xref: /linux/drivers/scsi/NCR5380.c (revision 32786fdc9506aeba98278c1844d4bfb766863832)
1 /*
2  * NCR 5380 generic driver routines.  These should make it *trivial*
3  * to implement 5380 SCSI drivers under Linux with a non-trantor
4  * architecture.
5  *
6  * Note that these routines also work with NR53c400 family chips.
7  *
8  * Copyright 1993, Drew Eckhardt
9  * Visionary Computing
10  * (Unix and Linux consulting and custom programming)
11  * drew@colorado.edu
12  * +1 (303) 666-5836
13  *
14  * For more information, please consult
15  *
16  * NCR 5380 Family
17  * SCSI Protocol Controller
18  * Databook
19  *
20  * NCR Microelectronics
21  * 1635 Aeroplaza Drive
22  * Colorado Springs, CO 80916
23  * 1+ (719) 578-3400
24  * 1+ (800) 334-5454
25  */
26 
27 /*
28  * With contributions from Ray Van Tassle, Ingmar Baumgart,
29  * Ronald van Cuijlenborg, Alan Cox and others.
30  */
31 
32 /* Ported to Atari by Roman Hodek and others. */
33 
34 /* Adapted for the Sun 3 by Sam Creasey. */
35 
36 /*
37  * Design
38  *
39  * This is a generic 5380 driver.  To use it on a different platform,
40  * one simply writes appropriate system specific macros (ie, data
41  * transfer - some PC's will use the I/O bus, 68K's must use
42  * memory mapped) and drops this file in their 'C' wrapper.
43  *
44  * As far as command queueing, two queues are maintained for
45  * each 5380 in the system - commands that haven't been issued yet,
46  * and commands that are currently executing.  This means that an
47  * unlimited number of commands may be queued, letting
48  * more commands propagate from the higher driver levels giving higher
49  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
50  * allowing multiple commands to propagate all the way to a SCSI-II device
51  * while a command is already executing.
52  *
53  *
54  * Issues specific to the NCR5380 :
55  *
56  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
57  * piece of hardware that requires you to sit in a loop polling for
58  * the REQ signal as long as you are connected.  Some devices are
59  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
60  * while doing long seek operations. [...] These
61  * broken devices are the exception rather than the rule and I'd rather
62  * spend my time optimizing for the normal case.
63  *
64  * Architecture :
65  *
66  * At the heart of the design is a coroutine, NCR5380_main,
67  * which is started from a workqueue for each NCR5380 host in the
68  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
69  * removing the commands from the issue queue and calling
70  * NCR5380_select() if a nexus is not established.
71  *
72  * Once a nexus is established, the NCR5380_information_transfer()
73  * phase goes through the various phases as instructed by the target.
74  * if the target goes into MSG IN and sends a DISCONNECT message,
75  * the command structure is placed into the per instance disconnected
76  * queue, and NCR5380_main tries to find more work.  If the target is
77  * idle for too long, the system will try to sleep.
78  *
79  * If a command has disconnected, eventually an interrupt will trigger,
80  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
81  * to reestablish a nexus.  This will run main if necessary.
82  *
83  * On command termination, the done function will be called as
84  * appropriate.
85  *
86  * SCSI pointers are maintained in the SCp field of SCSI command
87  * structures, being initialized after the command is connected
88  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
89  * Note that in violation of the standard, an implicit SAVE POINTERS operation
90  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
91  */
92 
93 /*
94  * Using this file :
95  * This file a skeleton Linux SCSI driver for the NCR 5380 series
96  * of chips.  To use it, you write an architecture specific functions
97  * and macros and include this file in your driver.
98  *
99  * These macros control options :
100  * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
101  * defined.
102  *
103  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
104  * for commands that return with a CHECK CONDITION status.
105  *
106  * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
107  * transceivers.
108  *
109  * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
110  *
111  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
112  *
113  * These macros MUST be defined :
114  *
115  * NCR5380_read(register)  - read from the specified register
116  *
117  * NCR5380_write(register, value) - write to the specific register
118  *
119  * NCR5380_implementation_fields  - additional fields needed for this
120  * specific implementation of the NCR5380
121  *
122  * Either real DMA *or* pseudo DMA may be implemented
123  *
124  * NCR5380_dma_xfer_len   - determine size of DMA/PDMA transfer
125  * NCR5380_dma_send_setup - execute DMA/PDMA from memory to 5380
126  * NCR5380_dma_recv_setup - execute DMA/PDMA from 5380 to memory
127  * NCR5380_dma_residual   - residual byte count
128  *
129  * The generic driver is initialized by calling NCR5380_init(instance),
130  * after setting the appropriate host specific fields and ID.  If the
131  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
132  * possible) function may be used.
133  */
134 
135 #ifndef NCR5380_io_delay
136 #define NCR5380_io_delay(x)
137 #endif
138 
139 #ifndef NCR5380_acquire_dma_irq
140 #define NCR5380_acquire_dma_irq(x)	(1)
141 #endif
142 
143 #ifndef NCR5380_release_dma_irq
144 #define NCR5380_release_dma_irq(x)
145 #endif
146 
147 static int do_abort(struct Scsi_Host *);
148 static void do_reset(struct Scsi_Host *);
149 
150 /**
151  * initialize_SCp - init the scsi pointer field
152  * @cmd: command block to set up
153  *
154  * Set up the internal fields in the SCSI command.
155  */
156 
157 static inline void initialize_SCp(struct scsi_cmnd *cmd)
158 {
159 	/*
160 	 * Initialize the Scsi Pointer field so that all of the commands in the
161 	 * various queues are valid.
162 	 */
163 
164 	if (scsi_bufflen(cmd)) {
165 		cmd->SCp.buffer = scsi_sglist(cmd);
166 		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
167 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
168 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
169 	} else {
170 		cmd->SCp.buffer = NULL;
171 		cmd->SCp.buffers_residual = 0;
172 		cmd->SCp.ptr = NULL;
173 		cmd->SCp.this_residual = 0;
174 	}
175 
176 	cmd->SCp.Status = 0;
177 	cmd->SCp.Message = 0;
178 }
179 
180 /**
181  * NCR5380_poll_politely2 - wait for two chip register values
182  * @hostdata: host private data
183  * @reg1: 5380 register to poll
184  * @bit1: Bitmask to check
185  * @val1: Expected value
186  * @reg2: Second 5380 register to poll
187  * @bit2: Second bitmask to check
188  * @val2: Second expected value
189  * @wait: Time-out in jiffies
190  *
191  * Polls the chip in a reasonably efficient manner waiting for an
192  * event to occur. After a short quick poll we begin to yield the CPU
193  * (if possible). In irq contexts the time-out is arbitrarily limited.
194  * Callers may hold locks as long as they are held in irq mode.
195  *
196  * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
197  */
198 
199 static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
200                                   unsigned int reg1, u8 bit1, u8 val1,
201                                   unsigned int reg2, u8 bit2, u8 val2,
202                                   unsigned long wait)
203 {
204 	unsigned long n = hostdata->poll_loops;
205 	unsigned long deadline = jiffies + wait;
206 
207 	do {
208 		if ((NCR5380_read(reg1) & bit1) == val1)
209 			return 0;
210 		if ((NCR5380_read(reg2) & bit2) == val2)
211 			return 0;
212 		cpu_relax();
213 	} while (n--);
214 
215 	if (irqs_disabled() || in_interrupt())
216 		return -ETIMEDOUT;
217 
218 	/* Repeatedly sleep for 1 ms until deadline */
219 	while (time_is_after_jiffies(deadline)) {
220 		schedule_timeout_uninterruptible(1);
221 		if ((NCR5380_read(reg1) & bit1) == val1)
222 			return 0;
223 		if ((NCR5380_read(reg2) & bit2) == val2)
224 			return 0;
225 	}
226 
227 	return -ETIMEDOUT;
228 }
229 
230 #if NDEBUG
231 static struct {
232 	unsigned char mask;
233 	const char *name;
234 } signals[] = {
235 	{SR_DBP, "PARITY"},
236 	{SR_RST, "RST"},
237 	{SR_BSY, "BSY"},
238 	{SR_REQ, "REQ"},
239 	{SR_MSG, "MSG"},
240 	{SR_CD, "CD"},
241 	{SR_IO, "IO"},
242 	{SR_SEL, "SEL"},
243 	{0, NULL}
244 },
245 basrs[] = {
246 	{BASR_END_DMA_TRANSFER, "END OF DMA"},
247 	{BASR_DRQ, "DRQ"},
248 	{BASR_PARITY_ERROR, "PARITY ERROR"},
249 	{BASR_IRQ, "IRQ"},
250 	{BASR_PHASE_MATCH, "PHASE MATCH"},
251 	{BASR_BUSY_ERROR, "BUSY ERROR"},
252 	{BASR_ATN, "ATN"},
253 	{BASR_ACK, "ACK"},
254 	{0, NULL}
255 },
256 icrs[] = {
257 	{ICR_ASSERT_RST, "ASSERT RST"},
258 	{ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
259 	{ICR_ARBITRATION_LOST, "LOST ARB."},
260 	{ICR_ASSERT_ACK, "ASSERT ACK"},
261 	{ICR_ASSERT_BSY, "ASSERT BSY"},
262 	{ICR_ASSERT_SEL, "ASSERT SEL"},
263 	{ICR_ASSERT_ATN, "ASSERT ATN"},
264 	{ICR_ASSERT_DATA, "ASSERT DATA"},
265 	{0, NULL}
266 },
267 mrs[] = {
268 	{MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
269 	{MR_TARGET, "TARGET"},
270 	{MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
271 	{MR_ENABLE_PAR_INTR, "PARITY INTR"},
272 	{MR_ENABLE_EOP_INTR, "EOP INTR"},
273 	{MR_MONITOR_BSY, "MONITOR BSY"},
274 	{MR_DMA_MODE, "DMA MODE"},
275 	{MR_ARBITRATE, "ARBITRATE"},
276 	{0, NULL}
277 };
278 
279 /**
280  * NCR5380_print - print scsi bus signals
281  * @instance: adapter state to dump
282  *
283  * Print the SCSI bus signals for debugging purposes
284  */
285 
286 static void NCR5380_print(struct Scsi_Host *instance)
287 {
288 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
289 	unsigned char status, data, basr, mr, icr, i;
290 
291 	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
292 	status = NCR5380_read(STATUS_REG);
293 	mr = NCR5380_read(MODE_REG);
294 	icr = NCR5380_read(INITIATOR_COMMAND_REG);
295 	basr = NCR5380_read(BUS_AND_STATUS_REG);
296 
297 	printk(KERN_DEBUG "SR =   0x%02x : ", status);
298 	for (i = 0; signals[i].mask; ++i)
299 		if (status & signals[i].mask)
300 			printk(KERN_CONT "%s, ", signals[i].name);
301 	printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
302 	for (i = 0; basrs[i].mask; ++i)
303 		if (basr & basrs[i].mask)
304 			printk(KERN_CONT "%s, ", basrs[i].name);
305 	printk(KERN_CONT "\nICR =  0x%02x : ", icr);
306 	for (i = 0; icrs[i].mask; ++i)
307 		if (icr & icrs[i].mask)
308 			printk(KERN_CONT "%s, ", icrs[i].name);
309 	printk(KERN_CONT "\nMR =   0x%02x : ", mr);
310 	for (i = 0; mrs[i].mask; ++i)
311 		if (mr & mrs[i].mask)
312 			printk(KERN_CONT "%s, ", mrs[i].name);
313 	printk(KERN_CONT "\n");
314 }
315 
316 static struct {
317 	unsigned char value;
318 	const char *name;
319 } phases[] = {
320 	{PHASE_DATAOUT, "DATAOUT"},
321 	{PHASE_DATAIN, "DATAIN"},
322 	{PHASE_CMDOUT, "CMDOUT"},
323 	{PHASE_STATIN, "STATIN"},
324 	{PHASE_MSGOUT, "MSGOUT"},
325 	{PHASE_MSGIN, "MSGIN"},
326 	{PHASE_UNKNOWN, "UNKNOWN"}
327 };
328 
329 /**
330  * NCR5380_print_phase - show SCSI phase
331  * @instance: adapter to dump
332  *
333  * Print the current SCSI phase for debugging purposes
334  */
335 
336 static void NCR5380_print_phase(struct Scsi_Host *instance)
337 {
338 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
339 	unsigned char status;
340 	int i;
341 
342 	status = NCR5380_read(STATUS_REG);
343 	if (!(status & SR_REQ))
344 		shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
345 	else {
346 		for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
347 		     (phases[i].value != (status & PHASE_MASK)); ++i)
348 			;
349 		shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
350 	}
351 }
352 #endif
353 
354 
355 static int probe_irq;
356 
357 /**
358  * probe_intr	-	helper for IRQ autoprobe
359  * @irq: interrupt number
360  * @dev_id: unused
361  * @regs: unused
362  *
363  * Set a flag to indicate the IRQ in question was received. This is
364  * used by the IRQ probe code.
