xref: /openbmc/linux/drivers/scsi/NCR5380.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 #include <scsi/scsi_transport_spi.h>
91 
92 #ifndef NDEBUG
93 #define NDEBUG 0
94 #endif
95 #ifndef NDEBUG_ABORT
96 #define NDEBUG_ABORT 0
97 #endif
98 
99 #if (NDEBUG & NDEBUG_LISTS)
100 #define LIST(x,y) {printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); }
101 #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); }
102 #else
103 #define LIST(x,y)
104 #define REMOVE(w,x,y,z)
105 #endif
106 
107 #ifndef notyet
108 #undef LINKED
109 #undef REAL_DMA
110 #endif
111 
112 #ifdef REAL_DMA_POLL
113 #undef READ_OVERRUNS
114 #define READ_OVERRUNS
115 #endif
116 
117 #ifdef BOARD_REQUIRES_NO_DELAY
118 #define io_recovery_delay(x)
119 #else
120 #define io_recovery_delay(x)	udelay(x)
121 #endif
122 
123 /*
124  * Design
125  *
126  * This is a generic 5380 driver.  To use it on a different platform,
127  * one simply writes appropriate system specific macros (ie, data
128  * transfer - some PC's will use the I/O bus, 68K's must use
129  * memory mapped) and drops this file in their 'C' wrapper.
130  *
131  * (Note from hch:  unfortunately it was not enough for the different
132  * m68k folks and instead of improving this driver they copied it
133  * and hacked it up for their needs.  As a consequence they lost
134  * most updates to this driver.  Maybe someone will fix all these
135  * drivers to use a common core one day..)
136  *
137  * As far as command queueing, two queues are maintained for
138  * each 5380 in the system - commands that haven't been issued yet,
139  * and commands that are currently executing.  This means that an
140  * unlimited number of commands may be queued, letting
141  * more commands propagate from the higher driver levels giving higher
142  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
143  * allowing multiple commands to propagate all the way to a SCSI-II device
144  * while a command is already executing.
145  *
146  *
147  * Issues specific to the NCR5380 :
148  *
149  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
150  * piece of hardware that requires you to sit in a loop polling for
151  * the REQ signal as long as you are connected.  Some devices are
152  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
153  * while doing long seek operations.
154  *
155  * The workaround for this is to keep track of devices that have
156  * disconnected.  If the device hasn't disconnected, for commands that
157  * should disconnect, we do something like
158  *
159  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
160  *
161  * Some tweaking of N and M needs to be done.  An algorithm based
162  * on "time to data" would give the best results as long as short time
163  * to datas (ie, on the same track) were considered, however these
164  * broken devices are the exception rather than the rule and I'd rather
165  * spend my time optimizing for the normal case.
166  *
167  * Architecture :
168  *
169  * At the heart of the design is a coroutine, NCR5380_main,
170  * which is started from a workqueue for each NCR5380 host in the
171  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
172  * removing the commands from the issue queue and calling
173  * NCR5380_select() if a nexus is not established.
174  *
175  * Once a nexus is established, the NCR5380_information_transfer()
176  * phase goes through the various phases as instructed by the target.
177  * if the target goes into MSG IN and sends a DISCONNECT message,
178  * the command structure is placed into the per instance disconnected
179  * queue, and NCR5380_main tries to find more work.  If the target is
180  * idle for too long, the system will try to sleep.
181  *
182  * If a command has disconnected, eventually an interrupt will trigger,
183  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
184  * to reestablish a nexus.  This will run main if necessary.
185  *
186  * On command termination, the done function will be called as
187  * appropriate.
188  *
189  * SCSI pointers are maintained in the SCp field of SCSI command
190  * structures, being initialized after the command is connected
191  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
192  * Note that in violation of the standard, an implicit SAVE POINTERS operation
193  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
194  */
195 
196 /*
197  * Using this file :
198  * This file a skeleton Linux SCSI driver for the NCR 5380 series
199  * of chips.  To use it, you write an architecture specific functions
200  * and macros and include this file in your driver.
201  *
202  * These macros control options :
203  * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
204  *      defined.
205  *
206  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
207  *      for commands that return with a CHECK CONDITION status.
208  *
209  * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
210  *      transceivers.
211  *
212  * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
213  *      override-configure an IRQ.
214  *
215  * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
216  *      bytes at a time.  Since interrupts are disabled by default during
217  *      these transfers, we might need this to give reasonable interrupt
218  *      service time if the transfer size gets too large.
219  *
220  * LINKED - if defined, linked commands are supported.
221  *
222  * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
223  *
224  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
225  *
226  * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
227  *      rely on phase mismatch and EOP interrupts to determine end
228  *      of phase.
229  *
230  * UNSAFE - leave interrupts enabled during pseudo-DMA transfers.  You
231  *          only really want to use this if you're having a problem with
232  *          dropped characters during high speed communications, and even
233  *          then, you're going to be better off twiddling with transfersize
234  *          in the high level code.
235  *
236  * Defaults for these will be provided although the user may want to adjust
237  * these to allocate CPU resources to the SCSI driver or "real" code.
238  *
239  * USLEEP_SLEEP - amount of time, in jiffies, to sleep
240  *
241  * USLEEP_POLL - amount of time, in jiffies, to poll
242  *
243  * These macros MUST be defined :
244  * NCR5380_local_declare() - declare any local variables needed for your
245  *      transfer routines.
246  *
247  * NCR5380_setup(instance) - initialize any local variables needed from a given
248  *      instance of the host adapter for NCR5380_{read,write,pread,pwrite}
249  *
250  * NCR5380_read(register)  - read from the specified register
251  *
252  * NCR5380_write(register, value) - write to the specific register
253  *
254  * NCR5380_implementation_fields  - additional fields needed for this
255  *      specific implementation of the NCR5380
256  *
257  * Either real DMA *or* pseudo DMA may be implemented
258  * REAL functions :
259  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
260  * Note that the DMA setup functions should return the number of bytes
261  *      that they were able to program the controller for.
262  *
263  * Also note that generic i386/PC versions of these macros are
264  *      available as NCR5380_i386_dma_write_setup,
265  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
266  *
267  * NCR5380_dma_write_setup(instance, src, count) - initialize
268  * NCR5380_dma_read_setup(instance, dst, count) - initialize
269  * NCR5380_dma_residual(instance); - residual count
270  *
271  * PSEUDO functions :
272  * NCR5380_pwrite(instance, src, count)
273  * NCR5380_pread(instance, dst, count);
274  *
275  * The generic driver is initialized by calling NCR5380_init(instance),
276  * after setting the appropriate host specific fields and ID.  If the
277  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
278  * possible) function may be used.
279  */
280 
281 static int do_abort(struct Scsi_Host *host);
282 static void do_reset(struct Scsi_Host *host);
283 
284 /*
285  *	initialize_SCp		-	init the scsi pointer field
286  *	@cmd: command block to set up
287  *
288  *	Set up the internal fields in the SCSI command.
289  */
290 
291 static __inline__ void initialize_SCp(Scsi_Cmnd * cmd)
292 {
293 	/*
294 	 * Initialize the Scsi Pointer field so that all of the commands in the
295 	 * various queues are valid.
296 	 */
297 
298 	if (cmd->use_sg) {
299 		cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
300 		cmd->SCp.buffers_residual = cmd->use_sg - 1;
301 		cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
302 			       cmd->SCp.buffer->offset;
303 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
304 	} else {
305 		cmd->SCp.buffer = NULL;
306 		cmd->SCp.buffers_residual = 0;
307 		cmd->SCp.ptr = (char *) cmd->request_buffer;
308 		cmd->SCp.this_residual = cmd->request_bufflen;
309 	}
310 }
311 
312 /**
313  *	NCR5380_poll_politely	-	wait for NCR5380 status bits
314  *	@instance: controller to poll
315  *	@reg: 5380 register to poll
316  *	@bit: Bitmask to check
317  *	@val: Value required to exit
318  *
319  *	Polls the NCR5380 in a reasonably efficient manner waiting for
320  *	an event to occur, after a short quick poll we begin giving the
321  *	CPU back in non IRQ contexts
322  *
323  *	Returns the value of the register or a negative error code.
324  */
325 
326 static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
327 {
328 	NCR5380_local_declare();
329 	int n = 500;		/* At about 8uS a cycle for the cpu access */
330 	unsigned long end = jiffies + t;
331 	int r;
332 
333 	NCR5380_setup(instance);
334 
335 	while( n-- > 0)
336 	{
337 		r = NCR5380_read(reg);
338 		if((r & bit) == val)
339 			return 0;
340 		cpu_relax();
341 	}
342 
343 	/* t time yet ? */
344 	while(time_before(jiffies, end))
345 	{
346 		r = NCR5380_read(reg);
347 		if((r & bit) == val)
348 			return 0;
349 		if(!in_interrupt())
350 			cond_resched();
351 		else
352 			cpu_relax();
353 	}
354 	return -ETIMEDOUT;
355 }
356 
357 static struct {
358 	unsigned char value;
359 	const char *name;
360 } phases[] __maybe_unused = {
361 	{PHASE_DATAOUT, "DATAOUT"},
362 	{PHASE_DATAIN, "DATAIN"},
363 	{PHASE_CMDOUT, "CMDOUT"},
364 	{PHASE_STATIN, "STATIN"},
365 	{PHASE_MSGOUT, "MSGOUT"},
366 	{PHASE_MSGIN, "MSGIN"},
367 	{PHASE_UNKNOWN, "UNKNOWN"}
368 };
369 
370 #if NDEBUG
371 static struct {
372 	unsigned char mask;
373 	const char *name;
374 } signals[] = {
375 	{SR_DBP, "PARITY"},
376 	{SR_RST, "RST"},
377 	{SR_BSY, "BSY"},
378 	{SR_REQ, "REQ"},
379 	{SR_MSG, "MSG"},
380 	{SR_CD, "CD"},
381 	{SR_IO, "IO"},
382 	{SR_SEL, "SEL"},
383 	{0, NULL}
384 },
385 basrs[] = {
386 	{BASR_ATN, "ATN"},
387 	{BASR_ACK, "ACK"},
388 	{0, NULL}
389 },
390 icrs[] = {
391 	{ICR_ASSERT_RST, "ASSERT RST"},
392 	{ICR_ASSERT_ACK, "ASSERT ACK"},
393 	{ICR_ASSERT_BSY, "ASSERT BSY"},
394 	{ICR_ASSERT_SEL, "ASSERT SEL"},
395 	{ICR_ASSERT_ATN, "ASSERT ATN"},
396 	{ICR_ASSERT_DATA, "ASSERT DATA"},
397 	{0, NULL}
398 },
399 mrs[] = {
400 	{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
401 	{MR_TARGET, "MODE TARGET"},
402 	{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
403 	{MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
404 	{MR_MONITOR_BSY, "MODE MONITOR BSY"},
405 	{MR_DMA_MODE, "MODE DMA"},
406 	{MR_ARBITRATE, "MODE ARBITRATION"},
407 	{0, NULL}
408 };
409 
410 /**
411  *	NCR5380_print	-	print scsi bus signals
412  *	@instance:	adapter state to dump
413  *
414  *	Print the SCSI bus signals for debugging purposes
415  *
416  *	Locks: caller holds hostdata lock (not essential)
417  */
418 
419 static void NCR5380_print(struct Scsi_Host *instance)
420 {
421 	NCR5380_local_declare();
422 	unsigned char status, data, basr, mr, icr, i;
423 	NCR5380_setup(instance);
424 
425 	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
426 	status = NCR5380_read(STATUS_REG);
427 	mr = NCR5380_read(MODE_REG);
428 	icr = NCR5380_read(INITIATOR_COMMAND_REG);
429 	basr = NCR5380_read(BUS_AND_STATUS_REG);
430 
431 	printk("STATUS_REG: %02x ", status);
432 	for (i = 0; signals[i].mask; ++i)
433 		if (status & signals[i].mask)
434 			printk(",%s", signals[i].name);
435 	printk("\nBASR: %02x ", basr);
436 	for (i = 0; basrs[i].mask; ++i)
437 		if (basr & basrs[i].mask)
438 			printk(",%s", basrs[i].name);
439 	printk("\nICR: %02x ", icr);
440 	for (i = 0; icrs[i].mask; ++i)
441 		if (icr & icrs[i].mask)
442 			printk(",%s", icrs[i].name);
443 	printk("\nMODE: %02x ", mr);
444 	for (i = 0; mrs[i].mask; ++i)
445 		if (mr & mrs[i].mask)
446 			printk(",%s", mrs[i].name);
447 	printk("\n");
448 }
449 
450 
451 /*
452  *	NCR5380_print_phase	-	show SCSI phase
453  *	@instance: adapter to dump
454  *
455  * 	Print the current SCSI phase for debugging purposes
456  *
457  *	Locks: none
458  */
459 
460 static void NCR5380_print_phase(struct Scsi_Host *instance)
461 {
462 	NCR5380_local_declare();
463 	unsigned char status;
464 	int i;
465 	NCR5380_setup(instance);
466 
467 	status = NCR5380_read(STATUS_REG);
468 	if (!(status & SR_REQ))
469 		printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
470 	else {
471 		for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
472 		printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
473 	}
474 }
475 #endif
476 
477 /*
478  * These need tweaking, and would probably work best as per-device
479  * flags initialized differently for disk, tape, cd, etc devices.
