xref: /openbmc/linux/drivers/scsi/NCR5380.c (revision 609e478b)
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  * DISTRIBUTION RELEASE 6.
15  *
16  * For more information, please consult
17  *
18  * NCR 5380 Family
19  * SCSI Protocol Controller
20  * Databook
21  *
22  * NCR Microelectronics
23  * 1635 Aeroplaza Drive
24  * Colorado Springs, CO 80916
25  * 1+ (719) 578-3400
26  * 1+ (800) 334-5454
27  */
28 
29 /*
30  * Revision 1.10 1998/9/2	Alan Cox
31  *				(alan@lxorguk.ukuu.org.uk)
32  * Fixed up the timer lockups reported so far. Things still suck. Looking
33  * forward to 2.3 and per device request queues. Then it'll be possible to
34  * SMP thread this beast and improve life no end.
35 
36  * Revision 1.9  1997/7/27	Ronald van Cuijlenborg
37  *				(ronald.van.cuijlenborg@tip.nl or nutty@dds.nl)
38  * (hopefully) fixed and enhanced USLEEP
39  * added support for DTC3181E card (for Mustek scanner)
40  *
41 
42  * Revision 1.8			Ingmar Baumgart
43  *				(ingmar@gonzo.schwaben.de)
44  * added support for NCR53C400a card
45  *
46 
47  * Revision 1.7  1996/3/2       Ray Van Tassle (rayvt@comm.mot.com)
48  * added proc_info
49  * added support needed for DTC 3180/3280
50  * fixed a couple of bugs
51  *
52 
53  * Revision 1.5  1994/01/19  09:14:57  drew
54  * Fixed udelay() hack that was being used on DATAOUT phases
55  * instead of a proper wait for the final handshake.
56  *
57  * Revision 1.4  1994/01/19  06:44:25  drew
58  * *** empty log message ***
59  *
60  * Revision 1.3  1994/01/19  05:24:40  drew
61  * Added support for TCR LAST_BYTE_SENT bit.
62  *
63  * Revision 1.2  1994/01/15  06:14:11  drew
64  * REAL DMA support, bug fixes.
65  *
66  * Revision 1.1  1994/01/15  06:00:54  drew
67  * Initial revision
68  *
69  */
70 
71 /*
72  * Further development / testing that should be done :
73  * 1.  Cleanup the NCR5380_transfer_dma function and DMA operation complete
74  *     code so that everything does the same thing that's done at the
75  *     end of a pseudo-DMA read operation.
76  *
77  * 2.  Fix REAL_DMA (interrupt driven, polled works fine) -
78  *     basically, transfer size needs to be reduced by one
79  *     and the last byte read as is done with PSEUDO_DMA.
80  *
81  * 4.  Test SCSI-II tagged queueing (I have no devices which support
82  *      tagged queueing)
83  *
84  * 5.  Test linked command handling code after Eric is ready with
85  *      the high level code.
86  */
87 #include <scsi/scsi_dbg.h>
88 #include <scsi/scsi_transport_spi.h>
89 
90 #if (NDEBUG & NDEBUG_LISTS)
91 #define LIST(x,y) {printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); }
92 #define REMOVE(w,x,y,z) {printk("LINE:%d   Removing: %p->%p  %p->%p \n", __LINE__, (void*)(w), (void*)(x), (void*)(y), (void*)(z)); if ((x)==(y)) udelay(5); }
93 #else
94 #define LIST(x,y)
95 #define REMOVE(w,x,y,z)
96 #endif
97 
98 #ifndef notyet
99 #undef LINKED
100 #undef REAL_DMA
101 #endif
102 
103 #ifdef REAL_DMA_POLL
104 #undef READ_OVERRUNS
105 #define READ_OVERRUNS
106 #endif
107 
108 #ifdef BOARD_REQUIRES_NO_DELAY
109 #define io_recovery_delay(x)
110 #else
111 #define io_recovery_delay(x)	udelay(x)
112 #endif
113 
114 /*
115  * Design
116  *
117  * This is a generic 5380 driver.  To use it on a different platform,
118  * one simply writes appropriate system specific macros (ie, data
119  * transfer - some PC's will use the I/O bus, 68K's must use
120  * memory mapped) and drops this file in their 'C' wrapper.
121  *
122  * (Note from hch:  unfortunately it was not enough for the different
123  * m68k folks and instead of improving this driver they copied it
124  * and hacked it up for their needs.  As a consequence they lost
125  * most updates to this driver.  Maybe someone will fix all these
126  * drivers to use a common core one day..)
127  *
128  * As far as command queueing, two queues are maintained for
129  * each 5380 in the system - commands that haven't been issued yet,
130  * and commands that are currently executing.  This means that an
131  * unlimited number of commands may be queued, letting
132  * more commands propagate from the higher driver levels giving higher
133  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
134  * allowing multiple commands to propagate all the way to a SCSI-II device
135  * while a command is already executing.
136  *
137  *
138  * Issues specific to the NCR5380 :
139  *
140  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
141  * piece of hardware that requires you to sit in a loop polling for
142  * the REQ signal as long as you are connected.  Some devices are
143  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
144  * while doing long seek operations.
145  *
146  * The workaround for this is to keep track of devices that have
147  * disconnected.  If the device hasn't disconnected, for commands that
148  * should disconnect, we do something like
149  *
150  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
151  *
152  * Some tweaking of N and M needs to be done.  An algorithm based
153  * on "time to data" would give the best results as long as short time
154  * to datas (ie, on the same track) were considered, however these
155  * broken devices are the exception rather than the rule and I'd rather
156  * spend my time optimizing for the normal case.
157  *
158  * Architecture :
159  *
160  * At the heart of the design is a coroutine, NCR5380_main,
161  * which is started from a workqueue for each NCR5380 host in the
162  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
163  * removing the commands from the issue queue and calling
164  * NCR5380_select() if a nexus is not established.
165  *
166  * Once a nexus is established, the NCR5380_information_transfer()
167  * phase goes through the various phases as instructed by the target.
168  * if the target goes into MSG IN and sends a DISCONNECT message,
169  * the command structure is placed into the per instance disconnected
170  * queue, and NCR5380_main tries to find more work.  If the target is
171  * idle for too long, the system will try to sleep.
172  *
173  * If a command has disconnected, eventually an interrupt will trigger,
174  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
175  * to reestablish a nexus.  This will run main if necessary.
176  *
177  * On command termination, the done function will be called as
178  * appropriate.
179  *
180  * SCSI pointers are maintained in the SCp field of SCSI command
181  * structures, being initialized after the command is connected
182  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
183  * Note that in violation of the standard, an implicit SAVE POINTERS operation
184  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
185  */
186 
187 /*
188  * Using this file :
189  * This file a skeleton Linux SCSI driver for the NCR 5380 series
190  * of chips.  To use it, you write an architecture specific functions
191  * and macros and include this file in your driver.
192  *
193  * These macros control options :
194  * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
195  *      defined.
196  *
197  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
198  *      for commands that return with a CHECK CONDITION status.
199  *
200  * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
201  *      transceivers.
202  *
203  * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
204  *      override-configure an IRQ.
205  *
206  * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
207  *      bytes at a time.  Since interrupts are disabled by default during
208  *      these transfers, we might need this to give reasonable interrupt
209  *      service time if the transfer size gets too large.
210  *
211  * LINKED - if defined, linked commands are supported.
212  *
213  * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
214  *
215  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
216  *
217  * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
218  *      rely on phase mismatch and EOP interrupts to determine end
219  *      of phase.
220  *
221  * UNSAFE - leave interrupts enabled during pseudo-DMA transfers.  You
222  *          only really want to use this if you're having a problem with
223  *          dropped characters during high speed communications, and even
224  *          then, you're going to be better off twiddling with transfersize
225  *          in the high level code.
226  *
227  * Defaults for these will be provided although the user may want to adjust
228  * these to allocate CPU resources to the SCSI driver or "real" code.
229  *
230  * USLEEP_SLEEP - amount of time, in jiffies, to sleep
231  *
232  * USLEEP_POLL - amount of time, in jiffies, to poll
233  *
234  * These macros MUST be defined :
235  * NCR5380_local_declare() - declare any local variables needed for your
236  *      transfer routines.
237  *
238  * NCR5380_setup(instance) - initialize any local variables needed from a given
239  *      instance of the host adapter for NCR5380_{read,write,pread,pwrite}
240  *
241  * NCR5380_read(register)  - read from the specified register
242  *
243  * NCR5380_write(register, value) - write to the specific register
244  *
245  * NCR5380_implementation_fields  - additional fields needed for this
246  *      specific implementation of the NCR5380
247  *
248  * Either real DMA *or* pseudo DMA may be implemented
249  * REAL functions :
250  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
251  * Note that the DMA setup functions should return the number of bytes
252  *      that they were able to program the controller for.
253  *
254  * Also note that generic i386/PC versions of these macros are
255  *      available as NCR5380_i386_dma_write_setup,
256  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
257  *
258  * NCR5380_dma_write_setup(instance, src, count) - initialize
259  * NCR5380_dma_read_setup(instance, dst, count) - initialize
260  * NCR5380_dma_residual(instance); - residual count
261  *
262  * PSEUDO functions :
263  * NCR5380_pwrite(instance, src, count)
264  * NCR5380_pread(instance, dst, count);
265  *
266  * The generic driver is initialized by calling NCR5380_init(instance),
267  * after setting the appropriate host specific fields and ID.  If the
268  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
269  * possible) function may be used.
270  */
271 
272 static int do_abort(struct Scsi_Host *host);
273 static void do_reset(struct Scsi_Host *host);
274 
275 /*
276  *	initialize_SCp		-	init the scsi pointer field
277  *	@cmd: command block to set up
278  *
279  *	Set up the internal fields in the SCSI command.
280  */
281 
282 static __inline__ void initialize_SCp(Scsi_Cmnd * cmd)
283 {
284 	/*
285 	 * Initialize the Scsi Pointer field so that all of the commands in the
286 	 * various queues are valid.
287 	 */
288 
289 	if (scsi_bufflen(cmd)) {
290 		cmd->SCp.buffer = scsi_sglist(cmd);
291 		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
292 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
293 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
294 	} else {
295 		cmd->SCp.buffer = NULL;
296 		cmd->SCp.buffers_residual = 0;
297 		cmd->SCp.ptr = NULL;
298 		cmd->SCp.this_residual = 0;
299 	}
300 }
301 
302 /**
303  *	NCR5380_poll_politely	-	wait for NCR5380 status bits
304  *	@instance: controller to poll
305  *	@reg: 5380 register to poll
306  *	@bit: Bitmask to check
307  *	@val: Value required to exit
308  *
309  *	Polls the NCR5380 in a reasonably efficient manner waiting for
310  *	an event to occur, after a short quick poll we begin giving the
311  *	CPU back in non IRQ contexts
312  *
313  *	Returns the value of the register or a negative error code.
