xref: /openbmc/linux/drivers/scsi/NCR5380.c (revision afb46f79)
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@lxorguk.ukuu.org.uk)
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 (scsi_bufflen(cmd)) {
299 		cmd->SCp.buffer = scsi_sglist(cmd);
300 		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
301 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
302 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
303 	} else {
304 		cmd->SCp.buffer = NULL;
305 		cmd->SCp.buffers_residual = 0;
306 		cmd->SCp.ptr = NULL;
307 		cmd->SCp.this_residual = 0;
308 	}
309 }
310 
311 /**
312  *	NCR5380_poll_politely	-	wait for NCR5380 status bits
313  *	@instance: controller to poll
314  *	@reg: 5380 register to poll
315  *	@bit: Bitmask to check
316  *	@val: Value required to exit
317  *
318  *	Polls the NCR5380 in a reasonably efficient manner waiting for
319  *	an event to occur, after a short quick poll we begin giving the
320  *	CPU back in non IRQ contexts
321  *
322  *	Returns the value of the register or a negative error code.
323  */
324 
325 static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
326 {
327 	NCR5380_local_declare();
328 	int n = 500;		/* At about 8uS a cycle for the cpu access */
329 	unsigned long end = jiffies + t;
330 	int r;
331 
332 	NCR5380_setup(instance);
333 
334 	while( n-- > 0)
335 	{
336 		r = NCR5380_read(reg);
337 		if((r & bit) == val)
338 			return 0;
339 		cpu_relax();
340 	}
341 
342 	/* t time yet ? */
343 	while(time_before(jiffies, end))
344 	{
345 		r = NCR5380_read(reg);
346 		if((r & bit) == val)
347 			return 0;
348 		if(!in_interrupt())
349 			cond_resched();
350 		else
351 			cpu_relax();
352 	}
353 	return -ETIMEDOUT;
354 }
355 
356 static struct {
357 	unsigned char value;
358 	const char *name;
359 } phases[] __maybe_unused = {
360 	{PHASE_DATAOUT, "DATAOUT"},
361 	{PHASE_DATAIN, "DATAIN"},
362 	{PHASE_CMDOUT, "CMDOUT"},
363 	{PHASE_STATIN, "STATIN"},
364 	{PHASE_MSGOUT, "MSGOUT"},
365 	{PHASE_MSGIN, "MSGIN"},
366 	{PHASE_UNKNOWN, "UNKNOWN"}
367 };
368 
369 #if NDEBUG
370 static struct {
371 	unsigned char mask;
372 	const char *name;
373 } signals[] = {
374 	{SR_DBP, "PARITY"},
375 	{SR_RST, "RST"},
376 	{SR_BSY, "BSY"},
377 	{SR_REQ, "REQ"},
378 	{SR_MSG, "MSG"},
379 	{SR_CD, "CD"},
380 	{SR_IO, "IO"},
381 	{SR_SEL, "SEL"},
382 	{0, NULL}
383 },
384 basrs[] = {
385 	{BASR_ATN, "ATN"},
386 	{BASR_ACK, "ACK"},
387 	{0, NULL}
388 },
389 icrs[] = {
390 	{ICR_ASSERT_RST, "ASSERT RST"},
391 	{ICR_ASSERT_ACK, "ASSERT ACK"},
392 	{ICR_ASSERT_BSY, "ASSERT BSY"},
393 	{ICR_ASSERT_SEL, "ASSERT SEL"},
394 	{ICR_ASSERT_ATN, "ASSERT ATN"},
395 	{ICR_ASSERT_DATA, "ASSERT DATA"},
396 	{0, NULL}
397 },
398 mrs[] = {
399 	{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
400 	{MR_TARGET, "MODE TARGET"},
401 	{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
402 	{MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
403 	{MR_MONITOR_BSY, "MODE MONITOR BSY"},
404 	{MR_DMA_MODE, "MODE DMA"},
405 	{MR_ARBITRATE, "MODE ARBITRATION"},
406 	{0, NULL}
407 };
408 
409 /**
410  *	NCR5380_print	-	print scsi bus signals
411  *	@instance:	adapter state to dump
412  *
413  *	Print the SCSI bus signals for debugging purposes
414  *
415  *	Locks: caller holds hostdata lock (not essential)
