xref: /linux/drivers/scsi/NCR5380.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
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  * $Log: NCR5380.c,v $
31 
32  * Revision 1.10 1998/9/2	Alan Cox
33  *				(alan@redhat.com)
34  * Fixed up the timer lockups reported so far. Things still suck. Looking
35  * forward to 2.3 and per device request queues. Then it'll be possible to
36  * SMP thread this beast and improve life no end.
37 
38  * Revision 1.9  1997/7/27	Ronald van Cuijlenborg
39  *				(ronald.van.cuijlenborg@tip.nl or nutty@dds.nl)
40  * (hopefully) fixed and enhanced USLEEP
41  * added support for DTC3181E card (for Mustek scanner)
42  *
43 
44  * Revision 1.8			Ingmar Baumgart
45  *				(ingmar@gonzo.schwaben.de)
46  * added support for NCR53C400a card
47  *
48 
49  * Revision 1.7  1996/3/2       Ray Van Tassle (rayvt@comm.mot.com)
50  * added proc_info
51  * added support needed for DTC 3180/3280
52  * fixed a couple of bugs
53  *
54 
55  * Revision 1.5  1994/01/19  09:14:57  drew
56  * Fixed udelay() hack that was being used on DATAOUT phases
57  * instead of a proper wait for the final handshake.
58  *
59  * Revision 1.4  1994/01/19  06:44:25  drew
60  * *** empty log message ***
61  *
62  * Revision 1.3  1994/01/19  05:24:40  drew
63  * Added support for TCR LAST_BYTE_SENT bit.
64  *
65  * Revision 1.2  1994/01/15  06:14:11  drew
66  * REAL DMA support, bug fixes.
67  *
68  * Revision 1.1  1994/01/15  06:00:54  drew
69  * Initial revision
70  *
71  */
72 
73 /*
74  * Further development / testing that should be done :
75  * 1.  Cleanup the NCR5380_transfer_dma function and DMA operation complete
76  *     code so that everything does the same thing that's done at the
77  *     end of a pseudo-DMA read operation.
78  *
79  * 2.  Fix REAL_DMA (interrupt driven, polled works fine) -
80  *     basically, transfer size needs to be reduced by one
81  *     and the last byte read as is done with PSEUDO_DMA.
82  *
83  * 4.  Test SCSI-II tagged queueing (I have no devices which support
84  *      tagged queueing)
85  *
86  * 5.  Test linked command handling code after Eric is ready with
87  *      the high level code.
88  */
89 #include <scsi/scsi_dbg.h>
90 
91 #ifndef NDEBUG
92 #define NDEBUG 0
93 #endif
94 #ifndef NDEBUG_ABORT
95 #define NDEBUG_ABORT 0
96 #endif
97 
98 #if (NDEBUG & NDEBUG_LISTS)
99 #define LIST(x,y) {printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); }
100 #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); }
101 #else
102 #define LIST(x,y)
103 #define REMOVE(w,x,y,z)
104 #endif
105 
106 #ifndef notyet
107 #undef LINKED
108 #undef REAL_DMA
109 #endif
110 
111 #ifdef REAL_DMA_POLL
112 #undef READ_OVERRUNS
113 #define READ_OVERRUNS
114 #endif
115 
116 #ifdef BOARD_REQUIRES_NO_DELAY
117 #define io_recovery_delay(x)
118 #else
119 #define io_recovery_delay(x)	udelay(x)
120 #endif
121 
122 /*
123  * Design
124  *
125  * This is a generic 5380 driver.  To use it on a different platform,
126  * one simply writes appropriate system specific macros (ie, data
127  * transfer - some PC's will use the I/O bus, 68K's must use
128  * memory mapped) and drops this file in their 'C' wrapper.
129  *
130  * (Note from hch:  unfortunately it was not enough for the different
131  * m68k folks and instead of improving this driver they copied it
132  * and hacked it up for their needs.  As a consequence they lost
133  * most updates to this driver.  Maybe someone will fix all these
134  * drivers to use a common core one day..)
135  *
136  * As far as command queueing, two queues are maintained for
137  * each 5380 in the system - commands that haven't been issued yet,
138  * and commands that are currently executing.  This means that an
139  * unlimited number of commands may be queued, letting
140  * more commands propagate from the higher driver levels giving higher
141  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
142  * allowing multiple commands to propagate all the way to a SCSI-II device
143  * while a command is already executing.
144  *
145  *
146  * Issues specific to the NCR5380 :
147  *
148  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
149  * piece of hardware that requires you to sit in a loop polling for
150  * the REQ signal as long as you are connected.  Some devices are
151  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
152  * while doing long seek operations.
153  *
154  * The workaround for this is to keep track of devices that have
155  * disconnected.  If the device hasn't disconnected, for commands that
156  * should disconnect, we do something like
157  *
158  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
159  *
160  * Some tweaking of N and M needs to be done.  An algorithm based
161  * on "time to data" would give the best results as long as short time
162  * to datas (ie, on the same track) were considered, however these
163  * broken devices are the exception rather than the rule and I'd rather
164  * spend my time optimizing for the normal case.
165  *
166  * Architecture :
167  *
168  * At the heart of the design is a coroutine, NCR5380_main,
169  * which is started from a workqueue for each NCR5380 host in the
170  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
171  * removing the commands from the issue queue and calling
172  * NCR5380_select() if a nexus is not established.
173  *
174  * Once a nexus is established, the NCR5380_information_transfer()
175  * phase goes through the various phases as instructed by the target.
176  * if the target goes into MSG IN and sends a DISCONNECT message,
177  * the command structure is placed into the per instance disconnected
178  * queue, and NCR5380_main tries to find more work.  If the target is
179  * idle for too long, the system will try to sleep.
180  *
181  * If a command has disconnected, eventually an interrupt will trigger,
182  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
183  * to reestablish a nexus.  This will run main if necessary.
184  *
185  * On command termination, the done function will be called as
186  * appropriate.
187  *
188  * SCSI pointers are maintained in the SCp field of SCSI command
189  * structures, being initialized after the command is connected
190  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
191  * Note that in violation of the standard, an implicit SAVE POINTERS operation
192  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
193  */
194 
195 /*
196  * Using this file :
197  * This file a skeleton Linux SCSI driver for the NCR 5380 series
198  * of chips.  To use it, you write an architecture specific functions
199  * and macros and include this file in your driver.
200  *
201  * These macros control options :
202  * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
203  *      defined.
204  *
205  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
206  *      for commands that return with a CHECK CONDITION status.
207  *
208  * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
209  *      transceivers.
210  *
211  * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
212  *      override-configure an IRQ.
213  *
214  * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
215  *      bytes at a time.  Since interrupts are disabled by default during
216  *      these transfers, we might need this to give reasonable interrupt
217  *      service time if the transfer size gets too large.
218  *
219  * LINKED - if defined, linked commands are supported.
220  *
221  * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
222  *
223  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
224  *
225  * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
226  *      rely on phase mismatch and EOP interrupts to determine end
227  *      of phase.
228  *
229  * UNSAFE - leave interrupts enabled during pseudo-DMA transfers.  You
230  *          only really want to use this if you're having a problem with
231  *          dropped characters during high speed communications, and even
232  *          then, you're going to be better off twiddling with transfersize
233  *          in the high level code.
234  *
235  * Defaults for these will be provided although the user may want to adjust
236  * these to allocate CPU resources to the SCSI driver or "real" code.
237  *
238  * USLEEP_SLEEP - amount of time, in jiffies, to sleep
239  *
240  * USLEEP_POLL - amount of time, in jiffies, to poll
241  *
242  * These macros MUST be defined :
243  * NCR5380_local_declare() - declare any local variables needed for your
244  *      transfer routines.
245  *
246  * NCR5380_setup(instance) - initialize any local variables needed from a given
247  *      instance of the host adapter for NCR5380_{read,write,pread,pwrite}
248  *
249  * NCR5380_read(register)  - read from the specified register
250  *
251  * NCR5380_write(register, value) - write to the specific register
252  *
253  * NCR5380_implementation_fields  - additional fields needed for this
254  *      specific implementation of the NCR5380
255  *
256  * Either real DMA *or* pseudo DMA may be implemented
257  * REAL functions :
258  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
259  * Note that the DMA setup functions should return the number of bytes
260  *      that they were able to program the controller for.
261  *
262  * Also note that generic i386/PC versions of these macros are
263  *      available as NCR5380_i386_dma_write_setup,
264  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
265  *
266  * NCR5380_dma_write_setup(instance, src, count) - initialize
267  * NCR5380_dma_read_setup(instance, dst, count) - initialize
268  * NCR5380_dma_residual(instance); - residual count
269  *
270  * PSEUDO functions :
271  * NCR5380_pwrite(instance, src, count)
272  * NCR5380_pread(instance, dst, count);
273  *
274  * The generic driver is initialized by calling NCR5380_init(instance),
275  * after setting the appropriate host specific fields and ID.  If the
276  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
277  * possible) function may be used.
278  */
279 
280 static int do_abort(struct Scsi_Host *host);
281 static void do_reset(struct Scsi_Host *host);
282 
283 /*
284  *	initialize_SCp		-	init the scsi pointer field
285  *	@cmd: command block to set up
286  *
287  *	Set up the internal fields in the SCSI command.
288  */
289 
290 static __inline__ void initialize_SCp(Scsi_Cmnd * cmd)
291 {
292 	/*
293 	 * Initialize the Scsi Pointer field so that all of the commands in the
294 	 * various queues are valid.
295 	 */
296 
297 	if (cmd->use_sg) {
298 		cmd->SCp.buffer = (struct scatterlist *) cmd->buffer;
299 		cmd->SCp.buffers_residual = cmd->use_sg - 1;
300 		cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
301 			       cmd->SCp.buffer->offset;
302 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
303 	} else {
304 		cmd->SCp.buffer = NULL;
305 		cmd->SCp.buffers_residual = 0;
306 		cmd->SCp.ptr = (char *) cmd->request_buffer;
307 		cmd->SCp.this_residual = cmd->request_bufflen;
308 	}
309 }
310 
311 /**
312  *	NCR5380_poll_politely	-	wait for NCR5380 status bits
313  *	@instance: controller to poll
314  *	@reg: 5380 register to poll
315  *	@bit: Bitmask to check
316  *	@val: Value required to exit
317  *
318  *	Polls the NCR5380 in a reasonably efficient manner waiting for
319  *	an event to occur, after a short quick poll we begin giving the
320  *	CPU back in non IRQ contexts
321  *
322  *	Returns the value of the register or a negative error code.