314  */
315 
316 static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
317 {
318 	NCR5380_local_declare();
319 	int n = 500;		/* At about 8uS a cycle for the cpu access */
320 	unsigned long end = jiffies + t;
321 	int r;
322 
323 	NCR5380_setup(instance);
324 
325 	while( n-- > 0)
326 	{
327 		r = NCR5380_read(reg);
328 		if((r & bit) == val)
329 			return 0;
330 		cpu_relax();
331 	}
332 
333 	/* t time yet ? */
334 	while(time_before(jiffies, end))
335 	{
336 		r = NCR5380_read(reg);
337 		if((r & bit) == val)
338 			return 0;
339 		if(!in_interrupt())
340 			cond_resched();
341 		else
342 			cpu_relax();
343 	}
344 	return -ETIMEDOUT;
345 }
346 
347 static struct {
348 	unsigned char value;
349 	const char *name;
350 } phases[] __maybe_unused = {
351 	{PHASE_DATAOUT, "DATAOUT"},
352 	{PHASE_DATAIN, "DATAIN"},
353 	{PHASE_CMDOUT, "CMDOUT"},
354 	{PHASE_STATIN, "STATIN"},
355 	{PHASE_MSGOUT, "MSGOUT"},
356 	{PHASE_MSGIN, "MSGIN"},
357 	{PHASE_UNKNOWN, "UNKNOWN"}
358 };
359 
360 #if NDEBUG
361 static struct {
362 	unsigned char mask;
363 	const char *name;
364 } signals[] = {
365 	{SR_DBP, "PARITY"},
366 	{SR_RST, "RST"},
367 	{SR_BSY, "BSY"},
368 	{SR_REQ, "REQ"},
369 	{SR_MSG, "MSG"},
370 	{SR_CD, "CD"},
371 	{SR_IO, "IO"},
372 	{SR_SEL, "SEL"},
373 	{0, NULL}
374 },
375 basrs[] = {
376 	{BASR_ATN, "ATN"},
377 	{BASR_ACK, "ACK"},
378 	{0, NULL}
379 },
380 icrs[] = {
381 	{ICR_ASSERT_RST, "ASSERT RST"},
382 	{ICR_ASSERT_ACK, "ASSERT ACK"},
383 	{ICR_ASSERT_BSY, "ASSERT BSY"},
384 	{ICR_ASSERT_SEL, "ASSERT SEL"},
385 	{ICR_ASSERT_ATN, "ASSERT ATN"},
386 	{ICR_ASSERT_DATA, "ASSERT DATA"},
387 	{0, NULL}
388 },
389 mrs[] = {
390 	{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
391 	{MR_TARGET, "MODE TARGET"},
392 	{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
393 	{MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
394 	{MR_MONITOR_BSY, "MODE MONITOR BSY"},
395 	{MR_DMA_MODE, "MODE DMA"},
396 	{MR_ARBITRATE, "MODE ARBITRATION"},
397 	{0, NULL}
398 };
399 
400 /**
401  *	NCR5380_print	-	print scsi bus signals
402  *	@instance:	adapter state to dump
403  *
404  *	Print the SCSI bus signals for debugging purposes
405  *
406  *	Locks: caller holds hostdata lock (not essential)
407  */
408 
409 static void NCR5380_print(struct Scsi_Host *instance)
410 {
411 	NCR5380_local_declare();
412 	unsigned char status, data, basr, mr, icr, i;
413 	NCR5380_setup(instance);
414 
415 	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
416 	status = NCR5380_read(STATUS_REG);
417 	mr = NCR5380_read(MODE_REG);
418 	icr = NCR5380_read(INITIATOR_COMMAND_REG);
419 	basr = NCR5380_read(BUS_AND_STATUS_REG);
420 
421 	printk("STATUS_REG: %02x ", status);
422 	for (i = 0; signals[i].mask; ++i)
423 		if (status & signals[i].mask)
424 			printk(",%s", signals[i].name);
425 	printk("\nBASR: %02x ", basr);
426 	for (i = 0; basrs[i].mask; ++i)
427 		if (basr & basrs[i].mask)
428 			printk(",%s", basrs[i].name);
429 	printk("\nICR: %02x ", icr);
430 	for (i = 0; icrs[i].mask; ++i)
431 		if (icr & icrs[i].mask)
432 			printk(",%s", icrs[i].name);
433 	printk("\nMODE: %02x ", mr);
434 	for (i = 0; mrs[i].mask; ++i)
435 		if (mr & mrs[i].mask)
436 			printk(",%s", mrs[i].name);
437 	printk("\n");
438 }
439 
440 
441 /*
442  *	NCR5380_print_phase	-	show SCSI phase
443  *	@instance: adapter to dump
444  *
445  * 	Print the current SCSI phase for debugging purposes
446  *
447  *	Locks: none
448  */
449 
450 static void NCR5380_print_phase(struct Scsi_Host *instance)
451 {
452 	NCR5380_local_declare();
453 	unsigned char status;
454 	int i;
455 	NCR5380_setup(instance);
456 
457 	status = NCR5380_read(STATUS_REG);
458 	if (!(status & SR_REQ))
459 		printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
460 	else {
461 		for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
462 		printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
463 	}
464 }
465 #endif
466 
467 /*
468  * These need tweaking, and would probably work best as per-device
469  * flags initialized differently for disk, tape, cd, etc devices.
470  * People with broken devices are free to experiment as to what gives
471  * the best results for them.
472  *
473  * USLEEP_SLEEP should be a minimum seek time.
474  *
475  * USLEEP_POLL should be a maximum rotational latency.
476  */
477 #ifndef USLEEP_SLEEP
478 /* 20 ms (reasonable hard disk speed) */
479 #define USLEEP_SLEEP (20*HZ/1000)
480 #endif
481 /* 300 RPM (floppy speed) */
482 #ifndef USLEEP_POLL
483 #define USLEEP_POLL (200*HZ/1000)
484 #endif
485 #ifndef USLEEP_WAITLONG
486 /* RvC: (reasonable time to wait on select error) */
487 #define USLEEP_WAITLONG USLEEP_SLEEP
488 #endif
489 
490 /*
491  * Function : int should_disconnect (unsigned char cmd)
492  *
493  * Purpose : decide whether a command would normally disconnect or
494  *      not, since if it won't disconnect we should go to sleep.
495  *
496  * Input : cmd - opcode of SCSI command
497  *
498  * Returns : DISCONNECT_LONG if we should disconnect for a really long
499  *      time (ie always, sleep, look for REQ active, sleep),
500  *      DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
501  *      time-to-data delay, DISCONNECT_NONE if this command would return
502  *      immediately.
503  *
504  *      Future sleep algorithms based on time to data can exploit
505  *      something like this so they can differentiate between "normal"
506  *      (ie, read, write, seek) and unusual commands (ie, * format).
507  *
508  * Note : We don't deal with commands that handle an immediate disconnect,
509  *
510  */
511 
512 static int should_disconnect(unsigned char cmd)
513 {
514 	switch (cmd) {
515 	case READ_6:
516 	case WRITE_6:
517 	case SEEK_6:
518 	case READ_10:
519 	case WRITE_10:
520 	case SEEK_10:
521 		return DISCONNECT_TIME_TO_DATA;
522 	case FORMAT_UNIT:
523 	case SEARCH_HIGH:
524 	case SEARCH_LOW:
525 	case SEARCH_EQUAL:
526 		return DISCONNECT_LONG;
527 	default:
528 		return DISCONNECT_NONE;
529 	}
530 }
531 
532 static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
533 {
534 	hostdata->time_expires = jiffies + timeout;
535 	schedule_delayed_work(&hostdata->coroutine, timeout);
536 }
537 
538 
539 static int probe_irq __initdata = 0;
540 
541 /**
542  *	probe_intr	-	helper for IRQ autoprobe
543  *	@irq: interrupt number
544  *	@dev_id: unused
545  *	@regs: unused
546  *
547  *	Set a flag to indicate the IRQ in question was received. This is
548  *	used by the IRQ probe code.
549  */
550 
551 static irqreturn_t __init probe_intr(int irq, void *dev_id)
552 {
553 	probe_irq = irq;
554 	return IRQ_HANDLED;
555 }
556 
557 /**
558  *	NCR5380_probe_irq	-	find the IRQ of an NCR5380
559  *	@instance: NCR5380 controller
560  *	@possible: bitmask of ISA IRQ lines
561  *
562  *	Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
563  *	and then looking to see what interrupt actually turned up.
564  *
565  *	Locks: none, irqs must be enabled on entry
566  */
567 
568 static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
569 						int possible)
570 {
571 	NCR5380_local_declare();
572 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
573 	unsigned long timeout;
574 	int trying_irqs, i, mask;
575 	NCR5380_setup(instance);
576 
577 	for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
578 		if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0))
579 			trying_irqs |= mask;
580 
581 	timeout = jiffies + (250 * HZ / 1000);
582 	probe_irq = SCSI_IRQ_NONE;
583 
584 	/*
585 	 * A interrupt is triggered whenever BSY = false, SEL = true
586 	 * and a bit set in the SELECT_ENABLE_REG is asserted on the
587 	 * SCSI bus.
588 	 *
589 	 * Note that the bus is only driven when the phase control signals
590 	 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
591 	 * to zero.
592 	 */
593 
594 	NCR5380_write(TARGET_COMMAND_REG, 0);
595 	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
596 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
597 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
598 
599 	while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
600 		schedule_timeout_uninterruptible(1);
601 
602 	NCR5380_write(SELECT_ENABLE_REG, 0);
603 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
604 
605 	for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
606 		if (trying_irqs & mask)
607 			free_irq(i, NULL);
608 
609 	return probe_irq;
610 }
611 
612 /**
613  *	NCR58380_print_options	-	show options
614  *	@instance: unused for now
615  *
616  *	Called by probe code indicating the NCR5380 driver options that
617  *	were selected. At some point this will switch to runtime options
618  *	read from the adapter in question
619  *
620  *	Locks: none
621  */
622 
623 static void __init __maybe_unused
624 NCR5380_print_options(struct Scsi_Host *instance)
625 {
626 	printk(" generic options"
627 #ifdef AUTOPROBE_IRQ
628 	       " AUTOPROBE_IRQ"
629 #endif
630 #ifdef AUTOSENSE
631 	       " AUTOSENSE"
632 #endif
633 #ifdef DIFFERENTIAL
634 	       " DIFFERENTIAL"
635 #endif
636 #ifdef REAL_DMA
637 	       " REAL DMA"
638 #endif
639 #ifdef REAL_DMA_POLL
640 	       " REAL DMA POLL"
641 #endif
642 #ifdef PARITY
643 	       " PARITY"
644 #endif
645 #ifdef PSEUDO_DMA
646 	       " PSEUDO DMA"
647 #endif
648 #ifdef UNSAFE
649 	       " UNSAFE "
650 #endif
651 	    );
652 	printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
653 	printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
654 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
655 		printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
656 	}
657 }
658 
659 /**
660  *	NCR5380_print_status 	-	dump controller info
661  *	@instance: controller to dump
662  *
663  *	Print commands in the various queues, called from NCR5380_abort
664  *	and NCR5380_debug to aid debugging.
665  *
666  *	Locks: called functions disable irqs
667  */
668 
669 static void NCR5380_print_status(struct Scsi_Host *instance)
670 {
671 	NCR5380_dprint(NDEBUG_ANY, instance);
672 	NCR5380_dprint_phase(NDEBUG_ANY, instance);
673 }
674 
675 /******************************************/
676 /*
677  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
678  *
679  * *buffer: I/O buffer
680  * **start: if inout == FALSE pointer into buffer where user read should start
681  * offset: current offset
682  * length: length of buffer
683  * hostno: Scsi_Host host_no
684  * inout: TRUE - user is writing; FALSE - user is reading
685  *
686  * Return the number of bytes read from or written
687  */
688 
689 static int __maybe_unused NCR5380_write_info(struct Scsi_Host *instance,
690 	char *buffer, int length)
691 {
692 #ifdef DTC_PUBLIC_RELEASE
693 	dtc_wmaxi = dtc_maxi = 0;
694 #endif
695 #ifdef PAS16_PUBLIC_RELEASE
696 	pas_wmaxi = pas_maxi = 0;
697 #endif
698 	return (-ENOSYS);	/* Currently this is a no-op */
699 }
700 
701 #undef SPRINTF
702 #define SPRINTF(args...) seq_printf(m, ## args)
703 static
704 void lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, struct seq_file *m);
705 static
706 void lprint_command(unsigned char *cmd, struct seq_file *m);
707 static
708 void lprint_opcode(int opcode, struct seq_file *m);
709 
710 static int __maybe_unused NCR5380_show_info(struct seq_file *m,
711 	struct Scsi_Host *instance)
712 {
713 	struct NCR5380_hostdata *hostdata;
714 	Scsi_Cmnd *ptr;
715 
716 	hostdata = (struct NCR5380_hostdata *) instance->hostdata;
717 
718 	SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
719 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
720 		SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
721 #ifdef DTC_PUBLIC_RELEASE
722 	SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
723 #endif
724 #ifdef T128_PUBLIC_RELEASE
725 	SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
726 #endif
727 #ifdef GENERIC_NCR5380_PUBLIC_RELEASE
728 	SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
729 #endif
730 #ifdef PAS16_PUBLIC_RELEASE
731 	SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
732 #endif
733 
734 	SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
735 	SPRINTF("io_port: %04x      ", (int) instance->io_port);
736 	if (instance->irq == SCSI_IRQ_NONE)
737 		SPRINTF("IRQ: None.\n");
738 	else
739 		SPRINTF("IRQ: %d.\n", instance->irq);
740 
741 #ifdef DTC_PUBLIC_RELEASE
742 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
743 #endif
744 #ifdef PAS16_PUBLIC_RELEASE
745 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
746 #endif
747 	spin_lock_irq(instance->host_lock);
748 	if (!hostdata->connected)
749 		SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
750 	else
751 		lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, m);
752 	SPRINTF("scsi%d: issue_queue\n", instance->host_no);
753 	for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
754 		lprint_Scsi_Cmnd(ptr, m);
755 
756 	SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
757 	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
758 		lprint_Scsi_Cmnd(ptr, m);
759 	spin_unlock_irq(instance->host_lock);
760 	return 0;
761 }
762 
763 static void lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, struct seq_file *m)
764 {
765 	SPRINTF("scsi%d : destination target %d, lun %llu\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
766 	SPRINTF("        command = ");
767 	lprint_command(cmd->cmnd, m);
768 }
769 
770 static void lprint_command(unsigned char *command, struct seq_file *m)
771 {
772 	int i, s;
773 	lprint_opcode(command[0], m);
774 	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
775 		SPRINTF("%02x ", command[i]);
776 	SPRINTF("\n");
777 }
778 
779 static void lprint_opcode(int opcode, struct seq_file *m)
780 {
781 	SPRINTF("%2d (0x%02x)", opcode, opcode);
782 }
783 
784 
785 /**
786  *	NCR5380_init	-	initialise an NCR5380
787  *	@instance: adapter to configure
788  *	@flags: control flags
789  *
790  *	Initializes *instance and corresponding 5380 chip,
791  *      with flags OR'd into the initial flags value.