480  * People with broken devices are free to experiment as to what gives
481  * the best results for them.
482  *
483  * USLEEP_SLEEP should be a minimum seek time.
484  *
485  * USLEEP_POLL should be a maximum rotational latency.
486  */
487 #ifndef USLEEP_SLEEP
488 /* 20 ms (reasonable hard disk speed) */
489 #define USLEEP_SLEEP (20*HZ/1000)
490 #endif
491 /* 300 RPM (floppy speed) */
492 #ifndef USLEEP_POLL
493 #define USLEEP_POLL (200*HZ/1000)
494 #endif
495 #ifndef USLEEP_WAITLONG
496 /* RvC: (reasonable time to wait on select error) */
497 #define USLEEP_WAITLONG USLEEP_SLEEP
498 #endif
499 
500 /*
501  * Function : int should_disconnect (unsigned char cmd)
502  *
503  * Purpose : decide whether a command would normally disconnect or
504  *      not, since if it won't disconnect we should go to sleep.
505  *
506  * Input : cmd - opcode of SCSI command
507  *
508  * Returns : DISCONNECT_LONG if we should disconnect for a really long
509  *      time (ie always, sleep, look for REQ active, sleep),
510  *      DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
511  *      time-to-data delay, DISCONNECT_NONE if this command would return
512  *      immediately.
513  *
514  *      Future sleep algorithms based on time to data can exploit
515  *      something like this so they can differentiate between "normal"
516  *      (ie, read, write, seek) and unusual commands (ie, * format).
517  *
518  * Note : We don't deal with commands that handle an immediate disconnect,
519  *
520  */
521 
522 static int should_disconnect(unsigned char cmd)
523 {
524 	switch (cmd) {
525 	case READ_6:
526 	case WRITE_6:
527 	case SEEK_6:
528 	case READ_10:
529 	case WRITE_10:
530 	case SEEK_10:
531 		return DISCONNECT_TIME_TO_DATA;
532 	case FORMAT_UNIT:
533 	case SEARCH_HIGH:
534 	case SEARCH_LOW:
535 	case SEARCH_EQUAL:
536 		return DISCONNECT_LONG;
537 	default:
538 		return DISCONNECT_NONE;
539 	}
540 }
541 
542 static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
543 {
544 	hostdata->time_expires = jiffies + timeout;
545 	schedule_delayed_work(&hostdata->coroutine, timeout);
546 }
547 
548 
549 static int probe_irq __initdata = 0;
550 
551 /**
552  *	probe_intr	-	helper for IRQ autoprobe
553  *	@irq: interrupt number
554  *	@dev_id: unused
555  *	@regs: unused
556  *
557  *	Set a flag to indicate the IRQ in question was received. This is
558  *	used by the IRQ probe code.
559  */
560 
561 static irqreturn_t __init probe_intr(int irq, void *dev_id)
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 __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
579 						int possible)
580 {
581 	NCR5380_local_declare();
582 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
583 	unsigned long timeout;
584 	int trying_irqs, i, mask;
585 	NCR5380_setup(instance);
586 
587 	for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
588 		if ((mask & possible) && (request_irq(i, &probe_intr, IRQF_DISABLED, "NCR-probe", NULL) == 0))
589 			trying_irqs |= mask;
590 
591 	timeout = jiffies + (250 * HZ / 1000);
592 	probe_irq = SCSI_IRQ_NONE;
593 
594 	/*
595 	 * A interrupt is triggered whenever BSY = false, SEL = true
596 	 * and a bit set in the SELECT_ENABLE_REG is asserted on the
597 	 * SCSI bus.
598 	 *
599 	 * Note that the bus is only driven when the phase control signals
600 	 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
601 	 * to zero.
602 	 */
603 
604 	NCR5380_write(TARGET_COMMAND_REG, 0);
605 	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
606 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
607 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
608 
609 	while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
610 		schedule_timeout_uninterruptible(1);
611 
612 	NCR5380_write(SELECT_ENABLE_REG, 0);
613 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
614 
615 	for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
616 		if (trying_irqs & mask)
617 			free_irq(i, NULL);
618 
619 	return probe_irq;
620 }
621 
622 /**
623  *	NCR58380_print_options	-	show options
624  *	@instance: unused for now
625  *
626  *	Called by probe code indicating the NCR5380 driver options that
627  *	were selected. At some point this will switch to runtime options
628  *	read from the adapter in question
629  *
630  *	Locks: none
631  */
632 
633 static void __init __maybe_unused
634 NCR5380_print_options(struct Scsi_Host *instance)
635 {
636 	printk(" generic options"
637 #ifdef AUTOPROBE_IRQ
638 	       " AUTOPROBE_IRQ"
639 #endif
640 #ifdef AUTOSENSE
641 	       " AUTOSENSE"
642 #endif
643 #ifdef DIFFERENTIAL
644 	       " DIFFERENTIAL"
645 #endif
646 #ifdef REAL_DMA
647 	       " REAL DMA"
648 #endif
649 #ifdef REAL_DMA_POLL
650 	       " REAL DMA POLL"
651 #endif
652 #ifdef PARITY
653 	       " PARITY"
654 #endif
655 #ifdef PSEUDO_DMA
656 	       " PSEUDO DMA"
657 #endif
658 #ifdef UNSAFE
659 	       " UNSAFE "
660 #endif
661 	    );
662 	printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
663 	printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
664 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
665 		printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
666 	}
667 }
668 
669 /**
670  *	NCR5380_print_status 	-	dump controller info
671  *	@instance: controller to dump
672  *
673  *	Print commands in the various queues, called from NCR5380_abort
674  *	and NCR5380_debug to aid debugging.
675  *
676  *	Locks: called functions disable irqs
677  */
678 
679 static void NCR5380_print_status(struct Scsi_Host *instance)
680 {
681 	NCR5380_dprint(NDEBUG_ANY, instance);
682 	NCR5380_dprint_phase(NDEBUG_ANY, instance);
683 }
684 
685 /******************************************/
686 /*
687  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
688  *
689  * *buffer: I/O buffer
690  * **start: if inout == FALSE pointer into buffer where user read should start
691  * offset: current offset
692  * length: length of buffer
693  * hostno: Scsi_Host host_no
694  * inout: TRUE - user is writing; FALSE - user is reading
695  *
696  * Return the number of bytes read from or written
697  */
698 
699 #undef SPRINTF
700 #define SPRINTF(args...) do { if(pos < buffer + length-80) pos += sprintf(pos, ## args); } while(0)
701 static
702 char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length);
703 static
704 char *lprint_command(unsigned char *cmd, char *pos, char *buffer, int len);
705 static
706 char *lprint_opcode(int opcode, char *pos, char *buffer, int length);
707 
708 static int __maybe_unused NCR5380_proc_info(struct Scsi_Host *instance,
709 	char *buffer, char **start, off_t offset, int length, int inout)
710 {
711 	char *pos = buffer;
712 	struct NCR5380_hostdata *hostdata;
713 	Scsi_Cmnd *ptr;
714 
715 	hostdata = (struct NCR5380_hostdata *) instance->hostdata;
716 
717 	if (inout) {		/* Has data been written to the file ? */
718 #ifdef DTC_PUBLIC_RELEASE
719 		dtc_wmaxi = dtc_maxi = 0;
720 #endif
721 #ifdef PAS16_PUBLIC_RELEASE
722 		pas_wmaxi = pas_maxi = 0;
723 #endif
724 		return (-ENOSYS);	/* Currently this is a no-op */
725 	}
726 	SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
727 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
728 		SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
729 #ifdef DTC_PUBLIC_RELEASE
730 	SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
731 #endif
732 #ifdef T128_PUBLIC_RELEASE
733 	SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
734 #endif
735 #ifdef GENERIC_NCR5380_PUBLIC_RELEASE
736 	SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
737 #endif
738 #ifdef PAS16_PUBLIC_RELEASE
739 	SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
740 #endif
741 
742 	SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
743 	SPRINTF("io_port: %04x      ", (int) instance->io_port);
744 	if (instance->irq == SCSI_IRQ_NONE)
745 		SPRINTF("IRQ: None.\n");
746 	else
747 		SPRINTF("IRQ: %d.\n", instance->irq);
748 
749 #ifdef DTC_PUBLIC_RELEASE
750 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
751 #endif
752 #ifdef PAS16_PUBLIC_RELEASE
753 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
754 #endif
755 	spin_lock_irq(instance->host_lock);
756 	if (!hostdata->connected)
757 		SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
758 	else
759 		pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, pos, buffer, length);
760 	SPRINTF("scsi%d: issue_queue\n", instance->host_no);
761 	for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
762 		pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
763 
764 	SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
765 	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
766 		pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
767 	spin_unlock_irq(instance->host_lock);
768 
769 	*start = buffer;
770 	if (pos - buffer < offset)
771 		return 0;
772 	else if (pos - buffer - offset < length)
773 		return pos - buffer - offset;
774 	return length;
775 }
776 
777 static char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length)
778 {
779 	SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
780 	SPRINTF("        command = ");
781 	pos = lprint_command(cmd->cmnd, pos, buffer, length);
782 	return (pos);
783 }
784 
785 static char *lprint_command(unsigned char *command, char *pos, char *buffer, int length)
786 {
787 	int i, s;
788 	pos = lprint_opcode(command[0], pos, buffer, length);
789 	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
790 		SPRINTF("%02x ", command[i]);
791 	SPRINTF("\n");
792 	return (pos);
793 }
794 
795 static char *lprint_opcode(int opcode, char *pos, char *buffer, int length)
796 {
797 	SPRINTF("%2d (0x%02x)", opcode, opcode);
798 	return (pos);
799 }
800 
801 
802 /**
803  *	NCR5380_init	-	initialise an NCR5380
804  *	@instance: adapter to configure
805  *	@flags: control flags
806  *
807  *	Initializes *instance and corresponding 5380 chip,
808  *      with flags OR'd into the initial flags value.