323  */
324 
325 static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
326 {
327 	NCR5380_local_declare();
328 	int n = 500;		/* At about 8uS a cycle for the cpu access */
329 	unsigned long end = jiffies + t;
330 	int r;
331 
332 	NCR5380_setup(instance);
333 
334 	while( n-- > 0)
335 	{
336 		r = NCR5380_read(reg);
337 		if((r & bit) == val)
338 			return 0;
339 		cpu_relax();
340 	}
341 
342 	/* t time yet ? */
343 	while(time_before(jiffies, end))
344 	{
345 		r = NCR5380_read(reg);
346 		if((r & bit) == val)
347 			return 0;
348 		if(!in_interrupt())
349 			yield();
350 		else
351 			cpu_relax();
352 	}
353 	return -ETIMEDOUT;
354 }
355 
356 static struct {
357 	unsigned char value;
358 	const char *name;
359 } phases[] = {
360 	{PHASE_DATAOUT, "DATAOUT"},
361 	{PHASE_DATAIN, "DATAIN"},
362 	{PHASE_CMDOUT, "CMDOUT"},
363 	{PHASE_STATIN, "STATIN"},
364 	{PHASE_MSGOUT, "MSGOUT"},
365 	{PHASE_MSGIN, "MSGIN"},
366 	{PHASE_UNKNOWN, "UNKNOWN"}
367 };
368 
369 #if NDEBUG
370 static struct {
371 	unsigned char mask;
372 	const char *name;
373 } signals[] = {
374 	{SR_DBP, "PARITY"},
375 	{SR_RST, "RST"},
376 	{SR_BSY, "BSY"},
377 	{SR_REQ, "REQ"},
378 	{SR_MSG, "MSG"},
379 	{SR_CD, "CD"},
380 	{SR_IO, "IO"},
381 	{SR_SEL, "SEL"},
382 	{0, NULL}
383 },
384 basrs[] = {
385 	{BASR_ATN, "ATN"},
386 	{BASR_ACK, "ACK"},
387 	{0, NULL}
388 },
389 icrs[] = {
390 	{ICR_ASSERT_RST, "ASSERT RST"},
391 	{ICR_ASSERT_ACK, "ASSERT ACK"},
392 	{ICR_ASSERT_BSY, "ASSERT BSY"},
393 	{ICR_ASSERT_SEL, "ASSERT SEL"},
394 	{ICR_ASSERT_ATN, "ASSERT ATN"},
395 	{ICR_ASSERT_DATA, "ASSERT DATA"},
396 	{0, NULL}
397 },
398 mrs[] = {
399 	{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
400 	{MR_TARGET, "MODE TARGET"},
401 	{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
402 	{MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
403 	{MR_MONITOR_BSY, "MODE MONITOR BSY"},
404 	{MR_DMA_MODE, "MODE DMA"},
405 	{MR_ARBITRATE, "MODE ARBITRATION"},
406 	{0, NULL}
407 };
408 
409 /**
410  *	NCR5380_print	-	print scsi bus signals
411  *	@instance:	adapter state to dump
412  *
413  *	Print the SCSI bus signals for debugging purposes
414  *
415  *	Locks: caller holds hostdata lock (not essential)
416  */
417 
418 static void NCR5380_print(struct Scsi_Host *instance)
419 {
420 	NCR5380_local_declare();
421 	unsigned char status, data, basr, mr, icr, i;
422 	NCR5380_setup(instance);
423 
424 	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
425 	status = NCR5380_read(STATUS_REG);
426 	mr = NCR5380_read(MODE_REG);
427 	icr = NCR5380_read(INITIATOR_COMMAND_REG);
428 	basr = NCR5380_read(BUS_AND_STATUS_REG);
429 
430 	printk("STATUS_REG: %02x ", status);
431 	for (i = 0; signals[i].mask; ++i)
432 		if (status & signals[i].mask)
433 			printk(",%s", signals[i].name);
434 	printk("\nBASR: %02x ", basr);
435 	for (i = 0; basrs[i].mask; ++i)
436 		if (basr & basrs[i].mask)
437 			printk(",%s", basrs[i].name);
438 	printk("\nICR: %02x ", icr);
439 	for (i = 0; icrs[i].mask; ++i)
440 		if (icr & icrs[i].mask)
441 			printk(",%s", icrs[i].name);
442 	printk("\nMODE: %02x ", mr);
443 	for (i = 0; mrs[i].mask; ++i)
444 		if (mr & mrs[i].mask)
445 			printk(",%s", mrs[i].name);
446 	printk("\n");
447 }
448 
449 
450 /*
451  *	NCR5380_print_phase	-	show SCSI phase
452  *	@instance: adapter to dump
453  *
454  * 	Print the current SCSI phase for debugging purposes
455  *
456  *	Locks: none
457  */
458 
459 static void NCR5380_print_phase(struct Scsi_Host *instance)
460 {
461 	NCR5380_local_declare();
462 	unsigned char status;
463 	int i;
464 	NCR5380_setup(instance);
465 
466 	status = NCR5380_read(STATUS_REG);
467 	if (!(status & SR_REQ))
468 		printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
469 	else {
470 		for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
471 		printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
472 	}
473 }
474 #endif
475 
476 /*
477  * These need tweaking, and would probably work best as per-device
478  * flags initialized differently for disk, tape, cd, etc devices.
479  * People with broken devices are free to experiment as to what gives
480  * the best results for them.
481  *
482  * USLEEP_SLEEP should be a minimum seek time.
483  *
484  * USLEEP_POLL should be a maximum rotational latency.
485  */
486 #ifndef USLEEP_SLEEP
487 /* 20 ms (reasonable hard disk speed) */
488 #define USLEEP_SLEEP (20*HZ/1000)
489 #endif
490 /* 300 RPM (floppy speed) */
491 #ifndef USLEEP_POLL
492 #define USLEEP_POLL (200*HZ/1000)
493 #endif
494 #ifndef USLEEP_WAITLONG
495 /* RvC: (reasonable time to wait on select error) */
496 #define USLEEP_WAITLONG USLEEP_SLEEP
497 #endif
498 
499 /*
500  * Function : int should_disconnect (unsigned char cmd)
501  *
502  * Purpose : decide weather a command would normally disconnect or
503  *      not, since if it won't disconnect we should go to sleep.
504  *
505  * Input : cmd - opcode of SCSI command
506  *
507  * Returns : DISCONNECT_LONG if we should disconnect for a really long
508  *      time (ie always, sleep, look for REQ active, sleep),
509  *      DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
510  *      time-to-data delay, DISCONNECT_NONE if this command would return
511  *      immediately.
512  *
513  *      Future sleep algorithms based on time to data can exploit
514  *      something like this so they can differentiate between "normal"
515  *      (ie, read, write, seek) and unusual commands (ie, * format).
516  *
517  * Note : We don't deal with commands that handle an immediate disconnect,
518  *
519  */
520 
521 static int should_disconnect(unsigned char cmd)
522 {
523 	switch (cmd) {
524 	case READ_6:
525 	case WRITE_6:
526 	case SEEK_6:
527 	case READ_10:
528 	case WRITE_10:
529 	case SEEK_10:
530 		return DISCONNECT_TIME_TO_DATA;
531 	case FORMAT_UNIT:
532 	case SEARCH_HIGH:
533 	case SEARCH_LOW:
534 	case SEARCH_EQUAL:
535 		return DISCONNECT_LONG;
536 	default:
537 		return DISCONNECT_NONE;
538 	}
539 }
540 
541 static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
542 {
543 	hostdata->time_expires = jiffies + timeout;
544 	schedule_delayed_work(&hostdata->coroutine, timeout);
545 }
546 
547 
548 static int probe_irq __initdata = 0;
549 
550 /**
551  *	probe_intr	-	helper for IRQ autoprobe
552  *	@irq: interrupt number
553  *	@dev_id: unused
554  *	@regs: unused
555  *
556  *	Set a flag to indicate the IRQ in question was received. This is
557  *	used by the IRQ probe code.
558  */
559 
560 static irqreturn_t __init probe_intr(int irq, void *dev_id,
561 					struct pt_regs *regs)
562 {
563 	probe_irq = irq;
564 	return IRQ_HANDLED;
565 }
566 
567 /**
568  *	NCR5380_probe_irq	-	find the IRQ of an NCR5380
569  *	@instance: NCR5380 controller
570  *	@possible: bitmask of ISA IRQ lines
571  *
572  *	Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
573  *	and then looking to see what interrupt actually turned up.
574  *
575  *	Locks: none, irqs must be enabled on entry
576  */
577 
578 static int __init NCR5380_probe_irq(struct Scsi_Host *instance, int possible)
579 {
580 	NCR5380_local_declare();
581 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
582 	unsigned long timeout;
583 	int trying_irqs, i, mask;
584 	NCR5380_setup(instance);
585 
586 	for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
587 		if ((mask & possible) && (request_irq(i, &probe_intr, SA_INTERRUPT, "NCR-probe", NULL) == 0))
588 			trying_irqs |= mask;
589 
590 	timeout = jiffies + (250 * HZ / 1000);
591 	probe_irq = SCSI_IRQ_NONE;
592 
593 	/*
594 	 * A interrupt is triggered whenever BSY = false, SEL = true
595 	 * and a bit set in the SELECT_ENABLE_REG is asserted on the
596 	 * SCSI bus.
597 	 *
598 	 * Note that the bus is only driven when the phase control signals
599 	 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
600 	 * to zero.
601 	 */
602 
603 	NCR5380_write(TARGET_COMMAND_REG, 0);
604 	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
605 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
606 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
607 
608 	while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
609 	{
610 		set_current_state(TASK_UNINTERRUPTIBLE);
611 		schedule_timeout(1);
612 	}
613 
614 	NCR5380_write(SELECT_ENABLE_REG, 0);
615 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
616 
617 	for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
618 		if (trying_irqs & mask)
619 			free_irq(i, NULL);
620 
621 	return probe_irq;
622 }
623 
624 /**
625  *	NCR58380_print_options	-	show options
626  *	@instance: unused for now
627  *
628  *	Called by probe code indicating the NCR5380 driver options that
629  *	were selected. At some point this will switch to runtime options
630  *	read from the adapter in question
631  *
632  *	Locks: none
633  */
634 
635 static void __init NCR5380_print_options(struct Scsi_Host *instance)
636 {
637 	printk(" generic options"
638 #ifdef AUTOPROBE_IRQ
639 	       " AUTOPROBE_IRQ"
640 #endif
641 #ifdef AUTOSENSE
642 	       " AUTOSENSE"
643 #endif
644 #ifdef DIFFERENTIAL
645 	       " DIFFERENTIAL"
646 #endif
647 #ifdef REAL_DMA
648 	       " REAL DMA"
649 #endif
650 #ifdef REAL_DMA_POLL
651 	       " REAL DMA POLL"
652 #endif
653 #ifdef PARITY
654 	       " PARITY"
655 #endif
656 #ifdef PSEUDO_DMA
657 	       " PSEUDO DMA"
658 #endif
659 #ifdef UNSAFE
660 	       " UNSAFE "
661 #endif
662 	    );
663 	printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
664 	printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
665 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
666 		printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
667 	}
668 }
669 
670 /**
671  *	NCR5380_print_status 	-	dump controller info
672  *	@instance: controller to dump
673  *
674  *	Print commands in the various queues, called from NCR5380_abort
675  *	and NCR5380_debug to aid debugging.