792  *
793  *	Notes : I assume that the host, hostno, and id bits have been
794  *      set correctly.  I don't care about the irq and other fields.
795  *
796  *	Returns 0 for success
797  *
798  *	Locks: interrupts must be enabled when we are called
799  */
800 
801 static int NCR5380_init(struct Scsi_Host *instance, int flags)
802 {
803 	NCR5380_local_declare();
804 	int i, pass;
805 	unsigned long timeout;
806 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
807 
808 	if(in_interrupt())
809 		printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
810 	/*
811 	 * On NCR53C400 boards, NCR5380 registers are mapped 8 past
812 	 * the base address.
813 	 */
814 
815 #ifdef NCR53C400
816 	if (flags & FLAG_NCR53C400)
817 		instance->NCR5380_instance_name += NCR53C400_address_adjust;
818 #endif
819 
820 	NCR5380_setup(instance);
821 
822 	hostdata->aborted = 0;
823 	hostdata->id_mask = 1 << instance->this_id;
824 	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
825 		if (i > hostdata->id_mask)
826 			hostdata->id_higher_mask |= i;
827 	for (i = 0; i < 8; ++i)
828 		hostdata->busy[i] = 0;
829 #ifdef REAL_DMA
830 	hostdata->dmalen = 0;
831 #endif
832 	hostdata->targets_present = 0;
833 	hostdata->connected = NULL;
834 	hostdata->issue_queue = NULL;
835 	hostdata->disconnected_queue = NULL;
836 
837 	INIT_DELAYED_WORK(&hostdata->coroutine, NCR5380_main);
838 
839 #ifdef NCR5380_STATS
840 	for (i = 0; i < 8; ++i) {
841 		hostdata->time_read[i] = 0;
842 		hostdata->time_write[i] = 0;
843 		hostdata->bytes_read[i] = 0;
844 		hostdata->bytes_write[i] = 0;
845 	}
846 	hostdata->timebase = 0;
847 	hostdata->pendingw = 0;
848 	hostdata->pendingr = 0;
849 #endif
850 
851 	/* The CHECK code seems to break the 53C400. Will check it later maybe */
852 	if (flags & FLAG_NCR53C400)
853 		hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
854 	else
855 		hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
856 
857 	hostdata->host = instance;
858 	hostdata->time_expires = 0;
859 
860 #ifndef AUTOSENSE
861 	if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
862 		    printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
863 		    	   "         be incorrectly cleared.\n", instance->host_no);
864 #endif				/* def AUTOSENSE */
865 
866 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
867 	NCR5380_write(MODE_REG, MR_BASE);
868 	NCR5380_write(TARGET_COMMAND_REG, 0);
869 	NCR5380_write(SELECT_ENABLE_REG, 0);
870 
871 #ifdef NCR53C400
872 	if (hostdata->flags & FLAG_NCR53C400) {
873 		NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
874 	}
875 #endif
876 
877 	/*
878 	 * Detect and correct bus wedge problems.
879 	 *
880 	 * If the system crashed, it may have crashed in a state
881 	 * where a SCSI command was still executing, and the
882 	 * SCSI bus is not in a BUS FREE STATE.
883 	 *
884 	 * If this is the case, we'll try to abort the currently
885 	 * established nexus which we know nothing about, and that
886 	 * failing, do a hard reset of the SCSI bus
887 	 */
888 
889 	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
890 		switch (pass) {
891 		case 1:
892 		case 3:
893 		case 5:
894 			printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
895 			timeout = jiffies + 5 * HZ;
896 			NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
897 			break;
898 		case 2:
899 			printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
900 			do_abort(instance);
901 			break;
902 		case 4:
903 			printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
904 			do_reset(instance);
905 			break;
906 		case 6:
907 			printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
908 			return -ENXIO;
909 		}
910 	}
911 	return 0;
912 }
913 
914 /**
915  *	NCR5380_exit	-	remove an NCR5380
916  *	@instance: adapter to remove
917  */
918 
919 static void NCR5380_exit(struct Scsi_Host *instance)
920 {
921 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
922 
923 	cancel_delayed_work_sync(&hostdata->coroutine);
924 }
925 
926 /**
927  *	NCR5380_queue_command 		-	queue a command
928  *	@cmd: SCSI command
929  *	@done: completion handler
930  *
931  *      cmd is added to the per instance issue_queue, with minor
932  *      twiddling done to the host specific fields of cmd.  If the
933  *      main coroutine is not running, it is restarted.
934  *
935  *	Locks: host lock taken by caller
936  */
937 
938 static int NCR5380_queue_command_lck(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
939 {
940 	struct Scsi_Host *instance = cmd->device->host;
941 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
942 	Scsi_Cmnd *tmp;
943 
944 #if (NDEBUG & NDEBUG_NO_WRITE)
945 	switch (cmd->cmnd[0]) {
946 	case WRITE_6:
947 	case WRITE_10:
948 		printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
949 		cmd->result = (DID_ERROR << 16);
950 		done(cmd);
951 		return 0;
952 	}
953 #endif				/* (NDEBUG & NDEBUG_NO_WRITE) */
954 
955 #ifdef NCR5380_STATS
956 	switch (cmd->cmnd[0]) {
957 		case WRITE:
958 		case WRITE_6:
959 		case WRITE_10:
960 			hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
961 			hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
962 			hostdata->pendingw++;
963 			break;
964 		case READ:
965 		case READ_6:
966 		case READ_10:
967 			hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
968 			hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
969 			hostdata->pendingr++;
970 			break;
971 	}
972 #endif
973 
974 	/*
975 	 * We use the host_scribble field as a pointer to the next command
976 	 * in a queue
977 	 */
978 
979 	cmd->host_scribble = NULL;
980 	cmd->scsi_done = done;
981 	cmd->result = 0;
982 
983 	/*
984 	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
985 	 * commands are added to the head of the queue since any command will
986 	 * clear the contingent allegiance condition that exists and the
987 	 * sense data is only guaranteed to be valid while the condition exists.
988 	 */
989 
990 	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
991 		LIST(cmd, hostdata->issue_queue);
992 		cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
993 		hostdata->issue_queue = cmd;
994 	} else {
995 		for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
996 		LIST(cmd, tmp);
997 		tmp->host_scribble = (unsigned char *) cmd;
998 	}
999 	dprintk(NDEBUG_QUEUES, "scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
1000 
1001 	/* Run the coroutine if it isn't already running. */
1002 	/* Kick off command processing */
1003 	schedule_delayed_work(&hostdata->coroutine, 0);
1004 	return 0;
1005 }
1006 
1007 static DEF_SCSI_QCMD(NCR5380_queue_command)
1008 
1009 /**
1010  *	NCR5380_main	-	NCR state machines
1011  *
1012  *	NCR5380_main is a coroutine that runs as long as more work can
1013  *      be done on the NCR5380 host adapters in a system.  Both
1014  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1015  *      in case it is not running.
1016  *
1017  *	Locks: called as its own thread with no locks held. Takes the
1018  *	host lock and called routines may take the isa dma lock.
1019  */
1020 
1021 static void NCR5380_main(struct work_struct *work)
1022 {
1023 	struct NCR5380_hostdata *hostdata =
1024 		container_of(work, struct NCR5380_hostdata, coroutine.work);
1025 	struct Scsi_Host *instance = hostdata->host;
1026 	Scsi_Cmnd *tmp, *prev;
1027 	int done;
1028 
1029 	spin_lock_irq(instance->host_lock);
1030 	do {
1031 		/* Lock held here */
1032 		done = 1;
1033 		if (!hostdata->connected && !hostdata->selecting) {
1034 			dprintk(NDEBUG_MAIN, "scsi%d : not connected\n", instance->host_no);
1035 			/*
1036 			 * Search through the issue_queue for a command destined
1037 			 * for a target that's not busy.
1038 			 */
1039 			for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
1040 			{
1041 				if (prev != tmp)
1042 				    dprintk(NDEBUG_LISTS, "MAIN tmp=%p   target=%d   busy=%d lun=%llu\n", tmp, tmp->device->id, hostdata->busy[tmp->device->id], tmp->device->lun);
1043 				/*  When we find one, remove it from the issue queue. */
1044 				if (!(hostdata->busy[tmp->device->id] &
1045 				      (1 << (u8)(tmp->device->lun & 0xff)))) {
1046 					if (prev) {
1047 						REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1048 						prev->host_scribble = tmp->host_scribble;
1049 					} else {
1050 						REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1051 						hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1052 					}
1053 					tmp->host_scribble = NULL;
1054 
1055 					/*
1056 					 * Attempt to establish an I_T_L nexus here.
1057 					 * On success, instance->hostdata->connected is set.
1058 					 * On failure, we must add the command back to the
1059 					 *   issue queue so we can keep trying.
1060 					 */
1061 					dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, "scsi%d : main() : command for target %d lun %llu removed from issue_queue\n", instance->host_no, tmp->device->id, tmp->device->lun);
1062 
1063 					/*
1064 					 * A successful selection is defined as one that
1065 					 * leaves us with the command connected and
1066 					 * in hostdata->connected, OR has terminated the
1067 					 * command.
1068 					 *
1069 					 * With successful commands, we fall through
1070 					 * and see if we can do an information transfer,
1071 					 * with failures we will restart.
1072 					 */
1073 					hostdata->selecting = NULL;
1074 					/* RvC: have to preset this to indicate a new command is being performed */
1075 
1076 					if (!NCR5380_select(instance, tmp,
1077 							    /*
1078 							     * REQUEST SENSE commands are issued without tagged
1079 							     * queueing, even on SCSI-II devices because the
1080 							     * contingent allegiance condition exists for the
1081 							     * entire unit.