809  *
810  *	Notes : I assume that the host, hostno, and id bits have been
811  *      set correctly.  I don't care about the irq and other fields.
812  *
813  *	Returns 0 for success
814  *
815  *	Locks: interrupts must be enabled when we are called
816  */
817 
818 static int __devinit NCR5380_init(struct Scsi_Host *instance, int flags)
819 {
820 	NCR5380_local_declare();
821 	int i, pass;
822 	unsigned long timeout;
823 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
824 
825 	if(in_interrupt())
826 		printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
827 	/*
828 	 * On NCR53C400 boards, NCR5380 registers are mapped 8 past
829 	 * the base address.
830 	 */
831 
832 #ifdef NCR53C400
833 	if (flags & FLAG_NCR53C400)
834 		instance->NCR5380_instance_name += NCR53C400_address_adjust;
835 #endif
836 
837 	NCR5380_setup(instance);
838 
839 	hostdata->aborted = 0;
840 	hostdata->id_mask = 1 << instance->this_id;
841 	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
842 		if (i > hostdata->id_mask)
843 			hostdata->id_higher_mask |= i;
844 	for (i = 0; i < 8; ++i)
845 		hostdata->busy[i] = 0;
846 #ifdef REAL_DMA
847 	hostdata->dmalen = 0;
848 #endif
849 	hostdata->targets_present = 0;
850 	hostdata->connected = NULL;
851 	hostdata->issue_queue = NULL;
852 	hostdata->disconnected_queue = NULL;
853 
854 	INIT_DELAYED_WORK(&hostdata->coroutine, NCR5380_main);
855 
856 #ifdef NCR5380_STATS
857 	for (i = 0; i < 8; ++i) {
858 		hostdata->time_read[i] = 0;
859 		hostdata->time_write[i] = 0;
860 		hostdata->bytes_read[i] = 0;
861 		hostdata->bytes_write[i] = 0;
862 	}
863 	hostdata->timebase = 0;
864 	hostdata->pendingw = 0;
865 	hostdata->pendingr = 0;
866 #endif
867 
868 	/* The CHECK code seems to break the 53C400. Will check it later maybe */
869 	if (flags & FLAG_NCR53C400)
870 		hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
871 	else
872 		hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
873 
874 	hostdata->host = instance;
875 	hostdata->time_expires = 0;
876 
877 #ifndef AUTOSENSE
878 	if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
879 		    printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
880 		    	   "         be incorrectly cleared.\n", instance->host_no);
881 #endif				/* def AUTOSENSE */
882 
883 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
884 	NCR5380_write(MODE_REG, MR_BASE);
885 	NCR5380_write(TARGET_COMMAND_REG, 0);
886 	NCR5380_write(SELECT_ENABLE_REG, 0);
887 
888 #ifdef NCR53C400
889 	if (hostdata->flags & FLAG_NCR53C400) {
890 		NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
891 	}
892 #endif
893 
894 	/*
895 	 * Detect and correct bus wedge problems.
896 	 *
897 	 * If the system crashed, it may have crashed in a state
898 	 * where a SCSI command was still executing, and the
899 	 * SCSI bus is not in a BUS FREE STATE.
900 	 *
901 	 * If this is the case, we'll try to abort the currently
902 	 * established nexus which we know nothing about, and that
903 	 * failing, do a hard reset of the SCSI bus
904 	 */
905 
906 	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
907 		switch (pass) {
908 		case 1:
909 		case 3:
910 		case 5:
911 			printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
912 			timeout = jiffies + 5 * HZ;
913 			NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
914 			break;
915 		case 2:
916 			printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
917 			do_abort(instance);
918 			break;
919 		case 4:
920 			printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
921 			do_reset(instance);
922 			break;
923 		case 6:
924 			printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
925 			return -ENXIO;
926 		}
927 	}
928 	return 0;
929 }
930 
931 /**
932  *	NCR5380_exit	-	remove an NCR5380
933  *	@instance: adapter to remove
934  */
935 
936 static void __devexit NCR5380_exit(struct Scsi_Host *instance)
937 {
938 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
939 
940 	cancel_delayed_work(&hostdata->coroutine);
941 	flush_scheduled_work();
942 }
943 
944 /**
945  *	NCR5380_queue_command 		-	queue a command
946  *	@cmd: SCSI command
947  *	@done: completion handler
948  *
949  *      cmd is added to the per instance issue_queue, with minor
950  *      twiddling done to the host specific fields of cmd.  If the
951  *      main coroutine is not running, it is restarted.
952  *
953  *	Locks: host lock taken by caller
954  */
955 
956 static int NCR5380_queue_command(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
957 {
958 	struct Scsi_Host *instance = cmd->device->host;
959 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
960 	Scsi_Cmnd *tmp;
961 
962 #if (NDEBUG & NDEBUG_NO_WRITE)
963 	switch (cmd->cmnd[0]) {
964 	case WRITE_6:
965 	case WRITE_10:
966 		printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
967 		cmd->result = (DID_ERROR << 16);
968 		done(cmd);
969 		return 0;
970 	}
971 #endif				/* (NDEBUG & NDEBUG_NO_WRITE) */
972 
973 #ifdef NCR5380_STATS
974 	switch (cmd->cmnd[0]) {
975 		case WRITE:
976 		case WRITE_6:
977 		case WRITE_10:
978 			hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
979 			hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;
980 			hostdata->pendingw++;
981 			break;
982 		case READ:
983 		case READ_6:
984 		case READ_10:
985 			hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
986 			hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;
987 			hostdata->pendingr++;
988 			break;
989 	}
990 #endif
991 
992 	/*
993 	 * We use the host_scribble field as a pointer to the next command
994 	 * in a queue
995 	 */
996 
997 	cmd->host_scribble = NULL;
998 	cmd->scsi_done = done;
999 	cmd->result = 0;
1000 
1001 	/*
1002 	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
1003 	 * commands are added to the head of the queue since any command will
1004 	 * clear the contingent allegiance condition that exists and the
1005 	 * sense data is only guaranteed to be valid while the condition exists.
1006 	 */
1007 
1008 	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1009 		LIST(cmd, hostdata->issue_queue);
1010 		cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
1011 		hostdata->issue_queue = cmd;
1012 	} else {
1013 		for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
1014 		LIST(cmd, tmp);
1015 		tmp->host_scribble = (unsigned char *) cmd;
1016 	}
1017 	dprintk(NDEBUG_QUEUES, ("scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"));
1018 
1019 	/* Run the coroutine if it isn't already running. */
1020 	/* Kick off command processing */
1021 	schedule_delayed_work(&hostdata->coroutine, 0);
1022 	return 0;
1023 }
1024 
1025 
1026 /**
1027  *	NCR5380_main	-	NCR state machines
1028  *
1029  *	NCR5380_main is a coroutine that runs as long as more work can
1030  *      be done on the NCR5380 host adapters in a system.  Both
1031  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1032  *      in case it is not running.
1033  *
1034  *	Locks: called as its own thread with no locks held. Takes the
1035  *	host lock and called routines may take the isa dma lock.
1036  */
1037 
1038 static void NCR5380_main(struct work_struct *work)
1039 {
1040 	struct NCR5380_hostdata *hostdata =
1041 		container_of(work, struct NCR5380_hostdata, coroutine.work);
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  *
1154  *	Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1155  *      from the disconnected queue, and restarting NCR5380_main()
1156  *      as required.
1157  *
1158  *	Locks: takes the needed instance locks
1159  */
1160 
1161 static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1162 {
1163 	NCR5380_local_declare();
1164 	struct Scsi_Host *instance = (struct Scsi_Host *)dev_id;
1165 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1166 	int done;
1167 	unsigned char basr;
1168 	unsigned long flags;
1169 
1170 	dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n", irq));
1171 
1172 	do {
1173 		done = 1;
1174 		spin_lock_irqsave(instance->host_lock, flags);
1175 		/* Look for pending interrupts */
1176 		NCR5380_setup(instance);
1177 		basr = NCR5380_read(BUS_AND_STATUS_REG);
1178 		/* XXX dispatch to appropriate routine if found and done=0 */
1179 		if (basr & BASR_IRQ) {
1180 			NCR5380_dprint(NDEBUG_INTR, instance);
1181 			if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1182 				done = 0;
1183 				dprintk(NDEBUG_INTR, ("scsi%d : SEL interrupt\n", instance->host_no));
1184 				NCR5380_reselect(instance);
1185 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1186 			} else if (basr & BASR_PARITY_ERROR) {
1187 				dprintk(NDEBUG_INTR, ("scsi%d : PARITY interrupt\n", instance->host_no));
1188 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1189 			} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1190 				dprintk(NDEBUG_INTR, ("scsi%d : RESET interrupt\n", instance->host_no));
1191 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1192 			} else {
1193 #if defined(REAL_DMA)
1194 				/*
1195 				 * We should only get PHASE MISMATCH and EOP interrupts
1196 				 * if we have DMA enabled, so do a sanity check based on
1197 				 * the current setting of the MODE register.