676  *
677  *	Locks: called functions disable irqs
678  */
679 
680 static void NCR5380_print_status(struct Scsi_Host *instance)
681 {
682 	NCR5380_dprint(NDEBUG_ANY, instance);
683 	NCR5380_dprint_phase(NDEBUG_ANY, instance);
684 }
685 
686 /******************************************/
687 /*
688  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
689  *
690  * *buffer: I/O buffer
691  * **start: if inout == FALSE pointer into buffer where user read should start
692  * offset: current offset
693  * length: length of buffer
694  * hostno: Scsi_Host host_no
695  * inout: TRUE - user is writing; FALSE - user is reading
696  *
697  * Return the number of bytes read from or written
698  */
699 
700 #undef SPRINTF
701 #define SPRINTF(args...) do { if(pos < buffer + length-80) pos += sprintf(pos, ## args); } while(0)
702 static
703 char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length);
704 static
705 char *lprint_command(unsigned char *cmd, char *pos, char *buffer, int len);
706 static
707 char *lprint_opcode(int opcode, char *pos, char *buffer, int length);
708 
709 static
710 int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer, char **start, off_t offset, int length, int inout)
711 {
712 	char *pos = buffer;
713 	struct NCR5380_hostdata *hostdata;
714 	Scsi_Cmnd *ptr;
715 
716 	hostdata = (struct NCR5380_hostdata *) instance->hostdata;
717 
718 	if (inout) {		/* Has data been written to the file ? */
719 #ifdef DTC_PUBLIC_RELEASE
720 		dtc_wmaxi = dtc_maxi = 0;
721 #endif
722 #ifdef PAS16_PUBLIC_RELEASE
723 		pas_wmaxi = pas_maxi = 0;
724 #endif
725 		return (-ENOSYS);	/* Currently this is a no-op */
726 	}
727 	SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
728 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
729 		SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
730 #ifdef DTC_PUBLIC_RELEASE
731 	SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
732 #endif
733 #ifdef T128_PUBLIC_RELEASE
734 	SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
735 #endif
736 #ifdef GENERIC_NCR5380_PUBLIC_RELEASE
737 	SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
738 #endif
739 #ifdef PAS16_PUBLIC_RELEASE
740 	SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
741 #endif
742 
743 	SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
744 	SPRINTF("io_port: %04x      ", (int) instance->io_port);
745 	if (instance->irq == SCSI_IRQ_NONE)
746 		SPRINTF("IRQ: None.\n");
747 	else
748 		SPRINTF("IRQ: %d.\n", instance->irq);
749 
750 #ifdef DTC_PUBLIC_RELEASE
751 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
752 #endif
753 #ifdef PAS16_PUBLIC_RELEASE
754 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
755 #endif
756 	spin_lock_irq(instance->host_lock);
757 	if (!hostdata->connected)
758 		SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
759 	else
760 		pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, pos, buffer, length);
761 	SPRINTF("scsi%d: issue_queue\n", instance->host_no);
762 	for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
763 		pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
764 
765 	SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
766 	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
767 		pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
768 	spin_unlock_irq(instance->host_lock);
769 
770 	*start = buffer;
771 	if (pos - buffer < offset)
772 		return 0;
773 	else if (pos - buffer - offset < length)
774 		return pos - buffer - offset;
775 	return length;
776 }
777 
778 static char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length)
779 {
780 	SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
781 	SPRINTF("        command = ");
782 	pos = lprint_command(cmd->cmnd, pos, buffer, length);
783 	return (pos);
784 }
785 
786 static char *lprint_command(unsigned char *command, char *pos, char *buffer, int length)
787 {
788 	int i, s;
789 	pos = lprint_opcode(command[0], pos, buffer, length);
790 	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
791 		SPRINTF("%02x ", command[i]);
792 	SPRINTF("\n");
793 	return (pos);
794 }
795 
796 static char *lprint_opcode(int opcode, char *pos, char *buffer, int length)
797 {
798 	SPRINTF("%2d (0x%02x)", opcode, opcode);
799 	return (pos);
800 }
801 
802 
803 /**
804  *	NCR5380_init	-	initialise an NCR5380
805  *	@instance: adapter to configure
806  *	@flags: control flags
807  *
808  *	Initializes *instance and corresponding 5380 chip,
809  *      with flags OR'd into the initial flags value.
810  *
811  *	Notes : I assume that the host, hostno, and id bits have been
812  *      set correctly.  I don't care about the irq and other fields.
813  *
814  *	Returns 0 for success
815  *
816  *	Locks: interrupts must be enabled when we are called
817  */
818 
819 static int __devinit NCR5380_init(struct Scsi_Host *instance, int flags)
820 {
821 	NCR5380_local_declare();
822 	int i, pass;
823 	unsigned long timeout;
824 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
825 
826 	if(in_interrupt())
827 		printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
828 	/*
829 	 * On NCR53C400 boards, NCR5380 registers are mapped 8 past
830 	 * the base address.
831 	 */
832 
833 #ifdef NCR53C400
834 	if (flags & FLAG_NCR53C400)
835 		instance->NCR5380_instance_name += NCR53C400_address_adjust;
836 #endif
837 
838 	NCR5380_setup(instance);
839 
840 	hostdata->aborted = 0;
841 	hostdata->id_mask = 1 << instance->this_id;
842 	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
843 		if (i > hostdata->id_mask)
844 			hostdata->id_higher_mask |= i;
845 	for (i = 0; i < 8; ++i)
846 		hostdata->busy[i] = 0;
847 #ifdef REAL_DMA
848 	hostdata->dmalen = 0;
849 #endif
850 	hostdata->targets_present = 0;
851 	hostdata->connected = NULL;
852 	hostdata->issue_queue = NULL;
853 	hostdata->disconnected_queue = NULL;
854 
855 	INIT_WORK(&hostdata->coroutine, NCR5380_main, hostdata);
856 
857 #ifdef NCR5380_STATS
858 	for (i = 0; i < 8; ++i) {
859 		hostdata->time_read[i] = 0;
860 		hostdata->time_write[i] = 0;
861 		hostdata->bytes_read[i] = 0;
862 		hostdata->bytes_write[i] = 0;
863 	}
864 	hostdata->timebase = 0;
865 	hostdata->pendingw = 0;
866 	hostdata->pendingr = 0;
867 #endif
868 
869 	/* The CHECK code seems to break the 53C400. Will check it later maybe */
870 	if (flags & FLAG_NCR53C400)
871 		hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
872 	else
873 		hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
874 
875 	hostdata->host = instance;
876 	hostdata->time_expires = 0;
877 
878 #ifndef AUTOSENSE
879 	if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
880 		    printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
881 		    	   "         be incorrectly cleared.\n", instance->host_no);
882 #endif				/* def AUTOSENSE */
883 
884 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
885 	NCR5380_write(MODE_REG, MR_BASE);
886 	NCR5380_write(TARGET_COMMAND_REG, 0);
887 	NCR5380_write(SELECT_ENABLE_REG, 0);
888 
889 #ifdef NCR53C400
890 	if (hostdata->flags & FLAG_NCR53C400) {
891 		NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
892 	}
893 #endif
894 
895 	/*
896 	 * Detect and correct bus wedge problems.
897 	 *
898 	 * If the system crashed, it may have crashed in a state
899 	 * where a SCSI command was still executing, and the
900 	 * SCSI bus is not in a BUS FREE STATE.
901 	 *
902 	 * If this is the case, we'll try to abort the currently
903 	 * established nexus which we know nothing about, and that
904 	 * failing, do a hard reset of the SCSI bus
905 	 */
906 
907 	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
908 		switch (pass) {
909 		case 1:
910 		case 3:
911 		case 5:
912 			printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
913 			timeout = jiffies + 5 * HZ;
914 			NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
915 			break;
916 		case 2:
917 			printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
918 			do_abort(instance);
919 			break;
920 		case 4:
921 			printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
922 			do_reset(instance);
923 			break;
924 		case 6:
925 			printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
926 			return -ENXIO;
927 		}
928 	}
929 	return 0;
930 }
931 
932 /**
933  *	NCR5380_exit	-	remove an NCR5380
934  *	@instance: adapter to remove
935  */
936 
937 static void __devexit NCR5380_exit(struct Scsi_Host *instance)
938 {
939 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
940 
941 	cancel_delayed_work(&hostdata->coroutine);
942 	flush_scheduled_work();
943 }
944 
945 /**
946  *	NCR5380_queue_command 		-	queue a command
947  *	@cmd: SCSI command
948  *	@done: completion handler
949  *
950  *      cmd is added to the per instance issue_queue, with minor
951  *      twiddling done to the host specific fields of cmd.  If the
952  *      main coroutine is not running, it is restarted.
953  *
954  *	Locks: host lock taken by caller
955  */
956 
957 static int NCR5380_queue_command(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
958 {
959 	struct Scsi_Host *instance = cmd->device->host;
960 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
961 	Scsi_Cmnd *tmp;
962 
963 #if (NDEBUG & NDEBUG_NO_WRITE)
964 	switch (cmd->cmnd[0]) {
965 	case WRITE_6:
966 	case WRITE_10:
967 		printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
968 		cmd->result = (DID_ERROR << 16);
969 		done(cmd);
970 		return 0;
971 	}
972 #endif				/* (NDEBUG & NDEBUG_NO_WRITE) */
973 
974 #ifdef NCR5380_STATS
975 	switch (cmd->cmnd[0]) {
976 		case WRITE:
977 		case WRITE_6:
978 		case WRITE_10:
979 			hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
980 			hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;
981 			hostdata->pendingw++;
982 			break;
983 		case READ:
984 		case READ_6:
985 		case READ_10:
986 			hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
987 			hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;
988 			hostdata->pendingr++;
989 			break;
990 	}
991 #endif
992 
993 	/*
994 	 * We use the host_scribble field as a pointer to the next command
995 	 * in a queue
996 	 */
997 
998 	cmd->host_scribble = NULL;
999 	cmd->scsi_done = done;
1000 	cmd->result = 0;
1001 
1002 	/*
1003 	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
1004 	 * commands are added to the head of the queue since any command will
1005 	 * clear the contingent allegiance condition that exists and the
1006 	 * sense data is only guaranteed to be valid while the condition exists.
1007 	 */
1008 
1009 	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1010 		LIST(cmd, hostdata->issue_queue);
1011 		cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
1012 		hostdata->issue_queue = cmd;
1013 	} else {
1014 		for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
1015 		LIST(cmd, tmp);
1016 		tmp->host_scribble = (unsigned char *) cmd;
1017 	}
1018 	dprintk(NDEBUG_QUEUES, ("scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"));
1019 
1020 	/* Run the coroutine if it isn't already running. */
1021 	/* Kick off command processing */
1022 	schedule_work(&hostdata->coroutine);
1023 	return 0;
1024 }
1025 
1026 
1027 /**
1028  *	NCR5380_main	-	NCR state machines
1029  *
1030  *	NCR5380_main is a coroutine that runs as long as more work can
1031  *      be done on the NCR5380 host adapters in a system.  Both
1032  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1033  *      in case it is not running.
1034  *
1035  *	Locks: called as its own thread with no locks held. Takes the
1036  *	host lock and called routines may take the isa dma lock.
1037  */
1038 
1039 static void NCR5380_main(void *p)
1040 {
1041 	struct NCR5380_hostdata *hostdata = p;
1042 	struct Scsi_Host *instance = hostdata->host;
1043 	Scsi_Cmnd *tmp, *prev;
1044 	int done;
1045 
1046 	spin_lock_irq(instance->host_lock);
1047 	do {
1048 		/* Lock held here */
1049 		done = 1;
1050 		if (!hostdata->connected && !hostdata->selecting) {
1051 			dprintk(NDEBUG_MAIN, ("scsi%d : not connected\n", instance->host_no));
1052 			/*
1053 			 * Search through the issue_queue for a command destined
1054 			 * for a target that's not busy.
1055 			 */
1056 			for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
1057 			{
1058 				if (prev != tmp)
1059 					dprintk(NDEBUG_LISTS, ("MAIN tmp=%p   target=%d   busy=%d lun=%d\n", tmp, tmp->target, hostdata->busy[tmp->target], tmp->lun));
1060 				/*  When we find one, remove it from the issue queue. */
1061 				if (!(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))) {
1062 					if (prev) {
1063 						REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1064 						prev->host_scribble = tmp->host_scribble;
1065 					} else {
1066 						REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1067 						hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1068 					}
1069 					tmp->host_scribble = NULL;
1070 
1071 					/*
1072 					 * Attempt to establish an I_T_L nexus here.
1073 					 * On success, instance->hostdata->connected is set.
1074 					 * On failure, we must add the command back to the
1075 					 *   issue queue so we can keep trying.
1076 					 */
1077 					dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main() : command for target %d lun %d removed from issue_queue\n", instance->host_no, tmp->target, tmp->lun));
1078 
1079 					/*
1080 					 * A successful selection is defined as one that
1081 					 * leaves us with the command connected and
1082 					 * in hostdata->connected, OR has terminated the
1083 					 * command.
1084 					 *
1085 					 * With successful commands, we fall through
1086 					 * and see if we can do an information transfer,
1087 					 * with failures we will restart.
1088 					 */
1089 					hostdata->selecting = NULL;
1090 					/* RvC: have to preset this to indicate a new command is being performed */
1091 
1092 					if (!NCR5380_select(instance, tmp,
1093 							    /*
1094 							     * REQUEST SENSE commands are issued without tagged
1095 							     * queueing, even on SCSI-II devices because the
1096 							     * contingent allegiance condition exists for the
1097 							     * entire unit.