365  */
366 
367 static irqreturn_t probe_intr(int irq, void *dev_id)
368 {
369 	probe_irq = irq;
370 	return IRQ_HANDLED;
371 }
372 
373 /**
374  * NCR5380_probe_irq	-	find the IRQ of an NCR5380
375  * @instance: NCR5380 controller
376  * @possible: bitmask of ISA IRQ lines
377  *
378  * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
379  * and then looking to see what interrupt actually turned up.
380  */
381 
382 static int __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
383 						int possible)
384 {
385 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
386 	unsigned long timeout;
387 	int trying_irqs, i, mask;
388 
389 	for (trying_irqs = 0, i = 1, mask = 2; i < 16; ++i, mask <<= 1)
390 		if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0))
391 			trying_irqs |= mask;
392 
393 	timeout = jiffies + msecs_to_jiffies(250);
394 	probe_irq = NO_IRQ;
395 
396 	/*
397 	 * A interrupt is triggered whenever BSY = false, SEL = true
398 	 * and a bit set in the SELECT_ENABLE_REG is asserted on the
399 	 * SCSI bus.
400 	 *
401 	 * Note that the bus is only driven when the phase control signals
402 	 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
403 	 * to zero.
404 	 */
405 
406 	NCR5380_write(TARGET_COMMAND_REG, 0);
407 	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
408 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
409 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
410 
411 	while (probe_irq == NO_IRQ && time_before(jiffies, timeout))
412 		schedule_timeout_uninterruptible(1);
413 
414 	NCR5380_write(SELECT_ENABLE_REG, 0);
415 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
416 
417 	for (i = 1, mask = 2; i < 16; ++i, mask <<= 1)
418 		if (trying_irqs & mask)
419 			free_irq(i, NULL);
420 
421 	return probe_irq;
422 }
423 
424 /**
425  * NCR58380_info - report driver and host information
426  * @instance: relevant scsi host instance
427  *
428  * For use as the host template info() handler.
429  */
430 
431 static const char *NCR5380_info(struct Scsi_Host *instance)
432 {
433 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
434 
435 	return hostdata->info;
436 }
437 
438 static void prepare_info(struct Scsi_Host *instance)
439 {
440 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
441 
442 	snprintf(hostdata->info, sizeof(hostdata->info),
443 	         "%s, irq %d, "
444 		 "io_port 0x%lx, base 0x%lx, "
445 	         "can_queue %d, cmd_per_lun %d, "
446 	         "sg_tablesize %d, this_id %d, "
447 	         "flags { %s%s%s}, "
448 	         "options { %s} ",
449 	         instance->hostt->name, instance->irq,
450 		 hostdata->io_port, hostdata->base,
451 	         instance->can_queue, instance->cmd_per_lun,
452 	         instance->sg_tablesize, instance->this_id,
453 	         hostdata->flags & FLAG_DMA_FIXUP     ? "DMA_FIXUP "     : "",
454 	         hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
455 	         hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY "  : "",
456 #ifdef DIFFERENTIAL
457 	         "DIFFERENTIAL "
458 #endif
459 #ifdef PARITY
460 	         "PARITY "
461 #endif
462 	         "");
463 }
464 
465 /**
466  * NCR5380_init - initialise an NCR5380
467  * @instance: adapter to configure
468  * @flags: control flags
469  *
470  * Initializes *instance and corresponding 5380 chip,
471  * with flags OR'd into the initial flags value.
472  *
473  * Notes : I assume that the host, hostno, and id bits have been
474  * set correctly. I don't care about the irq and other fields.
475  *
476  * Returns 0 for success
477  */
478 
479 static int NCR5380_init(struct Scsi_Host *instance, int flags)
480 {
481 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
482 	int i;
483 	unsigned long deadline;
484 	unsigned long accesses_per_ms;
485 
486 	instance->max_lun = 7;
487 
488 	hostdata->host = instance;
489 	hostdata->id_mask = 1 << instance->this_id;
490 	hostdata->id_higher_mask = 0;
491 	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
492 		if (i > hostdata->id_mask)
493 			hostdata->id_higher_mask |= i;
494 	for (i = 0; i < 8; ++i)
495 		hostdata->busy[i] = 0;
496 	hostdata->dma_len = 0;
497 
498 	spin_lock_init(&hostdata->lock);
499 	hostdata->connected = NULL;
500 	hostdata->sensing = NULL;
501 	INIT_LIST_HEAD(&hostdata->autosense);
502 	INIT_LIST_HEAD(&hostdata->unissued);
503 	INIT_LIST_HEAD(&hostdata->disconnected);
504 
505 	hostdata->flags = flags;
506 
507 	INIT_WORK(&hostdata->main_task, NCR5380_main);
508 	hostdata->work_q = alloc_workqueue("ncr5380_%d",
509 	                        WQ_UNBOUND | WQ_MEM_RECLAIM,
510 	                        1, instance->host_no);
511 	if (!hostdata->work_q)
512 		return -ENOMEM;
513 
514 	prepare_info(instance);
515 
516 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
517 	NCR5380_write(MODE_REG, MR_BASE);
518 	NCR5380_write(TARGET_COMMAND_REG, 0);
519 	NCR5380_write(SELECT_ENABLE_REG, 0);
520 
521 	/* Calibrate register polling loop */
522 	i = 0;
523 	deadline = jiffies + 1;
524 	do {
525 		cpu_relax();
526 	} while (time_is_after_jiffies(deadline));
527 	deadline += msecs_to_jiffies(256);
528 	do {
529 		NCR5380_read(STATUS_REG);
530 		++i;
531 		cpu_relax();
532 	} while (time_is_after_jiffies(deadline));
533 	accesses_per_ms = i / 256;
534 	hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
535 
536 	return 0;
537 }
538 
539 /**
540  * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
541  * @instance: adapter to check
542  *
543  * If the system crashed, it may have crashed with a connected target and
544  * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
545  * currently established nexus, which we know nothing about. Failing that
546  * do a bus reset.
547  *
548  * Note that a bus reset will cause the chip to assert IRQ.
549  *
550  * Returns 0 if successful, otherwise -ENXIO.
551  */
552 
553 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
554 {
555 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
556 	int pass;
557 
558 	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
559 		switch (pass) {
560 		case 1:
561 		case 3:
562 		case 5:
563 			shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
564 			NCR5380_poll_politely(hostdata,
565 			                      STATUS_REG, SR_BSY, 0, 5 * HZ);
566 			break;
567 		case 2:
568 			shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
569 			do_abort(instance);
570 			break;
571 		case 4:
572 			shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
573 			do_reset(instance);
574 			/* Wait after a reset; the SCSI standard calls for
575 			 * 250ms, we wait 500ms to be on the safe side.
576 			 * But some Toshiba CD-ROMs need ten times that.
577 			 */
578 			if (hostdata->flags & FLAG_TOSHIBA_DELAY)
579 				msleep(2500);
580 			else
581 				msleep(500);
582 			break;
583 		case 6:
584 			shost_printk(KERN_ERR, instance, "bus locked solid\n");
585 			return -ENXIO;
586 		}
587 	}
588 	return 0;
589 }
590 
591 /**
592  * NCR5380_exit - remove an NCR5380
593  * @instance: adapter to remove
594  *
595  * Assumes that no more work can be queued (e.g. by NCR5380_intr).