1198 				 */
1199 
1200 				if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1201 					int transfered;
1202 
1203 					if (!hostdata->connected)
1204 						panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1205 
1206 					transfered = (hostdata->dmalen - NCR5380_dma_residual(instance));
1207 					hostdata->connected->SCp.this_residual -= transferred;
1208 					hostdata->connected->SCp.ptr += transferred;
1209 					hostdata->dmalen = 0;
1210 
1211 					(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1212 
1213 					/* FIXME: we need to poll briefly then defer a workqueue task ! */
1214 					NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1215 
1216 					NCR5380_write(MODE_REG, MR_BASE);
1217 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1218 				}
1219 #else
1220 				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)));
1221 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1222 #endif
1223 			}
1224 		}	/* if BASR_IRQ */
1225 		spin_unlock_irqrestore(instance->host_lock, flags);
1226 		if(!done)
1227 			schedule_delayed_work(&hostdata->coroutine, 0);
1228 	} while (!done);
1229 	return IRQ_HANDLED;
1230 }
1231 
1232 #endif
1233 
1234 /**
1235  *	collect_stats		-	collect stats on a scsi command
1236  *	@hostdata: adapter
1237  *	@cmd: command being issued
1238  *
1239  *	Update the statistical data by parsing the command in question
1240  */
1241 
1242 static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd)
1243 {
1244 #ifdef NCR5380_STATS
1245 	switch (cmd->cmnd[0]) {
1246 	case WRITE:
1247 	case WRITE_6:
1248 	case WRITE_10:
1249 		hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1250 		hostdata->pendingw--;
1251 		break;
1252 	case READ:
1253 	case READ_6:
1254 	case READ_10:
1255 		hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1256 		hostdata->pendingr--;
1257 		break;
1258 	}
1259 #endif
1260 }
1261 
1262 
1263 /*
1264  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1265  *      int tag);
1266  *
1267  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1268  *      including ARBITRATION, SELECTION, and initial message out for
1269  *      IDENTIFY and queue messages.
1270  *
1271  * Inputs : instance - instantiation of the 5380 driver on which this
1272  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1273  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1274  *      the command that is presently connected.
1275  *
1276  * Returns : -1 if selection could not execute for some reason,
1277  *      0 if selection succeeded or failed because the target
1278  *      did not respond.
1279  *
1280  * Side effects :
1281  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1282  *              with registers as they should have been on entry - ie
1283  *              SELECT_ENABLE will be set appropriately, the NCR5380
1284  *              will cease to drive any SCSI bus signals.
1285  *
1286  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1287  *              instance->connected will be set to cmd.
1288  *              SELECT interrupt will be disabled.
1289  *
1290  *      If failed (no target) : cmd->scsi_done() will be called, and the
1291  *              cmd->result host byte set to DID_BAD_TARGET.
1292  *
1293  *	Locks: caller holds hostdata lock in IRQ mode
1294  */
1295 
1296 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag)
1297 {
1298 	NCR5380_local_declare();
1299 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1300 	unsigned char tmp[3], phase;
1301 	unsigned char *data;
1302 	int len;
1303 	unsigned long timeout;
1304 	unsigned char value;
1305 	int err;
1306 	NCR5380_setup(instance);
1307 
1308 	if (hostdata->selecting)
1309 		goto part2;
1310 
1311 	hostdata->restart_select = 0;
1312 
1313 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1314 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id));
1315 
1316 	/*
1317 	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1318 	 * data bus during SELECTION.
1319 	 */
1320 
1321 	NCR5380_write(TARGET_COMMAND_REG, 0);
1322 
1323 	/*
1324 	 * Start arbitration.
1325 	 */
1326 
1327 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1328 	NCR5380_write(MODE_REG, MR_ARBITRATE);
1329 
1330 
1331 	/* We can be relaxed here, interrupts are on, we are
1332 	   in workqueue context, the birds are singing in the trees */
1333 	spin_unlock_irq(instance->host_lock);
1334 	err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1335 	spin_lock_irq(instance->host_lock);
1336 	if (err < 0) {
1337 		printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1338 		NCR5380_write(MODE_REG, MR_BASE);
1339 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1340 		goto failed;
1341 	}
1342 
1343 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : arbitration complete\n", instance->host_no));
1344 
1345 	/*
1346 	 * The arbitration delay is 2.2us, but this is a minimum and there is
1347 	 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1348 	 * the integral nature of udelay().
1349 	 *
1350 	 */
1351 
1352 	udelay(3);
1353 
1354 	/* Check for lost arbitration */
1355 	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)) {
1356 		NCR5380_write(MODE_REG, MR_BASE);
1357 		dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no));
1358 		goto failed;
1359 	}
1360 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1361 
1362 	if (!(hostdata->flags & FLAG_DTC3181E) &&
1363 	    /* RvC: DTC3181E has some trouble with this
1364 	     *      so we simply removed it. Seems to work with
1365 	     *      only Mustek scanner attached
1366 	     */
1367 	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1368 		NCR5380_write(MODE_REG, MR_BASE);
1369 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1370 		dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no));
1371 		goto failed;
1372 	}
1373 	/*
1374 	 * Again, bus clear + bus settle time is 1.2us, however, this is
1375 	 * a minimum so we'll udelay ceil(1.2)
1376 	 */
1377 
1378 	udelay(2);
1379 
1380 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : won arbitration\n", instance->host_no));
1381 
1382 	/*
1383 	 * Now that we have won arbitration, start Selection process, asserting
1384 	 * the host and target ID's on the SCSI bus.
1385 	 */
1386 
1387 	NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1388 
1389 	/*
1390 	 * Raise ATN while SEL is true before BSY goes false from arbitration,
1391 	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1392 	 * phase immediately after selection.
1393 	 */
1394 
1395 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1396 	NCR5380_write(MODE_REG, MR_BASE);
1397 
1398 	/*
1399 	 * Reselect interrupts must be turned off prior to the dropping of BSY,
1400 	 * otherwise we will trigger an interrupt.
1401 	 */
1402 	NCR5380_write(SELECT_ENABLE_REG, 0);
1403 
1404 	/*
1405 	 * The initiator shall then wait at least two deskew delays and release
1406 	 * the BSY signal.
1407 	 */
1408 	udelay(1);		/* wingel -- wait two bus deskew delay >2*45ns */
1409 
1410 	/* Reset BSY */
1411 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1412 
1413 	/*
1414 	 * Something weird happens when we cease to drive BSY - looks
1415 	 * like the board/chip is letting us do another read before the
1416 	 * appropriate propagation delay has expired, and we're confusing
1417 	 * a BSY signal from ourselves as the target's response to SELECTION.
1418 	 *
1419 	 * A small delay (the 'C++' frontend breaks the pipeline with an
1420 	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1421 	 * tighter 'C' code breaks and requires this) solves the problem -
1422 	 * the 1 us delay is arbitrary, and only used because this delay will
1423 	 * be the same on other platforms and since it works here, it should
1424 	 * work there.
1425 	 *
1426 	 * wingel suggests that this could be due to failing to wait
1427 	 * one deskew delay.
1428 	 */
1429 
1430 	udelay(1);
1431 
1432 	dprintk(NDEBUG_SELECTION, ("scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd)));
1433 
1434 	/*
1435 	 * The SCSI specification calls for a 250 ms timeout for the actual
1436 	 * selection.
1437 	 */
1438 
1439 	timeout = jiffies + (250 * HZ / 1000);
1440 
1441 	/*
1442 	 * XXX very interesting - we're seeing a bounce where the BSY we
1443 	 * asserted is being reflected / still asserted (propagation delay?)
1444 	 * and it's detecting as true.  Sigh.
1445 	 */
1446 
1447 	hostdata->select_time = 0;	/* we count the clock ticks at which we polled */
1448 	hostdata->selecting = cmd;
1449 
1450 part2:
1451 	/* RvC: here we enter after a sleeping period, or immediately after
1452 	   execution of part 1
1453 	   we poll only once ech clock tick */
1454 	value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1455 
1456 	if (!value && (hostdata->select_time < HZ/4)) {
1457 		/* RvC: we still must wait for a device response */
1458 		hostdata->select_time++;	/* after 25 ticks the device has failed */
1459 		NCR5380_set_timer(hostdata, 1);
1460 		return 0;	/* RvC: we return here with hostdata->selecting set,
1461 				   to go to sleep */
1462 	}
1463 
1464 	hostdata->selecting = NULL;/* clear this pointer, because we passed the
1465 					   waiting period */
1466 	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1467 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1468 		NCR5380_reselect(instance);
1469 		printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1470 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1471 		return -1;
1472 	}
1473 	/*
1474 	 * No less than two deskew delays after the initiator detects the
1475 	 * BSY signal is true, it shall release the SEL signal and may
1476 	 * change the DATA BUS.                                     -wingel
1477 	 */
1478 
1479 	udelay(1);
1480 
1481 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1482 
1483 	if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1484 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1485 		if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1486 			printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1487 			if (hostdata->restart_select)
1488 				printk(KERN_DEBUG "\trestart select\n");
1489 			NCR5380_dprint(NDEBUG_SELECTION, instance);
1490 			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1491 			return -1;
1492 		}
1493 		cmd->result = DID_BAD_TARGET << 16;
1494 		collect_stats(hostdata, cmd);
1495 		cmd->scsi_done(cmd);
1496 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1497 		dprintk(NDEBUG_SELECTION, ("scsi%d : target did not respond within 250ms\n", instance->host_no));
1498 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1499 		return 0;
1500 	}
1501 	hostdata->targets_present |= (1 << scmd_id(cmd));
1502 
1503 	/*
1504 	 * Since we followed the SCSI spec, and raised ATN while SEL
1505 	 * was true but before BSY was false during selection, the information
1506 	 * transfer phase should be a MESSAGE OUT phase so that we can send the
1507 	 * IDENTIFY message.
1508 	 *
1509 	 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1510 	 * message (2 bytes) with a tag ID that we increment with every command
1511 	 * until it wraps back to 0.
1512 	 *
1513 	 * XXX - it turns out that there are some broken SCSI-II devices,
1514 	 *       which claim to support tagged queuing but fail when more than
1515 	 *       some number of commands are issued at once.
1516 	 */
1517 
1518 	/* Wait for start of REQ/ACK handshake */
1519 
1520 	spin_unlock_irq(instance->host_lock);
1521 	err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1522 	spin_lock_irq(instance->host_lock);
1523 
1524 	if(err) {
1525 		printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1526 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1527 		goto failed;
1528 	}
1529 
1530 	dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
1531 	tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1532 
1533 	len = 1;
1534 	cmd->tag = 0;
1535 
1536 	/* Send message(s) */
1537 	data = tmp;
1538 	phase = PHASE_MSGOUT;
1539 	NCR5380_transfer_pio(instance, &phase, &len, &data);
1540 	dprintk(NDEBUG_SELECTION, ("scsi%d : nexus established.\n", instance->host_no));
1541 	/* XXX need to handle errors here */
1542 	hostdata->connected = cmd;
1543 	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1544 
1545 	initialize_SCp(cmd);
1546 
1547 	return 0;
1548 
1549 	/* Selection failed */
1550 failed:
1551 	return -1;
1552 
1553 }
1554 
1555 /*
1556  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1557  *      unsigned char *phase, int *count, unsigned char **data)
1558  *
1559  * Purpose : transfers data in given phase using polled I/O
1560  *
1561  * Inputs : instance - instance of driver, *phase - pointer to
1562  *      what phase is expected, *count - pointer to number of
1563  *      bytes to transfer, **data - pointer to data pointer.