1098 							     */
1099 							    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1100 						break;
1101 					} else {
1102 						LIST(tmp, hostdata->issue_queue);
1103 						tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1104 						hostdata->issue_queue = tmp;
1105 						done = 0;
1106 						dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no));
1107 					}
1108 					/* lock held here still */
1109 				}	/* if target/lun is not busy */
1110 			}	/* for */
1111 			/* exited locked */
1112 		}	/* if (!hostdata->connected) */
1113 		if (hostdata->selecting) {
1114 			tmp = (Scsi_Cmnd *) hostdata->selecting;
1115 			/* Selection will drop and retake the lock */
1116 			if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1117 				/* Ok ?? */
1118 			} else {
1119 				/* RvC: device failed, so we wait a long time
1120 				   this is needed for Mustek scanners, that
1121 				   do not respond to commands immediately
1122 				   after a scan */
1123 				printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1124 				LIST(tmp, hostdata->issue_queue);
1125 				tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1126 				hostdata->issue_queue = tmp;
1127 				NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1128 			}
1129 		}	/* if hostdata->selecting */
1130 		if (hostdata->connected
1131 #ifdef REAL_DMA
1132 		    && !hostdata->dmalen
1133 #endif
1134 		    && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1135 		    ) {
1136 			dprintk(NDEBUG_MAIN, ("scsi%d : main() : performing information transfer\n", instance->host_no));
1137 			NCR5380_information_transfer(instance);
1138 			dprintk(NDEBUG_MAIN, ("scsi%d : main() : done set false\n", instance->host_no));
1139 			done = 0;
1140 		} else
1141 			break;
1142 	} while (!done);
1143 
1144 	spin_unlock_irq(instance->host_lock);
1145 }
1146 
1147 #ifndef DONT_USE_INTR
1148 
1149 /**
1150  * 	NCR5380_intr	-	generic NCR5380 irq handler
1151  *	@irq: interrupt number
1152  *	@dev_id: device info
1153  *	@regs: registers (unused)
1154  *
1155  *	Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1156  *      from the disconnected queue, and restarting NCR5380_main()
1157  *      as required.
1158  *
1159  *	Locks: takes the needed instance locks
1160  */
1161 
1162 static irqreturn_t NCR5380_intr(int irq, void *dev_id, struct pt_regs *regs)
1163 {
1164 	NCR5380_local_declare();
1165 	struct Scsi_Host *instance = (struct Scsi_Host *)dev_id;
1166 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1167 	int done;
1168 	unsigned char basr;
1169 	unsigned long flags;
1170 
1171 	dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n", irq));
1172 
1173 	do {
1174 		done = 1;
1175 		spin_lock_irqsave(instance->host_lock, flags);
1176 		/* Look for pending interrupts */
1177 		NCR5380_setup(instance);
1178 		basr = NCR5380_read(BUS_AND_STATUS_REG);
1179 		/* XXX dispatch to appropriate routine if found and done=0 */
1180 		if (basr & BASR_IRQ) {
1181 			NCR5380_dprint(NDEBUG_INTR, instance);
1182 			if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1183 				done = 0;
1184 				dprintk(NDEBUG_INTR, ("scsi%d : SEL interrupt\n", instance->host_no));
1185 				NCR5380_reselect(instance);
1186 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1187 			} else if (basr & BASR_PARITY_ERROR) {
1188 				dprintk(NDEBUG_INTR, ("scsi%d : PARITY interrupt\n", instance->host_no));
1189 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1190 			} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1191 				dprintk(NDEBUG_INTR, ("scsi%d : RESET interrupt\n", instance->host_no));
1192 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1193 			} else {
1194 #if defined(REAL_DMA)
1195 				/*
1196 				 * We should only get PHASE MISMATCH and EOP interrupts
1197 				 * if we have DMA enabled, so do a sanity check based on
1198 				 * the current setting of the MODE register.
1199 				 */
1200 
1201 				if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1202 					int transfered;
1203 
1204 					if (!hostdata->connected)
1205 						panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1206 
1207 					transfered = (hostdata->dmalen - NCR5380_dma_residual(instance));
1208 					hostdata->connected->SCp.this_residual -= transferred;
1209 					hostdata->connected->SCp.ptr += transferred;
1210 					hostdata->dmalen = 0;
1211 
1212 					(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1213 
1214 					/* FIXME: we need to poll briefly then defer a workqueue task ! */
1215 					NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1216 
1217 					NCR5380_write(MODE_REG, MR_BASE);
1218 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1219 				}
1220 #else
1221 				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)));
1222 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1223 #endif
1224 			}
1225 		}	/* if BASR_IRQ */
1226 		spin_unlock_irqrestore(instance->host_lock, flags);
1227 		if(!done)
1228 			schedule_work(&hostdata->coroutine);
1229 	} while (!done);
1230 	return IRQ_HANDLED;
1231 }
1232 
1233 #endif
1234 
1235 /**
1236  *	collect_stats		-	collect stats on a scsi command
1237  *	@hostdata: adapter
1238  *	@cmd: command being issued
1239  *
1240  *	Update the statistical data by parsing the command in question
1241  */
1242 
1243 static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd)
1244 {
1245 #ifdef NCR5380_STATS
1246 	switch (cmd->cmnd[0]) {
1247 	case WRITE:
1248 	case WRITE_6:
1249 	case WRITE_10:
1250 		hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1251 		hostdata->pendingw--;
1252 		break;
1253 	case READ:
1254 	case READ_6:
1255 	case READ_10:
1256 		hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1257 		hostdata->pendingr--;
1258 		break;
1259 	}
1260 #endif
1261 }
1262 
1263 
1264 /*
1265  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1266  *      int tag);
1267  *
1268  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1269  *      including ARBITRATION, SELECTION, and initial message out for
1270  *      IDENTIFY and queue messages.
1271  *
1272  * Inputs : instance - instantiation of the 5380 driver on which this
1273  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1274  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1275  *      the command that is presently connected.
1276  *
1277  * Returns : -1 if selection could not execute for some reason,
1278  *      0 if selection succeeded or failed because the target
1279  *      did not respond.
1280  *
1281  * Side effects :
1282  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1283  *              with registers as they should have been on entry - ie
1284  *              SELECT_ENABLE will be set appropriately, the NCR5380
1285  *              will cease to drive any SCSI bus signals.
1286  *
1287  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1288  *              instance->connected will be set to cmd.
1289  *              SELECT interrupt will be disabled.
1290  *
1291  *      If failed (no target) : cmd->scsi_done() will be called, and the
1292  *              cmd->result host byte set to DID_BAD_TARGET.
1293  *
1294  *	Locks: caller holds hostdata lock in IRQ mode
1295  */
1296 
1297 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag)
1298 {
1299 	NCR5380_local_declare();
1300 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1301 	unsigned char tmp[3], phase;
1302 	unsigned char *data;
1303 	int len;
1304 	unsigned long timeout;
1305 	unsigned char value;
1306 	int err;
1307 	NCR5380_setup(instance);
1308 
1309 	if (hostdata->selecting)
1310 		goto part2;
1311 
1312 	hostdata->restart_select = 0;
1313 
1314 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1315 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id));
1316 
1317 	/*
1318 	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1319 	 * data bus during SELECTION.
1320 	 */
1321 
1322 	NCR5380_write(TARGET_COMMAND_REG, 0);
1323 
1324 	/*
1325 	 * Start arbitration.
1326 	 */
1327 
1328 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1329 	NCR5380_write(MODE_REG, MR_ARBITRATE);
1330 
1331 
1332 	/* We can be relaxed here, interrupts are on, we are
1333 	   in workqueue context, the birds are singing in the trees */
1334 	spin_unlock_irq(instance->host_lock);
1335 	err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1336 	spin_lock_irq(instance->host_lock);
1337 	if (err < 0) {
1338 		printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1339 		NCR5380_write(MODE_REG, MR_BASE);
1340 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1341 		goto failed;
1342 	}
1343 
1344 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : arbitration complete\n", instance->host_no));
1345 
1346 	/*
1347 	 * The arbitration delay is 2.2us, but this is a minimum and there is
1348 	 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1349 	 * the integral nature of udelay().
1350 	 *
1351 	 */
1352 
1353 	udelay(3);
1354 
1355 	/* Check for lost arbitration */
1356 	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)) {
1357 		NCR5380_write(MODE_REG, MR_BASE);
1358 		dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no));
1359 		goto failed;
1360 	}
1361 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1362 
1363 	if (!(hostdata->flags & FLAG_DTC3181E) &&
1364 	    /* RvC: DTC3181E has some trouble with this
1365 	     *      so we simply removed it. Seems to work with
1366 	     *      only Mustek scanner attached
1367 	     */
1368 	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1369 		NCR5380_write(MODE_REG, MR_BASE);
1370 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1371 		dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no));
1372 		goto failed;
1373 	}
1374 	/*
1375 	 * Again, bus clear + bus settle time is 1.2us, however, this is
1376 	 * a minimum so we'll udelay ceil(1.2)
1377 	 */
1378 
1379 	udelay(2);
1380 
1381 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : won arbitration\n", instance->host_no));
1382 
1383 	/*
1384 	 * Now that we have won arbitration, start Selection process, asserting
1385 	 * the host and target ID's on the SCSI bus.
1386 	 */
1387 
1388 	NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1389 
1390 	/*
1391 	 * Raise ATN while SEL is true before BSY goes false from arbitration,
1392 	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1393 	 * phase immediately after selection.
1394 	 */
1395 
1396 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1397 	NCR5380_write(MODE_REG, MR_BASE);
1398 
1399 	/*
1400 	 * Reselect interrupts must be turned off prior to the dropping of BSY,
1401 	 * otherwise we will trigger an interrupt.
1402 	 */
1403 	NCR5380_write(SELECT_ENABLE_REG, 0);
1404 
1405 	/*
1406 	 * The initiator shall then wait at least two deskew delays and release
1407 	 * the BSY signal.
1408 	 */
1409 	udelay(1);		/* wingel -- wait two bus deskew delay >2*45ns */
1410 
1411 	/* Reset BSY */
1412 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1413 
1414 	/*
1415 	 * Something weird happens when we cease to drive BSY - looks
1416 	 * like the board/chip is letting us do another read before the
1417 	 * appropriate propagation delay has expired, and we're confusing
1418 	 * a BSY signal from ourselves as the target's response to SELECTION.
1419 	 *
1420 	 * A small delay (the 'C++' frontend breaks the pipeline with an
1421 	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1422 	 * tighter 'C' code breaks and requires this) solves the problem -
1423 	 * the 1 us delay is arbitrary, and only used because this delay will
1424 	 * be the same on other platforms and since it works here, it should
1425 	 * work there.
1426 	 *
1427 	 * wingel suggests that this could be due to failing to wait
1428 	 * one deskew delay.
1429 	 */
1430 
1431 	udelay(1);
1432 
1433 	dprintk(NDEBUG_SELECTION, ("scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd)));
1434 
1435 	/*
1436 	 * The SCSI specification calls for a 250 ms timeout for the actual
1437 	 * selection.
1438 	 */
1439 
1440 	timeout = jiffies + (250 * HZ / 1000);
1441 
1442 	/*
1443 	 * XXX very interesting - we're seeing a bounce where the BSY we
1444 	 * asserted is being reflected / still asserted (propagation delay?)
1445 	 * and it's detecting as true.  Sigh.