596  */
597 
598 static void NCR5380_exit(struct Scsi_Host *instance)
599 {
600 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
601 
602 	cancel_work_sync(&hostdata->main_task);
603 	destroy_workqueue(hostdata->work_q);
604 }
605 
606 /**
607  * complete_cmd - finish processing a command and return it to the SCSI ML
608  * @instance: the host instance
609  * @cmd: command to complete
610  */
611 
612 static void complete_cmd(struct Scsi_Host *instance,
613                          struct scsi_cmnd *cmd)
614 {
615 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
616 
617 	dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
618 
619 	if (hostdata->sensing == cmd) {
620 		/* Autosense processing ends here */
621 		if ((cmd->result & 0xff) != SAM_STAT_GOOD) {
622 			scsi_eh_restore_cmnd(cmd, &hostdata->ses);
623 			set_host_byte(cmd, DID_ERROR);
624 		} else
625 			scsi_eh_restore_cmnd(cmd, &hostdata->ses);
626 		hostdata->sensing = NULL;
627 	}
628 
629 	hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
630 
631 	cmd->scsi_done(cmd);
632 }
633 
634 /**
635  * NCR5380_queue_command - queue a command
636  * @instance: the relevant SCSI adapter
637  * @cmd: SCSI command
638  *
639  * cmd is added to the per-instance issue queue, with minor
640  * twiddling done to the host specific fields of cmd.  If the
641  * main coroutine is not running, it is restarted.
642  */
643 
644 static int NCR5380_queue_command(struct Scsi_Host *instance,
645                                  struct scsi_cmnd *cmd)
646 {
647 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
648 	struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
649 	unsigned long flags;
650 
651 #if (NDEBUG & NDEBUG_NO_WRITE)
652 	switch (cmd->cmnd[0]) {
653 	case WRITE_6:
654 	case WRITE_10:
655 		shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
656 		cmd->result = (DID_ERROR << 16);
657 		cmd->scsi_done(cmd);
658 		return 0;
659 	}
660 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
661 
662 	cmd->result = 0;
663 
664 	if (!NCR5380_acquire_dma_irq(instance))
665 		return SCSI_MLQUEUE_HOST_BUSY;
666 
667 	spin_lock_irqsave(&hostdata->lock, flags);
668 
669 	/*
670 	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
671 	 * commands are added to the head of the queue since any command will
672 	 * clear the contingent allegiance condition that exists and the
673 	 * sense data is only guaranteed to be valid while the condition exists.
674 	 */
675 
676 	if (cmd->cmnd[0] == REQUEST_SENSE)
677 		list_add(&ncmd->list, &hostdata->unissued);
678 	else
679 		list_add_tail(&ncmd->list, &hostdata->unissued);
680 
681 	spin_unlock_irqrestore(&hostdata->lock, flags);
682 
683 	dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
684 	         cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
685 
686 	/* Kick off command processing */
687 	queue_work(hostdata->work_q, &hostdata->main_task);
688 	return 0;
689 }
690 
691 static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
692 {
693 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
694 
695 	/* Caller does the locking needed to set & test these data atomically */
696 	if (list_empty(&hostdata->disconnected) &&
697 	    list_empty(&hostdata->unissued) &&
698 	    list_empty(&hostdata->autosense) &&
699 	    !hostdata->connected &&
700 	    !hostdata->selecting)
701 		NCR5380_release_dma_irq(instance);
702 }
703 
704 /**
705  * dequeue_next_cmd - dequeue a command for processing
706  * @instance: the scsi host instance
707  *
708  * Priority is given to commands on the autosense queue. These commands
709  * need autosense because of a CHECK CONDITION result.
710  *
711  * Returns a command pointer if a command is found for a target that is
712  * not already busy. Otherwise returns NULL.
713  */
714 
715 static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
716 {
717 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
718 	struct NCR5380_cmd *ncmd;
719 	struct scsi_cmnd *cmd;
720 
721 	if (hostdata->sensing || list_empty(&hostdata->autosense)) {
722 		list_for_each_entry(ncmd, &hostdata->unissued, list) {
723 			cmd = NCR5380_to_scmd(ncmd);
724 			dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
725 			         cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
726 
727 			if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
728 				list_del(&ncmd->list);
729 				dsprintk(NDEBUG_QUEUES, instance,
730 				         "dequeue: removed %p from issue queue\n", cmd);
731 				return cmd;
732 			}
733 		}
734 	} else {
735 		/* Autosense processing begins here */
736 		ncmd = list_first_entry(&hostdata->autosense,
737 		                        struct NCR5380_cmd, list);
738 		list_del(&ncmd->list);
739 		cmd = NCR5380_to_scmd(ncmd);
740 		dsprintk(NDEBUG_QUEUES, instance,
741 		         "dequeue: removed %p from autosense queue\n", cmd);
742 		scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
743 		hostdata->sensing = cmd;
744 		return cmd;
745 	}
746 	return NULL;
747 }
748 
749 static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
750 {
751 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
752 	struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
753 
754 	if (hostdata->sensing == cmd) {
755 		scsi_eh_restore_cmnd(cmd, &hostdata->ses);
756 		list_add(&ncmd->list, &hostdata->autosense);
757 		hostdata->sensing = NULL;
758 	} else
759 		list_add(&ncmd->list, &hostdata->unissued);
760 }
761 
762 /**
763  * NCR5380_main - NCR state machines
764  *
765  * NCR5380_main is a coroutine that runs as long as more work can
766  * be done on the NCR5380 host adapters in a system.  Both
767  * NCR5380_queue_command() and NCR5380_intr() will try to start it
768  * in case it is not running.
769  */
770 
771 static void NCR5380_main(struct work_struct *work)
772 {
773 	struct NCR5380_hostdata *hostdata =
774 		container_of(work, struct NCR5380_hostdata, main_task);
775 	struct Scsi_Host *instance = hostdata->host;
776 	int done;
777 
778 	do {
779 		done = 1;
780 
781 		spin_lock_irq(&hostdata->lock);
782 		while (!hostdata->connected && !hostdata->selecting) {
783 			struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
784 
785 			if (!cmd)
786 				break;
787 
788 			dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
789 
790 			/*
791 			 * Attempt to establish an I_T_L nexus here.
792 			 * On success, instance->hostdata->connected is set.
793 			 * On failure, we must add the command back to the
794 			 * issue queue so we can keep trying.
795 			 */
796 			/*
797 			 * REQUEST SENSE commands are issued without tagged
798 			 * queueing, even on SCSI-II devices because the
799 			 * contingent allegiance condition exists for the
800 			 * entire unit.
801 			 */
802 
803 			if (!NCR5380_select(instance, cmd)) {
804 				dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
805 				maybe_release_dma_irq(instance);
806 			} else {
807 				dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
808 				         "main: select failed, returning %p to queue\n", cmd);
809 				requeue_cmd(instance, cmd);
810 			}
811 		}
812 		if (hostdata->connected && !hostdata->dma_len) {
813 			dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
814 			NCR5380_information_transfer(instance);
815 			done = 0;
816 		}
817 		spin_unlock_irq(&hostdata->lock);
818 		if (!done)
819 			cond_resched();
820 	} while (!done);
821 }
822 
823 /*
824  * NCR5380_dma_complete - finish DMA transfer
825  * @instance: the scsi host instance
826  *
827  * Called by the interrupt handler when DMA finishes or a phase
828  * mismatch occurs (which would end the DMA transfer).
829  */
830 
831 static void NCR5380_dma_complete(struct Scsi_Host *instance)
832 {
833 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
834 	int transferred;
835 	unsigned char **data;
836 	int *count;
837 	int saved_data = 0, overrun = 0;
838 	unsigned char p;
839 
840 	if (hostdata->read_overruns) {
841 		p = hostdata->connected->SCp.phase;
842 		if (p & SR_IO) {
843 			udelay(10);
844 			if ((NCR5380_read(BUS_AND_STATUS_REG) &
845 			     (BASR_PHASE_MATCH | BASR_ACK)) ==
846 			    (BASR_PHASE_MATCH | BASR_ACK)) {
847 				saved_data = NCR5380_read(INPUT_DATA_REG);
848 				overrun = 1;
849 				dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
850 			}
851 		}
852 	}
853 
854 #ifdef CONFIG_SUN3
855 	if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
856 		pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
857 		       instance->host_no);
858 		BUG();
859 	}
860 
861 	if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
862 	    (BASR_PHASE_MATCH | BASR_ACK)) {
863 		pr_err("scsi%d: BASR %02x\n", instance->host_no,
864 		       NCR5380_read(BUS_AND_STATUS_REG));
865 		pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
866 		       instance->host_no);
867 		BUG();
868 	}
869 #endif
870 
871 	NCR5380_write(MODE_REG, MR_BASE);
872 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
873 	NCR5380_read(RESET_PARITY_INTERRUPT_REG);
874 
875 	transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
876 	hostdata->dma_len = 0;
877 
878 	data = (unsigned char **)&hostdata->connected->SCp.ptr;
879 	count = &hostdata->connected->SCp.this_residual;
880 	*data += transferred;
881 	*count -= transferred;
882 
883 	if (hostdata->read_overruns) {
884 		int cnt, toPIO;
885 
886 		if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
887 			cnt = toPIO = hostdata->read_overruns;
888 			if (overrun) {
889 				dsprintk(NDEBUG_DMA, instance,
890 				         "Got an input overrun, using saved byte\n");
891 				*(*data)++ = saved_data;
892 				(*count)--;
893 				cnt--;
894 				toPIO--;
895 			}
896 			if (toPIO > 0) {
897 				dsprintk(NDEBUG_DMA, instance,
898 				         "Doing %d byte PIO to 0x%p\n", cnt, *data);
899 				NCR5380_transfer_pio(instance, &p, &cnt, data);
900 				*count -= toPIO - cnt;
901 			}
902 		}
903 	}
904 }
905 
906 /**
907  * NCR5380_intr - generic NCR5380 irq handler
908  * @irq: interrupt number
909  * @dev_id: device info
910  *
911  * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
912  * from the disconnected queue, and restarting NCR5380_main()
913  * as required.
914  *
915  * The chip can assert IRQ in any of six different conditions. The IRQ flag
916  * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
917  * Three of these six conditions are latched in the Bus and Status Register:
918  * - End of DMA (cleared by ending DMA Mode)
919  * - Parity error (cleared by reading RPIR)
920  * - Loss of BSY (cleared by reading RPIR)
921  * Two conditions have flag bits that are not latched:
922  * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
923  * - Bus reset (non-maskable)
924  * The remaining condition has no flag bit at all:
925  * - Selection/reselection
926  *
927  * Hence, establishing the cause(s) of any interrupt is partly guesswork.
928  * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
929  * claimed that "the design of the [DP8490] interrupt logic ensures
930  * interrupts will not be lost (they can be on the DP5380)."