1564  *
1565  * Returns : -1 when different phase is entered without transferring
1566  *      maximum number of bytes, 0 if all bytes or transfered or exit
1567  *      is in same phase.
1568  *
1569  *      Also, *phase, *count, *data are modified in place.
1570  *
1571  * XXX Note : handling for bus free may be useful.
1572  */
1573 
1574 /*
1575  * Note : this code is not as quick as it could be, however it
1576  * IS 100% reliable, and for the actual data transfer where speed
1577  * counts, we will always do a pseudo DMA or DMA transfer.
1578  */
1579 
1580 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1581 	NCR5380_local_declare();
1582 	unsigned char p = *phase, tmp;
1583 	int c = *count;
1584 	unsigned char *d = *data;
1585 	/*
1586 	 *      RvC: some administrative data to process polling time
1587 	 */
1588 	int break_allowed = 0;
1589 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1590 	NCR5380_setup(instance);
1591 
1592 	if (!(p & SR_IO))
1593 		dprintk(NDEBUG_PIO, ("scsi%d : pio write %d bytes\n", instance->host_no, c));
1594 	else
1595 		dprintk(NDEBUG_PIO, ("scsi%d : pio read %d bytes\n", instance->host_no, c));
1596 
1597 	/*
1598 	 * The NCR5380 chip will only drive the SCSI bus when the
1599 	 * phase specified in the appropriate bits of the TARGET COMMAND
1600 	 * REGISTER match the STATUS REGISTER
1601 	 */
1602 
1603 	 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1604 
1605 	/* RvC: don't know if this is necessary, but other SCSI I/O is short
1606 	 *      so breaks are not necessary there
1607 	 */
1608 	if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1609 		break_allowed = 1;
1610 	}
1611 	do {
1612 		/*
1613 		 * Wait for assertion of REQ, after which the phase bits will be
1614 		 * valid
1615 		 */
1616 
1617 		/* RvC: we simply poll once, after that we stop temporarily
1618 		 *      and let the device buffer fill up
1619 		 *      if breaking is not allowed, we keep polling as long as needed
1620 		 */
1621 
1622 		/* FIXME */
1623 		while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1624 		if (!(tmp & SR_REQ)) {
1625 			/* timeout condition */
1626 			NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1627 			break;
1628 		}
1629 
1630 		dprintk(NDEBUG_HANDSHAKE, ("scsi%d : REQ detected\n", instance->host_no));
1631 
1632 		/* Check for phase mismatch */
1633 		if ((tmp & PHASE_MASK) != p) {
1634 			dprintk(NDEBUG_HANDSHAKE, ("scsi%d : phase mismatch\n", instance->host_no));
1635 			NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1636 			break;
1637 		}
1638 		/* Do actual transfer from SCSI bus to / from memory */
1639 		if (!(p & SR_IO))
1640 			NCR5380_write(OUTPUT_DATA_REG, *d);
1641 		else
1642 			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1643 
1644 		++d;
1645 
1646 		/*
1647 		 * The SCSI standard suggests that in MSGOUT phase, the initiator
1648 		 * should drop ATN on the last byte of the message phase
1649 		 * after REQ has been asserted for the handshake but before
1650 		 * the initiator raises ACK.
1651 		 */
1652 
1653 		if (!(p & SR_IO)) {
1654 			if (!((p & SR_MSG) && c > 1)) {
1655 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1656 				NCR5380_dprint(NDEBUG_PIO, instance);
1657 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1658 			} else {
1659 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1660 				NCR5380_dprint(NDEBUG_PIO, instance);
1661 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1662 			}
1663 		} else {
1664 			NCR5380_dprint(NDEBUG_PIO, instance);
1665 			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1666 		}
1667 
1668 		/* FIXME - if this fails bus reset ?? */
1669 		NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1670 		dprintk(NDEBUG_HANDSHAKE, ("scsi%d : req false, handshake complete\n", instance->host_no));
1671 
1672 /*
1673  * We have several special cases to consider during REQ/ACK handshaking :
1674  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1675  *      message.  ATN must be dropped as ACK is dropped.
1676  *
1677  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1678  *      message.  We must exit with ACK asserted, so that the calling
1679  *      code may raise ATN before dropping ACK to reject the message.
1680  *
1681  * 3.  ACK and ATN are clear and the target may proceed as normal.
1682  */
1683 		if (!(p == PHASE_MSGIN && c == 1)) {
1684 			if (p == PHASE_MSGOUT && c > 1)
1685 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1686 			else
1687 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1688 		}
1689 	} while (--c);
1690 
1691 	dprintk(NDEBUG_PIO, ("scsi%d : residual %d\n", instance->host_no, c));
1692 
1693 	*count = c;
1694 	*data = d;
1695 	tmp = NCR5380_read(STATUS_REG);
1696 	if (tmp & SR_REQ)
1697 		*phase = tmp & PHASE_MASK;
1698 	else
1699 		*phase = PHASE_UNKNOWN;
1700 
1701 	if (!c || (*phase == p))
1702 		return 0;
1703 	else
1704 		return -1;
1705 }
1706 
1707 /**
1708  *	do_reset	-	issue a reset command
1709  *	@host: adapter to reset
1710  *
1711  *	Issue a reset sequence to the NCR5380 and try and get the bus
1712  *	back into sane shape.
1713  *
1714  *	Locks: caller holds queue lock
1715  */
1716 
1717 static void do_reset(struct Scsi_Host *host) {
1718 	NCR5380_local_declare();
1719 	NCR5380_setup(host);
1720 
1721 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1722 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1723 	udelay(25);
1724 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1725 }
1726 
1727 /*
1728  * Function : do_abort (Scsi_Host *host)
1729  *
1730  * Purpose : abort the currently established nexus.  Should only be
1731  *      called from a routine which can drop into a
1732  *
1733  * Returns : 0 on success, -1 on failure.
1734  *
1735  * Locks: queue lock held by caller
1736  *	FIXME: sort this out and get new_eh running
1737  */
1738 
1739 static int do_abort(struct Scsi_Host *host) {
1740 	NCR5380_local_declare();
1741 	unsigned char *msgptr, phase, tmp;
1742 	int len;
1743 	int rc;
1744 	NCR5380_setup(host);
1745 
1746 
1747 	/* Request message out phase */
1748 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1749 
1750 	/*
1751 	 * Wait for the target to indicate a valid phase by asserting
1752 	 * REQ.  Once this happens, we'll have either a MSGOUT phase
1753 	 * and can immediately send the ABORT message, or we'll have some
1754 	 * other phase and will have to source/sink data.
1755 	 *
1756 	 * We really don't care what value was on the bus or what value
1757 	 * the target sees, so we just handshake.
1758 	 */
1759 
1760 	rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1761 
1762 	if(rc < 0)
1763 		return -1;
1764 
1765 	tmp = (unsigned char)rc;
1766 
1767 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1768 
1769 	if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1770 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1771 		rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1772 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1773 		if(rc == -1)
1774 			return -1;
1775 	}
1776 	tmp = ABORT;
1777 	msgptr = &tmp;
1778 	len = 1;
1779 	phase = PHASE_MSGOUT;
1780 	NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1781 
1782 	/*
1783 	 * If we got here, and the command completed successfully,
1784 	 * we're about to go into bus free state.
1785 	 */
1786 
1787 	return len ? -1 : 0;
1788 }
1789 
1790 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1791 /*
1792  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1793  *      unsigned char *phase, int *count, unsigned char **data)
1794  *
1795  * Purpose : transfers data in given phase using either real
1796  *      or pseudo DMA.
1797  *
1798  * Inputs : instance - instance of driver, *phase - pointer to
1799  *      what phase is expected, *count - pointer to number of
1800  *      bytes to transfer, **data - pointer to data pointer.
1801  *
1802  * Returns : -1 when different phase is entered without transferring
1803  *      maximum number of bytes, 0 if all bytes or transfered or exit
1804  *      is in same phase.
1805  *
1806  *      Also, *phase, *count, *data are modified in place.
1807  *
1808  *	Locks: io_request lock held by caller
1809  */
1810 
1811 
1812 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1813 	NCR5380_local_declare();
1814 	register int c = *count;
1815 	register unsigned char p = *phase;
1816 	register unsigned char *d = *data;
1817 	unsigned char tmp;
1818 	int foo;
1819 #if defined(REAL_DMA_POLL)
1820 	int cnt, toPIO;
1821 	unsigned char saved_data = 0, overrun = 0, residue;
1822 #endif
1823 
1824 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1825 
1826 	NCR5380_setup(instance);
1827 
1828 	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1829 		*phase = tmp;
1830 		return -1;
1831 	}
1832 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1833 #ifdef READ_OVERRUNS
1834 	if (p & SR_IO) {
1835 		c -= 2;
1836 	}
1837 #endif
1838 	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));
1839 	hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1840 #endif
1841 
1842 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1843 
1844 #ifdef REAL_DMA
1845 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1846 #elif defined(REAL_DMA_POLL)
1847 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1848 #else
1849 	/*
1850 	 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1851 	 * were not disabled for the duration of a single DMA transfer, from
1852 	 * before the setting of DMA mode to after transfer of the last byte.
1853 	 */
1854 
1855 #if defined(PSEUDO_DMA) && defined(UNSAFE)
1856 	spin_unlock_irq(instance->host_lock);
1857 #endif
1858 	/* KLL May need eop and parity in 53c400 */
1859 	if (hostdata->flags & FLAG_NCR53C400)
1860 		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);
1861 	else
1862 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1863 #endif				/* def REAL_DMA */
1864 
1865 	dprintk(NDEBUG_DMA, ("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)));
1866 
1867 	/*
1868 	 *	On the PAS16 at least I/O recovery delays are not needed here.
1869 	 *	Everyone else seems to want them.
1870 	 */
1871 
1872 	if (p & SR_IO) {
1873 		io_recovery_delay(1);
1874 		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1875 	} else {
1876 		io_recovery_delay(1);
1877 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1878 		io_recovery_delay(1);
1879 		NCR5380_write(START_DMA_SEND_REG, 0);
1880 		io_recovery_delay(1);
1881 	}
1882 
1883 #if defined(REAL_DMA_POLL)
1884 	do {
1885 		tmp = NCR5380_read(BUS_AND_STATUS_REG);
1886 	} while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1887 
1888 /*
1889    At this point, either we've completed DMA, or we have a phase mismatch,
1890    or we've unexpectedly lost BUSY (which is a real error).
1891 
1892    For write DMAs, we want to wait until the last byte has been
1893    transferred out over the bus before we turn off DMA mode.  Alas, there
1894    seems to be no terribly good way of doing this on a 5380 under all
1895    conditions.  For non-scatter-gather operations, we can wait until REQ
1896    and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1897    are nastier, since the device will be expecting more data than we
1898    are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1899    could test LAST BIT SENT to assure transfer (I imagine this is precisely
1900    why this signal was added to the newer chips) but on the older 538[01]
1901    this signal does not exist.  The workaround for this lack is a watchdog;
1902    we bail out of the wait-loop after a modest amount of wait-time if
1903    the usual exit conditions are not met.  Not a terribly clean or
1904    correct solution :-%
1905 
1906    Reads are equally tricky due to a nasty characteristic of the NCR5380.
1907    If the chip is in DMA mode for an READ, it will respond to a target's
1908    REQ by latching the SCSI data into the INPUT DATA register and asserting
1909    ACK, even if it has _already_ been notified by the DMA controller that
1910    the current DMA transfer has completed!  If the NCR5380 is then taken
1911    out of DMA mode, this already-acknowledged byte is lost.