1446 	 */
1447 
1448 	hostdata->select_time = 0;	/* we count the clock ticks at which we polled */
1449 	hostdata->selecting = cmd;
1450 
1451 part2:
1452 	/* RvC: here we enter after a sleeping period, or immediately after
1453 	   execution of part 1
1454 	   we poll only once ech clock tick */
1455 	value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1456 
1457 	if (!value && (hostdata->select_time < HZ/4)) {
1458 		/* RvC: we still must wait for a device response */
1459 		hostdata->select_time++;	/* after 25 ticks the device has failed */
1460 		NCR5380_set_timer(hostdata, 1);
1461 		return 0;	/* RvC: we return here with hostdata->selecting set,
1462 				   to go to sleep */
1463 	}
1464 
1465 	hostdata->selecting = NULL;/* clear this pointer, because we passed the
1466 					   waiting period */
1467 	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1468 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1469 		NCR5380_reselect(instance);
1470 		printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1471 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1472 		return -1;
1473 	}
1474 	/*
1475 	 * No less than two deskew delays after the initiator detects the
1476 	 * BSY signal is true, it shall release the SEL signal and may
1477 	 * change the DATA BUS.                                     -wingel
1478 	 */
1479 
1480 	udelay(1);
1481 
1482 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1483 
1484 	if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1485 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1486 		if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1487 			printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1488 			if (hostdata->restart_select)
1489 				printk(KERN_DEBUG "\trestart select\n");
1490 			NCR5380_dprint(NDEBUG_SELECTION, instance);
1491 			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1492 			return -1;
1493 		}
1494 		cmd->result = DID_BAD_TARGET << 16;
1495 		collect_stats(hostdata, cmd);
1496 		cmd->scsi_done(cmd);
1497 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1498 		dprintk(NDEBUG_SELECTION, ("scsi%d : target did not respond within 250ms\n", instance->host_no));
1499 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1500 		return 0;
1501 	}
1502 	hostdata->targets_present |= (1 << scmd_id(cmd));
1503 
1504 	/*
1505 	 * Since we followed the SCSI spec, and raised ATN while SEL
1506 	 * was true but before BSY was false during selection, the information
1507 	 * transfer phase should be a MESSAGE OUT phase so that we can send the
1508 	 * IDENTIFY message.
1509 	 *
1510 	 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1511 	 * message (2 bytes) with a tag ID that we increment with every command
1512 	 * until it wraps back to 0.
1513 	 *
1514 	 * XXX - it turns out that there are some broken SCSI-II devices,
1515 	 *       which claim to support tagged queuing but fail when more than
1516 	 *       some number of commands are issued at once.
1517 	 */
1518 
1519 	/* Wait for start of REQ/ACK handshake */
1520 
1521 	spin_unlock_irq(instance->host_lock);
1522 	err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1523 	spin_lock_irq(instance->host_lock);
1524 
1525 	if(err) {
1526 		printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1527 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1528 		goto failed;
1529 	}
1530 
1531 	dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
1532 	tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1533 
1534 	len = 1;
1535 	cmd->tag = 0;
1536 
1537 	/* Send message(s) */
1538 	data = tmp;
1539 	phase = PHASE_MSGOUT;
1540 	NCR5380_transfer_pio(instance, &phase, &len, &data);
1541 	dprintk(NDEBUG_SELECTION, ("scsi%d : nexus established.\n", instance->host_no));
1542 	/* XXX need to handle errors here */
1543 	hostdata->connected = cmd;
1544 	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1545 
1546 	if (cmd->SCp.ptr != (char *)cmd->sense_buffer) {
1547 		initialize_SCp(cmd);
1548 	}
1549 
1550 	return 0;
1551 
1552 	/* Selection failed */
1553 failed:
1554 	return -1;
1555 
1556 }
1557 
1558 /*
1559  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1560  *      unsigned char *phase, int *count, unsigned char **data)
1561  *
1562  * Purpose : transfers data in given phase using polled I/O
1563  *
1564  * Inputs : instance - instance of driver, *phase - pointer to
1565  *      what phase is expected, *count - pointer to number of
1566  *      bytes to transfer, **data - pointer to data pointer.
1567  *
1568  * Returns : -1 when different phase is entered without transferring
1569  *      maximum number of bytes, 0 if all bytes or transfered or exit
1570  *      is in same phase.
1571  *
1572  *      Also, *phase, *count, *data are modified in place.
1573  *
1574  * XXX Note : handling for bus free may be useful.
1575  */
1576 
1577 /*
1578  * Note : this code is not as quick as it could be, however it
1579  * IS 100% reliable, and for the actual data transfer where speed
1580  * counts, we will always do a pseudo DMA or DMA transfer.
1581  */
1582 
1583 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1584 	NCR5380_local_declare();
1585 	unsigned char p = *phase, tmp;
1586 	int c = *count;
1587 	unsigned char *d = *data;
1588 	/*
1589 	 *      RvC: some administrative data to process polling time
1590 	 */
1591 	int break_allowed = 0;
1592 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1593 	NCR5380_setup(instance);
1594 
1595 	if (!(p & SR_IO))
1596 		dprintk(NDEBUG_PIO, ("scsi%d : pio write %d bytes\n", instance->host_no, c));
1597 	else
1598 		dprintk(NDEBUG_PIO, ("scsi%d : pio read %d bytes\n", instance->host_no, c));
1599 
1600 	/*
1601 	 * The NCR5380 chip will only drive the SCSI bus when the
1602 	 * phase specified in the appropriate bits of the TARGET COMMAND
1603 	 * REGISTER match the STATUS REGISTER
1604 	 */
1605 
1606 	 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1607 
1608 	/* RvC: don't know if this is necessary, but other SCSI I/O is short
1609 	 *      so breaks are not necessary there
1610 	 */
1611 	if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1612 		break_allowed = 1;
1613 	}
1614 	do {
1615 		/*
1616 		 * Wait for assertion of REQ, after which the phase bits will be
1617 		 * valid
1618 		 */
1619 
1620 		/* RvC: we simply poll once, after that we stop temporarily
1621 		 *      and let the device buffer fill up
1622 		 *      if breaking is not allowed, we keep polling as long as needed
1623 		 */
1624 
1625 		/* FIXME */
1626 		while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1627 		if (!(tmp & SR_REQ)) {
1628 			/* timeout condition */
1629 			NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1630 			break;
1631 		}
1632 
1633 		dprintk(NDEBUG_HANDSHAKE, ("scsi%d : REQ detected\n", instance->host_no));
1634 
1635 		/* Check for phase mismatch */
1636 		if ((tmp & PHASE_MASK) != p) {
1637 			dprintk(NDEBUG_HANDSHAKE, ("scsi%d : phase mismatch\n", instance->host_no));
1638 			NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1639 			break;
1640 		}
1641 		/* Do actual transfer from SCSI bus to / from memory */
1642 		if (!(p & SR_IO))
1643 			NCR5380_write(OUTPUT_DATA_REG, *d);
1644 		else
1645 			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1646 
1647 		++d;
1648 
1649 		/*
1650 		 * The SCSI standard suggests that in MSGOUT phase, the initiator
1651 		 * should drop ATN on the last byte of the message phase
1652 		 * after REQ has been asserted for the handshake but before
1653 		 * the initiator raises ACK.
1654 		 */
1655 
1656 		if (!(p & SR_IO)) {
1657 			if (!((p & SR_MSG) && c > 1)) {
1658 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1659 				NCR5380_dprint(NDEBUG_PIO, instance);
1660 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1661 			} else {
1662 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1663 				NCR5380_dprint(NDEBUG_PIO, instance);
1664 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1665 			}
1666 		} else {
1667 			NCR5380_dprint(NDEBUG_PIO, instance);
1668 			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1669 		}
1670 
1671 		/* FIXME - if this fails bus reset ?? */
1672 		NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1673 		dprintk(NDEBUG_HANDSHAKE, ("scsi%d : req false, handshake complete\n", instance->host_no));
1674 
1675 /*
1676  * We have several special cases to consider during REQ/ACK handshaking :
1677  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1678  *      message.  ATN must be dropped as ACK is dropped.
1679  *
1680  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1681  *      message.  We must exit with ACK asserted, so that the calling
1682  *      code may raise ATN before dropping ACK to reject the message.
1683  *
1684  * 3.  ACK and ATN are clear and the target may proceed as normal.
1685  */
1686 		if (!(p == PHASE_MSGIN && c == 1)) {
1687 			if (p == PHASE_MSGOUT && c > 1)
1688 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1689 			else
1690 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1691 		}
1692 	} while (--c);
1693 
1694 	dprintk(NDEBUG_PIO, ("scsi%d : residual %d\n", instance->host_no, c));
1695 
1696 	*count = c;
1697 	*data = d;
1698 	tmp = NCR5380_read(STATUS_REG);
1699 	if (tmp & SR_REQ)
1700 		*phase = tmp & PHASE_MASK;
1701 	else
1702 		*phase = PHASE_UNKNOWN;
1703 
1704 	if (!c || (*phase == p))
1705 		return 0;
1706 	else
1707 		return -1;
1708 }
1709 
1710 /**
1711  *	do_reset	-	issue a reset command
1712  *	@host: adapter to reset
1713  *
1714  *	Issue a reset sequence to the NCR5380 and try and get the bus
1715  *	back into sane shape.
1716  *
1717  *	Locks: caller holds queue lock
1718  */
1719 
1720 static void do_reset(struct Scsi_Host *host) {
1721 	NCR5380_local_declare();
1722 	NCR5380_setup(host);
1723 
1724 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1725 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1726 	udelay(25);
1727 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1728 }
1729 
1730 /*
1731  * Function : do_abort (Scsi_Host *host)
1732  *
1733  * Purpose : abort the currently established nexus.  Should only be
1734  *      called from a routine which can drop into a
1735  *
1736  * Returns : 0 on success, -1 on failure.
1737  *
1738  * Locks: queue lock held by caller
1739  *	FIXME: sort this out and get new_eh running
1740  */
1741 
1742 static int do_abort(struct Scsi_Host *host) {
1743 	NCR5380_local_declare();
1744 	unsigned char *msgptr, phase, tmp;
1745 	int len;
1746 	int rc;
1747 	NCR5380_setup(host);
1748 
1749 
1750 	/* Request message out phase */
1751 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1752 
1753 	/*
1754 	 * Wait for the target to indicate a valid phase by asserting
1755 	 * REQ.  Once this happens, we'll have either a MSGOUT phase
1756 	 * and can immediately send the ABORT message, or we'll have some
1757 	 * other phase and will have to source/sink data.
1758 	 *
1759 	 * We really don't care what value was on the bus or what value
1760 	 * the target sees, so we just handshake.
1761 	 */
1762 
1763 	rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1764 
1765 	if(rc < 0)
1766 		return -1;
1767 
1768 	tmp = (unsigned char)rc;
1769 
1770 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1771 
1772 	if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1773 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1774 		rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1775 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1776 		if(rc == -1)
1777 			return -1;
1778 	}
1779 	tmp = ABORT;
1780 	msgptr = &tmp;
1781 	len = 1;
1782 	phase = PHASE_MSGOUT;
1783 	NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1784 
1785 	/*
1786 	 * If we got here, and the command completed successfully,
1787 	 * we're about to go into bus free state.
1788 	 */
1789 
1790 	return len ? -1 : 0;
1791 }
1792 
1793 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1794 /*
1795  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1796  *      unsigned char *phase, int *count, unsigned char **data)
1797  *
1798  * Purpose : transfers data in given phase using either real
1799  *      or pseudo DMA.
1800  *
1801  * Inputs : instance - instance of driver, *phase - pointer to
1802  *      what phase is expected, *count - pointer to number of
1803  *      bytes to transfer, **data - pointer to data pointer.
1804  *
1805  * Returns : -1 when different phase is entered without transferring
1806  *      maximum number of bytes, 0 if all bytes or transfered or exit
1807  *      is in same phase.
1808  *
1809  *      Also, *phase, *count, *data are modified in place.
1810  *
1811  *	Locks: io_request lock held by caller
1812  */
1813 
1814 
1815 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1816 	NCR5380_local_declare();
1817 	register int c = *count;
1818 	register unsigned char p = *phase;
1819 	register unsigned char *d = *data;
1820 	unsigned char tmp;
1821 	int foo;
1822 #if defined(REAL_DMA_POLL)
1823 	int cnt, toPIO;
1824 	unsigned char saved_data = 0, overrun = 0, residue;
1825 #endif
1826 
1827 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1828 
1829 	NCR5380_setup(instance);
1830 
1831 	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1832 		*phase = tmp;
1833 		return -1;
1834 	}
1835 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1836 #ifdef READ_OVERRUNS
1837 	if (p & SR_IO) {
1838 		c -= 2;
1839 	}
1840 #endif
1841 	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));
1842 	hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1843 #endif
1844 
1845 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1846 
1847 #ifdef REAL_DMA
1848 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1849 #elif defined(REAL_DMA_POLL)
1850 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1851 #else
1852 	/*
1853 	 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1854 	 * were not disabled for the duration of a single DMA transfer, from
1855 	 * before the setting of DMA mode to after transfer of the last byte.