931  * The L5380/53C80 datasheet from LOGIC Devices has more details.
932  *
933  * Checking for bus reset by reading RST is futile because of interrupt
934  * latency, but a bus reset will reset chip logic. Checking for parity error
935  * is unnecessary because that interrupt is never enabled. A Loss of BSY
936  * condition will clear DMA Mode. We can tell when this occurs because the
937  * the Busy Monitor interrupt is enabled together with DMA Mode.
938  */
939 
940 static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
941 {
942 	struct Scsi_Host *instance = dev_id;
943 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
944 	int handled = 0;
945 	unsigned char basr;
946 	unsigned long flags;
947 
948 	spin_lock_irqsave(&hostdata->lock, flags);
949 
950 	basr = NCR5380_read(BUS_AND_STATUS_REG);
951 	if (basr & BASR_IRQ) {
952 		unsigned char mr = NCR5380_read(MODE_REG);
953 		unsigned char sr = NCR5380_read(STATUS_REG);
954 
955 		dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
956 		         irq, basr, sr, mr);
957 
958 		if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
959 			/* Probably End of DMA, Phase Mismatch or Loss of BSY.
960 			 * We ack IRQ after clearing Mode Register. Workarounds
961 			 * for End of DMA errata need to happen in DMA Mode.
962 			 */
963 
964 			dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
965 
966 			if (hostdata->connected) {
967 				NCR5380_dma_complete(instance);
968 				queue_work(hostdata->work_q, &hostdata->main_task);
969 			} else {
970 				NCR5380_write(MODE_REG, MR_BASE);
971 				NCR5380_read(RESET_PARITY_INTERRUPT_REG);
972 			}
973 		} else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
974 		    (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
975 			/* Probably reselected */
976 			NCR5380_write(SELECT_ENABLE_REG, 0);
977 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
978 
979 			dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
980 
981 			if (!hostdata->connected) {
982 				NCR5380_reselect(instance);
983 				queue_work(hostdata->work_q, &hostdata->main_task);
984 			}
985 			if (!hostdata->connected)
986 				NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
987 		} else {
988 			/* Probably Bus Reset */
989 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
990 
991 			dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
992 #ifdef SUN3_SCSI_VME
993 			dregs->csr |= CSR_DMA_ENABLE;
994 #endif
995 		}
996 		handled = 1;
997 	} else {
998 		dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
999 #ifdef SUN3_SCSI_VME
1000 		dregs->csr |= CSR_DMA_ENABLE;
1001 #endif
1002 	}
1003 
1004 	spin_unlock_irqrestore(&hostdata->lock, flags);
1005 
1006 	return IRQ_RETVAL(handled);
1007 }
1008 
1009 /*
1010  * Function : int NCR5380_select(struct Scsi_Host *instance,
1011  * struct scsi_cmnd *cmd)
1012  *
1013  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1014  * including ARBITRATION, SELECTION, and initial message out for
1015  * IDENTIFY and queue messages.
1016  *
1017  * Inputs : instance - instantiation of the 5380 driver on which this
1018  * target lives, cmd - SCSI command to execute.
1019  *
1020  * Returns cmd if selection failed but should be retried,
1021  * NULL if selection failed and should not be retried, or
1022  * NULL if selection succeeded (hostdata->connected == cmd).
1023  *
1024  * Side effects :
1025  * If bus busy, arbitration failed, etc, NCR5380_select() will exit
1026  * with registers as they should have been on entry - ie
1027  * SELECT_ENABLE will be set appropriately, the NCR5380
1028  * will cease to drive any SCSI bus signals.
1029  *
1030  * If successful : I_T_L or I_T_L_Q nexus will be established,
1031  * instance->connected will be set to cmd.
1032  * SELECT interrupt will be disabled.
1033  *
1034  * If failed (no target) : cmd->scsi_done() will be called, and the
1035  * cmd->result host byte set to DID_BAD_TARGET.
1036  */
1037 
1038 static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
1039                                         struct scsi_cmnd *cmd)
1040 {
1041 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
1042 	unsigned char tmp[3], phase;
1043 	unsigned char *data;
1044 	int len;
1045 	int err;
1046 
1047 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1048 	dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
1049 	         instance->this_id);
1050 
1051 	/*
1052 	 * Arbitration and selection phases are slow and involve dropping the
1053 	 * lock, so we have to watch out for EH. An exception handler may
1054 	 * change 'selecting' to NULL. This function will then return NULL
1055 	 * so that the caller will forget about 'cmd'. (During information
1056 	 * transfer phases, EH may change 'connected' to NULL.)
1057 	 */
1058 	hostdata->selecting = cmd;
1059 
1060 	/*
1061 	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1062 	 * data bus during SELECTION.
1063 	 */
1064 
1065 	NCR5380_write(TARGET_COMMAND_REG, 0);
1066 
1067 	/*
1068 	 * Start arbitration.
1069 	 */
1070 
1071 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1072 	NCR5380_write(MODE_REG, MR_ARBITRATE);
1073 
1074 	/* The chip now waits for BUS FREE phase. Then after the 800 ns
1075 	 * Bus Free Delay, arbitration will begin.
1076 	 */
1077 
1078 	spin_unlock_irq(&hostdata->lock);
1079 	err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
1080 	                INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
1081 	                                       ICR_ARBITRATION_PROGRESS, HZ);
1082 	spin_lock_irq(&hostdata->lock);
1083 	if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
1084 		/* Reselection interrupt */
1085 		goto out;
1086 	}
1087 	if (!hostdata->selecting) {
1088 		/* Command was aborted */
1089 		NCR5380_write(MODE_REG, MR_BASE);
1090 		goto out;
1091 	}
1092 	if (err < 0) {
1093 		NCR5380_write(MODE_REG, MR_BASE);
1094 		shost_printk(KERN_ERR, instance,
1095 		             "select: arbitration timeout\n");
1096 		goto out;
1097 	}
1098 	spin_unlock_irq(&hostdata->lock);
1099 
1100 	/* The SCSI-2 arbitration delay is 2.4 us */
1101 	udelay(3);
1102 
1103 	/* Check for lost arbitration */
1104 	if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1105 	    (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1106 	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1107 		NCR5380_write(MODE_REG, MR_BASE);
1108 		dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1109 		spin_lock_irq(&hostdata->lock);
1110 		goto out;
1111 	}
1112 
1113 	/* After/during arbitration, BSY should be asserted.
1114 	 * IBM DPES-31080 Version S31Q works now
1115 	 * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1116 	 */
1117 	NCR5380_write(INITIATOR_COMMAND_REG,
1118 		      ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1119 
1120 	/*
1121 	 * Again, bus clear + bus settle time is 1.2us, however, this is
1122 	 * a minimum so we'll udelay ceil(1.2)
1123 	 */
1124 
1125 	if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1126 		udelay(15);
1127 	else
1128 		udelay(2);
1129 
1130 	spin_lock_irq(&hostdata->lock);
1131 
1132 	/* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1133 	if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1134 		goto out;
1135 
1136 	if (!hostdata->selecting) {
1137 		NCR5380_write(MODE_REG, MR_BASE);
1138 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1139 		goto out;
1140 	}
1141 
1142 	dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1143 
1144 	/*
1145 	 * Now that we have won arbitration, start Selection process, asserting
1146 	 * the host and target ID's on the SCSI bus.
1147 	 */
1148 
1149 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1150 
1151 	/*
1152 	 * Raise ATN while SEL is true before BSY goes false from arbitration,
1153 	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1154 	 * phase immediately after selection.
1155 	 */
1156 
1157 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1158 	              ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1159 	NCR5380_write(MODE_REG, MR_BASE);
1160 
1161 	/*
1162 	 * Reselect interrupts must be turned off prior to the dropping of BSY,
1163 	 * otherwise we will trigger an interrupt.
1164 	 */
1165 	NCR5380_write(SELECT_ENABLE_REG, 0);
1166 
1167 	spin_unlock_irq(&hostdata->lock);
1168 
1169 	/*
1170 	 * The initiator shall then wait at least two deskew delays and release
1171 	 * the BSY signal.
1172 	 */
1173 	udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1174 
1175 	/* Reset BSY */
1176 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1177 	              ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1178 
1179 	/*
1180 	 * Something weird happens when we cease to drive BSY - looks
1181 	 * like the board/chip is letting us do another read before the
1182 	 * appropriate propagation delay has expired, and we're confusing
1183 	 * a BSY signal from ourselves as the target's response to SELECTION.
1184 	 *
1185 	 * A small delay (the 'C++' frontend breaks the pipeline with an
1186 	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1187 	 * tighter 'C' code breaks and requires this) solves the problem -
1188 	 * the 1 us delay is arbitrary, and only used because this delay will
1189 	 * be the same on other platforms and since it works here, it should
1190 	 * work there.
1191 	 *
1192 	 * wingel suggests that this could be due to failing to wait
1193 	 * one deskew delay.
1194 	 */
1195 
1196 	udelay(1);
1197 
1198 	dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1199 
1200 	/*
1201 	 * The SCSI specification calls for a 250 ms timeout for the actual
1202 	 * selection.
1203 	 */
1204 
1205 	err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
1206 	                            msecs_to_jiffies(250));
1207 
1208 	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1209 		spin_lock_irq(&hostdata->lock);
1210 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1211 		NCR5380_reselect(instance);
1212 		if (!hostdata->connected)
1213 			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1214 		shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1215 		goto out;
1216 	}
1217 
1218 	if (err < 0) {
1219 		spin_lock_irq(&hostdata->lock);
1220 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1221 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1222 		/* Can't touch cmd if it has been reclaimed by the scsi ML */
1223 		if (hostdata->selecting) {
1224 			cmd->result = DID_BAD_TARGET << 16;
1225 			complete_cmd(instance, cmd);
1226 			dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n");
1227 			cmd = NULL;
1228 		}
1229 		goto out;
1230 	}
1231 
1232 	/*
1233 	 * No less than two deskew delays after the initiator detects the
1234 	 * BSY signal is true, it shall release the SEL signal and may
1235 	 * change the DATA BUS.                                     -wingel
1236 	 */
1237 
1238 	udelay(1);
1239 
1240 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1241 
1242 	/*
1243 	 * Since we followed the SCSI spec, and raised ATN while SEL
1244 	 * was true but before BSY was false during selection, the information
1245 	 * transfer phase should be a MESSAGE OUT phase so that we can send the
1246 	 * IDENTIFY message.