1912 
1913    This is not a problem for "one DMA transfer per command" reads, because
1914    the situation will never arise... either all of the data is DMA'ed
1915    properly, or the target switches to MESSAGE IN phase to signal a
1916    disconnection (either operation bringing the DMA to a clean halt).
1917    However, in order to handle scatter-reads, we must work around the
1918    problem.  The chosen fix is to DMA N-2 bytes, then check for the
1919    condition before taking the NCR5380 out of DMA mode.  One or two extra
1920    bytes are transferred via PIO as necessary to fill out the original
1921    request.
1922  */
1923 
1924 	if (p & SR_IO) {
1925 #ifdef READ_OVERRUNS
1926 		udelay(10);
1927 		if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1928 			saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1929 			overrun = 1;
1930 		}
1931 #endif
1932 	} else {
1933 		int limit = 100;
1934 		while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1935 			if (!(tmp & BASR_PHASE_MATCH))
1936 				break;
1937 			if (--limit < 0)
1938 				break;
1939 		}
1940 	}
1941 
1942 	dprintk(NDEBUG_DMA, ("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG)));
1943 
1944 	NCR5380_write(MODE_REG, MR_BASE);
1945 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1946 
1947 	residue = NCR5380_dma_residual(instance);
1948 	c -= residue;
1949 	*count -= c;
1950 	*data += c;
1951 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1952 
1953 #ifdef READ_OVERRUNS
1954 	if (*phase == p && (p & SR_IO) && residue == 0) {
1955 		if (overrun) {
1956 			dprintk(NDEBUG_DMA, ("Got an input overrun, using saved byte\n"));
1957 			**data = saved_data;
1958 			*data += 1;
1959 			*count -= 1;
1960 			cnt = toPIO = 1;
1961 		} else {
1962 			printk("No overrun??\n");
1963 			cnt = toPIO = 2;
1964 		}
1965 		dprintk(NDEBUG_DMA, ("Doing %d-byte PIO to 0x%X\n", cnt, *data));
1966 		NCR5380_transfer_pio(instance, phase, &cnt, data);
1967 		*count -= toPIO - cnt;
1968 	}
1969 #endif
1970 
1971 	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)));
1972 	return 0;
1973 
1974 #elif defined(REAL_DMA)
1975 	return 0;
1976 #else				/* defined(REAL_DMA_POLL) */
1977 	if (p & SR_IO) {
1978 #ifdef DMA_WORKS_RIGHT
1979 		foo = NCR5380_pread(instance, d, c);
1980 #else
1981 		int diff = 1;
1982 		if (hostdata->flags & FLAG_NCR53C400) {
1983 			diff = 0;
1984 		}
1985 		if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1986 			/*
1987 			 * We can't disable DMA mode after successfully transferring
1988 			 * what we plan to be the last byte, since that would open up
1989 			 * a race condition where if the target asserted REQ before
1990 			 * we got the DMA mode reset, the NCR5380 would have latched
1991 			 * an additional byte into the INPUT DATA register and we'd
1992 			 * have dropped it.
1993 			 *
1994 			 * The workaround was to transfer one fewer bytes than we
1995 			 * intended to with the pseudo-DMA read function, wait for
1996 			 * the chip to latch the last byte, read it, and then disable
1997 			 * pseudo-DMA mode.
1998 			 *
1999 			 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
2000 			 * REQ is deasserted when ACK is asserted, and not reasserted
2001 			 * until ACK goes false.  Since the NCR5380 won't lower ACK
2002 			 * until DACK is asserted, which won't happen unless we twiddle
2003 			 * the DMA port or we take the NCR5380 out of DMA mode, we
2004 			 * can guarantee that we won't handshake another extra
2005 			 * byte.
2006 			 */
2007 
2008 			if (!(hostdata->flags & FLAG_NCR53C400)) {
2009 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
2010 				/* Wait for clean handshake */
2011 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2012 				d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2013 			}
2014 		}
2015 #endif
2016 	} else {
2017 #ifdef DMA_WORKS_RIGHT
2018 		foo = NCR5380_pwrite(instance, d, c);
2019 #else
2020 		int timeout;
2021 		dprintk(NDEBUG_C400_PWRITE, ("About to pwrite %d bytes\n", c));
2022 		if (!(foo = NCR5380_pwrite(instance, d, c))) {
2023 			/*
2024 			 * Wait for the last byte to be sent.  If REQ is being asserted for
2025 			 * the byte we're interested, we'll ACK it and it will go false.
2026 			 */
2027 			if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2028 				timeout = 20000;
2029 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2030 
2031 				if (!timeout)
2032 					dprintk(NDEBUG_LAST_BYTE_SENT, ("scsi%d : timed out on last byte\n", instance->host_no));
2033 
2034 				if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2035 					hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2036 					if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2037 						hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2038 						dprintk(NDEBUG_LAST_WRITE_SENT, ("scsi%d : last bit sent works\n", instance->host_no));
2039 					}
2040 				}
2041 			} else {
2042 				dprintk(NDEBUG_C400_PWRITE, ("Waiting for LASTBYTE\n"));
2043 				while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2044 				dprintk(NDEBUG_C400_PWRITE, ("Got LASTBYTE\n"));
2045 			}
2046 		}
2047 #endif
2048 	}
2049 	NCR5380_write(MODE_REG, MR_BASE);
2050 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2051 
2052 	if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2053 		dprintk(NDEBUG_C400_PWRITE, ("53C400w: Checking for IRQ\n"));
2054 		if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2055 			dprintk(NDEBUG_C400_PWRITE, ("53C400w:    got it, reading reset interrupt reg\n"));
2056 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2057 		} else {
2058 			printk("53C400w:    IRQ NOT THERE!\n");
2059 		}
2060 	}
2061 	*data = d + c;
2062 	*count = 0;
2063 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2064 #if defined(PSEUDO_DMA) && defined(UNSAFE)
2065 	spin_lock_irq(instance->host_lock);
2066 #endif				/* defined(REAL_DMA_POLL) */
2067 	return foo;
2068 #endif				/* def REAL_DMA */
2069 }
2070 #endif				/* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2071 
2072 /*
2073  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2074  *
2075  * Purpose : run through the various SCSI phases and do as the target
2076  *      directs us to.  Operates on the currently connected command,
2077  *      instance->connected.
2078  *
2079  * Inputs : instance, instance for which we are doing commands
2080  *
2081  * Side effects : SCSI things happen, the disconnected queue will be
2082  *      modified if a command disconnects, *instance->connected will
2083  *      change.
2084  *
2085  * XXX Note : we need to watch for bus free or a reset condition here
2086  *      to recover from an unexpected bus free condition.
2087  *
2088  * Locks: io_request_lock held by caller in IRQ mode
2089  */
2090 
2091 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2092 	NCR5380_local_declare();
2093 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2094 	unsigned char msgout = NOP;
2095 	int sink = 0;
2096 	int len;
2097 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2098 	int transfersize;
2099 #endif
2100 	unsigned char *data;
2101 	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2102 	Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2103 	/* RvC: we need to set the end of the polling time */
2104 	unsigned long poll_time = jiffies + USLEEP_POLL;
2105 
2106 	NCR5380_setup(instance);
2107 
2108 	while (1) {
2109 		tmp = NCR5380_read(STATUS_REG);
2110 		/* We only have a valid SCSI phase when REQ is asserted */
2111 		if (tmp & SR_REQ) {
2112 			phase = (tmp & PHASE_MASK);
2113 			if (phase != old_phase) {
2114 				old_phase = phase;
2115 				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2116 			}
2117 			if (sink && (phase != PHASE_MSGOUT)) {
2118 				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2119 
2120 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2121 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2122 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2123 				sink = 0;
2124 				continue;
2125 			}
2126 			switch (phase) {
2127 			case PHASE_DATAIN:
2128 			case PHASE_DATAOUT:
2129 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2130 				printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2131 				sink = 1;
2132 				do_abort(instance);
2133 				cmd->result = DID_ERROR << 16;
2134 				cmd->scsi_done(cmd);
2135 				return;
2136 #endif
2137 				/*
2138 				 * If there is no room left in the current buffer in the
2139 				 * scatter-gather list, move onto the next one.
2140 				 */
2141 
2142 				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2143 					++cmd->SCp.buffer;
2144 					--cmd->SCp.buffers_residual;
2145 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
2146 					cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
2147 						       cmd->SCp.buffer->offset;
2148 					dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
2149 				}
2150 				/*
2151 				 * The preferred transfer method is going to be
2152 				 * PSEUDO-DMA for systems that are strictly PIO,
2153 				 * since we can let the hardware do the handshaking.
2154 				 *
2155 				 * For this to work, we need to know the transfersize
2156 				 * ahead of time, since the pseudo-DMA code will sit
2157 				 * in an unconditional loop.
2158 				 */
2159 
2160 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2161 				/* KLL
2162 				 * PSEUDO_DMA is defined here. If this is the g_NCR5380
2163 				 * driver then it will always be defined, so the
2164 				 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2165 				 * NCR5380 case.  I think this is a fairly clean solution.
2166 				 * We supplement these 2 if's with the flag.
2167 				 */
2168 #ifdef NCR5380_dma_xfer_len
2169 				if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2170 #else
2171 				transfersize = cmd->transfersize;
2172 
2173 #ifdef LIMIT_TRANSFERSIZE	/* If we have problems with interrupt service */
2174 				if (transfersize > 512)
2175 					transfersize = 512;
2176 #endif				/* LIMIT_TRANSFERSIZE */
2177 
2178 				if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2179 					/* Limit transfers to 32K, for xx400 & xx406
2180 					 * pseudoDMA that transfers in 128 bytes blocks. */
2181 					if (transfersize > 32 * 1024)
2182 						transfersize = 32 * 1024;
2183 #endif
2184 					len = transfersize;
2185 					if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2186 						/*
2187 						 * If the watchdog timer fires, all future accesses to this
2188 						 * device will use the polled-IO.
2189 						 */
2190 						scmd_printk(KERN_INFO, cmd,
2191 							    "switching to slow handshake\n");
2192 						cmd->device->borken = 1;
2193 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2194 						sink = 1;
2195 						do_abort(instance);
2196 						cmd->result = DID_ERROR << 16;
2197 						cmd->scsi_done(cmd);
2198 						/* XXX - need to source or sink data here, as appropriate */
2199 					} else
2200 						cmd->SCp.this_residual -= transfersize - len;
2201 				} else
2202 #endif				/* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2203 					NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2204 							     &cmd->SCp.ptr);
2205 				break;
2206 			case PHASE_MSGIN:
2207 				len = 1;
2208 				data = &tmp;
2209 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2210 				cmd->SCp.Message = tmp;
2211 
2212 				switch (tmp) {
2213 					/*
2214 					 * Linking lets us reduce the time required to get the
2215 					 * next command out to the device, hopefully this will
2216 					 * mean we don't waste another revolution due to the delays
2217 					 * required by ARBITRATION and another SELECTION.