1082 							     */
1083 							    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1084 						break;
1085 					} else {
1086 						LIST(tmp, hostdata->issue_queue);
1087 						tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1088 						hostdata->issue_queue = tmp;
1089 						done = 0;
1090 						dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, "scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no);
1091 					}
1092 					/* lock held here still */
1093 				}	/* if target/lun is not busy */
1094 			}	/* for */
1095 			/* exited locked */
1096 		}	/* if (!hostdata->connected) */
1097 		if (hostdata->selecting) {
1098 			tmp = (Scsi_Cmnd *) hostdata->selecting;
1099 			/* Selection will drop and retake the lock */
1100 			if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1101 				/* Ok ?? */
1102 			} else {
1103 				/* RvC: device failed, so we wait a long time
1104 				   this is needed for Mustek scanners, that
1105 				   do not respond to commands immediately
1106 				   after a scan */
1107 				printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1108 				LIST(tmp, hostdata->issue_queue);
1109 				tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1110 				hostdata->issue_queue = tmp;
1111 				NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1112 			}
1113 		}	/* if hostdata->selecting */
1114 		if (hostdata->connected
1115 #ifdef REAL_DMA
1116 		    && !hostdata->dmalen
1117 #endif
1118 		    && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1119 		    ) {
1120 			dprintk(NDEBUG_MAIN, "scsi%d : main() : performing information transfer\n", instance->host_no);
1121 			NCR5380_information_transfer(instance);
1122 			dprintk(NDEBUG_MAIN, "scsi%d : main() : done set false\n", instance->host_no);
1123 			done = 0;
1124 		} else
1125 			break;
1126 	} while (!done);
1127 
1128 	spin_unlock_irq(instance->host_lock);
1129 }
1130 
1131 #ifndef DONT_USE_INTR
1132 
1133 /**
1134  * 	NCR5380_intr	-	generic NCR5380 irq handler
1135  *	@irq: interrupt number
1136  *	@dev_id: device info
1137  *
1138  *	Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1139  *      from the disconnected queue, and restarting NCR5380_main()
1140  *      as required.
1141  *
1142  *	Locks: takes the needed instance locks
1143  */
1144 
1145 static irqreturn_t NCR5380_intr(int dummy, void *dev_id)
1146 {
1147 	NCR5380_local_declare();
1148 	struct Scsi_Host *instance = dev_id;
1149 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1150 	int done;
1151 	unsigned char basr;
1152 	unsigned long flags;
1153 
1154 	dprintk(NDEBUG_INTR, "scsi : NCR5380 irq %d triggered\n",
1155 		instance->irq);
1156 
1157 	do {
1158 		done = 1;
1159 		spin_lock_irqsave(instance->host_lock, flags);
1160 		/* Look for pending interrupts */
1161 		NCR5380_setup(instance);
1162 		basr = NCR5380_read(BUS_AND_STATUS_REG);
1163 		/* XXX dispatch to appropriate routine if found and done=0 */
1164 		if (basr & BASR_IRQ) {
1165 			NCR5380_dprint(NDEBUG_INTR, instance);
1166 			if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1167 				done = 0;
1168 				dprintk(NDEBUG_INTR, "scsi%d : SEL interrupt\n", instance->host_no);
1169 				NCR5380_reselect(instance);
1170 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1171 			} else if (basr & BASR_PARITY_ERROR) {
1172 				dprintk(NDEBUG_INTR, "scsi%d : PARITY interrupt\n", instance->host_no);
1173 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1174 			} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1175 				dprintk(NDEBUG_INTR, "scsi%d : RESET interrupt\n", instance->host_no);
1176 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1177 			} else {
1178 #if defined(REAL_DMA)
1179 				/*
1180 				 * We should only get PHASE MISMATCH and EOP interrupts
1181 				 * if we have DMA enabled, so do a sanity check based on
1182 				 * the current setting of the MODE register.
1183 				 */
1184 
1185 				if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1186 					int transferred;
1187 
1188 					if (!hostdata->connected)
1189 						panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1190 
1191 					transferred = (hostdata->dmalen - NCR5380_dma_residual(instance));
1192 					hostdata->connected->SCp.this_residual -= transferred;
1193 					hostdata->connected->SCp.ptr += transferred;
1194 					hostdata->dmalen = 0;
1195 
1196 					(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1197 
1198 					/* FIXME: we need to poll briefly then defer a workqueue task ! */
1199 					NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1200 
1201 					NCR5380_write(MODE_REG, MR_BASE);
1202 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1203 				}
1204 #else
1205 				dprintk(NDEBUG_INTR, "scsi : unknown interrupt, BASR 0x%X, MR 0x%X, SR 0x%x\n", basr, NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1206 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1207 #endif
1208 			}
1209 		}	/* if BASR_IRQ */
1210 		spin_unlock_irqrestore(instance->host_lock, flags);
1211 		if(!done)
1212 			schedule_delayed_work(&hostdata->coroutine, 0);
1213 	} while (!done);
1214 	return IRQ_HANDLED;
1215 }
1216 
1217 #endif
1218 
1219 /**
1220  *	collect_stats		-	collect stats on a scsi command
1221  *	@hostdata: adapter
1222  *	@cmd: command being issued
1223  *
1224  *	Update the statistical data by parsing the command in question
1225  */
1226 
1227 static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd)
1228 {
1229 #ifdef NCR5380_STATS
1230 	switch (cmd->cmnd[0]) {
1231 	case WRITE:
1232 	case WRITE_6:
1233 	case WRITE_10:
1234 		hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1235 		hostdata->pendingw--;
1236 		break;
1237 	case READ:
1238 	case READ_6:
1239 	case READ_10:
1240 		hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1241 		hostdata->pendingr--;
1242 		break;
1243 	}
1244 #endif
1245 }
1246 
1247 
1248 /*
1249  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1250  *      int tag);
1251  *
1252  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1253  *      including ARBITRATION, SELECTION, and initial message out for
1254  *      IDENTIFY and queue messages.
1255  *
1256  * Inputs : instance - instantiation of the 5380 driver on which this
1257  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1258  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1259  *      the command that is presently connected.
1260  *
1261  * Returns : -1 if selection could not execute for some reason,
1262  *      0 if selection succeeded or failed because the target
1263  *      did not respond.
1264  *
1265  * Side effects :
1266  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1267  *              with registers as they should have been on entry - ie
1268  *              SELECT_ENABLE will be set appropriately, the NCR5380
1269  *              will cease to drive any SCSI bus signals.
1270  *
1271  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1272  *              instance->connected will be set to cmd.
1273  *              SELECT interrupt will be disabled.
1274  *
1275  *      If failed (no target) : cmd->scsi_done() will be called, and the
1276  *              cmd->result host byte set to DID_BAD_TARGET.
1277  *
1278  *	Locks: caller holds hostdata lock in IRQ mode
1279  */
1280 
1281 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag)
1282 {
1283 	NCR5380_local_declare();
1284 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1285 	unsigned char tmp[3], phase;
1286 	unsigned char *data;
1287 	int len;
1288 	unsigned long timeout;
1289 	unsigned char value;
1290 	int err;
1291 	NCR5380_setup(instance);
1292 
1293 	if (hostdata->selecting)
1294 		goto part2;
1295 
1296 	hostdata->restart_select = 0;
1297 
1298 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1299 	dprintk(NDEBUG_ARBITRATION, "scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id);
1300 
1301 	/*
1302 	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1303 	 * data bus during SELECTION.
1304 	 */
1305 
1306 	NCR5380_write(TARGET_COMMAND_REG, 0);
1307 
1308 	/*
1309 	 * Start arbitration.
1310 	 */
1311 
1312 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1313 	NCR5380_write(MODE_REG, MR_ARBITRATE);
1314 
1315 
1316 	/* We can be relaxed here, interrupts are on, we are
1317 	   in workqueue context, the birds are singing in the trees */
1318 	spin_unlock_irq(instance->host_lock);
1319 	err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1320 	spin_lock_irq(instance->host_lock);
1321 	if (err < 0) {
1322 		printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1323 		NCR5380_write(MODE_REG, MR_BASE);
1324 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1325 		goto failed;
1326 	}
1327 
1328 	dprintk(NDEBUG_ARBITRATION, "scsi%d : arbitration complete\n", instance->host_no);
1329 
1330 	/*
1331 	 * The arbitration delay is 2.2us, but this is a minimum and there is
1332 	 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1333 	 * the integral nature of udelay().
1334 	 *
1335 	 */
1336 
1337 	udelay(3);
1338 
1339 	/* Check for lost arbitration */
1340 	if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1341 		NCR5380_write(MODE_REG, MR_BASE);
1342 		dprintk(NDEBUG_ARBITRATION, "scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no);
1343 		goto failed;
1344 	}
1345 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1346 
1347 	if (!(hostdata->flags & FLAG_DTC3181E) &&
1348 	    /* RvC: DTC3181E has some trouble with this
1349 	     *      so we simply removed it. Seems to work with
1350 	     *      only Mustek scanner attached
1351 	     */
1352 	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1353 		NCR5380_write(MODE_REG, MR_BASE);
1354 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1355 		dprintk(NDEBUG_ARBITRATION, "scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no);
1356 		goto failed;
1357 	}
1358 	/*
1359 	 * Again, bus clear + bus settle time is 1.2us, however, this is
1360 	 * a minimum so we'll udelay ceil(1.2)
1361 	 */
1362 
1363 	udelay(2);
1364 
1365 	dprintk(NDEBUG_ARBITRATION, "scsi%d : won arbitration\n", instance->host_no);
1366 
1367 	/*
1368 	 * Now that we have won arbitration, start Selection process, asserting
1369 	 * the host and target ID's on the SCSI bus.
1370 	 */
1371 
1372 	NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1373 
1374 	/*
1375 	 * Raise ATN while SEL is true before BSY goes false from arbitration,
1376 	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1377 	 * phase immediately after selection.
1378 	 */
1379 
1380 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1381 	NCR5380_write(MODE_REG, MR_BASE);
1382 
1383 	/*
1384 	 * Reselect interrupts must be turned off prior to the dropping of BSY,
1385 	 * otherwise we will trigger an interrupt.
1386 	 */
1387 	NCR5380_write(SELECT_ENABLE_REG, 0);
1388 
1389 	/*
1390 	 * The initiator shall then wait at least two deskew delays and release
1391 	 * the BSY signal.
1392 	 */
1393 	udelay(1);		/* wingel -- wait two bus deskew delay >2*45ns */
1394 
1395 	/* Reset BSY */
1396 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1397 
1398 	/*
1399 	 * Something weird happens when we cease to drive BSY - looks
1400 	 * like the board/chip is letting us do another read before the
1401 	 * appropriate propagation delay has expired, and we're confusing
1402 	 * a BSY signal from ourselves as the target's response to SELECTION.
1403 	 *
1404 	 * A small delay (the 'C++' frontend breaks the pipeline with an
1405 	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1406 	 * tighter 'C' code breaks and requires this) solves the problem -
1407 	 * the 1 us delay is arbitrary, and only used because this delay will
1408 	 * be the same on other platforms and since it works here, it should
1409 	 * work there.
1410 	 *
1411 	 * wingel suggests that this could be due to failing to wait
1412 	 * one deskew delay.
1413 	 */
1414 
1415 	udelay(1);
1416 
1417 	dprintk(NDEBUG_SELECTION, "scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd));
1418 
1419 	/*
1420 	 * The SCSI specification calls for a 250 ms timeout for the actual
1421 	 * selection.
1422 	 */
1423 
1424 	timeout = jiffies + (250 * HZ / 1000);
1425 
1426 	/*
1427 	 * XXX very interesting - we're seeing a bounce where the BSY we
1428 	 * asserted is being reflected / still asserted (propagation delay?)
1429 	 * and it's detecting as true.  Sigh.
1430 	 */
1431 
1432 	hostdata->select_time = 0;	/* we count the clock ticks at which we polled */
1433 	hostdata->selecting = cmd;
1434 
1435 part2:
1436 	/* RvC: here we enter after a sleeping period, or immediately after
1437 	   execution of part 1
1438 	   we poll only once ech clock tick */
1439 	value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1440 
1441 	if (!value && (hostdata->select_time < HZ/4)) {
1442 		/* RvC: we still must wait for a device response */
1443 		hostdata->select_time++;	/* after 25 ticks the device has failed */
1444 		NCR5380_set_timer(hostdata, 1);
1445 		return 0;	/* RvC: we return here with hostdata->selecting set,
1446 				   to go to sleep */
1447 	}
1448 
1449 	hostdata->selecting = NULL;/* clear this pointer, because we passed the
1450 					   waiting period */
1451 	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1452 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1453 		NCR5380_reselect(instance);
1454 		printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1455 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1456 		return -1;
1457 	}
1458 	/*
1459 	 * No less than two deskew delays after the initiator detects the
1460 	 * BSY signal is true, it shall release the SEL signal and may
1461 	 * change the DATA BUS.                                     -wingel
1462 	 */
1463 
1464 	udelay(1);
1465 
1466 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1467 
1468 	if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1469 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1470 		if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1471 			printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1472 			if (hostdata->restart_select)
1473 				printk(KERN_DEBUG "\trestart select\n");
1474 			NCR5380_dprint(NDEBUG_SELECTION, instance);
1475 			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1476 			return -1;
1477 		}
1478 		cmd->result = DID_BAD_TARGET << 16;
1479 		collect_stats(hostdata, cmd);
1480 		cmd->scsi_done(cmd);
1481 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1482 		dprintk(NDEBUG_SELECTION, "scsi%d : target did not respond within 250ms\n", instance->host_no);
1483 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1484 		return 0;
1485 	}
1486 	hostdata->targets_present |= (1 << scmd_id(cmd));
1487 
1488 	/*
1489 	 * Since we followed the SCSI spec, and raised ATN while SEL
1490 	 * was true but before BSY was false during selection, the information
1491 	 * transfer phase should be a MESSAGE OUT phase so that we can send the
1492 	 * IDENTIFY message.