416  */
417 
418 static void NCR5380_print(struct Scsi_Host *instance)
419 {
420 	NCR5380_local_declare();
421 	unsigned char status, data, basr, mr, icr, i;
422 	NCR5380_setup(instance);
423 
424 	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
425 	status = NCR5380_read(STATUS_REG);
426 	mr = NCR5380_read(MODE_REG);
427 	icr = NCR5380_read(INITIATOR_COMMAND_REG);
428 	basr = NCR5380_read(BUS_AND_STATUS_REG);
429 
430 	printk("STATUS_REG: %02x ", status);
431 	for (i = 0; signals[i].mask; ++i)
432 		if (status & signals[i].mask)
433 			printk(",%s", signals[i].name);
434 	printk("\nBASR: %02x ", basr);
435 	for (i = 0; basrs[i].mask; ++i)
436 		if (basr & basrs[i].mask)
437 			printk(",%s", basrs[i].name);
438 	printk("\nICR: %02x ", icr);
439 	for (i = 0; icrs[i].mask; ++i)
440 		if (icr & icrs[i].mask)
441 			printk(",%s", icrs[i].name);
442 	printk("\nMODE: %02x ", mr);
443 	for (i = 0; mrs[i].mask; ++i)
444 		if (mr & mrs[i].mask)
445 			printk(",%s", mrs[i].name);
446 	printk("\n");
447 }
448 
449 
450 /*
451  *	NCR5380_print_phase	-	show SCSI phase
452  *	@instance: adapter to dump
453  *
454  * 	Print the current SCSI phase for debugging purposes
455  *
456  *	Locks: none
457  */
458 
459 static void NCR5380_print_phase(struct Scsi_Host *instance)
460 {
461 	NCR5380_local_declare();
462 	unsigned char status;
463 	int i;
464 	NCR5380_setup(instance);
465 
466 	status = NCR5380_read(STATUS_REG);
467 	if (!(status & SR_REQ))
468 		printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
469 	else {
470 		for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
471 		printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
472 	}
473 }
474 #endif
475 
476 /*
477  * These need tweaking, and would probably work best as per-device
478  * flags initialized differently for disk, tape, cd, etc devices.
479  * People with broken devices are free to experiment as to what gives
480  * the best results for them.
481  *
482  * USLEEP_SLEEP should be a minimum seek time.
483  *
484  * USLEEP_POLL should be a maximum rotational latency.
485  */
486 #ifndef USLEEP_SLEEP
487 /* 20 ms (reasonable hard disk speed) */
488 #define USLEEP_SLEEP (20*HZ/1000)
489 #endif
490 /* 300 RPM (floppy speed) */
491 #ifndef USLEEP_POLL
492 #define USLEEP_POLL (200*HZ/1000)
493 #endif
494 #ifndef USLEEP_WAITLONG
495 /* RvC: (reasonable time to wait on select error) */
496 #define USLEEP_WAITLONG USLEEP_SLEEP
497 #endif
498 
499 /*
500  * Function : int should_disconnect (unsigned char cmd)
501  *
502  * Purpose : decide whether a command would normally disconnect or
503  *      not, since if it won't disconnect we should go to sleep.
504  *
505  * Input : cmd - opcode of SCSI command
506  *
507  * Returns : DISCONNECT_LONG if we should disconnect for a really long
508  *      time (ie always, sleep, look for REQ active, sleep),
509  *      DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
510  *      time-to-data delay, DISCONNECT_NONE if this command would return
511  *      immediately.
512  *
513  *      Future sleep algorithms based on time to data can exploit
514  *      something like this so they can differentiate between "normal"
515  *      (ie, read, write, seek) and unusual commands (ie, * format).