2218 					 *
2219 					 * In the current implementation proposal, low level drivers
2220 					 * merely have to start the next command, pointed to by
2221 					 * next_link, done() is called as with unlinked commands.
2222 					 */
2223 #ifdef LINKED
2224 				case LINKED_CMD_COMPLETE:
2225 				case LINKED_FLG_CMD_COMPLETE:
2226 					/* Accept message by clearing ACK */
2227 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2228 					dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun));
2229 					/*
2230 					 * Sanity check : A linked command should only terminate with
2231 					 * one of these messages if there are more linked commands
2232 					 * available.
2233 					 */
2234 					if (!cmd->next_link) {
2235 						printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2236 						sink = 1;
2237 						do_abort(instance);
2238 						return;
2239 					}
2240 					initialize_SCp(cmd->next_link);
2241 					/* The next command is still part of this process */
2242 					cmd->next_link->tag = cmd->tag;
2243 					cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2244 					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));
2245 					collect_stats(hostdata, cmd);
2246 					cmd->scsi_done(cmd);
2247 					cmd = hostdata->connected;
2248 					break;
2249 #endif				/* def LINKED */
2250 				case ABORT:
2251 				case COMMAND_COMPLETE:
2252 					/* Accept message by clearing ACK */
2253 					sink = 1;
2254 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2255 					hostdata->connected = NULL;
2256 					dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun));
2257 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2258 
2259 					/*
2260 					 * I'm not sure what the correct thing to do here is :
2261 					 *
2262 					 * If the command that just executed is NOT a request
2263 					 * sense, the obvious thing to do is to set the result
2264 					 * code to the values of the stored parameters.
2265 					 *
2266 					 * If it was a REQUEST SENSE command, we need some way
2267 					 * to differentiate between the failure code of the original
2268 					 * and the failure code of the REQUEST sense - the obvious
2269 					 * case is success, where we fall through and leave the result
2270 					 * code unchanged.
2271 					 *
2272 					 * The non-obvious place is where the REQUEST SENSE failed
2273 					 */
2274 
2275 					if (cmd->cmnd[0] != REQUEST_SENSE)
2276 						cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2277 					else if (status_byte(cmd->SCp.Status) != GOOD)
2278 						cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2279 
2280 #ifdef AUTOSENSE
2281 					if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2282 						hostdata->ses.cmd_len) {
2283 						scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2284 						hostdata->ses.cmd_len = 0 ;
2285 					}
2286 
2287 					if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2288 						scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2289 
2290 						dprintk(NDEBUG_AUTOSENSE, ("scsi%d : performing request sense\n", instance->host_no));
2291 
2292 						LIST(cmd, hostdata->issue_queue);
2293 						cmd->host_scribble = (unsigned char *)
2294 						    hostdata->issue_queue;
2295 						hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2296 						dprintk(NDEBUG_QUEUES, ("scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no));
2297 					} else
2298 #endif				/* def AUTOSENSE */
2299 					{
2300 						collect_stats(hostdata, cmd);
2301 						cmd->scsi_done(cmd);
2302 					}
2303 
2304 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2305 					/*
2306 					 * Restore phase bits to 0 so an interrupted selection,
2307 					 * arbitration can resume.
2308 					 */
2309 					NCR5380_write(TARGET_COMMAND_REG, 0);
2310 
2311 					while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2312 						barrier();
2313 					return;
2314 				case MESSAGE_REJECT:
2315 					/* Accept message by clearing ACK */
2316 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2317 					switch (hostdata->last_message) {
2318 					case HEAD_OF_QUEUE_TAG:
2319 					case ORDERED_QUEUE_TAG:
2320 					case SIMPLE_QUEUE_TAG:
2321 						cmd->device->simple_tags = 0;
2322 						hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2323 						break;
2324 					default:
2325 						break;
2326 					}
2327 				case DISCONNECT:{
2328 						/* Accept message by clearing ACK */
2329 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2330 						cmd->device->disconnect = 1;
2331 						LIST(cmd, hostdata->disconnected_queue);
2332 						cmd->host_scribble = (unsigned char *)
2333 						    hostdata->disconnected_queue;
2334 						hostdata->connected = NULL;
2335 						hostdata->disconnected_queue = cmd;
2336 						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));
2337 						/*
2338 						 * Restore phase bits to 0 so an interrupted selection,
2339 						 * arbitration can resume.
2340 						 */
2341 						NCR5380_write(TARGET_COMMAND_REG, 0);
2342 
2343 						/* Enable reselect interrupts */
2344 						NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2345 						/* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2346 						/* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2347 						while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2348 							barrier();
2349 						return;
2350 					}
2351 					/*
2352 					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2353 					 * operation, in violation of the SCSI spec so we can safely
2354 					 * ignore SAVE/RESTORE pointers calls.
2355 					 *
2356 					 * Unfortunately, some disks violate the SCSI spec and
2357 					 * don't issue the required SAVE_POINTERS message before
2358 					 * disconnecting, and we have to break spec to remain
2359 					 * compatible.
2360 					 */
2361 				case SAVE_POINTERS:
2362 				case RESTORE_POINTERS:
2363 					/* Accept message by clearing ACK */
2364 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2365 					break;
2366 				case EXTENDED_MESSAGE:
2367 /*
2368  * Extended messages are sent in the following format :
2369  * Byte
2370  * 0            EXTENDED_MESSAGE == 1
2371  * 1            length (includes one byte for code, doesn't
2372  *              include first two bytes)
2373  * 2            code
2374  * 3..length+1  arguments
2375  *
2376  * Start the extended message buffer with the EXTENDED_MESSAGE
2377  * byte, since spi_print_msg() wants the whole thing.
2378  */
2379 					extended_msg[0] = EXTENDED_MESSAGE;
2380 					/* Accept first byte by clearing ACK */
2381 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2382 					dprintk(NDEBUG_EXTENDED, ("scsi%d : receiving extended message\n", instance->host_no));
2383 
2384 					len = 2;
2385 					data = extended_msg + 1;
2386 					phase = PHASE_MSGIN;
2387 					NCR5380_transfer_pio(instance, &phase, &len, &data);
2388 
2389 					dprintk(NDEBUG_EXTENDED, ("scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]));
2390 
2391 					if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2392 						/* Accept third byte by clearing ACK */
2393 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2394 						len = extended_msg[1] - 1;
2395 						data = extended_msg + 3;
2396 						phase = PHASE_MSGIN;
2397 
2398 						NCR5380_transfer_pio(instance, &phase, &len, &data);
2399 						dprintk(NDEBUG_EXTENDED, ("scsi%d : message received, residual %d\n", instance->host_no, len));
2400 
2401 						switch (extended_msg[2]) {
2402 						case EXTENDED_SDTR:
2403 						case EXTENDED_WDTR:
2404 						case EXTENDED_MODIFY_DATA_POINTER:
2405 						case EXTENDED_EXTENDED_IDENTIFY:
2406 							tmp = 0;
2407 						}
2408 					} else if (len) {
2409 						printk("scsi%d: error receiving extended message\n", instance->host_no);
2410 						tmp = 0;
2411 					} else {
2412 						printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2413 						tmp = 0;
2414 					}
2415 					/* Fall through to reject message */
2416 
2417 					/*
2418 					 * If we get something weird that we aren't expecting,
2419 					 * reject it.
2420 					 */
2421 				default:
2422 					if (!tmp) {
2423 						printk("scsi%d: rejecting message ", instance->host_no);
2424 						spi_print_msg(extended_msg);
2425 						printk("\n");
2426 					} else if (tmp != EXTENDED_MESSAGE)
2427 						scmd_printk(KERN_INFO, cmd,
2428 							"rejecting unknown message %02x\n",tmp);
2429 					else
2430 						scmd_printk(KERN_INFO, cmd,
2431 							"rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2432 
2433 					msgout = MESSAGE_REJECT;
2434 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2435 					break;
2436 				}	/* switch (tmp) */
2437 				break;
2438 			case PHASE_MSGOUT:
2439 				len = 1;
2440 				data = &msgout;
2441 				hostdata->last_message = msgout;
2442 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2443 				if (msgout == ABORT) {
2444 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2445 					hostdata->connected = NULL;
2446 					cmd->result = DID_ERROR << 16;
2447 					collect_stats(hostdata, cmd);
2448 					cmd->scsi_done(cmd);
2449 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2450 					return;
2451 				}
2452 				msgout = NOP;
2453 				break;
2454 			case PHASE_CMDOUT:
2455 				len = cmd->cmd_len;
2456 				data = cmd->cmnd;
2457 				/*
2458 				 * XXX for performance reasons, on machines with a
2459 				 * PSEUDO-DMA architecture we should probably
2460 				 * use the dma transfer function.
2461 				 */
2462 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2463 				if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2464 					NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2465 					dprintk(NDEBUG_USLEEP, ("scsi%d : issued command, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2466 					return;
2467 				}
2468 				break;
2469 			case PHASE_STATIN:
2470 				len = 1;
2471 				data = &tmp;
2472 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2473 				cmd->SCp.Status = tmp;
2474 				break;
2475 			default:
2476 				printk("scsi%d : unknown phase\n", instance->host_no);
2477 				NCR5380_dprint(NDEBUG_ALL, instance);
2478 			}	/* switch(phase) */
2479 		}		/* if (tmp * SR_REQ) */
2480 		else {
2481 			/* RvC: go to sleep if polling time expired
2482 			 */
2483 			if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2484 				NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2485 				dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2486 				return;
2487 			}
2488 		}
2489 	}			/* while (1) */
2490 }
2491 
2492 /*
2493  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2494  *
2495  * Purpose : does reselection, initializing the instance->connected
2496  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2497  *      nexus has been reestablished,
2498  *
2499  * Inputs : instance - this instance of the NCR5380.
2500  *
2501  * Locks: io_request_lock held by caller if IRQ driven
2502  */
2503 
2504 static void NCR5380_reselect(struct Scsi_Host *instance) {
2505 	NCR5380_local_declare();
2506 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2507 	 instance->hostdata;
2508 	unsigned char target_mask;
2509 	unsigned char lun, phase;
2510 	int len;
2511 	unsigned char msg[3];
2512 	unsigned char *data;
2513 	Scsi_Cmnd *tmp = NULL, *prev;
2514 	int abort = 0;
2515 	NCR5380_setup(instance);
2516 
2517 	/*
2518 	 * Disable arbitration, etc. since the host adapter obviously
2519 	 * lost, and tell an interrupted NCR5380_select() to restart.