1247 	 */
1248 
1249 	/* Wait for start of REQ/ACK handshake */
1250 
1251 	err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1252 	spin_lock_irq(&hostdata->lock);
1253 	if (err < 0) {
1254 		shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1255 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1256 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1257 		goto out;
1258 	}
1259 	if (!hostdata->selecting) {
1260 		do_abort(instance);
1261 		goto out;
1262 	}
1263 
1264 	dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1265 	         scmd_id(cmd));
1266 	tmp[0] = IDENTIFY(((instance->irq == NO_IRQ) ? 0 : 1), cmd->device->lun);
1267 
1268 	len = 1;
1269 	data = tmp;
1270 	phase = PHASE_MSGOUT;
1271 	NCR5380_transfer_pio(instance, &phase, &len, &data);
1272 	dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1273 	/* XXX need to handle errors here */
1274 
1275 	hostdata->connected = cmd;
1276 	hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1277 
1278 #ifdef SUN3_SCSI_VME
1279 	dregs->csr |= CSR_INTR;
1280 #endif
1281 
1282 	initialize_SCp(cmd);
1283 
1284 	cmd = NULL;
1285 
1286 out:
1287 	if (!hostdata->selecting)
1288 		return NULL;
1289 	hostdata->selecting = NULL;
1290 	return cmd;
1291 }
1292 
1293 /*
1294  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1295  * unsigned char *phase, int *count, unsigned char **data)
1296  *
1297  * Purpose : transfers data in given phase using polled I/O
1298  *
1299  * Inputs : instance - instance of driver, *phase - pointer to
1300  * what phase is expected, *count - pointer to number of
1301  * bytes to transfer, **data - pointer to data pointer.
1302  *
1303  * Returns : -1 when different phase is entered without transferring
1304  * maximum number of bytes, 0 if all bytes are transferred or exit
1305  * is in same phase.
1306  *
1307  * Also, *phase, *count, *data are modified in place.
1308  *
1309  * XXX Note : handling for bus free may be useful.
1310  */
1311 
1312 /*
1313  * Note : this code is not as quick as it could be, however it
1314  * IS 100% reliable, and for the actual data transfer where speed
1315  * counts, we will always do a pseudo DMA or DMA transfer.
1316  */
1317 
1318 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1319 				unsigned char *phase, int *count,
1320 				unsigned char **data)
1321 {
1322 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
1323 	unsigned char p = *phase, tmp;
1324 	int c = *count;
1325 	unsigned char *d = *data;
1326 
1327 	/*
1328 	 * The NCR5380 chip will only drive the SCSI bus when the
1329 	 * phase specified in the appropriate bits of the TARGET COMMAND
1330 	 * REGISTER match the STATUS REGISTER
1331 	 */
1332 
1333 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1334 
1335 	do {
1336 		/*
1337 		 * Wait for assertion of REQ, after which the phase bits will be
1338 		 * valid
1339 		 */
1340 
1341 		if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1342 			break;
1343 
1344 		dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1345 
1346 		/* Check for phase mismatch */
1347 		if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1348 			dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1349 			NCR5380_dprint_phase(NDEBUG_PIO, instance);
1350 			break;
1351 		}
1352 
1353 		/* Do actual transfer from SCSI bus to / from memory */
1354 		if (!(p & SR_IO))
1355 			NCR5380_write(OUTPUT_DATA_REG, *d);
1356 		else
1357 			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1358 
1359 		++d;
1360 
1361 		/*
1362 		 * The SCSI standard suggests that in MSGOUT phase, the initiator
1363 		 * should drop ATN on the last byte of the message phase
1364 		 * after REQ has been asserted for the handshake but before
1365 		 * the initiator raises ACK.
1366 		 */
1367 
1368 		if (!(p & SR_IO)) {
1369 			if (!((p & SR_MSG) && c > 1)) {
1370 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1371 				NCR5380_dprint(NDEBUG_PIO, instance);
1372 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1373 				              ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1374 			} else {
1375 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1376 				              ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1377 				NCR5380_dprint(NDEBUG_PIO, instance);
1378 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1379 				              ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1380 			}
1381 		} else {
1382 			NCR5380_dprint(NDEBUG_PIO, instance);
1383 			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1384 		}
1385 
1386 		if (NCR5380_poll_politely(hostdata,
1387 		                          STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1388 			break;
1389 
1390 		dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1391 
1392 /*
1393  * We have several special cases to consider during REQ/ACK handshaking :
1394  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1395  * message.  ATN must be dropped as ACK is dropped.
1396  *
1397  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1398  * message.  We must exit with ACK asserted, so that the calling
1399  * code may raise ATN before dropping ACK to reject the message.
1400  *
1401  * 3.  ACK and ATN are clear and the target may proceed as normal.
1402  */
1403 		if (!(p == PHASE_MSGIN && c == 1)) {
1404 			if (p == PHASE_MSGOUT && c > 1)
1405 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1406 			else
1407 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1408 		}
1409 	} while (--c);
1410 
1411 	dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1412 
1413 	*count = c;
1414 	*data = d;
1415 	tmp = NCR5380_read(STATUS_REG);
1416 	/* The phase read from the bus is valid if either REQ is (already)
1417 	 * asserted or if ACK hasn't been released yet. The latter applies if
1418 	 * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1419 	 */
1420 	if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1421 		*phase = tmp & PHASE_MASK;
1422 	else
1423 		*phase = PHASE_UNKNOWN;
1424 
1425 	if (!c || (*phase == p))
1426 		return 0;
1427 	else
1428 		return -1;
1429 }
1430 
1431 /**
1432  * do_reset - issue a reset command
1433  * @instance: adapter to reset
1434  *
1435  * Issue a reset sequence to the NCR5380 and try and get the bus
1436  * back into sane shape.
1437  *
1438  * This clears the reset interrupt flag because there may be no handler for
1439  * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1440  * been installed. And when in EH we may have released the ST DMA interrupt.
1441  */
1442 
1443 static void do_reset(struct Scsi_Host *instance)
1444 {
1445 	struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
1446 	unsigned long flags;
1447 
1448 	local_irq_save(flags);
1449 	NCR5380_write(TARGET_COMMAND_REG,
1450 	              PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1451 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1452 	udelay(50);
1453 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1454 	(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1455 	local_irq_restore(flags);
1456 }
1457 
1458 /**
1459  * do_abort - abort the currently established nexus by going to
1460  * MESSAGE OUT phase and sending an ABORT message.
1461  * @instance: relevant scsi host instance
1462  *
1463  * Returns 0 on success, -1 on failure.
1464  */
1465 
1466 static int do_abort(struct Scsi_Host *instance)
1467 {
1468 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
1469 	unsigned char *msgptr, phase, tmp;
1470 	int len;
1471 	int rc;
1472 
1473 	/* Request message out phase */
1474 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1475 
1476 	/*
1477 	 * Wait for the target to indicate a valid phase by asserting
1478 	 * REQ.  Once this happens, we'll have either a MSGOUT phase
1479 	 * and can immediately send the ABORT message, or we'll have some
1480 	 * other phase and will have to source/sink data.
1481 	 *
1482 	 * We really don't care what value was on the bus or what value
1483 	 * the target sees, so we just handshake.
1484 	 */
1485 
1486 	rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1487 	if (rc < 0)
1488 		goto timeout;
1489 
1490 	tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1491 
1492 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1493 
1494 	if (tmp != PHASE_MSGOUT) {
1495 		NCR5380_write(INITIATOR_COMMAND_REG,
1496 		              ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1497 		rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
1498 		if (rc < 0)
1499 			goto timeout;
1500 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1501 	}
1502 
1503 	tmp = ABORT;
1504 	msgptr = &tmp;
1505 	len = 1;
1506 	phase = PHASE_MSGOUT;
1507 	NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1508 
1509 	/*
1510 	 * If we got here, and the command completed successfully,
1511 	 * we're about to go into bus free state.
1512 	 */
1513 
1514 	return len ? -1 : 0;
1515 
1516 timeout:
1517 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1518 	return -1;
1519 }
1520 
1521 /*
1522  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1523  * unsigned char *phase, int *count, unsigned char **data)
1524  *
1525  * Purpose : transfers data in given phase using either real
1526  * or pseudo DMA.
1527  *
1528  * Inputs : instance - instance of driver, *phase - pointer to
1529  * what phase is expected, *count - pointer to number of
1530  * bytes to transfer, **data - pointer to data pointer.
1531  *
1532  * Returns : -1 when different phase is entered without transferring
1533  * maximum number of bytes, 0 if all bytes or transferred or exit
1534  * is in same phase.
1535  *
1536  * Also, *phase, *count, *data are modified in place.
1537  */
1538 
1539 
1540 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1541 				unsigned char *phase, int *count,
1542 				unsigned char **data)
1543 {
1544 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
1545 	int c = *count;
1546 	unsigned char p = *phase;
1547 	unsigned char *d = *data;
1548 	unsigned char tmp;
1549 	int result = 0;
1550 
1551 	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1552 		*phase = tmp;
1553 		return -1;
1554 	}
1555 
1556 	hostdata->connected->SCp.phase = p;
1557 
1558 	if (p & SR_IO) {
1559 		if (hostdata->read_overruns)
1560 			c -= hostdata->read_overruns;
1561 		else if (hostdata->flags & FLAG_DMA_FIXUP)
1562 			--c;
1563 	}
1564 
1565 	dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1566 	         (p & SR_IO) ? "receive" : "send", c, d);
1567 
1568 #ifdef CONFIG_SUN3
1569 	/* send start chain */
1570 	sun3scsi_dma_start(c, *data);
1571 #endif
1572 
1573 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1574 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1575 	                        MR_ENABLE_EOP_INTR);
1576 
1577 	if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1578 		/* On the Medusa, it is a must to initialize the DMA before
1579 		 * starting the NCR. This is also the cleaner way for the TT.
1580 		 */
1581 		if (p & SR_IO)
1582 			result = NCR5380_dma_recv_setup(hostdata, d, c);
1583 		else
1584 			result = NCR5380_dma_send_setup(hostdata, d, c);
1585 	}
1586 
1587 	/*
1588 	 * On the PAS16 at least I/O recovery delays are not needed here.
1589 	 * Everyone else seems to want them.