516  *
517  * Note : We don't deal with commands that handle an immediate disconnect,
518  *
519  */
520 
521 static int should_disconnect(unsigned char cmd)
522 {
523 	switch (cmd) {
524 	case READ_6:
525 	case WRITE_6:
526 	case SEEK_6:
527 	case READ_10:
528 	case WRITE_10:
529 	case SEEK_10:
530 		return DISCONNECT_TIME_TO_DATA;
531 	case FORMAT_UNIT:
532 	case SEARCH_HIGH:
533 	case SEARCH_LOW:
534 	case SEARCH_EQUAL:
535 		return DISCONNECT_LONG;
536 	default:
537 		return DISCONNECT_NONE;
538 	}
539 }
540 
541 static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
542 {
543 	hostdata->time_expires = jiffies + timeout;
544 	schedule_delayed_work(&hostdata->coroutine, timeout);
545 }
546 
547 
548 static int probe_irq __initdata = 0;
549 
550 /**
551  *	probe_intr	-	helper for IRQ autoprobe
552  *	@irq: interrupt number
553  *	@dev_id: unused
554  *	@regs: unused
555  *
556  *	Set a flag to indicate the IRQ in question was received. This is
557  *	used by the IRQ probe code.
558  */
559 
560 static irqreturn_t __init probe_intr(int irq, void *dev_id)
561 {
562 	probe_irq = irq;
563 	return IRQ_HANDLED;
564 }
565 
566 /**
567  *	NCR5380_probe_irq	-	find the IRQ of an NCR5380
568  *	@instance: NCR5380 controller
569  *	@possible: bitmask of ISA IRQ lines
570  *
571  *	Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
572  *	and then looking to see what interrupt actually turned up.
573  *
574  *	Locks: none, irqs must be enabled on entry
575  */
576 
577 static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
578 						int possible)
579 {
580 	NCR5380_local_declare();
581 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
582 	unsigned long timeout;
583 	int trying_irqs, i, mask;
584 	NCR5380_setup(instance);
585 
586 	for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
587 		if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0))
588 			trying_irqs |= mask;
589 
590 	timeout = jiffies + (250 * HZ / 1000);
591 	probe_irq = SCSI_IRQ_NONE;
592 
593 	/*
594 	 * A interrupt is triggered whenever BSY = false, SEL = true
595 	 * and a bit set in the SELECT_ENABLE_REG is asserted on the
596 	 * SCSI bus.
597 	 *
598 	 * Note that the bus is only driven when the phase control signals
599 	 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
600 	 * to zero.
601 	 */
602 
603 	NCR5380_write(TARGET_COMMAND_REG, 0);
604 	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
605 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
606 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
607 
608 	while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
609 		schedule_timeout_uninterruptible(1);
610 
611 	NCR5380_write(SELECT_ENABLE_REG, 0);
612 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
613 
614 	for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
615 		if (trying_irqs & mask)
616 			free_irq(i, NULL);
617 
618 	return probe_irq;
619 }
620 
621 /**
622  *	NCR58380_print_options	-	show options
623  *	@instance: unused for now
624  *
625  *	Called by probe code indicating the NCR5380 driver options that
626  *	were selected. At some point this will switch to runtime options
627  *	read from the adapter in question
628  *
629  *	Locks: none
630  */
631 
632 static void __init __maybe_unused
633 NCR5380_print_options(struct Scsi_Host *instance)
634 {
635 	printk(" generic options"
636 #ifdef AUTOPROBE_IRQ
637 	       " AUTOPROBE_IRQ"
638 #endif
639 #ifdef AUTOSENSE
640 	       " AUTOSENSE"
641 #endif
642 #ifdef DIFFERENTIAL
643 	       " DIFFERENTIAL"
644 #endif
645 #ifdef REAL_DMA
646 	       " REAL DMA"
647 #endif
648 #ifdef REAL_DMA_POLL
649 	       " REAL DMA POLL"
650 #endif
651 #ifdef PARITY
652 	       " PARITY"
653 #endif
654 #ifdef PSEUDO_DMA
655 	       " PSEUDO DMA"
656 #endif
657 #ifdef UNSAFE
658 	       " UNSAFE "
659 #endif
660 	    );
661 	printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
662 	printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
663 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
664 		printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
665 	}
666 }
667 
668 /**
669  *	NCR5380_print_status 	-	dump controller info
670  *	@instance: controller to dump
671  *
672  *	Print commands in the various queues, called from NCR5380_abort
673  *	and NCR5380_debug to aid debugging.