2520 	 */
2521 
2522 	NCR5380_write(MODE_REG, MR_BASE);
2523 	hostdata->restart_select = 1;
2524 
2525 	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2526 	dprintk(NDEBUG_SELECTION, ("scsi%d : reselect\n", instance->host_no));
2527 
2528 	/*
2529 	 * At this point, we have detected that our SCSI ID is on the bus,
2530 	 * SEL is true and BSY was false for at least one bus settle delay
2531 	 * (400 ns).
2532 	 *
2533 	 * We must assert BSY ourselves, until the target drops the SEL
2534 	 * signal.
2535 	 */
2536 
2537 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2538 
2539 	/* FIXME: timeout too long, must fail to workqueue */
2540 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2541 		abort = 1;
2542 
2543 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2544 
2545 	/*
2546 	 * Wait for target to go into MSGIN.
2547 	 * FIXME: timeout needed and fail to work queeu
2548 	 */
2549 
2550 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2551 		abort = 1;
2552 
2553 	len = 1;
2554 	data = msg;
2555 	phase = PHASE_MSGIN;
2556 	NCR5380_transfer_pio(instance, &phase, &len, &data);
2557 
2558 	if (!(msg[0] & 0x80)) {
2559 		printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2560 		spi_print_msg(msg);
2561 		abort = 1;
2562 	} else {
2563 		/* Accept message by clearing ACK */
2564 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2565 		lun = (msg[0] & 0x07);
2566 
2567 		/*
2568 		 * We need to add code for SCSI-II to track which devices have
2569 		 * I_T_L_Q nexuses established, and which have simple I_T_L
2570 		 * nexuses so we can chose to do additional data transfer.
2571 		 */
2572 
2573 		/*
2574 		 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2575 		 * just reestablished, and remove it from the disconnected queue.
2576 		 */
2577 
2578 
2579 		for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2580 			if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2581 			    ) {
2582 				if (prev) {
2583 					REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2584 					prev->host_scribble = tmp->host_scribble;
2585 				} else {
2586 					REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2587 					hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2588 				}
2589 				tmp->host_scribble = NULL;
2590 				break;
2591 			}
2592 		if (!tmp) {
2593 			printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2594 			/*
2595 			 * Since we have an established nexus that we can't do anything with,
2596 			 * we must abort it.
2597 			 */
2598 			abort = 1;
2599 		}
2600 	}
2601 
2602 	if (abort) {
2603 		do_abort(instance);
2604 	} else {
2605 		hostdata->connected = tmp;
2606 		dprintk(NDEBUG_RESELECTION, ("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->target, tmp->lun, tmp->tag));
2607 	}
2608 }
2609 
2610 /*
2611  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2612  *
2613  * Purpose : called by interrupt handler when DMA finishes or a phase
2614  *      mismatch occurs (which would finish the DMA transfer).
2615  *
2616  * Inputs : instance - this instance of the NCR5380.
2617  *
2618  * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2619  *      nexus has been reestablished, on failure NULL is returned.
2620  */
2621 
2622 #ifdef REAL_DMA
2623 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2624 	NCR5380_local_declare();
2625 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2626 	int transferred;
2627 	NCR5380_setup(instance);
2628 
2629 	/*
2630 	 * XXX this might not be right.
2631 	 *
2632 	 * Wait for final byte to transfer, ie wait for ACK to go false.
2633 	 *
2634 	 * We should use the Last Byte Sent bit, unfortunately this is
2635 	 * not available on the 5380/5381 (only the various CMOS chips)
2636 	 *
2637 	 * FIXME: timeout, and need to handle long timeout/irq case
2638 	 */
2639 
2640 	NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2641 
2642 	NCR5380_write(MODE_REG, MR_BASE);
2643 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2644 
2645 	/*
2646 	 * The only places we should see a phase mismatch and have to send
2647 	 * data from the same set of pointers will be the data transfer
2648 	 * phases.  So, residual, requested length are only important here.
2649 	 */
2650 
2651 	if (!(hostdata->connected->SCp.phase & SR_CD)) {
2652 		transferred = instance->dmalen - NCR5380_dma_residual();
2653 		hostdata->connected->SCp.this_residual -= transferred;
2654 		hostdata->connected->SCp.ptr += transferred;
2655 	}
2656 }
2657 #endif				/* def REAL_DMA */
2658 
2659 /*
2660  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2661  *
2662  * Purpose : abort a command
2663  *
2664  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2665  *      host byte of the result field to, if zero DID_ABORTED is
2666  *      used.
2667  *
2668  * Returns : 0 - success, -1 on failure.
2669  *
2670  *	XXX - there is no way to abort the command that is currently
2671  *	connected, you have to wait for it to complete.  If this is
2672  *	a problem, we could implement longjmp() / setjmp(), setjmp()
2673  *	called where the loop started in NCR5380_main().
2674  *
2675  * Locks: host lock taken by caller
2676  */
2677 
2678 static int NCR5380_abort(Scsi_Cmnd * cmd) {
2679 	NCR5380_local_declare();
2680 	struct Scsi_Host *instance = cmd->device->host;
2681 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2682 	Scsi_Cmnd *tmp, **prev;
2683 
2684 	printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2685 	scsi_print_command(cmd);
2686 
2687 	NCR5380_print_status(instance);
2688 
2689 	NCR5380_setup(instance);
2690 
2691 	dprintk(NDEBUG_ABORT, ("scsi%d : abort called\n", instance->host_no));
2692 	dprintk(NDEBUG_ABORT, ("        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)));
2693 
2694 #if 0
2695 /*
2696  * Case 1 : If the command is the currently executing command,
2697  * we'll set the aborted flag and return control so that
2698  * information transfer routine can exit cleanly.
2699  */
2700 
2701 	if (hostdata->connected == cmd) {
2702 		dprintk(NDEBUG_ABORT, ("scsi%d : aborting connected command\n", instance->host_no));
2703 		hostdata->aborted = 1;
2704 /*
2705  * We should perform BSY checking, and make sure we haven't slipped
2706  * into BUS FREE.
2707  */
2708 
2709 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2710 /*
2711  * Since we can't change phases until we've completed the current
2712  * handshake, we have to source or sink a byte of data if the current
2713  * phase is not MSGOUT.
2714  */
2715 
2716 /*
2717  * Return control to the executing NCR drive so we can clear the
2718  * aborted flag and get back into our main loop.
2719  */
2720 
2721 		return 0;
2722 	}
2723 #endif
2724 
2725 /*
2726  * Case 2 : If the command hasn't been issued yet, we simply remove it
2727  *          from the issue queue.
2728  */
2729 
2730 	dprintk(NDEBUG_ABORT, ("scsi%d : abort going into loop.\n", instance->host_no));
2731 	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)
2732 		if (cmd == tmp) {
2733 			REMOVE(5, *prev, tmp, tmp->host_scribble);
2734 			(*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2735 			tmp->host_scribble = NULL;
2736 			tmp->result = DID_ABORT << 16;
2737 			dprintk(NDEBUG_ABORT, ("scsi%d : abort removed command from issue queue.\n", instance->host_no));
2738 			tmp->scsi_done(tmp);
2739 			return SUCCESS;
2740 		}
2741 #if (NDEBUG  & NDEBUG_ABORT)
2742 	/* KLL */
2743 		else if (prev == tmp)
2744 			printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2745 #endif
2746 
2747 /*
2748  * Case 3 : If any commands are connected, we're going to fail the abort
2749  *          and let the high level SCSI driver retry at a later time or
2750  *          issue a reset.
2751  *
2752  *          Timeouts, and therefore aborted commands, will be highly unlikely
2753  *          and handling them cleanly in this situation would make the common
2754  *          case of noresets less efficient, and would pollute our code.  So,
2755  *          we fail.
2756  */
2757 
2758 	if (hostdata->connected) {
2759 		dprintk(NDEBUG_ABORT, ("scsi%d : abort failed, command connected.\n", instance->host_no));
2760 		return FAILED;
2761 	}
2762 /*
2763  * Case 4: If the command is currently disconnected from the bus, and
2764  *      there are no connected commands, we reconnect the I_T_L or
2765  *      I_T_L_Q nexus associated with it, go into message out, and send
2766  *      an abort message.
2767  *
2768  * This case is especially ugly. In order to reestablish the nexus, we
2769  * need to call NCR5380_select().  The easiest way to implement this
2770  * function was to abort if the bus was busy, and let the interrupt
2771  * handler triggered on the SEL for reselect take care of lost arbitrations
2772  * where necessary, meaning interrupts need to be enabled.
2773  *
2774  * When interrupts are enabled, the queues may change - so we
2775  * can't remove it from the disconnected queue before selecting it
2776  * because that could cause a failure in hashing the nexus if that
2777  * device reselected.
2778  *
2779  * Since the queues may change, we can't use the pointers from when we
2780  * first locate it.
2781  *
2782  * So, we must first locate the command, and if NCR5380_select()
2783  * succeeds, then issue the abort, relocate the command and remove
2784  * it from the disconnected queue.
2785  */
2786 
2787 	for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2788 		if (cmd == tmp) {
2789 			dprintk(NDEBUG_ABORT, ("scsi%d : aborting disconnected command.\n", instance->host_no));
2790 
2791 			if (NCR5380_select(instance, cmd, (int) cmd->tag))
2792 				return FAILED;
2793 			dprintk(NDEBUG_ABORT, ("scsi%d : nexus reestablished.\n", instance->host_no));
2794 
2795 			do_abort(instance);
2796 
2797 			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)
2798 				if (cmd == tmp) {
2799 					REMOVE(5, *prev, tmp, tmp->host_scribble);
2800 					*prev = (Scsi_Cmnd *) tmp->host_scribble;
2801 					tmp->host_scribble = NULL;
2802 					tmp->result = DID_ABORT << 16;
2803 					tmp->scsi_done(tmp);
2804 					return SUCCESS;
2805 				}
2806 		}
2807 /*
2808  * Case 5 : If we reached this point, the command was not found in any of
2809  *          the queues.
2810  *
2811  * We probably reached this point because of an unlikely race condition
2812  * between the command completing successfully and the abortion code,
2813  * so we won't panic, but we will notify the user in case something really
2814  * broke.
2815  */
2816 	printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2817 			"         before abortion\n", instance->host_no);
2818 	return FAILED;
2819 }
2820 
2821 
2822 /*
2823  * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2824  *
2825  * Purpose : reset the SCSI bus.
2826  *
2827  * Returns : SUCCESS
2828  *
2829  * Locks: host lock taken by caller
2830  */
2831 
2832 static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2833 {
2834 	struct Scsi_Host *instance = cmd->device->host;
2835 
2836 	NCR5380_local_declare();
2837 	NCR5380_setup(instance);
2838 	NCR5380_print_status(instance);
2839 
2840 	spin_lock_irq(instance->host_lock);
2841 	do_reset(instance);
2842 	spin_unlock_irq(instance->host_lock);
2843 
2844 	return SUCCESS;
2845 }
2846