (struct scsi_cmnd *) hd->input_Q;
2174 		while (cmd) {
2175 			seq_printf(m, " %d:%llu(%02x)",
2176 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2177 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
2178 		}
2179 	}
2180 	if (hd->proc & PR_DISCQ) {
2181 		seq_puts(m, "\ndisconnected_Q:");
2182 		cmd = (struct scsi_cmnd *) hd->disconnected_Q;
2183 		while (cmd) {
2184 			seq_printf(m, " %d:%llu(%02x)",
2185 				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
2186 			cmd = (struct scsi_cmnd *) cmd->host_scribble;
2187 		}
2188 	}
2189 	seq_putc(m, '\n');
2190 	spin_unlock_irq(&hd->lock);
2191 #endif				/* PROC_INTERFACE */
2192 	return 0;
2193 }
2194 
2195 EXPORT_SYMBOL(wd33c93_host_reset);
2196 EXPORT_SYMBOL(wd33c93_init);
2197 EXPORT_SYMBOL(wd33c93_abort);
2198 EXPORT_SYMBOL(wd33c93_queuecommand);
2199 EXPORT_SYMBOL(wd33c93_intr);
2200 EXPORT_SYMBOL(wd33c93_show_info);
2201 EXPORT_SYMBOL(wd33c93_write_info);
2202