1493 	 *
1494 	 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1495 	 * message (2 bytes) with a tag ID that we increment with every command
1496 	 * until it wraps back to 0.
1497 	 *
1498 	 * XXX - it turns out that there are some broken SCSI-II devices,
1499 	 *       which claim to support tagged queuing but fail when more than
1500 	 *       some number of commands are issued at once.
1501 	 */
1502 
1503 	/* Wait for start of REQ/ACK handshake */
1504 
1505 	spin_unlock_irq(instance->host_lock);
1506 	err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1507 	spin_lock_irq(instance->host_lock);
1508 
1509 	if(err) {
1510 		printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1511 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1512 		goto failed;
1513 	}
1514 
1515 	dprintk(NDEBUG_SELECTION, "scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id);
1516 	tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1517 
1518 	len = 1;
1519 	cmd->tag = 0;
1520 
1521 	/* Send message(s) */
1522 	data = tmp;
1523 	phase = PHASE_MSGOUT;
1524 	NCR5380_transfer_pio(instance, &phase, &len, &data);
1525 	dprintk(NDEBUG_SELECTION, "scsi%d : nexus established.\n", instance->host_no);
1526 	/* XXX need to handle errors here */
1527 	hostdata->connected = cmd;
1528 	hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1529 
1530 	initialize_SCp(cmd);
1531 
1532 	return 0;
1533 
1534 	/* Selection failed */
1535 failed:
1536 	return -1;
1537 
1538 }
1539 
1540 /*
1541  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1542  *      unsigned char *phase, int *count, unsigned char **data)
1543  *
1544  * Purpose : transfers data in given phase using polled I/O
1545  *
1546  * Inputs : instance - instance of driver, *phase - pointer to
1547  *      what phase is expected, *count - pointer to number of
1548  *      bytes to transfer, **data - pointer to data pointer.
1549  *
1550  * Returns : -1 when different phase is entered without transferring
1551  *      maximum number of bytes, 0 if all bytes or transferred or exit
1552  *      is in same phase.
1553  *
1554  *      Also, *phase, *count, *data are modified in place.
1555  *
1556  * XXX Note : handling for bus free may be useful.
1557  */
1558 
1559 /*
1560  * Note : this code is not as quick as it could be, however it
1561  * IS 100% reliable, and for the actual data transfer where speed
1562  * counts, we will always do a pseudo DMA or DMA transfer.
1563  */
1564 
1565 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1566 	NCR5380_local_declare();
1567 	unsigned char p = *phase, tmp;
1568 	int c = *count;
1569 	unsigned char *d = *data;
1570 	/*
1571 	 *      RvC: some administrative data to process polling time
1572 	 */
1573 	int break_allowed = 0;
1574 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1575 	NCR5380_setup(instance);
1576 
1577 	if (!(p & SR_IO))
1578 		dprintk(NDEBUG_PIO, "scsi%d : pio write %d bytes\n", instance->host_no, c);
1579 	else
1580 		dprintk(NDEBUG_PIO, "scsi%d : pio read %d bytes\n", instance->host_no, c);
1581 
1582 	/*
1583 	 * The NCR5380 chip will only drive the SCSI bus when the
1584 	 * phase specified in the appropriate bits of the TARGET COMMAND
1585 	 * REGISTER match the STATUS REGISTER
1586 	 */
1587 
1588 	 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1589 
1590 	/* RvC: don't know if this is necessary, but other SCSI I/O is short
1591 	 *      so breaks are not necessary there
1592 	 */
1593 	if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1594 		break_allowed = 1;
1595 	}
1596 	do {
1597 		/*
1598 		 * Wait for assertion of REQ, after which the phase bits will be
1599 		 * valid
1600 		 */
1601 
1602 		/* RvC: we simply poll once, after that we stop temporarily
1603 		 *      and let the device buffer fill up
1604 		 *      if breaking is not allowed, we keep polling as long as needed
1605 		 */
1606 
1607 		/* FIXME */
1608 		while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1609 		if (!(tmp & SR_REQ)) {
1610 			/* timeout condition */
1611 			NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1612 			break;
1613 		}
1614 
1615 		dprintk(NDEBUG_HANDSHAKE, "scsi%d : REQ detected\n", instance->host_no);
1616 
1617 		/* Check for phase mismatch */
1618 		if ((tmp & PHASE_MASK) != p) {
1619 			dprintk(NDEBUG_HANDSHAKE, "scsi%d : phase mismatch\n", instance->host_no);
1620 			NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1621 			break;
1622 		}
1623 		/* Do actual transfer from SCSI bus to / from memory */
1624 		if (!(p & SR_IO))
1625 			NCR5380_write(OUTPUT_DATA_REG, *d);
1626 		else
1627 			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1628 
1629 		++d;
1630 
1631 		/*
1632 		 * The SCSI standard suggests that in MSGOUT phase, the initiator
1633 		 * should drop ATN on the last byte of the message phase
1634 		 * after REQ has been asserted for the handshake but before
1635 		 * the initiator raises ACK.
1636 		 */
1637 
1638 		if (!(p & SR_IO)) {
1639 			if (!((p & SR_MSG) && c > 1)) {
1640 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1641 				NCR5380_dprint(NDEBUG_PIO, instance);
1642 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1643 			} else {
1644 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1645 				NCR5380_dprint(NDEBUG_PIO, instance);
1646 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1647 			}
1648 		} else {
1649 			NCR5380_dprint(NDEBUG_PIO, instance);
1650 			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1651 		}
1652 
1653 		/* FIXME - if this fails bus reset ?? */
1654 		NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1655 		dprintk(NDEBUG_HANDSHAKE, "scsi%d : req false, handshake complete\n", instance->host_no);
1656 
1657 /*
1658  * We have several special cases to consider during REQ/ACK handshaking :
1659  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1660  *      message.  ATN must be dropped as ACK is dropped.
1661  *
1662  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1663  *      message.  We must exit with ACK asserted, so that the calling
1664  *      code may raise ATN before dropping ACK to reject the message.
1665  *
1666  * 3.  ACK and ATN are clear and the target may proceed as normal.
1667  */
1668 		if (!(p == PHASE_MSGIN && c == 1)) {
1669 			if (p == PHASE_MSGOUT && c > 1)
1670 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1671 			else
1672 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1673 		}
1674 	} while (--c);
1675 
1676 	dprintk(NDEBUG_PIO, "scsi%d : residual %d\n", instance->host_no, c);
1677 
1678 	*count = c;
1679 	*data = d;
1680 	tmp = NCR5380_read(STATUS_REG);
1681 	if (tmp & SR_REQ)
1682 		*phase = tmp & PHASE_MASK;
1683 	else
1684 		*phase = PHASE_UNKNOWN;
1685 
1686 	if (!c || (*phase == p))
1687 		return 0;
1688 	else
1689 		return -1;
1690 }
1691 
1692 /**
1693  *	do_reset	-	issue a reset command
1694  *	@host: adapter to reset
1695  *
1696  *	Issue a reset sequence to the NCR5380 and try and get the bus
1697  *	back into sane shape.
1698  *
1699  *	Locks: caller holds queue lock
1700  */
1701 
1702 static void do_reset(struct Scsi_Host *host) {
1703 	NCR5380_local_declare();
1704 	NCR5380_setup(host);
1705 
1706 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1707 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1708 	udelay(25);
1709 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1710 }
1711 
1712 /*
1713  * Function : do_abort (Scsi_Host *host)
1714  *
1715  * Purpose : abort the currently established nexus.  Should only be
1716  *      called from a routine which can drop into a
1717  *
1718  * Returns : 0 on success, -1 on failure.
1719  *
1720  * Locks: queue lock held by caller
1721  *	FIXME: sort this out and get new_eh running
1722  */
1723 
1724 static int do_abort(struct Scsi_Host *host) {
1725 	NCR5380_local_declare();
1726 	unsigned char *msgptr, phase, tmp;
1727 	int len;
1728 	int rc;
1729 	NCR5380_setup(host);
1730 
1731 
1732 	/* Request message out phase */
1733 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1734 
1735 	/*
1736 	 * Wait for the target to indicate a valid phase by asserting
1737 	 * REQ.  Once this happens, we'll have either a MSGOUT phase
1738 	 * and can immediately send the ABORT message, or we'll have some
1739 	 * other phase and will have to source/sink data.
1740 	 *
1741 	 * We really don't care what value was on the bus or what value
1742 	 * the target sees, so we just handshake.
1743 	 */
1744 
1745 	rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1746 
1747 	if(rc < 0)
1748 		return -1;
1749 
1750 	tmp = (unsigned char)rc;
1751 
1752 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1753 
1754 	if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1755 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1756 		rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1757 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1758 		if(rc == -1)
1759 			return -1;
1760 	}
1761 	tmp = ABORT;
1762 	msgptr = &tmp;
1763 	len = 1;
1764 	phase = PHASE_MSGOUT;
1765 	NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1766 
1767 	/*
1768 	 * If we got here, and the command completed successfully,
1769 	 * we're about to go into bus free state.
1770 	 */
1771 
1772 	return len ? -1 : 0;
1773 }
1774 
1775 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1776 /*
1777  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1778  *      unsigned char *phase, int *count, unsigned char **data)
1779  *
1780  * Purpose : transfers data in given phase using either real
1781  *      or pseudo DMA.
1782  *
1783  * Inputs : instance - instance of driver, *phase - pointer to
1784  *      what phase is expected, *count - pointer to number of
1785  *      bytes to transfer, **data - pointer to data pointer.
1786  *
1787  * Returns : -1 when different phase is entered without transferring
1788  *      maximum number of bytes, 0 if all bytes or transferred or exit
1789  *      is in same phase.
1790  *
1791  *      Also, *phase, *count, *data are modified in place.
1792  *
1793  *	Locks: io_request lock held by caller
1794  */
1795 
1796 
1797 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1798 	NCR5380_local_declare();
1799 	register int c = *count;
1800 	register unsigned char p = *phase;
1801 	register unsigned char *d = *data;
1802 	unsigned char tmp;
1803 	int foo;
1804 #if defined(REAL_DMA_POLL)
1805 	int cnt, toPIO;
1806 	unsigned char saved_data = 0, overrun = 0, residue;
1807 #endif
1808 
1809 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1810 
1811 	NCR5380_setup(instance);
1812 
1813 	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1814 		*phase = tmp;
1815 		return -1;
1816 	}
1817 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1818 #ifdef READ_OVERRUNS
1819 	if (p & SR_IO) {
1820 		c -= 2;
1821 	}
1822 #endif
1823 	dprintk(NDEBUG_DMA, "scsi%d : initializing DMA channel %d for %s, %d bytes %s %0x\n", instance->host_no, instance->dma_channel, (p & SR_IO) ? "reading" : "writing", c, (p & SR_IO) ? "to" : "from", (unsigned) d);
1824 	hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1825 #endif
1826 
1827 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1828 
1829 #ifdef REAL_DMA
1830 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1831 #elif defined(REAL_DMA_POLL)
1832 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1833 #else
1834 	/*
1835 	 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1836 	 * were not disabled for the duration of a single DMA transfer, from
1837 	 * before the setting of DMA mode to after transfer of the last byte.