1856 	 */
1857 
1858 #if defined(PSEUDO_DMA) && defined(UNSAFE)
1859 	spin_unlock_irq(instance->host_lock);
1860 #endif
1861 	/* KLL May need eop and parity in 53c400 */
1862 	if (hostdata->flags & FLAG_NCR53C400)
1863 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_PAR_CHECK | MR_ENABLE_PAR_INTR | MR_ENABLE_EOP_INTR | MR_DMA_MODE | MR_MONITOR_BSY);
1864 	else
1865 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1866 #endif				/* def REAL_DMA */
1867 
1868 	dprintk(NDEBUG_DMA, ("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)));
1869 
1870 	/*
1871 	 *	On the PAS16 at least I/O recovery delays are not needed here.
1872 	 *	Everyone else seems to want them.
1873 	 */
1874 
1875 	if (p & SR_IO) {
1876 		io_recovery_delay(1);
1877 		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1878 	} else {
1879 		io_recovery_delay(1);
1880 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1881 		io_recovery_delay(1);
1882 		NCR5380_write(START_DMA_SEND_REG, 0);
1883 		io_recovery_delay(1);
1884 	}
1885 
1886 #if defined(REAL_DMA_POLL)
1887 	do {
1888 		tmp = NCR5380_read(BUS_AND_STATUS_REG);
1889 	} while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1890 
1891 /*
1892    At this point, either we've completed DMA, or we have a phase mismatch,
1893    or we've unexpectedly lost BUSY (which is a real error).
1894 
1895    For write DMAs, we want to wait until the last byte has been
1896    transferred out over the bus before we turn off DMA mode.  Alas, there
1897    seems to be no terribly good way of doing this on a 5380 under all
1898    conditions.  For non-scatter-gather operations, we can wait until REQ
1899    and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1900    are nastier, since the device will be expecting more data than we
1901    are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1902    could test LAST BIT SENT to assure transfer (I imagine this is precisely
1903    why this signal was added to the newer chips) but on the older 538[01]
1904    this signal does not exist.  The workaround for this lack is a watchdog;
1905    we bail out of the wait-loop after a modest amount of wait-time if
1906    the usual exit conditions are not met.  Not a terribly clean or
1907    correct solution :-%
1908 
1909    Reads are equally tricky due to a nasty characteristic of the NCR5380.
1910    If the chip is in DMA mode for an READ, it will respond to a target's
1911    REQ by latching the SCSI data into the INPUT DATA register and asserting
1912    ACK, even if it has _already_ been notified by the DMA controller that
1913    the current DMA transfer has completed!  If the NCR5380 is then taken
1914    out of DMA mode, this already-acknowledged byte is lost.
1915 
1916    This is not a problem for "one DMA transfer per command" reads, because
1917    the situation will never arise... either all of the data is DMA'ed
1918    properly, or the target switches to MESSAGE IN phase to signal a
1919    disconnection (either operation bringing the DMA to a clean halt).
1920    However, in order to handle scatter-reads, we must work around the
1921    problem.  The chosen fix is to DMA N-2 bytes, then check for the
1922    condition before taking the NCR5380 out of DMA mode.  One or two extra
1923    bytes are transferred via PIO as necessary to fill out the original
1924    request.
1925  */
1926 
1927 	if (p & SR_IO) {
1928 #ifdef READ_OVERRUNS
1929 		udelay(10);
1930 		if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1931 			saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1932 			overrun = 1;
1933 		}
1934 #endif
1935 	} else {
1936 		int limit = 100;
1937 		while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1938 			if (!(tmp & BASR_PHASE_MATCH))
1939 				break;
1940 			if (--limit < 0)
1941 				break;
1942 		}
1943 	}
1944 
1945 	dprintk(NDEBUG_DMA, ("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG)));
1946 
1947 	NCR5380_write(MODE_REG, MR_BASE);
1948 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1949 
1950 	residue = NCR5380_dma_residual(instance);
1951 	c -= residue;
1952 	*count -= c;
1953 	*data += c;
1954 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1955 
1956 #ifdef READ_OVERRUNS
1957 	if (*phase == p && (p & SR_IO) && residue == 0) {
1958 		if (overrun) {
1959 			dprintk(NDEBUG_DMA, ("Got an input overrun, using saved byte\n"));
1960 			**data = saved_data;
1961 			*data += 1;
1962 			*count -= 1;
1963 			cnt = toPIO = 1;
1964 		} else {
1965 			printk("No overrun??\n");
1966 			cnt = toPIO = 2;
1967 		}
1968 		dprintk(NDEBUG_DMA, ("Doing %d-byte PIO to 0x%X\n", cnt, *data));
1969 		NCR5380_transfer_pio(instance, phase, &cnt, data);
1970 		*count -= toPIO - cnt;
1971 	}
1972 #endif
1973 
1974 	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)));
1975 	return 0;
1976 
1977 #elif defined(REAL_DMA)
1978 	return 0;
1979 #else				/* defined(REAL_DMA_POLL) */
1980 	if (p & SR_IO) {
1981 #ifdef DMA_WORKS_RIGHT
1982 		foo = NCR5380_pread(instance, d, c);
1983 #else
1984 		int diff = 1;
1985 		if (hostdata->flags & FLAG_NCR53C400) {
1986 			diff = 0;
1987 		}
1988 		if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1989 			/*
1990 			 * We can't disable DMA mode after successfully transferring
1991 			 * what we plan to be the last byte, since that would open up
1992 			 * a race condition where if the target asserted REQ before
1993 			 * we got the DMA mode reset, the NCR5380 would have latched
1994 			 * an additional byte into the INPUT DATA register and we'd
1995 			 * have dropped it.
1996 			 *
1997 			 * The workaround was to transfer one fewer bytes than we
1998 			 * intended to with the pseudo-DMA read function, wait for
1999 			 * the chip to latch the last byte, read it, and then disable
2000 			 * pseudo-DMA mode.
2001 			 *
2002 			 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
2003 			 * REQ is deasserted when ACK is asserted, and not reasserted
2004 			 * until ACK goes false.  Since the NCR5380 won't lower ACK
2005 			 * until DACK is asserted, which won't happen unless we twiddle
2006 			 * the DMA port or we take the NCR5380 out of DMA mode, we
2007 			 * can guarantee that we won't handshake another extra
2008 			 * byte.
2009 			 */
2010 
2011 			if (!(hostdata->flags & FLAG_NCR53C400)) {
2012 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
2013 				/* Wait for clean handshake */
2014 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2015 				d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2016 			}
2017 		}
2018 #endif
2019 	} else {
2020 #ifdef DMA_WORKS_RIGHT
2021 		foo = NCR5380_pwrite(instance, d, c);
2022 #else
2023 		int timeout;
2024 		dprintk(NDEBUG_C400_PWRITE, ("About to pwrite %d bytes\n", c));
2025 		if (!(foo = NCR5380_pwrite(instance, d, c))) {
2026 			/*
2027 			 * Wait for the last byte to be sent.  If REQ is being asserted for
2028 			 * the byte we're interested, we'll ACK it and it will go false.
2029 			 */
2030 			if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2031 				timeout = 20000;
2032 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2033 
2034 				if (!timeout)
2035 					dprintk(NDEBUG_LAST_BYTE_SENT, ("scsi%d : timed out on last byte\n", instance->host_no));
2036 
2037 				if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2038 					hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2039 					if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2040 						hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2041 						dprintk(NDEBUG_LAST_WRITE_SENT, ("scsi%d : last bit sent works\n", instance->host_no));
2042 					}
2043 				}
2044 			} else {
2045 				dprintk(NDEBUG_C400_PWRITE, ("Waiting for LASTBYTE\n"));
2046 				while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2047 				dprintk(NDEBUG_C400_PWRITE, ("Got LASTBYTE\n"));
2048 			}
2049 		}
2050 #endif
2051 	}
2052 	NCR5380_write(MODE_REG, MR_BASE);
2053 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2054 
2055 	if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2056 		dprintk(NDEBUG_C400_PWRITE, ("53C400w: Checking for IRQ\n"));
2057 		if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2058 			dprintk(NDEBUG_C400_PWRITE, ("53C400w:    got it, reading reset interrupt reg\n"));
2059 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2060 		} else {
2061 			printk("53C400w:    IRQ NOT THERE!\n");
2062 		}
2063 	}
2064 	*data = d + c;
2065 	*count = 0;
2066 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2067 #if defined(PSEUDO_DMA) && defined(UNSAFE)
2068 	spin_lock_irq(instance->host_lock);
2069 #endif				/* defined(REAL_DMA_POLL) */
2070 	return foo;
2071 #endif				/* def REAL_DMA */
2072 }
2073 #endif				/* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2074 
2075 /*
2076  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2077  *
2078  * Purpose : run through the various SCSI phases and do as the target
2079  *      directs us to.  Operates on the currently connected command,
2080  *      instance->connected.
2081  *
2082  * Inputs : instance, instance for which we are doing commands
2083  *
2084  * Side effects : SCSI things happen, the disconnected queue will be
2085  *      modified if a command disconnects, *instance->connected will
2086  *      change.
2087  *
2088  * XXX Note : we need to watch for bus free or a reset condition here
2089  *      to recover from an unexpected bus free condition.
2090  *
2091  * Locks: io_request_lock held by caller in IRQ mode
2092  */
2093 
2094 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2095 	NCR5380_local_declare();
2096 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2097 	unsigned char msgout = NOP;
2098 	int sink = 0;
2099 	int len;
2100 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2101 	int transfersize;
2102 #endif
2103 	unsigned char *data;
2104 	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2105 	Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2106 	/* RvC: we need to set the end of the polling time */
2107 	unsigned long poll_time = jiffies + USLEEP_POLL;
2108 
2109 	NCR5380_setup(instance);
2110 
2111 	while (1) {
2112 		tmp = NCR5380_read(STATUS_REG);
2113 		/* We only have a valid SCSI phase when REQ is asserted */
2114 		if (tmp & SR_REQ) {
2115 			phase = (tmp & PHASE_MASK);
2116 			if (phase != old_phase) {
2117 				old_phase = phase;
2118 				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2119 			}
2120 			if (sink && (phase != PHASE_MSGOUT)) {
2121 				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2122 
2123 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2124 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2125 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2126 				sink = 0;
2127 				continue;
2128 			}
2129 			switch (phase) {
2130 			case PHASE_DATAIN:
2131 			case PHASE_DATAOUT:
2132 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2133 				printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2134 				sink = 1;
2135 				do_abort(instance);
2136 				cmd->result = DID_ERROR << 16;
2137 				cmd->done(cmd);
2138 				return;
2139 #endif
2140 				/*
2141 				 * If there is no room left in the current buffer in the
2142 				 * scatter-gather list, move onto the next one.
2143 				 */
2144 
2145 				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2146 					++cmd->SCp.buffer;
2147 					--cmd->SCp.buffers_residual;
2148 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
2149 					cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
2150 						       cmd->SCp.buffer->offset;
2151 					dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
2152 				}
2153 				/*
2154 				 * The preferred transfer method is going to be
2155 				 * PSEUDO-DMA for systems that are strictly PIO,
2156 				 * since we can let the hardware do the handshaking.
2157 				 *
2158 				 * For this to work, we need to know the transfersize
2159 				 * ahead of time, since the pseudo-DMA code will sit
2160 				 * in an unconditional loop.
2161 				 */
2162 
2163 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2164 				/* KLL
2165 				 * PSEUDO_DMA is defined here. If this is the g_NCR5380
2166 				 * driver then it will always be defined, so the
2167 				 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2168 				 * NCR5380 case.  I think this is a fairly clean solution.
2169 				 * We supplement these 2 if's with the flag.