674  *
675  *	Locks: called functions disable irqs
676  */
677 
678 static void NCR5380_print_status(struct Scsi_Host *instance)
679 {
680 	NCR5380_dprint(NDEBUG_ANY, instance);
681 	NCR5380_dprint_phase(NDEBUG_ANY, instance);
682 }
683 
684 /******************************************/
685 /*
686  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
687  *
688  * *buffer: I/O buffer
689  * **start: if inout == FALSE pointer into buffer where user read should start
690  * offset: current offset
691  * length: length of buffer
692  * hostno: Scsi_Host host_no
693  * inout: TRUE - user is writing; FALSE - user is reading
694  *
695  * Return the number of bytes read from or written
696  */
697 
698 static int __maybe_unused NCR5380_write_info(struct Scsi_Host *instance,
699 	char *buffer, int length)
700 {
701 #ifdef DTC_PUBLIC_RELEASE
702 	dtc_wmaxi = dtc_maxi = 0;
703 #endif
704 #ifdef PAS16_PUBLIC_RELEASE
705 	pas_wmaxi = pas_maxi = 0;
706 #endif
707 	return (-ENOSYS);	/* Currently this is a no-op */
708 }
709 
710 #undef SPRINTF
711 #define SPRINTF(args...) seq_printf(m, ## args)
712 static
713 void lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, struct seq_file *m);
714 static
715 void lprint_command(unsigned char *cmd, struct seq_file *m);
716 static
717 void lprint_opcode(int opcode, struct seq_file *m);
718 
719 static int __maybe_unused NCR5380_show_info(struct seq_file *m,
720 	struct Scsi_Host *instance)
721 {
722 	struct NCR5380_hostdata *hostdata;
723 	Scsi_Cmnd *ptr;
724 
725 	hostdata = (struct NCR5380_hostdata *) instance->hostdata;
726 
727 	SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
728 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
729 		SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
730 #ifdef DTC_PUBLIC_RELEASE
731 	SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
732 #endif
733 #ifdef T128_PUBLIC_RELEASE
734 	SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
735 #endif
736 #ifdef GENERIC_NCR5380_PUBLIC_RELEASE
737 	SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
738 #endif
739 #ifdef PAS16_PUBLIC_RELEASE
740 	SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
741 #endif
742 
743 	SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
744 	SPRINTF("io_port: %04x      ", (int) instance->io_port);
745 	if (instance->irq == SCSI_IRQ_NONE)
746 		SPRINTF("IRQ: None.\n");
747 	else
748 		SPRINTF("IRQ: %d.\n", instance->irq);
749 
750 #ifdef DTC_PUBLIC_RELEASE
751 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
752 #endif
753 #ifdef PAS16_PUBLIC_RELEASE
754 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
755 #endif
756 	spin_lock_irq(instance->host_lock);
757 	if (!hostdata->connected)
758 		SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
759 	else
760 		lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, m);
761 	SPRINTF("scsi%d: issue_queue\n", instance->host_no);
762 	for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
763 		lprint_Scsi_Cmnd(ptr, m);
764 
765 	SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
766 	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
767 		lprint_Scsi_Cmnd(ptr, m);
768 	spin_unlock_irq(instance->host_lock);
769 	return 0;
770 }
771 
772 static void lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, struct seq_file *m)
773 {
774 	SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
775 	SPRINTF("        command = ");
776 	lprint_command(cmd->cmnd, m);
777 }
778 
779 static void lprint_command(unsigned char *command, struct seq_file *m)
780 {
781 	int i, s;
782 	lprint_opcode(command[0], m);
783 	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
784 		SPRINTF("%02x ", command[i]);
785 	SPRINTF("\n");
786 }
787 
788 static void lprint_opcode(int opcode, struct seq_file *m)
789 {
790 	SPRINTF("%2d (0x%02x)", opcode, opcode);
791 }
792 
793 
794 /**
795  *	NCR5380_init	-	initialise an NCR5380
796  *	@instance: adapter to configure
797  *	@flags: control flags
798  *
799  *	Initializes *instance and corresponding 5380 chip,
800  *      with flags OR'd into the initial flags value.