1590 	 */
1591 
1592 	if (p & SR_IO) {
1593 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1594 		NCR5380_io_delay(1);
1595 		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1596 	} else {
1597 		NCR5380_io_delay(1);
1598 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1599 		NCR5380_io_delay(1);
1600 		NCR5380_write(START_DMA_SEND_REG, 0);
1601 		NCR5380_io_delay(1);
1602 	}
1603 
1604 #ifdef CONFIG_SUN3
1605 #ifdef SUN3_SCSI_VME
1606 	dregs->csr |= CSR_DMA_ENABLE;
1607 #endif
1608 	sun3_dma_active = 1;
1609 #endif
1610 
1611 	if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1612 		/* On the Falcon, the DMA setup must be done after the last
1613 		 * NCR access, else the DMA setup gets trashed!
1614 		 */
1615 		if (p & SR_IO)
1616 			result = NCR5380_dma_recv_setup(hostdata, d, c);
1617 		else
1618 			result = NCR5380_dma_send_setup(hostdata, d, c);
1619 	}
1620 
1621 	/* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
1622 	if (result < 0)
1623 		return result;
1624 
1625 	/* For real DMA, result is the byte count. DMA interrupt is expected. */
1626 	if (result > 0) {
1627 		hostdata->dma_len = result;
1628 		return 0;
1629 	}
1630 
1631 	/* The result is zero iff pseudo DMA send/receive was completed. */
1632 	hostdata->dma_len = c;
1633 
1634 /*
1635  * A note regarding the DMA errata workarounds for early NMOS silicon.
1636  *
1637  * For DMA sends, we want to wait until the last byte has been
1638  * transferred out over the bus before we turn off DMA mode.  Alas, there
1639  * seems to be no terribly good way of doing this on a 5380 under all
1640  * conditions.  For non-scatter-gather operations, we can wait until REQ
1641  * and ACK both go false, or until a phase mismatch occurs.  Gather-sends
1642  * are nastier, since the device will be expecting more data than we
1643  * are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1644  * could test Last Byte Sent to assure transfer (I imagine this is precisely
1645  * why this signal was added to the newer chips) but on the older 538[01]
1646  * this signal does not exist.  The workaround for this lack is a watchdog;
1647  * we bail out of the wait-loop after a modest amount of wait-time if
1648  * the usual exit conditions are not met.  Not a terribly clean or
1649  * correct solution :-%
1650  *
1651  * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1652  * If the chip is in DMA receive mode, it will respond to a target's
1653  * REQ by latching the SCSI data into the INPUT DATA register and asserting
1654  * ACK, even if it has _already_ been notified by the DMA controller that
1655  * the current DMA transfer has completed!  If the NCR5380 is then taken
1656  * out of DMA mode, this already-acknowledged byte is lost. This is
1657  * not a problem for "one DMA transfer per READ command", because
1658  * the situation will never arise... either all of the data is DMA'ed
1659  * properly, or the target switches to MESSAGE IN phase to signal a
1660  * disconnection (either operation bringing the DMA to a clean halt).
1661  * However, in order to handle scatter-receive, we must work around the
1662  * problem.  The chosen fix is to DMA fewer bytes, then check for the
1663  * condition before taking the NCR5380 out of DMA mode.  One or two extra
1664  * bytes are transferred via PIO as necessary to fill out the original
1665  * request.
1666  */
1667 
1668 	if (hostdata->flags & FLAG_DMA_FIXUP) {
1669 		if (p & SR_IO) {
1670 			/*
1671 			 * The workaround was to transfer fewer bytes than we
1672 			 * intended to with the pseudo-DMA read function, wait for
1673 			 * the chip to latch the last byte, read it, and then disable
1674 			 * pseudo-DMA mode.
1675 			 *
1676 			 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1677 			 * REQ is deasserted when ACK is asserted, and not reasserted
1678 			 * until ACK goes false.  Since the NCR5380 won't lower ACK
1679 			 * until DACK is asserted, which won't happen unless we twiddle
1680 			 * the DMA port or we take the NCR5380 out of DMA mode, we
1681 			 * can guarantee that we won't handshake another extra
1682 			 * byte.
1683 			 */
1684 
1685 			if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
1686 			                          BASR_DRQ, BASR_DRQ, HZ) < 0) {
1687 				result = -1;
1688 				shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1689 			}
1690 			if (NCR5380_poll_politely(hostdata, STATUS_REG,
1691 			                          SR_REQ, 0, HZ) < 0) {
1692 				result = -1;
1693 				shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1694 			}
1695 			d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
1696 		} else {
1697 			/*
1698 			 * Wait for the last byte to be sent.  If REQ is being asserted for
1699 			 * the byte we're interested, we'll ACK it and it will go false.
1700 			 */
1701 			if (NCR5380_poll_politely2(hostdata,
1702 			     BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1703 			     BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
1704 				result = -1;
1705 				shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1706 			}
1707 		}
1708 	}
1709 
1710 	NCR5380_dma_complete(instance);
1711 	return result;
1712 }
1713 
1714 /*
1715  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1716  *
1717  * Purpose : run through the various SCSI phases and do as the target
1718  * directs us to.  Operates on the currently connected command,
1719  * instance->connected.
1720  *
1721  * Inputs : instance, instance for which we are doing commands
1722  *
1723  * Side effects : SCSI things happen, the disconnected queue will be
1724  * modified if a command disconnects, *instance->connected will
1725  * change.
1726  *
1727  * XXX Note : we need to watch for bus free or a reset condition here
1728  * to recover from an unexpected bus free condition.
1729  */
1730 
1731 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1732 {
1733 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
1734 	unsigned char msgout = NOP;
1735 	int sink = 0;
1736 	int len;
1737 	int transfersize;
1738 	unsigned char *data;
1739 	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1740 	struct scsi_cmnd *cmd;
1741 
1742 #ifdef SUN3_SCSI_VME
1743 	dregs->csr |= CSR_INTR;
1744 #endif
1745 
1746 	while ((cmd = hostdata->connected)) {
1747 		struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1748 
1749 		tmp = NCR5380_read(STATUS_REG);
1750 		/* We only have a valid SCSI phase when REQ is asserted */
1751 		if (tmp & SR_REQ) {
1752 			phase = (tmp & PHASE_MASK);
1753 			if (phase != old_phase) {
1754 				old_phase = phase;
1755 				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1756 			}
1757 #ifdef CONFIG_SUN3
1758 			if (phase == PHASE_CMDOUT &&
1759 			    sun3_dma_setup_done != cmd) {
1760 				int count;
1761 
1762 				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1763 					++cmd->SCp.buffer;
1764 					--cmd->SCp.buffers_residual;
1765 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
1766 					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1767 				}
1768 
1769 				count = sun3scsi_dma_xfer_len(hostdata, cmd);
1770 
1771 				if (count > 0) {
1772 					if (rq_data_dir(cmd->request))
1773 						sun3scsi_dma_send_setup(hostdata,
1774 						                        cmd->SCp.ptr, count);
1775 					else
1776 						sun3scsi_dma_recv_setup(hostdata,
1777 						                        cmd->SCp.ptr, count);
1778 					sun3_dma_setup_done = cmd;
1779 				}
1780 #ifdef SUN3_SCSI_VME
1781 				dregs->csr |= CSR_INTR;
1782 #endif
1783 			}
1784 #endif /* CONFIG_SUN3 */
1785 
1786 			if (sink && (phase != PHASE_MSGOUT)) {
1787 				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1788 
1789 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1790 				              ICR_ASSERT_ACK);
1791 				while (NCR5380_read(STATUS_REG) & SR_REQ)
1792 					;
1793 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1794 				              ICR_ASSERT_ATN);
1795 				sink = 0;
1796 				continue;
1797 			}
1798 
1799 			switch (phase) {
1800 			case PHASE_DATAOUT:
1801 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1802 				shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1803 				sink = 1;
1804 				do_abort(instance);
1805 				cmd->result = DID_ERROR << 16;
1806 				complete_cmd(instance, cmd);
1807 				hostdata->connected = NULL;
1808 				return;
1809 #endif
1810 			case PHASE_DATAIN:
1811 				/*
1812 				 * If there is no room left in the current buffer in the
1813 				 * scatter-gather list, move onto the next one.
1814 				 */
1815 
1816 				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1817 					++cmd->SCp.buffer;
1818 					--cmd->SCp.buffers_residual;
1819 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
1820 					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1821 					dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
1822 					         cmd->SCp.this_residual,
1823 					         cmd->SCp.buffers_residual);
1824 				}
1825 
1826 				/*
1827 				 * The preferred transfer method is going to be
1828 				 * PSEUDO-DMA for systems that are strictly PIO,
1829 				 * since we can let the hardware do the handshaking.
1830 				 *
1831 				 * For this to work, we need to know the transfersize
1832 				 * ahead of time, since the pseudo-DMA code will sit
1833 				 * in an unconditional loop.
1834 				 */
1835 
1836 				transfersize = 0;
1837 				if (!cmd->device->borken)
1838 					transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
1839 
1840 				if (transfersize > 0) {
1841 					len = transfersize;
1842 					if (NCR5380_transfer_dma(instance, &phase,
1843 					    &len, (unsigned char **)&cmd->SCp.ptr)) {
1844 						/*
1845 						 * If the watchdog timer fires, all future
1846 						 * accesses to this device will use the
1847 						 * polled-IO.
1848 						 */
1849 						scmd_printk(KERN_INFO, cmd,
1850 							"switching to slow handshake\n");
1851 						cmd->device->borken = 1;
1852 						sink = 1;
1853 						do_abort(instance);
1854 						cmd->result = DID_ERROR << 16;
1855 						/* XXX - need to source or sink data here, as appropriate */
1856 					}
1857 				} else {
1858 					/* Transfer a small chunk so that the
1859 					 * irq mode lock is not held too long.