2170 				 */
2171 #ifdef NCR5380_dma_xfer_len
2172 				if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2173 #else
2174 				transfersize = cmd->transfersize;
2175 
2176 #ifdef LIMIT_TRANSFERSIZE	/* If we have problems with interrupt service */
2177 				if (transfersize > 512)
2178 					transfersize = 512;
2179 #endif				/* LIMIT_TRANSFERSIZE */
2180 
2181 				if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2182 					/* Limit transfers to 32K, for xx400 & xx406
2183 					 * pseudoDMA that transfers in 128 bytes blocks. */
2184 					if (transfersize > 32 * 1024)
2185 						transfersize = 32 * 1024;
2186 #endif
2187 					len = transfersize;
2188 					if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2189 						/*
2190 						 * If the watchdog timer fires, all future accesses to this
2191 						 * device will use the polled-IO.
2192 						 */
2193 						scmd_printk(KERN_INFO, cmd,
2194 							    "switching to slow handshake\n");
2195 						cmd->device->borken = 1;
2196 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2197 						sink = 1;
2198 						do_abort(instance);
2199 						cmd->result = DID_ERROR << 16;
2200 						cmd->done(cmd);
2201 						/* XXX - need to source or sink data here, as appropriate */
2202 					} else
2203 						cmd->SCp.this_residual -= transfersize - len;
2204 				} else
2205 #endif				/* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2206 					NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2207 							     &cmd->SCp.ptr);
2208 				break;
2209 			case PHASE_MSGIN:
2210 				len = 1;
2211 				data = &tmp;
2212 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2213 				cmd->SCp.Message = tmp;
2214 
2215 				switch (tmp) {
2216 					/*
2217 					 * Linking lets us reduce the time required to get the
2218 					 * next command out to the device, hopefully this will
2219 					 * mean we don't waste another revolution due to the delays
2220 					 * required by ARBITRATION and another SELECTION.
2221 					 *
2222 					 * In the current implementation proposal, low level drivers
2223 					 * merely have to start the next command, pointed to by
2224 					 * next_link, done() is called as with unlinked commands.
2225 					 */
2226 #ifdef LINKED
2227 				case LINKED_CMD_COMPLETE:
2228 				case LINKED_FLG_CMD_COMPLETE:
2229 					/* Accept message by clearing ACK */
2230 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2231 					dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun));
2232 					/*
2233 					 * Sanity check : A linked command should only terminate with
2234 					 * one of these messages if there are more linked commands
2235 					 * available.
2236 					 */
2237 					if (!cmd->next_link) {
2238 						printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2239 						sink = 1;
2240 						do_abort(instance);
2241 						return;
2242 					}
2243 					initialize_SCp(cmd->next_link);
2244 					/* The next command is still part of this process */
2245 					cmd->next_link->tag = cmd->tag;
2246 					cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2247 					dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked request done, calling scsi_done().\n", instance->host_no, cmd->device->id, cmd->device->lun));
2248 					collect_stats(hostdata, cmd);
2249 					cmd->scsi_done(cmd);
2250 					cmd = hostdata->connected;
2251 					break;
2252 #endif				/* def LINKED */
2253 				case ABORT:
2254 				case COMMAND_COMPLETE:
2255 					/* Accept message by clearing ACK */
2256 					sink = 1;
2257 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2258 					hostdata->connected = NULL;
2259 					dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun));
2260 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2261 
2262 					/*
2263 					 * I'm not sure what the correct thing to do here is :
2264 					 *
2265 					 * If the command that just executed is NOT a request
2266 					 * sense, the obvious thing to do is to set the result
2267 					 * code to the values of the stored parameters.
2268 					 *
2269 					 * If it was a REQUEST SENSE command, we need some way
2270 					 * to differentiate between the failure code of the original
2271 					 * and the failure code of the REQUEST sense - the obvious
2272 					 * case is success, where we fall through and leave the result
2273 					 * code unchanged.
2274 					 *
2275 					 * The non-obvious place is where the REQUEST SENSE failed
2276 					 */
2277 
2278 					if (cmd->cmnd[0] != REQUEST_SENSE)
2279 						cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2280 					else if (status_byte(cmd->SCp.Status) != GOOD)
2281 						cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2282 
2283 #ifdef AUTOSENSE
2284 					if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2285 						dprintk(NDEBUG_AUTOSENSE, ("scsi%d : performing request sense\n", instance->host_no));
2286 						cmd->cmnd[0] = REQUEST_SENSE;
2287 						cmd->cmnd[1] &= 0xe0;
2288 						cmd->cmnd[2] = 0;
2289 						cmd->cmnd[3] = 0;
2290 						cmd->cmnd[4] = sizeof(cmd->sense_buffer);
2291 						cmd->cmnd[5] = 0;
2292 
2293 						cmd->SCp.buffer = NULL;
2294 						cmd->SCp.buffers_residual = 0;
2295 						cmd->SCp.ptr = (char *) cmd->sense_buffer;
2296 						cmd->SCp.this_residual = sizeof(cmd->sense_buffer);
2297 
2298 						LIST(cmd, hostdata->issue_queue);
2299 						cmd->host_scribble = (unsigned char *)
2300 						    hostdata->issue_queue;
2301 						hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2302 						dprintk(NDEBUG_QUEUES, ("scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no));
2303 					} else
2304 #endif				/* def AUTOSENSE */
2305 					{
2306 						collect_stats(hostdata, cmd);
2307 						cmd->scsi_done(cmd);
2308 					}
2309 
2310 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2311 					/*
2312 					 * Restore phase bits to 0 so an interrupted selection,
2313 					 * arbitration can resume.
2314 					 */
2315 					NCR5380_write(TARGET_COMMAND_REG, 0);
2316 
2317 					while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2318 						barrier();
2319 					return;
2320 				case MESSAGE_REJECT:
2321 					/* Accept message by clearing ACK */
2322 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2323 					switch (hostdata->last_message) {
2324 					case HEAD_OF_QUEUE_TAG:
2325 					case ORDERED_QUEUE_TAG:
2326 					case SIMPLE_QUEUE_TAG:
2327 						cmd->device->simple_tags = 0;
2328 						hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2329 						break;
2330 					default:
2331 						break;
2332 					}
2333 				case DISCONNECT:{
2334 						/* Accept message by clearing ACK */
2335 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2336 						cmd->device->disconnect = 1;
2337 						LIST(cmd, hostdata->disconnected_queue);
2338 						cmd->host_scribble = (unsigned char *)
2339 						    hostdata->disconnected_queue;
2340 						hostdata->connected = NULL;
2341 						hostdata->disconnected_queue = cmd;
2342 						dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d lun %d was moved from connected to" "  the disconnected_queue\n", instance->host_no, cmd->device->id, cmd->device->lun));
2343 						/*
2344 						 * Restore phase bits to 0 so an interrupted selection,
2345 						 * arbitration can resume.
2346 						 */
2347 						NCR5380_write(TARGET_COMMAND_REG, 0);
2348 
2349 						/* Enable reselect interrupts */
2350 						NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2351 						/* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2352 						/* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2353 						while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2354 							barrier();
2355 						return;
2356 					}
2357 					/*
2358 					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2359 					 * operation, in violation of the SCSI spec so we can safely
2360 					 * ignore SAVE/RESTORE pointers calls.
2361 					 *
2362 					 * Unfortunately, some disks violate the SCSI spec and
2363 					 * don't issue the required SAVE_POINTERS message before
2364 					 * disconnecting, and we have to break spec to remain
2365 					 * compatible.
2366 					 */
2367 				case SAVE_POINTERS:
2368 				case RESTORE_POINTERS:
2369 					/* Accept message by clearing ACK */
2370 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2371 					break;
2372 				case EXTENDED_MESSAGE:
2373 /*
2374  * Extended messages are sent in the following format :
2375  * Byte
2376  * 0            EXTENDED_MESSAGE == 1
2377  * 1            length (includes one byte for code, doesn't
2378  *              include first two bytes)
2379  * 2            code
2380  * 3..length+1  arguments
2381  *
2382  * Start the extended message buffer with the EXTENDED_MESSAGE
2383  * byte, since scsi_print_msg() wants the whole thing.
2384  */
2385 					extended_msg[0] = EXTENDED_MESSAGE;
2386 					/* Accept first byte by clearing ACK */
2387 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2388 					dprintk(NDEBUG_EXTENDED, ("scsi%d : receiving extended message\n", instance->host_no));
2389 
2390 					len = 2;
2391 					data = extended_msg + 1;
2392 					phase = PHASE_MSGIN;
2393 					NCR5380_transfer_pio(instance, &phase, &len, &data);
2394 
2395 					dprintk(NDEBUG_EXTENDED, ("scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]));
2396 
2397 					if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2398 						/* Accept third byte by clearing ACK */
2399 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2400 						len = extended_msg[1] - 1;
2401 						data = extended_msg + 3;
2402 						phase = PHASE_MSGIN;
2403 
2404 						NCR5380_transfer_pio(instance, &phase, &len, &data);
2405 						dprintk(NDEBUG_EXTENDED, ("scsi%d : message received, residual %d\n", instance->host_no, len));
2406 
2407 						switch (extended_msg[2]) {
2408 						case EXTENDED_SDTR:
2409 						case EXTENDED_WDTR:
2410 						case EXTENDED_MODIFY_DATA_POINTER:
2411 						case EXTENDED_EXTENDED_IDENTIFY:
2412 							tmp = 0;
2413 						}
2414 					} else if (len) {
2415 						printk("scsi%d: error receiving extended message\n", instance->host_no);
2416 						tmp = 0;
2417 					} else {
2418 						printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2419 						tmp = 0;
2420 					}
2421 					/* Fall through to reject message */
2422 
2423 					/*
2424 					 * If we get something weird that we aren't expecting,
2425 					 * reject it.
2426 					 */
2427 				default:
2428 					if (!tmp) {
2429 						printk("scsi%d: rejecting message ", instance->host_no);
2430 						scsi_print_msg(extended_msg);
2431 						printk("\n");
2432 					} else if (tmp != EXTENDED_MESSAGE)
2433 						scmd_printk(KERN_INFO, cmd,
2434 							"rejecting unknown message %02x\n",tmp);
2435 					else
2436 						scmd_printk(KERN_INFO, cmd,
2437 							"rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2438 
2439 					msgout = MESSAGE_REJECT;
2440 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2441 					break;
2442 				}	/* switch (tmp) */
2443 				break;
2444 			case PHASE_MSGOUT:
2445 				len = 1;
2446 				data = &msgout;
2447 				hostdata->last_message = msgout;
2448 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2449 				if (msgout == ABORT) {
2450 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2451 					hostdata->connected = NULL;
2452 					cmd->result = DID_ERROR << 16;
2453 					collect_stats(hostdata, cmd);
2454 					cmd->scsi_done(cmd);
2455 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2456 					return;
2457 				}
2458 				msgout = NOP;
2459 				break;
2460 			case PHASE_CMDOUT:
2461 				len = cmd->cmd_len;
2462 				data = cmd->cmnd;
2463 				/*
2464 				 * XXX for performance reasons, on machines with a
2465 				 * PSEUDO-DMA architecture we should probably
2466 				 * use the dma transfer function.
2467 				 */
2468 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2469 				if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2470 					NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2471 					dprintk(NDEBUG_USLEEP, ("scsi%d : issued command, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2472 					return;
2473 				}
2474 				break;
2475 			case PHASE_STATIN:
2476 				len = 1;
2477 				data = &tmp;
2478 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2479 				cmd->SCp.Status = tmp;
2480 				break;
2481 			default:
2482 				printk("scsi%d : unknown phase\n", instance->host_no);
2483 				NCR5380_dprint(NDEBUG_ALL, instance);
2484 			}	/* switch(phase) */
2485 		}		/* if (tmp * SR_REQ) */
2486 		else {
2487 			/* RvC: go to sleep if polling time expired
2488 			 */
2489 			if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2490 				NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2491 				dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2492 				return;
2493 			}
2494 		}
2495 	}			/* while (1) */
2496 }
2497 
2498 /*
2499  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2500  *
2501  * Purpose : does reselection, initializing the instance->connected
2502  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2503  *      nexus has been reestablished,
2504  *
2505  * Inputs : instance - this instance of the NCR5380.