1838 	 */
1839 
1840 #if defined(PSEUDO_DMA) && defined(UNSAFE)
1841 	spin_unlock_irq(instance->host_lock);
1842 #endif
1843 	/* KLL May need eop and parity in 53c400 */
1844 	if (hostdata->flags & FLAG_NCR53C400)
1845 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE |
1846 				MR_ENABLE_PAR_CHECK | MR_ENABLE_PAR_INTR |
1847 				MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1848 	else
1849 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1850 #endif				/* def REAL_DMA */
1851 
1852 	dprintk(NDEBUG_DMA, "scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG));
1853 
1854 	/*
1855 	 *	On the PAS16 at least I/O recovery delays are not needed here.
1856 	 *	Everyone else seems to want them.
1857 	 */
1858 
1859 	if (p & SR_IO) {
1860 		io_recovery_delay(1);
1861 		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1862 	} else {
1863 		io_recovery_delay(1);
1864 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1865 		io_recovery_delay(1);
1866 		NCR5380_write(START_DMA_SEND_REG, 0);
1867 		io_recovery_delay(1);
1868 	}
1869 
1870 #if defined(REAL_DMA_POLL)
1871 	do {
1872 		tmp = NCR5380_read(BUS_AND_STATUS_REG);
1873 	} while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1874 
1875 /*
1876    At this point, either we've completed DMA, or we have a phase mismatch,
1877    or we've unexpectedly lost BUSY (which is a real error).
1878 
1879    For write DMAs, we want to wait until the last byte has been
1880    transferred out over the bus before we turn off DMA mode.  Alas, there
1881    seems to be no terribly good way of doing this on a 5380 under all
1882    conditions.  For non-scatter-gather operations, we can wait until REQ
1883    and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1884    are nastier, since the device will be expecting more data than we
1885    are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1886    could test LAST BIT SENT to assure transfer (I imagine this is precisely
1887    why this signal was added to the newer chips) but on the older 538[01]
1888    this signal does not exist.  The workaround for this lack is a watchdog;
1889    we bail out of the wait-loop after a modest amount of wait-time if
1890    the usual exit conditions are not met.  Not a terribly clean or
1891    correct solution :-%
1892 
1893    Reads are equally tricky due to a nasty characteristic of the NCR5380.
1894    If the chip is in DMA mode for an READ, it will respond to a target's
1895    REQ by latching the SCSI data into the INPUT DATA register and asserting
1896    ACK, even if it has _already_ been notified by the DMA controller that
1897    the current DMA transfer has completed!  If the NCR5380 is then taken
1898    out of DMA mode, this already-acknowledged byte is lost.
1899 
1900    This is not a problem for "one DMA transfer per command" reads, because
1901    the situation will never arise... either all of the data is DMA'ed
1902    properly, or the target switches to MESSAGE IN phase to signal a
1903    disconnection (either operation bringing the DMA to a clean halt).
1904    However, in order to handle scatter-reads, we must work around the
1905    problem.  The chosen fix is to DMA N-2 bytes, then check for the
1906    condition before taking the NCR5380 out of DMA mode.  One or two extra
1907    bytes are transferred via PIO as necessary to fill out the original
1908    request.
1909  */
1910 
1911 	if (p & SR_IO) {
1912 #ifdef READ_OVERRUNS
1913 		udelay(10);
1914 		if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1915 			saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1916 			overrun = 1;
1917 		}
1918 #endif
1919 	} else {
1920 		int limit = 100;
1921 		while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1922 			if (!(tmp & BASR_PHASE_MATCH))
1923 				break;
1924 			if (--limit < 0)
1925 				break;
1926 		}
1927 	}
1928 
1929 	dprintk(NDEBUG_DMA, "scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG));
1930 
1931 	NCR5380_write(MODE_REG, MR_BASE);
1932 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1933 
1934 	residue = NCR5380_dma_residual(instance);
1935 	c -= residue;
1936 	*count -= c;
1937 	*data += c;
1938 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1939 
1940 #ifdef READ_OVERRUNS
1941 	if (*phase == p && (p & SR_IO) && residue == 0) {
1942 		if (overrun) {
1943 			dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1944 			**data = saved_data;
1945 			*data += 1;
1946 			*count -= 1;
1947 			cnt = toPIO = 1;
1948 		} else {
1949 			printk("No overrun??\n");
1950 			cnt = toPIO = 2;
1951 		}
1952 		dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%X\n", cnt, *data);
1953 		NCR5380_transfer_pio(instance, phase, &cnt, data);
1954 		*count -= toPIO - cnt;
1955 	}
1956 #endif
1957 
1958 	dprintk(NDEBUG_DMA, "Return with data ptr = 0x%X, count %d, last 0x%X, next 0x%X\n", *data, *count, *(*data + *count - 1), *(*data + *count));
1959 	return 0;
1960 
1961 #elif defined(REAL_DMA)
1962 	return 0;
1963 #else				/* defined(REAL_DMA_POLL) */
1964 	if (p & SR_IO) {
1965 #ifdef DMA_WORKS_RIGHT
1966 		foo = NCR5380_pread(instance, d, c);
1967 #else
1968 		int diff = 1;
1969 		if (hostdata->flags & FLAG_NCR53C400) {
1970 			diff = 0;
1971 		}
1972 		if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1973 			/*
1974 			 * We can't disable DMA mode after successfully transferring
1975 			 * what we plan to be the last byte, since that would open up
1976 			 * a race condition where if the target asserted REQ before
1977 			 * we got the DMA mode reset, the NCR5380 would have latched
1978 			 * an additional byte into the INPUT DATA register and we'd
1979 			 * have dropped it.
1980 			 *
1981 			 * The workaround was to transfer one fewer bytes than we
1982 			 * intended to with the pseudo-DMA read function, wait for
1983 			 * the chip to latch the last byte, read it, and then disable
1984 			 * pseudo-DMA mode.
1985 			 *
1986 			 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1987 			 * REQ is deasserted when ACK is asserted, and not reasserted
1988 			 * until ACK goes false.  Since the NCR5380 won't lower ACK
1989 			 * until DACK is asserted, which won't happen unless we twiddle
1990 			 * the DMA port or we take the NCR5380 out of DMA mode, we
1991 			 * can guarantee that we won't handshake another extra
1992 			 * byte.
1993 			 */
1994 
1995 			if (!(hostdata->flags & FLAG_NCR53C400)) {
1996 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
1997 				/* Wait for clean handshake */
1998 				while (NCR5380_read(STATUS_REG) & SR_REQ);
1999 				d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2000 			}
2001 		}
2002 #endif
2003 	} else {
2004 #ifdef DMA_WORKS_RIGHT
2005 		foo = NCR5380_pwrite(instance, d, c);
2006 #else
2007 		int timeout;
2008 		dprintk(NDEBUG_C400_PWRITE, "About to pwrite %d bytes\n", c);
2009 		if (!(foo = NCR5380_pwrite(instance, d, c))) {
2010 			/*
2011 			 * Wait for the last byte to be sent.  If REQ is being asserted for
2012 			 * the byte we're interested, we'll ACK it and it will go false.
2013 			 */
2014 			if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2015 				timeout = 20000;
2016 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2017 
2018 				if (!timeout)
2019 					dprintk(NDEBUG_LAST_BYTE_SENT, "scsi%d : timed out on last byte\n", instance->host_no);
2020 
2021 				if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2022 					hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2023 					if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2024 						hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2025 						dprintk(NDEBUG_LAST_BYTE_SENT, "scsi%d : last byte sent works\n", instance->host_no);
2026 					}
2027 				}
2028 			} else {
2029 				dprintk(NDEBUG_C400_PWRITE, "Waiting for LASTBYTE\n");
2030 				while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2031 				dprintk(NDEBUG_C400_PWRITE, "Got LASTBYTE\n");
2032 			}
2033 		}
2034 #endif
2035 	}
2036 	NCR5380_write(MODE_REG, MR_BASE);
2037 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2038 
2039 	if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2040 		dprintk(NDEBUG_C400_PWRITE, "53C400w: Checking for IRQ\n");
2041 		if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2042 			dprintk(NDEBUG_C400_PWRITE, "53C400w:    got it, reading reset interrupt reg\n");
2043 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2044 		} else {
2045 			printk("53C400w:    IRQ NOT THERE!\n");
2046 		}
2047 	}
2048 	*data = d + c;
2049 	*count = 0;
2050 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2051 #if defined(PSEUDO_DMA) && defined(UNSAFE)
2052 	spin_lock_irq(instance->host_lock);
2053 #endif				/* defined(REAL_DMA_POLL) */
2054 	return foo;
2055 #endif				/* def REAL_DMA */
2056 }
2057 #endif				/* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2058 
2059 /*
2060  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2061  *
2062  * Purpose : run through the various SCSI phases and do as the target
2063  *      directs us to.  Operates on the currently connected command,
2064  *      instance->connected.
2065  *
2066  * Inputs : instance, instance for which we are doing commands
2067  *
2068  * Side effects : SCSI things happen, the disconnected queue will be
2069  *      modified if a command disconnects, *instance->connected will
2070  *      change.
2071  *
2072  * XXX Note : we need to watch for bus free or a reset condition here
2073  *      to recover from an unexpected bus free condition.
2074  *
2075  * Locks: io_request_lock held by caller in IRQ mode
2076  */
2077 
2078 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2079 	NCR5380_local_declare();
2080 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2081 	unsigned char msgout = NOP;
2082 	int sink = 0;
2083 	int len;
2084 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2085 	int transfersize;
2086 #endif
2087 	unsigned char *data;
2088 	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2089 	Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2090 	/* RvC: we need to set the end of the polling time */
2091 	unsigned long poll_time = jiffies + USLEEP_POLL;
2092 
2093 	NCR5380_setup(instance);
2094 
2095 	while (1) {
2096 		tmp = NCR5380_read(STATUS_REG);
2097 		/* We only have a valid SCSI phase when REQ is asserted */
2098 		if (tmp & SR_REQ) {
2099 			phase = (tmp & PHASE_MASK);
2100 			if (phase != old_phase) {
2101 				old_phase = phase;
2102 				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2103 			}
2104 			if (sink && (phase != PHASE_MSGOUT)) {
2105 				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2106 
2107 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2108 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2109 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2110 				sink = 0;
2111 				continue;
2112 			}
2113 			switch (phase) {
2114 			case PHASE_DATAIN:
2115 			case PHASE_DATAOUT:
2116 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2117 				printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2118 				sink = 1;
2119 				do_abort(instance);
2120 				cmd->result = DID_ERROR << 16;
2121 				cmd->scsi_done(cmd);
2122 				return;
2123 #endif
2124 				/*
2125 				 * If there is no room left in the current buffer in the
2126 				 * scatter-gather list, move onto the next one.
2127 				 */
2128 
2129 				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2130 					++cmd->SCp.buffer;
2131 					--cmd->SCp.buffers_residual;
2132 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
2133 					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2134 					dprintk(NDEBUG_INFORMATION, "scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual);
2135 				}
2136 				/*
2137 				 * The preferred transfer method is going to be
2138 				 * PSEUDO-DMA for systems that are strictly PIO,
2139 				 * since we can let the hardware do the handshaking.
2140 				 *
2141 				 * For this to work, we need to know the transfersize
2142 				 * ahead of time, since the pseudo-DMA code will sit
2143 				 * in an unconditional loop.
2144 				 */
2145 
2146 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2147 				/* KLL
2148 				 * PSEUDO_DMA is defined here. If this is the g_NCR5380
2149 				 * driver then it will always be defined, so the
2150 				 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2151 				 * NCR5380 case.  I think this is a fairly clean solution.
2152 				 * We supplement these 2 if's with the flag.