1860 					 */
1861 					transfersize = min(cmd->SCp.this_residual,
1862 							   NCR5380_PIO_CHUNK_SIZE);
1863 					len = transfersize;
1864 					NCR5380_transfer_pio(instance, &phase, &len,
1865 					                     (unsigned char **)&cmd->SCp.ptr);
1866 					cmd->SCp.this_residual -= transfersize - len;
1867 				}
1868 #ifdef CONFIG_SUN3
1869 				if (sun3_dma_setup_done == cmd)
1870 					sun3_dma_setup_done = NULL;
1871 #endif
1872 				return;
1873 			case PHASE_MSGIN:
1874 				len = 1;
1875 				data = &tmp;
1876 				NCR5380_transfer_pio(instance, &phase, &len, &data);
1877 				cmd->SCp.Message = tmp;
1878 
1879 				switch (tmp) {
1880 				case ABORT:
1881 				case COMMAND_COMPLETE:
1882 					/* Accept message by clearing ACK */
1883 					sink = 1;
1884 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1885 					dsprintk(NDEBUG_QUEUES, instance,
1886 					         "COMMAND COMPLETE %p target %d lun %llu\n",
1887 					         cmd, scmd_id(cmd), cmd->device->lun);
1888 
1889 					hostdata->connected = NULL;
1890 
1891 					cmd->result &= ~0xffff;
1892 					cmd->result |= cmd->SCp.Status;
1893 					cmd->result |= cmd->SCp.Message << 8;
1894 
1895 					if (cmd->cmnd[0] == REQUEST_SENSE)
1896 						complete_cmd(instance, cmd);
1897 					else {
1898 						if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1899 						    cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1900 							dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1901 							         cmd);
1902 							list_add_tail(&ncmd->list,
1903 							              &hostdata->autosense);
1904 						} else
1905 							complete_cmd(instance, cmd);
1906 					}
1907 
1908 					/*
1909 					 * Restore phase bits to 0 so an interrupted selection,
1910 					 * arbitration can resume.
1911 					 */
1912 					NCR5380_write(TARGET_COMMAND_REG, 0);
1913 
1914 					/* Enable reselect interrupts */
1915 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1916 
1917 					maybe_release_dma_irq(instance);
1918 					return;
1919 				case MESSAGE_REJECT:
1920 					/* Accept message by clearing ACK */
1921 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1922 					switch (hostdata->last_message) {
1923 					case HEAD_OF_QUEUE_TAG:
1924 					case ORDERED_QUEUE_TAG:
1925 					case SIMPLE_QUEUE_TAG:
1926 						cmd->device->simple_tags = 0;
1927 						hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1928 						break;
1929 					default:
1930 						break;
1931 					}
1932 					break;
1933 				case DISCONNECT:
1934 					/* Accept message by clearing ACK */
1935 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1936 					hostdata->connected = NULL;
1937 					list_add(&ncmd->list, &hostdata->disconnected);
1938 					dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1939 					         instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1940 					         cmd, scmd_id(cmd), cmd->device->lun);
1941 
1942 					/*
1943 					 * Restore phase bits to 0 so an interrupted selection,
1944 					 * arbitration can resume.
1945 					 */
1946 					NCR5380_write(TARGET_COMMAND_REG, 0);
1947 
1948 					/* Enable reselect interrupts */
1949 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1950 #ifdef SUN3_SCSI_VME
1951 					dregs->csr |= CSR_DMA_ENABLE;
1952 #endif
1953 					return;
1954 					/*
1955 					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1956 					 * operation, in violation of the SCSI spec so we can safely
1957 					 * ignore SAVE/RESTORE pointers calls.
1958 					 *
1959 					 * Unfortunately, some disks violate the SCSI spec and
1960 					 * don't issue the required SAVE_POINTERS message before
1961 					 * disconnecting, and we have to break spec to remain
1962 					 * compatible.
1963 					 */
1964 				case SAVE_POINTERS:
1965 				case RESTORE_POINTERS:
1966 					/* Accept message by clearing ACK */
1967 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1968 					break;
1969 				case EXTENDED_MESSAGE:
1970 					/*
1971 					 * Start the message buffer with the EXTENDED_MESSAGE
1972 					 * byte, since spi_print_msg() wants the whole thing.
1973 					 */
1974 					extended_msg[0] = EXTENDED_MESSAGE;
1975 					/* Accept first byte by clearing ACK */
1976 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1977 
1978 					spin_unlock_irq(&hostdata->lock);
1979 
1980 					dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1981 
1982 					len = 2;
1983 					data = extended_msg + 1;
1984 					phase = PHASE_MSGIN;
1985 					NCR5380_transfer_pio(instance, &phase, &len, &data);
1986 					dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1987 					         (int)extended_msg[1],
1988 					         (int)extended_msg[2]);
1989 
1990 					if (!len && extended_msg[1] > 0 &&
1991 					    extended_msg[1] <= sizeof(extended_msg) - 2) {
1992 						/* Accept third byte by clearing ACK */
1993 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1994 						len = extended_msg[1] - 1;
1995 						data = extended_msg + 3;
1996 						phase = PHASE_MSGIN;
1997 
1998 						NCR5380_transfer_pio(instance, &phase, &len, &data);
1999 						dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
2000 						         len);
2001 
2002 						switch (extended_msg[2]) {
2003 						case EXTENDED_SDTR:
2004 						case EXTENDED_WDTR:
2005 						case EXTENDED_MODIFY_DATA_POINTER:
2006 						case EXTENDED_EXTENDED_IDENTIFY:
2007 							tmp = 0;
2008 						}
2009 					} else if (len) {
2010 						shost_printk(KERN_ERR, instance, "error receiving extended message\n");
2011 						tmp = 0;
2012 					} else {
2013 						shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
2014 						             extended_msg[2], extended_msg[1]);
2015 						tmp = 0;
2016 					}
2017 
2018 					spin_lock_irq(&hostdata->lock);
2019 					if (!hostdata->connected)
2020 						return;
2021 
2022 					/* Fall through to reject message */
2023 
2024 					/*
2025 					 * If we get something weird that we aren't expecting,
2026 					 * reject it.
2027 					 */
2028 				default:
2029 					if (!tmp) {
2030 						shost_printk(KERN_ERR, instance, "rejecting message ");
2031 						spi_print_msg(extended_msg);
2032 						printk("\n");
2033 					} else if (tmp != EXTENDED_MESSAGE)
2034 						scmd_printk(KERN_INFO, cmd,
2035 						            "rejecting unknown message %02x\n",
2036 						            tmp);
2037 					else
2038 						scmd_printk(KERN_INFO, cmd,
2039 						            "rejecting unknown extended message code %02x, length %d\n",
2040 						            extended_msg[1], extended_msg[0]);
2041 
2042 					msgout = MESSAGE_REJECT;
2043 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2044 					break;
2045 				} /* switch (tmp) */
2046 				break;
2047 			case PHASE_MSGOUT:
2048 				len = 1;
2049 				data = &msgout;
2050 				hostdata->last_message = msgout;
2051 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2052 				if (msgout == ABORT) {
2053 					hostdata->connected = NULL;
2054 					cmd->result = DID_ERROR << 16;
2055 					complete_cmd(instance, cmd);
2056 					maybe_release_dma_irq(instance);
2057 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2058 					return;
2059 				}
2060 				msgout = NOP;
2061 				break;
2062 			case PHASE_CMDOUT:
2063 				len = cmd->cmd_len;
2064 				data = cmd->cmnd;
2065 				/*
2066 				 * XXX for performance reasons, on machines with a
2067 				 * PSEUDO-DMA architecture we should probably
2068 				 * use the dma transfer function.
2069 				 */
2070 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2071 				break;
2072 			case PHASE_STATIN:
2073 				len = 1;
2074 				data = &tmp;
2075 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2076 				cmd->SCp.Status = tmp;
2077 				break;
2078 			default:
2079 				shost_printk(KERN_ERR, instance, "unknown phase\n");
2080 				NCR5380_dprint(NDEBUG_ANY, instance);
2081 			} /* switch(phase) */
2082 		} else {
2083 			spin_unlock_irq(&hostdata->lock);
2084 			NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
2085 			spin_lock_irq(&hostdata->lock);
2086 		}
2087 	}
2088 }
2089 
2090 /*
2091  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2092  *
2093  * Purpose : does reselection, initializing the instance->connected
2094  * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2095  * nexus has been reestablished,
2096  *
2097  * Inputs : instance - this instance of the NCR5380.
2098  */
2099 
2100 static void NCR5380_reselect(struct Scsi_Host *instance)
2101 {
2102 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
2103 	unsigned char target_mask;
2104 	unsigned char lun;
2105 	unsigned char msg[3];
2106 	struct NCR5380_cmd *ncmd;
2107 	struct scsi_cmnd *tmp;
2108 
2109 	/*
2110 	 * Disable arbitration, etc. since the host adapter obviously
2111 	 * lost, and tell an interrupted NCR5380_select() to restart.
2112 	 */
2113 
2114 	NCR5380_write(MODE_REG, MR_BASE);
2115 
2116 	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2117 
2118 	dsprintk(NDEBUG_RESELECTION, instance, "reselect\n");
2119 
2120 	/*
2121 	 * At this point, we have detected that our SCSI ID is on the bus,
2122 	 * SEL is true and BSY was false for at least one bus settle delay
2123 	 * (400 ns).
2124 	 *
2125 	 * We must assert BSY ourselves, until the target drops the SEL
2126 	 * signal.
2127 	 */
2128 
2129 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2130 	if (NCR5380_poll_politely(hostdata,
2131 	                          STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2132 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2133 		return;
2134 	}
2135 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2136 
2137 	/*
2138 	 * Wait for target to go into MSGIN.
2139 	 */
2140 
2141 	if (NCR5380_poll_politely(hostdata,
2142 	                          STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2143 		do_abort(instance);
2144 		return;
2145 	}
2146 
2147 #ifdef CONFIG_SUN3
2148 	/* acknowledge toggle to MSGIN */
2149 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2150 
2151 	/* peek at the byte without really hitting the bus */
2152 	msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2153 #else
2154 	{
2155 		int len = 1;
2156 		unsigned char *data = msg;
2157 		unsigned char phase = PHASE_MSGIN;
2158 
2159 		NCR5380_transfer_pio(instance, &phase, &len, &data);
2160 
2161 		if (len) {
2162 			do_abort(instance);
2163 			return;
2164 		}
2165 	}
2166 #endif /* CONFIG_SUN3 */
2167 
2168 	if (!(msg[0] & 0x80)) {
2169 		shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2170 		spi_print_msg(msg);
2171 		printk("\n");
2172 		do_abort(instance);
2173 		return;
2174 	}
2175 	lun = msg[0] & 0x07;
2176 
2177 	/*
2178 	 * We need to add code for SCSI-II to track which devices have
2179 	 * I_T_L_Q nexuses established, and which have simple I_T_L
2180 	 * nexuses so we can chose to do additional data transfer.