2506  *
2507  * Locks: io_request_lock held by caller if IRQ driven
2508  */
2509 
2510 static void NCR5380_reselect(struct Scsi_Host *instance) {
2511 	NCR5380_local_declare();
2512 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2513 	 instance->hostdata;
2514 	unsigned char target_mask;
2515 	unsigned char lun, phase;
2516 	int len;
2517 	unsigned char msg[3];
2518 	unsigned char *data;
2519 	Scsi_Cmnd *tmp = NULL, *prev;
2520 	int abort = 0;
2521 	NCR5380_setup(instance);
2522 
2523 	/*
2524 	 * Disable arbitration, etc. since the host adapter obviously
2525 	 * lost, and tell an interrupted NCR5380_select() to restart.
2526 	 */
2527 
2528 	NCR5380_write(MODE_REG, MR_BASE);
2529 	hostdata->restart_select = 1;
2530 
2531 	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2532 	dprintk(NDEBUG_SELECTION, ("scsi%d : reselect\n", instance->host_no));
2533 
2534 	/*
2535 	 * At this point, we have detected that our SCSI ID is on the bus,
2536 	 * SEL is true and BSY was false for at least one bus settle delay
2537 	 * (400 ns).
2538 	 *
2539 	 * We must assert BSY ourselves, until the target drops the SEL
2540 	 * signal.
2541 	 */
2542 
2543 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2544 
2545 	/* FIXME: timeout too long, must fail to workqueue */
2546 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2547 		abort = 1;
2548 
2549 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2550 
2551 	/*
2552 	 * Wait for target to go into MSGIN.
2553 	 * FIXME: timeout needed and fail to work queeu
2554 	 */
2555 
2556 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2557 		abort = 1;
2558 
2559 	len = 1;
2560 	data = msg;
2561 	phase = PHASE_MSGIN;
2562 	NCR5380_transfer_pio(instance, &phase, &len, &data);
2563 
2564 	if (!(msg[0] & 0x80)) {
2565 		printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2566 		scsi_print_msg(msg);
2567 		abort = 1;
2568 	} else {
2569 		/* Accept message by clearing ACK */
2570 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2571 		lun = (msg[0] & 0x07);
2572 
2573 		/*
2574 		 * We need to add code for SCSI-II to track which devices have
2575 		 * I_T_L_Q nexuses established, and which have simple I_T_L
2576 		 * nexuses so we can chose to do additional data transfer.
2577 		 */
2578 
2579 		/*
2580 		 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2581 		 * just reestablished, and remove it from the disconnected queue.
2582 		 */
2583 
2584 
2585 		for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2586 			if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2587 			    ) {
2588 				if (prev) {
2589 					REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2590 					prev->host_scribble = tmp->host_scribble;
2591 				} else {
2592 					REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2593 					hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2594 				}
2595 				tmp->host_scribble = NULL;
2596 				break;
2597 			}
2598 		if (!tmp) {
2599 			printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2600 			/*
2601 			 * Since we have an established nexus that we can't do anything with,
2602 			 * we must abort it.
2603 			 */
2604 			abort = 1;
2605 		}
2606 	}
2607 
2608 	if (abort) {
2609 		do_abort(instance);
2610 	} else {
2611 		hostdata->connected = tmp;
2612 		dprintk(NDEBUG_RESELECTION, ("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->target, tmp->lun, tmp->tag));
2613 	}
2614 }
2615 
2616 /*
2617  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2618  *
2619  * Purpose : called by interrupt handler when DMA finishes or a phase
2620  *      mismatch occurs (which would finish the DMA transfer).
2621  *
2622  * Inputs : instance - this instance of the NCR5380.
2623  *
2624  * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2625  *      nexus has been reestablished, on failure NULL is returned.
2626  */
2627 
2628 #ifdef REAL_DMA
2629 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2630 	NCR5380_local_declare();
2631 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata * instance->hostdata);
2632 	int transferred;
2633 	NCR5380_setup(instance);
2634 
2635 	/*
2636 	 * XXX this might not be right.
2637 	 *
2638 	 * Wait for final byte to transfer, ie wait for ACK to go false.
2639 	 *
2640 	 * We should use the Last Byte Sent bit, unfortunately this is
2641 	 * not available on the 5380/5381 (only the various CMOS chips)
2642 	 *
2643 	 * FIXME: timeout, and need to handle long timeout/irq case
2644 	 */
2645 
2646 	NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2647 
2648 	NCR5380_write(MODE_REG, MR_BASE);
2649 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2650 
2651 	/*
2652 	 * The only places we should see a phase mismatch and have to send
2653 	 * data from the same set of pointers will be the data transfer
2654 	 * phases.  So, residual, requested length are only important here.
2655 	 */
2656 
2657 	if (!(hostdata->connected->SCp.phase & SR_CD)) {
2658 		transferred = instance->dmalen - NCR5380_dma_residual();
2659 		hostdata->connected->SCp.this_residual -= transferred;
2660 		hostdata->connected->SCp.ptr += transferred;
2661 	}
2662 }
2663 #endif				/* def REAL_DMA */
2664 
2665 /*
2666  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2667  *
2668  * Purpose : abort a command
2669  *
2670  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2671  *      host byte of the result field to, if zero DID_ABORTED is
2672  *      used.
2673  *
2674  * Returns : 0 - success, -1 on failure.
2675  *
2676  *	XXX - there is no way to abort the command that is currently
2677  *	connected, you have to wait for it to complete.  If this is
2678  *	a problem, we could implement longjmp() / setjmp(), setjmp()
2679  *	called where the loop started in NCR5380_main().
2680  *
2681  * Locks: host lock taken by caller
2682  */
2683 
2684 static int NCR5380_abort(Scsi_Cmnd * cmd) {
2685 	NCR5380_local_declare();
2686 	struct Scsi_Host *instance = cmd->device->host;
2687 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2688 	Scsi_Cmnd *tmp, **prev;
2689 
2690 	printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2691 	scsi_print_command(cmd);
2692 
2693 	NCR5380_print_status(instance);
2694 
2695 	NCR5380_setup(instance);
2696 
2697 	dprintk(NDEBUG_ABORT, ("scsi%d : abort called\n", instance->host_no));
2698 	dprintk(NDEBUG_ABORT, ("        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)));
2699 
2700 #if 0
2701 /*
2702  * Case 1 : If the command is the currently executing command,
2703  * we'll set the aborted flag and return control so that
2704  * information transfer routine can exit cleanly.
2705  */
2706 
2707 	if (hostdata->connected == cmd) {
2708 		dprintk(NDEBUG_ABORT, ("scsi%d : aborting connected command\n", instance->host_no));
2709 		hostdata->aborted = 1;
2710 /*
2711  * We should perform BSY checking, and make sure we haven't slipped
2712  * into BUS FREE.
2713  */
2714 
2715 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2716 /*
2717  * Since we can't change phases until we've completed the current
2718  * handshake, we have to source or sink a byte of data if the current
2719  * phase is not MSGOUT.
2720  */
2721 
2722 /*
2723  * Return control to the executing NCR drive so we can clear the
2724  * aborted flag and get back into our main loop.
2725  */
2726 
2727 		return 0;
2728 	}
2729 #endif
2730 
2731 /*
2732  * Case 2 : If the command hasn't been issued yet, we simply remove it
2733  *          from the issue queue.
2734  */
2735 
2736 	dprintk(NDEBUG_ABORT, ("scsi%d : abort going into loop.\n", instance->host_no));
2737 	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)
2738 		if (cmd == tmp) {
2739 			REMOVE(5, *prev, tmp, tmp->host_scribble);
2740 			(*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2741 			tmp->host_scribble = NULL;
2742 			tmp->result = DID_ABORT << 16;
2743 			dprintk(NDEBUG_ABORT, ("scsi%d : abort removed command from issue queue.\n", instance->host_no));
2744 			tmp->done(tmp);
2745 			return SUCCESS;
2746 		}
2747 #if (NDEBUG  & NDEBUG_ABORT)
2748 	/* KLL */
2749 		else if (prev == tmp)
2750 			printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2751 #endif
2752 
2753 /*
2754  * Case 3 : If any commands are connected, we're going to fail the abort
2755  *          and let the high level SCSI driver retry at a later time or
2756  *          issue a reset.
2757  *
2758  *          Timeouts, and therefore aborted commands, will be highly unlikely
2759  *          and handling them cleanly in this situation would make the common
2760  *          case of noresets less efficient, and would pollute our code.  So,
2761  *          we fail.
2762  */
2763 
2764 	if (hostdata->connected) {
2765 		dprintk(NDEBUG_ABORT, ("scsi%d : abort failed, command connected.\n", instance->host_no));
2766 		return FAILED;
2767 	}
2768 /*
2769  * Case 4: If the command is currently disconnected from the bus, and
2770  *      there are no connected commands, we reconnect the I_T_L or
2771  *      I_T_L_Q nexus associated with it, go into message out, and send
2772  *      an abort message.
2773  *
2774  * This case is especially ugly. In order to reestablish the nexus, we
2775  * need to call NCR5380_select().  The easiest way to implement this
2776  * function was to abort if the bus was busy, and let the interrupt
2777  * handler triggered on the SEL for reselect take care of lost arbitrations
2778  * where necessary, meaning interrupts need to be enabled.
2779  *
2780  * When interrupts are enabled, the queues may change - so we
2781  * can't remove it from the disconnected queue before selecting it
2782  * because that could cause a failure in hashing the nexus if that
2783  * device reselected.
2784  *
2785  * Since the queues may change, we can't use the pointers from when we
2786  * first locate it.
2787  *
2788  * So, we must first locate the command, and if NCR5380_select()
2789  * succeeds, then issue the abort, relocate the command and remove
2790  * it from the disconnected queue.
2791  */
2792 
2793 	for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2794 		if (cmd == tmp) {
2795 			dprintk(NDEBUG_ABORT, ("scsi%d : aborting disconnected command.\n", instance->host_no));
2796 
2797 			if (NCR5380_select(instance, cmd, (int) cmd->tag))
2798 				return FAILED;
2799 			dprintk(NDEBUG_ABORT, ("scsi%d : nexus reestablished.\n", instance->host_no));
2800 
2801 			do_abort(instance);
2802 
2803 			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)
2804 				if (cmd == tmp) {
2805 					REMOVE(5, *prev, tmp, tmp->host_scribble);
2806 					*prev = (Scsi_Cmnd *) tmp->host_scribble;
2807 					tmp->host_scribble = NULL;
2808 					tmp->result = DID_ABORT << 16;
2809 					tmp->done(tmp);
2810 					return SUCCESS;
2811 				}
2812 		}
2813 /*
2814  * Case 5 : If we reached this point, the command was not found in any of
2815  *          the queues.
2816  *
2817  * We probably reached this point because of an unlikely race condition
2818  * between the command completing successfully and the abortion code,
2819  * so we won't panic, but we will notify the user in case something really
2820  * broke.
2821  */
2822 	printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2823 			"         before abortion\n", instance->host_no);
2824 	return FAILED;
2825 }
2826 
2827 
2828 /*
2829  * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2830  *
2831  * Purpose : reset the SCSI bus.
2832  *
2833  * Returns : SUCCESS
2834  *
2835  * Locks: host lock taken by caller
2836  */
2837 
2838 static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2839 {
2840 	struct Scsi_Host *instance = cmd->device->host;
2841 
2842 	NCR5380_local_declare();
2843 	NCR5380_setup(instance);
2844 	NCR5380_print_status(instance);
2845 
2846 	spin_lock_irq(instance->host_lock);
2847 	do_reset(instance);
2848 	spin_unlock_irq(instance->host_lock);
2849 
2850 	return SUCCESS;
2851 }
2852