2153 				 */
2154 #ifdef NCR5380_dma_xfer_len
2155 				if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2156 #else
2157 				transfersize = cmd->transfersize;
2158 
2159 #ifdef LIMIT_TRANSFERSIZE	/* If we have problems with interrupt service */
2160 				if (transfersize > 512)
2161 					transfersize = 512;
2162 #endif				/* LIMIT_TRANSFERSIZE */
2163 
2164 				if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2165 					/* Limit transfers to 32K, for xx400 & xx406
2166 					 * pseudoDMA that transfers in 128 bytes blocks. */
2167 					if (transfersize > 32 * 1024)
2168 						transfersize = 32 * 1024;
2169 #endif
2170 					len = transfersize;
2171 					if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2172 						/*
2173 						 * If the watchdog timer fires, all future accesses to this
2174 						 * device will use the polled-IO.
2175 						 */
2176 						scmd_printk(KERN_INFO, cmd,
2177 							    "switching to slow handshake\n");
2178 						cmd->device->borken = 1;
2179 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2180 						sink = 1;
2181 						do_abort(instance);
2182 						cmd->result = DID_ERROR << 16;
2183 						cmd->scsi_done(cmd);
2184 						/* XXX - need to source or sink data here, as appropriate */
2185 					} else
2186 						cmd->SCp.this_residual -= transfersize - len;
2187 				} else
2188 #endif				/* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2189 					NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2190 							     &cmd->SCp.ptr);
2191 				break;
2192 			case PHASE_MSGIN:
2193 				len = 1;
2194 				data = &tmp;
2195 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2196 				cmd->SCp.Message = tmp;
2197 
2198 				switch (tmp) {
2199 					/*
2200 					 * Linking lets us reduce the time required to get the
2201 					 * next command out to the device, hopefully this will
2202 					 * mean we don't waste another revolution due to the delays
2203 					 * required by ARBITRATION and another SELECTION.
2204 					 *
2205 					 * In the current implementation proposal, low level drivers
2206 					 * merely have to start the next command, pointed to by
2207 					 * next_link, done() is called as with unlinked commands.
2208 					 */
2209 #ifdef LINKED
2210 				case LINKED_CMD_COMPLETE:
2211 				case LINKED_FLG_CMD_COMPLETE:
2212 					/* Accept message by clearing ACK */
2213 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2214 					dprintk(NDEBUG_LINKED, "scsi%d : target %d lun %llu linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun);
2215 					/*
2216 					 * Sanity check : A linked command should only terminate with
2217 					 * one of these messages if there are more linked commands
2218 					 * available.
2219 					 */
2220 					if (!cmd->next_link) {
2221 					    printk("scsi%d : target %d lun %llu linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2222 						sink = 1;
2223 						do_abort(instance);
2224 						return;
2225 					}
2226 					initialize_SCp(cmd->next_link);
2227 					/* The next command is still part of this process */
2228 					cmd->next_link->tag = cmd->tag;
2229 					cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2230 					dprintk(NDEBUG_LINKED, "scsi%d : target %d lun %llu linked request done, calling scsi_done().\n", instance->host_no, cmd->device->id, cmd->device->lun);
2231 					collect_stats(hostdata, cmd);
2232 					cmd->scsi_done(cmd);
2233 					cmd = hostdata->connected;
2234 					break;
2235 #endif				/* def LINKED */
2236 				case ABORT:
2237 				case COMMAND_COMPLETE:
2238 					/* Accept message by clearing ACK */
2239 					sink = 1;
2240 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2241 					hostdata->connected = NULL;
2242 					dprintk(NDEBUG_QUEUES, "scsi%d : command for target %d, lun %llu completed\n", instance->host_no, cmd->device->id, cmd->device->lun);
2243 					hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xFF));
2244 
2245 					/*
2246 					 * I'm not sure what the correct thing to do here is :
2247 					 *
2248 					 * If the command that just executed is NOT a request
2249 					 * sense, the obvious thing to do is to set the result
2250 					 * code to the values of the stored parameters.
2251 					 *
2252 					 * If it was a REQUEST SENSE command, we need some way
2253 					 * to differentiate between the failure code of the original
2254 					 * and the failure code of the REQUEST sense - the obvious
2255 					 * case is success, where we fall through and leave the result
2256 					 * code unchanged.
2257 					 *
2258 					 * The non-obvious place is where the REQUEST SENSE failed
2259 					 */
2260 
2261 					if (cmd->cmnd[0] != REQUEST_SENSE)
2262 						cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2263 					else if (status_byte(cmd->SCp.Status) != GOOD)
2264 						cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2265 
2266 #ifdef AUTOSENSE
2267 					if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2268 						hostdata->ses.cmd_len) {
2269 						scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2270 						hostdata->ses.cmd_len = 0 ;
2271 					}
2272 
2273 					if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2274 						scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2275 
2276 						dprintk(NDEBUG_AUTOSENSE, "scsi%d : performing request sense\n", instance->host_no);
2277 
2278 						LIST(cmd, hostdata->issue_queue);
2279 						cmd->host_scribble = (unsigned char *)
2280 						    hostdata->issue_queue;
2281 						hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2282 						dprintk(NDEBUG_QUEUES, "scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no);
2283 					} else
2284 #endif				/* def AUTOSENSE */
2285 					{
2286 						collect_stats(hostdata, cmd);
2287 						cmd->scsi_done(cmd);
2288 					}
2289 
2290 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2291 					/*
2292 					 * Restore phase bits to 0 so an interrupted selection,
2293 					 * arbitration can resume.
2294 					 */
2295 					NCR5380_write(TARGET_COMMAND_REG, 0);
2296 
2297 					while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2298 						barrier();
2299 					return;
2300 				case MESSAGE_REJECT:
2301 					/* Accept message by clearing ACK */
2302 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2303 					switch (hostdata->last_message) {
2304 					case HEAD_OF_QUEUE_TAG:
2305 					case ORDERED_QUEUE_TAG:
2306 					case SIMPLE_QUEUE_TAG:
2307 						cmd->device->simple_tags = 0;
2308 						hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
2309 						break;
2310 					default:
2311 						break;
2312 					}
2313 				case DISCONNECT:{
2314 						/* Accept message by clearing ACK */
2315 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2316 						cmd->device->disconnect = 1;
2317 						LIST(cmd, hostdata->disconnected_queue);
2318 						cmd->host_scribble = (unsigned char *)
2319 						    hostdata->disconnected_queue;
2320 						hostdata->connected = NULL;
2321 						hostdata->disconnected_queue = cmd;
2322 						dprintk(NDEBUG_QUEUES, "scsi%d : command for target %d lun %llu was moved from connected to" "  the disconnected_queue\n", instance->host_no, cmd->device->id, cmd->device->lun);
2323 						/*
2324 						 * Restore phase bits to 0 so an interrupted selection,
2325 						 * arbitration can resume.
2326 						 */
2327 						NCR5380_write(TARGET_COMMAND_REG, 0);
2328 
2329 						/* Enable reselect interrupts */
2330 						NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2331 						/* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2332 						/* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2333 						while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2334 							barrier();
2335 						return;
2336 					}
2337 					/*
2338 					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2339 					 * operation, in violation of the SCSI spec so we can safely
2340 					 * ignore SAVE/RESTORE pointers calls.
2341 					 *
2342 					 * Unfortunately, some disks violate the SCSI spec and
2343 					 * don't issue the required SAVE_POINTERS message before
2344 					 * disconnecting, and we have to break spec to remain
2345 					 * compatible.
2346 					 */
2347 				case SAVE_POINTERS:
2348 				case RESTORE_POINTERS:
2349 					/* Accept message by clearing ACK */
2350 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2351 					break;
2352 				case EXTENDED_MESSAGE:
2353 /*
2354  * Extended messages are sent in the following format :
2355  * Byte
2356  * 0            EXTENDED_MESSAGE == 1
2357  * 1            length (includes one byte for code, doesn't
2358  *              include first two bytes)
2359  * 2            code
2360  * 3..length+1  arguments
2361  *
2362  * Start the extended message buffer with the EXTENDED_MESSAGE
2363  * byte, since spi_print_msg() wants the whole thing.
2364  */
2365 					extended_msg[0] = EXTENDED_MESSAGE;
2366 					/* Accept first byte by clearing ACK */
2367 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2368 					dprintk(NDEBUG_EXTENDED, "scsi%d : receiving extended message\n", instance->host_no);
2369 
2370 					len = 2;
2371 					data = extended_msg + 1;
2372 					phase = PHASE_MSGIN;
2373 					NCR5380_transfer_pio(instance, &phase, &len, &data);
2374 
2375 					dprintk(NDEBUG_EXTENDED, "scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]);
2376 
2377 					if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2378 						/* Accept third byte by clearing ACK */
2379 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2380 						len = extended_msg[1] - 1;
2381 						data = extended_msg + 3;
2382 						phase = PHASE_MSGIN;
2383 
2384 						NCR5380_transfer_pio(instance, &phase, &len, &data);
2385 						dprintk(NDEBUG_EXTENDED, "scsi%d : message received, residual %d\n", instance->host_no, len);
2386 
2387 						switch (extended_msg[2]) {
2388 						case EXTENDED_SDTR:
2389 						case EXTENDED_WDTR:
2390 						case EXTENDED_MODIFY_DATA_POINTER:
2391 						case EXTENDED_EXTENDED_IDENTIFY:
2392 							tmp = 0;
2393 						}
2394 					} else if (len) {
2395 						printk("scsi%d: error receiving extended message\n", instance->host_no);
2396 						tmp = 0;
2397 					} else {
2398 						printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2399 						tmp = 0;
2400 					}
2401 					/* Fall through to reject message */
2402 
2403 					/*
2404 					 * If we get something weird that we aren't expecting,
2405 					 * reject it.
2406 					 */
2407 				default:
2408 					if (!tmp) {
2409 						printk("scsi%d: rejecting message ", instance->host_no);
2410 						spi_print_msg(extended_msg);
2411 						printk("\n");
2412 					} else if (tmp != EXTENDED_MESSAGE)
2413 						scmd_printk(KERN_INFO, cmd,
2414 							"rejecting unknown message %02x\n",tmp);
2415 					else
2416 						scmd_printk(KERN_INFO, cmd,
2417 							"rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2418 
2419 					msgout = MESSAGE_REJECT;
2420 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2421 					break;
2422 				}	/* switch (tmp) */
2423 				break;
2424 			case PHASE_MSGOUT:
2425 				len = 1;
2426 				data = &msgout;
2427 				hostdata->last_message = msgout;
2428 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2429 				if (msgout == ABORT) {
2430 					hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xFF));
2431 					hostdata->connected = NULL;
2432 					cmd->result = DID_ERROR << 16;
2433 					collect_stats(hostdata, cmd);
2434 					cmd->scsi_done(cmd);
2435 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2436 					return;
2437 				}
2438 				msgout = NOP;
2439 				break;
2440 			case PHASE_CMDOUT:
2441 				len = cmd->cmd_len;
2442 				data = cmd->cmnd;
2443 				/*
2444 				 * XXX for performance reasons, on machines with a
2445 				 * PSEUDO-DMA architecture we should probably
2446 				 * use the dma transfer function.
2447 				 */
2448 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2449 				if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2450 					NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2451 					dprintk(NDEBUG_USLEEP, "scsi%d : issued command, sleeping until %lu\n", instance->host_no, hostdata->time_expires);
2452 					return;
2453 				}
2454 				break;
2455 			case PHASE_STATIN:
2456 				len = 1;
2457 				data = &tmp;
2458 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2459 				cmd->SCp.Status = tmp;
2460 				break;
2461 			default:
2462 				printk("scsi%d : unknown phase\n", instance->host_no);
2463 				NCR5380_dprint(NDEBUG_ANY, instance);
2464 			}	/* switch(phase) */
2465 		}		/* if (tmp * SR_REQ) */
2466 		else {
2467 			/* RvC: go to sleep if polling time expired
2468 			 */
2469 			if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2470 				NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2471 				dprintk(NDEBUG_USLEEP, "scsi%d : poll timed out, sleeping until %lu\n", instance->host_no, hostdata->time_expires);
2472 				return;
2473 			}
2474 		}
2475 	}			/* while (1) */
2476 }
2477 
2478 /*
2479  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2480  *
2481  * Purpose : does reselection, initializing the instance->connected
2482  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2483  *      nexus has been reestablished,
2484  *
2485  * Inputs : instance - this instance of the NCR5380.