2181 	 */
2182 
2183 	/*
2184 	 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2185 	 * just reestablished, and remove it from the disconnected queue.
2186 	 */
2187 
2188 	tmp = NULL;
2189 	list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2190 		struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2191 
2192 		if (target_mask == (1 << scmd_id(cmd)) &&
2193 		    lun == (u8)cmd->device->lun) {
2194 			list_del(&ncmd->list);
2195 			tmp = cmd;
2196 			break;
2197 		}
2198 	}
2199 
2200 	if (tmp) {
2201 		dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2202 		         "reselect: removed %p from disconnected queue\n", tmp);
2203 	} else {
2204 		shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2205 		             target_mask, lun);
2206 		/*
2207 		 * Since we have an established nexus that we can't do anything
2208 		 * with, we must abort it.
2209 		 */
2210 		do_abort(instance);
2211 		return;
2212 	}
2213 
2214 #ifdef CONFIG_SUN3
2215 	if (sun3_dma_setup_done != tmp) {
2216 		int count;
2217 
2218 		if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
2219 			++tmp->SCp.buffer;
2220 			--tmp->SCp.buffers_residual;
2221 			tmp->SCp.this_residual = tmp->SCp.buffer->length;
2222 			tmp->SCp.ptr = sg_virt(tmp->SCp.buffer);
2223 		}
2224 
2225 		count = sun3scsi_dma_xfer_len(hostdata, tmp);
2226 
2227 		if (count > 0) {
2228 			if (rq_data_dir(tmp->request))
2229 				sun3scsi_dma_send_setup(hostdata,
2230 				                        tmp->SCp.ptr, count);
2231 			else
2232 				sun3scsi_dma_recv_setup(hostdata,
2233 				                        tmp->SCp.ptr, count);
2234 			sun3_dma_setup_done = tmp;
2235 		}
2236 	}
2237 
2238 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2239 #endif /* CONFIG_SUN3 */
2240 
2241 	/* Accept message by clearing ACK */
2242 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2243 
2244 	hostdata->connected = tmp;
2245 	dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
2246 	         scmd_id(tmp), tmp->device->lun);
2247 }
2248 
2249 /**
2250  * list_find_cmd - test for presence of a command in a linked list
2251  * @haystack: list of commands
2252  * @needle: command to search for
2253  */
2254 
2255 static bool list_find_cmd(struct list_head *haystack,
2256                           struct scsi_cmnd *needle)
2257 {
2258 	struct NCR5380_cmd *ncmd;
2259 
2260 	list_for_each_entry(ncmd, haystack, list)
2261 		if (NCR5380_to_scmd(ncmd) == needle)
2262 			return true;
2263 	return false;
2264 }
2265 
2266 /**
2267  * list_remove_cmd - remove a command from linked list
2268  * @haystack: list of commands
2269  * @needle: command to remove
2270  */
2271 
2272 static bool list_del_cmd(struct list_head *haystack,
2273                          struct scsi_cmnd *needle)
2274 {
2275 	if (list_find_cmd(haystack, needle)) {
2276 		struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2277 
2278 		list_del(&ncmd->list);
2279 		return true;
2280 	}
2281 	return false;
2282 }
2283 
2284 /**
2285  * NCR5380_abort - scsi host eh_abort_handler() method
2286  * @cmd: the command to be aborted
2287  *
2288  * Try to abort a given command by removing it from queues and/or sending
2289  * the target an abort message. This may not succeed in causing a target
2290  * to abort the command. Nonetheless, the low-level driver must forget about
2291  * the command because the mid-layer reclaims it and it may be re-issued.
2292  *
2293  * The normal path taken by a command is as follows. For EH we trace this
2294  * same path to locate and abort the command.
2295  *
2296  * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2297  * [disconnected -> connected ->]...
2298  * [autosense -> connected ->] done
2299  *
2300  * If cmd was not found at all then presumably it has already been completed,
2301  * in which case return SUCCESS to try to avoid further EH measures.
2302  *
2303  * If the command has not completed yet, we must not fail to find it.
2304  * We have no option but to forget the aborted command (even if it still
2305  * lacks sense data). The mid-layer may re-issue a command that is in error
2306  * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2307  * this driver are such that a command can appear on one queue only.
2308  *
2309  * The lock protects driver data structures, but EH handlers also use it
2310  * to serialize their own execution and prevent their own re-entry.
2311  */
2312 
2313 static int NCR5380_abort(struct scsi_cmnd *cmd)
2314 {
2315 	struct Scsi_Host *instance = cmd->device->host;
2316 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
2317 	unsigned long flags;
2318 	int result = SUCCESS;
2319 
2320 	spin_lock_irqsave(&hostdata->lock, flags);
2321 
2322 #if (NDEBUG & NDEBUG_ANY)
2323 	scmd_printk(KERN_INFO, cmd, __func__);
2324 #endif
2325 	NCR5380_dprint(NDEBUG_ANY, instance);
2326 	NCR5380_dprint_phase(NDEBUG_ANY, instance);
2327 
2328 	if (list_del_cmd(&hostdata->unissued, cmd)) {
2329 		dsprintk(NDEBUG_ABORT, instance,
2330 		         "abort: removed %p from issue queue\n", cmd);
2331 		cmd->result = DID_ABORT << 16;
2332 		cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2333 		goto out;
2334 	}
2335 
2336 	if (hostdata->selecting == cmd) {
2337 		dsprintk(NDEBUG_ABORT, instance,
2338 		         "abort: cmd %p == selecting\n", cmd);
2339 		hostdata->selecting = NULL;
2340 		cmd->result = DID_ABORT << 16;
2341 		complete_cmd(instance, cmd);
2342 		goto out;
2343 	}
2344 
2345 	if (list_del_cmd(&hostdata->disconnected, cmd)) {
2346 		dsprintk(NDEBUG_ABORT, instance,
2347 		         "abort: removed %p from disconnected list\n", cmd);
2348 		/* Can't call NCR5380_select() and send ABORT because that
2349 		 * means releasing the lock. Need a bus reset.
2350 		 */
2351 		set_host_byte(cmd, DID_ERROR);
2352 		complete_cmd(instance, cmd);
2353 		result = FAILED;
2354 		goto out;
2355 	}
2356 
2357 	if (hostdata->connected == cmd) {
2358 		dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2359 		hostdata->connected = NULL;
2360 		hostdata->dma_len = 0;
2361 		if (do_abort(instance)) {
2362 			set_host_byte(cmd, DID_ERROR);
2363 			complete_cmd(instance, cmd);
2364 			result = FAILED;
2365 			goto out;
2366 		}
2367 		set_host_byte(cmd, DID_ABORT);
2368 		complete_cmd(instance, cmd);
2369 		goto out;
2370 	}
2371 
2372 	if (list_del_cmd(&hostdata->autosense, cmd)) {
2373 		dsprintk(NDEBUG_ABORT, instance,
2374 		         "abort: removed %p from sense queue\n", cmd);
2375 		set_host_byte(cmd, DID_ERROR);
2376 		complete_cmd(instance, cmd);
2377 	}
2378 
2379 out:
2380 	if (result == FAILED)
2381 		dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2382 	else
2383 		dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2384 
2385 	queue_work(hostdata->work_q, &hostdata->main_task);
2386 	maybe_release_dma_irq(instance);
2387 	spin_unlock_irqrestore(&hostdata->lock, flags);
2388 
2389 	return result;
2390 }
2391 
2392 
2393 /**
2394  * NCR5380_bus_reset - reset the SCSI bus
2395  * @cmd: SCSI command undergoing EH
2396  *
2397  * Returns SUCCESS
2398  */
2399 
2400 static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
2401 {
2402 	struct Scsi_Host *instance = cmd->device->host;
2403 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
2404 	int i;
2405 	unsigned long flags;
2406 	struct NCR5380_cmd *ncmd;
2407 
2408 	spin_lock_irqsave(&hostdata->lock, flags);
2409 
2410 #if (NDEBUG & NDEBUG_ANY)
2411 	scmd_printk(KERN_INFO, cmd, __func__);
2412 #endif
2413 	NCR5380_dprint(NDEBUG_ANY, instance);
2414 	NCR5380_dprint_phase(NDEBUG_ANY, instance);
2415 
2416 	do_reset(instance);
2417 
2418 	/* reset NCR registers */
2419 	NCR5380_write(MODE_REG, MR_BASE);
2420 	NCR5380_write(TARGET_COMMAND_REG, 0);
2421 	NCR5380_write(SELECT_ENABLE_REG, 0);
2422 
2423 	/* After the reset, there are no more connected or disconnected commands
2424 	 * and no busy units; so clear the low-level status here to avoid
2425 	 * conflicts when the mid-level code tries to wake up the affected
2426 	 * commands!
2427 	 */
2428 
2429 	if (list_del_cmd(&hostdata->unissued, cmd)) {
2430 		cmd->result = DID_RESET << 16;
2431 		cmd->scsi_done(cmd);
2432 	}
2433 
2434 	if (hostdata->selecting) {
2435 		hostdata->selecting->result = DID_RESET << 16;
2436 		complete_cmd(instance, hostdata->selecting);
2437 		hostdata->selecting = NULL;
2438 	}
2439 
2440 	list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2441 		struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2442 
2443 		set_host_byte(cmd, DID_RESET);
2444 		complete_cmd(instance, cmd);
2445 	}
2446 	INIT_LIST_HEAD(&hostdata->disconnected);
2447 
2448 	list_for_each_entry(ncmd, &hostdata->autosense, list) {
2449 		struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2450 
2451 		set_host_byte(cmd, DID_RESET);
2452 		cmd->scsi_done(cmd);
2453 	}
2454 	INIT_LIST_HEAD(&hostdata->autosense);
2455 
2456 	if (hostdata->connected) {
2457 		set_host_byte(hostdata->connected, DID_RESET);
2458 		complete_cmd(instance, hostdata->connected);
2459 		hostdata->connected = NULL;
2460 	}
2461 
2462 	for (i = 0; i < 8; ++i)
2463 		hostdata->busy[i] = 0;
2464 	hostdata->dma_len = 0;
2465 
2466 	queue_work(hostdata->work_q, &hostdata->main_task);
2467 	maybe_release_dma_irq(instance);
2468 	spin_unlock_irqrestore(&hostdata->lock, flags);
2469 
2470 	return SUCCESS;
2471 }
2472