2486  *
2487  * Locks: io_request_lock held by caller if IRQ driven
2488  */
2489 
2490 static void NCR5380_reselect(struct Scsi_Host *instance) {
2491 	NCR5380_local_declare();
2492 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2493 	 instance->hostdata;
2494 	unsigned char target_mask;
2495 	unsigned char lun, phase;
2496 	int len;
2497 	unsigned char msg[3];
2498 	unsigned char *data;
2499 	Scsi_Cmnd *tmp = NULL, *prev;
2500 	int abort = 0;
2501 	NCR5380_setup(instance);
2502 
2503 	/*
2504 	 * Disable arbitration, etc. since the host adapter obviously
2505 	 * lost, and tell an interrupted NCR5380_select() to restart.
2506 	 */
2507 
2508 	NCR5380_write(MODE_REG, MR_BASE);
2509 	hostdata->restart_select = 1;
2510 
2511 	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2512 	dprintk(NDEBUG_SELECTION, "scsi%d : reselect\n", instance->host_no);
2513 
2514 	/*
2515 	 * At this point, we have detected that our SCSI ID is on the bus,
2516 	 * SEL is true and BSY was false for at least one bus settle delay
2517 	 * (400 ns).
2518 	 *
2519 	 * We must assert BSY ourselves, until the target drops the SEL
2520 	 * signal.
2521 	 */
2522 
2523 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2524 
2525 	/* FIXME: timeout too long, must fail to workqueue */
2526 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2527 		abort = 1;
2528 
2529 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2530 
2531 	/*
2532 	 * Wait for target to go into MSGIN.
2533 	 * FIXME: timeout needed and fail to work queeu
2534 	 */
2535 
2536 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2537 		abort = 1;
2538 
2539 	len = 1;
2540 	data = msg;
2541 	phase = PHASE_MSGIN;
2542 	NCR5380_transfer_pio(instance, &phase, &len, &data);
2543 
2544 	if (!(msg[0] & 0x80)) {
2545 		printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2546 		spi_print_msg(msg);
2547 		abort = 1;
2548 	} else {
2549 		/* Accept message by clearing ACK */
2550 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2551 		lun = (msg[0] & 0x07);
2552 
2553 		/*
2554 		 * We need to add code for SCSI-II to track which devices have
2555 		 * I_T_L_Q nexuses established, and which have simple I_T_L
2556 		 * nexuses so we can chose to do additional data transfer.
2557 		 */
2558 
2559 		/*
2560 		 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2561 		 * just reestablished, and remove it from the disconnected queue.
2562 		 */
2563 
2564 
2565 		for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2566 			if ((target_mask == (1 << tmp->device->id)) && (lun == (u8)tmp->device->lun)
2567 			    ) {
2568 				if (prev) {
2569 					REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2570 					prev->host_scribble = tmp->host_scribble;
2571 				} else {
2572 					REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2573 					hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2574 				}
2575 				tmp->host_scribble = NULL;
2576 				break;
2577 			}
2578 		if (!tmp) {
2579 			printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2580 			/*
2581 			 * Since we have an established nexus that we can't do anything with,
2582 			 * we must abort it.
2583 			 */
2584 			abort = 1;
2585 		}
2586 	}
2587 
2588 	if (abort) {
2589 		do_abort(instance);
2590 	} else {
2591 		hostdata->connected = tmp;
2592 		dprintk(NDEBUG_RESELECTION, "scsi%d : nexus established, target = %d, lun = %llu, tag = %d\n", instance->host_no, tmp->device->id, tmp->device->lun, tmp->tag);
2593 	}
2594 }
2595 
2596 /*
2597  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2598  *
2599  * Purpose : called by interrupt handler when DMA finishes or a phase
2600  *      mismatch occurs (which would finish the DMA transfer).
2601  *
2602  * Inputs : instance - this instance of the NCR5380.
2603  *
2604  * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2605  *      nexus has been reestablished, on failure NULL is returned.
2606  */
2607 
2608 #ifdef REAL_DMA
2609 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2610 	NCR5380_local_declare();
2611 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2612 	int transferred;
2613 	NCR5380_setup(instance);
2614 
2615 	/*
2616 	 * XXX this might not be right.
2617 	 *
2618 	 * Wait for final byte to transfer, ie wait for ACK to go false.
2619 	 *
2620 	 * We should use the Last Byte Sent bit, unfortunately this is
2621 	 * not available on the 5380/5381 (only the various CMOS chips)
2622 	 *
2623 	 * FIXME: timeout, and need to handle long timeout/irq case
2624 	 */
2625 
2626 	NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2627 
2628 	NCR5380_write(MODE_REG, MR_BASE);
2629 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2630 
2631 	/*
2632 	 * The only places we should see a phase mismatch and have to send
2633 	 * data from the same set of pointers will be the data transfer
2634 	 * phases.  So, residual, requested length are only important here.
2635 	 */
2636 
2637 	if (!(hostdata->connected->SCp.phase & SR_CD)) {
2638 		transferred = instance->dmalen - NCR5380_dma_residual();
2639 		hostdata->connected->SCp.this_residual -= transferred;
2640 		hostdata->connected->SCp.ptr += transferred;
2641 	}
2642 }
2643 #endif				/* def REAL_DMA */
2644 
2645 /*
2646  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2647  *
2648  * Purpose : abort a command
2649  *
2650  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2651  *      host byte of the result field to, if zero DID_ABORTED is
2652  *      used.
2653  *
2654  * Returns : 0 - success, -1 on failure.
2655  *
2656  *	XXX - there is no way to abort the command that is currently
2657  *	connected, you have to wait for it to complete.  If this is
2658  *	a problem, we could implement longjmp() / setjmp(), setjmp()
2659  *	called where the loop started in NCR5380_main().
2660  *
2661  * Locks: host lock taken by caller
2662  */
2663 
2664 static int NCR5380_abort(Scsi_Cmnd * cmd) {
2665 	NCR5380_local_declare();
2666 	struct Scsi_Host *instance = cmd->device->host;
2667 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2668 	Scsi_Cmnd *tmp, **prev;
2669 
2670 	printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2671 	scsi_print_command(cmd);
2672 
2673 	NCR5380_print_status(instance);
2674 
2675 	NCR5380_setup(instance);
2676 
2677 	dprintk(NDEBUG_ABORT, "scsi%d : abort called\n", instance->host_no);
2678 	dprintk(NDEBUG_ABORT, "        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG));
2679 
2680 #if 0
2681 /*
2682  * Case 1 : If the command is the currently executing command,
2683  * we'll set the aborted flag and return control so that
2684  * information transfer routine can exit cleanly.
2685  */
2686 
2687 	if (hostdata->connected == cmd) {
2688 		dprintk(NDEBUG_ABORT, "scsi%d : aborting connected command\n", instance->host_no);
2689 		hostdata->aborted = 1;
2690 /*
2691  * We should perform BSY checking, and make sure we haven't slipped
2692  * into BUS FREE.
2693  */
2694 
2695 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2696 /*
2697  * Since we can't change phases until we've completed the current
2698  * handshake, we have to source or sink a byte of data if the current
2699  * phase is not MSGOUT.
2700  */
2701 
2702 /*
2703  * Return control to the executing NCR drive so we can clear the
2704  * aborted flag and get back into our main loop.
2705  */
2706 
2707 		return 0;
2708 	}
2709 #endif
2710 
2711 /*
2712  * Case 2 : If the command hasn't been issued yet, we simply remove it
2713  *          from the issue queue.
2714  */
2715 
2716 	dprintk(NDEBUG_ABORT, "scsi%d : abort going into loop.\n", instance->host_no);
2717 	for (prev = (Scsi_Cmnd **) & (hostdata->issue_queue), tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp; prev = (Scsi_Cmnd **) & (tmp->host_scribble), tmp = (Scsi_Cmnd *) tmp->host_scribble)
2718 		if (cmd == tmp) {
2719 			REMOVE(5, *prev, tmp, tmp->host_scribble);
2720 			(*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2721 			tmp->host_scribble = NULL;
2722 			tmp->result = DID_ABORT << 16;
2723 			dprintk(NDEBUG_ABORT, "scsi%d : abort removed command from issue queue.\n", instance->host_no);
2724 			tmp->scsi_done(tmp);
2725 			return SUCCESS;
2726 		}
2727 #if (NDEBUG  & NDEBUG_ABORT)
2728 	/* KLL */
2729 		else if (prev == tmp)
2730 			printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2731 #endif
2732 
2733 /*
2734  * Case 3 : If any commands are connected, we're going to fail the abort
2735  *          and let the high level SCSI driver retry at a later time or
2736  *          issue a reset.
2737  *
2738  *          Timeouts, and therefore aborted commands, will be highly unlikely
2739  *          and handling them cleanly in this situation would make the common
2740  *          case of noresets less efficient, and would pollute our code.  So,
2741  *          we fail.
2742  */
2743 
2744 	if (hostdata->connected) {
2745 		dprintk(NDEBUG_ABORT, "scsi%d : abort failed, command connected.\n", instance->host_no);
2746 		return FAILED;
2747 	}
2748 /*
2749  * Case 4: If the command is currently disconnected from the bus, and
2750  *      there are no connected commands, we reconnect the I_T_L or
2751  *      I_T_L_Q nexus associated with it, go into message out, and send
2752  *      an abort message.
2753  *
2754  * This case is especially ugly. In order to reestablish the nexus, we
2755  * need to call NCR5380_select().  The easiest way to implement this
2756  * function was to abort if the bus was busy, and let the interrupt
2757  * handler triggered on the SEL for reselect take care of lost arbitrations
2758  * where necessary, meaning interrupts need to be enabled.
2759  *
2760  * When interrupts are enabled, the queues may change - so we
2761  * can't remove it from the disconnected queue before selecting it
2762  * because that could cause a failure in hashing the nexus if that
2763  * device reselected.
2764  *
2765  * Since the queues may change, we can't use the pointers from when we
2766  * first locate it.
2767  *
2768  * So, we must first locate the command, and if NCR5380_select()
2769  * succeeds, then issue the abort, relocate the command and remove
2770  * it from the disconnected queue.
2771  */
2772 
2773 	for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2774 		if (cmd == tmp) {
2775 			dprintk(NDEBUG_ABORT, "scsi%d : aborting disconnected command.\n", instance->host_no);
2776 
2777 			if (NCR5380_select(instance, cmd, (int) cmd->tag))
2778 				return FAILED;
2779 			dprintk(NDEBUG_ABORT, "scsi%d : nexus reestablished.\n", instance->host_no);
2780 
2781 			do_abort(instance);
2782 
2783 			for (prev = (Scsi_Cmnd **) & (hostdata->disconnected_queue), tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; prev = (Scsi_Cmnd **) & (tmp->host_scribble), tmp = (Scsi_Cmnd *) tmp->host_scribble)
2784 				if (cmd == tmp) {
2785 					REMOVE(5, *prev, tmp, tmp->host_scribble);
2786 					*prev = (Scsi_Cmnd *) tmp->host_scribble;
2787 					tmp->host_scribble = NULL;
2788 					tmp->result = DID_ABORT << 16;
2789 					tmp->scsi_done(tmp);
2790 					return SUCCESS;
2791 				}
2792 		}
2793 /*
2794  * Case 5 : If we reached this point, the command was not found in any of
2795  *          the queues.
2796  *
2797  * We probably reached this point because of an unlikely race condition
2798  * between the command completing successfully and the abortion code,
2799  * so we won't panic, but we will notify the user in case something really
2800  * broke.
2801  */
2802 	printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2803 			"         before abortion\n", instance->host_no);
2804 	return FAILED;
2805 }
2806 
2807 
2808 /*
2809  * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2810  *
2811  * Purpose : reset the SCSI bus.
2812  *
2813  * Returns : SUCCESS
2814  *
2815  * Locks: host lock taken by caller
2816  */
2817 
2818 static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2819 {
2820 	struct Scsi_Host *instance = cmd->device->host;
2821 
2822 	NCR5380_local_declare();
2823 	NCR5380_setup(instance);
2824 	NCR5380_print_status(instance);
2825 
2826 	spin_lock_irq(instance->host_lock);
2827 	do_reset(instance);
2828 	spin_unlock_irq(instance->host_lock);
2829 
2830 	return SUCCESS;
2831 }
2832