801  *
802  *	Notes : I assume that the host, hostno, and id bits have been
803  *      set correctly.  I don't care about the irq and other fields.
804  *
805  *	Returns 0 for success
806  *
807  *	Locks: interrupts must be enabled when we are called
808  */
809 
810 static int NCR5380_init(struct Scsi_Host *instance, int flags)
811 {
812 	NCR5380_local_declare();
813 	int i, pass;
814 	unsigned long timeout;
815 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
816 
817 	if(in_interrupt())
818 		printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
819 	/*
820 	 * On NCR53C400 boards, NCR5380 registers are mapped 8 past
821 	 * the base address.
822 	 */
823 
824 #ifdef NCR53C400
825 	if (flags & FLAG_NCR53C400)
826 		instance->NCR5380_instance_name += NCR53C400_address_adjust;
827 #endif
828 
829 	NCR5380_setup(instance);
830 
831 	hostdata->aborted = 0;
832 	hostdata->id_mask = 1 << instance->this_id;
833 	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
834 		if (i > hostdata->id_mask)
835 			hostdata->id_higher_mask |= i;
836 	for (i = 0; i < 8; ++i)
837 		hostdata->busy[i] = 0;
838 #ifdef REAL_DMA
839 	hostdata->dmalen = 0;
840 #endif
841 	hostdata->targets_present = 0;
842 	hostdata->connected = NULL;
843 	hostdata->issue_queue = NULL;
844 	hostdata->disconnected_queue = NULL;
845 
846 	INIT_DELAYED_WORK(&hostdata->coroutine, NCR5380_main);
847 
848 #ifdef NCR5380_STATS
849 	for (i = 0; i < 8; ++i) {
850 		hostdata->time_read[i] = 0;
851 		hostdata->time_write[i] = 0;
852 		hostdata->bytes_read[i] = 0;
853 		hostdata->bytes_write[i] = 0;
854 	}
855 	hostdata->timebase = 0;
856 	hostdata->pendingw = 0;
857 	hostdata->pendingr = 0;
858 #endif
859 
860 	/* The CHECK code seems to break the 53C400. Will check it later maybe */
861 	if (flags & FLAG_NCR53C400)
862 		hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
863 	else
864 		hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
865 
866 	hostdata->host = instance;
867 	hostdata->time_expires = 0;
868 
869 #ifndef AUTOSENSE
870 	if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
871 		    printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
872 		    	   "         be incorrectly cleared.\n", instance->host_no);
873 #endif				/* def AUTOSENSE */
874 
875 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
876 	NCR5380_write(MODE_REG, MR_BASE);
877 	NCR5380_write(TARGET_COMMAND_REG, 0);
878 	NCR5380_write(SELECT_ENABLE_REG, 0);
879 
880 #ifdef NCR53C400
881 	if (hostdata->flags & FLAG_NCR53C400) {
882 		NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
883 	}
884 #endif
885 
886 	/*
887 	 * Detect and correct bus wedge problems.
888 	 *
889 	 * If the system crashed, it may have crashed in a state
890 	 * where a SCSI command was still executing, and the
891 	 * SCSI bus is not in a BUS FREE STATE.
892 	 *
893 	 * If this is the case, we'll try to abort the currently
894 	 * established nexus which we know nothing about, and that
895 	 * failing, do a hard reset of the SCSI bus
896 	 */
897 
898 	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
899 		switch (pass) {
900 		case 1:
901 		case 3:
902 		case 5:
903 			printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
904 			timeout = jiffies + 5 * HZ;
905 			NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
906 			break;
907 		case 2:
908 			printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
909 			do_abort(instance);
910 			break;
911 		case 4:
912 			printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
913 			do_reset(instance);
914 			break;
915 		case 6:
916 			printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
917 			return -ENXIO;
918 		}
919 	}
920 	return 0;
921 }
922 
923 /**
924  *	NCR5380_exit	-	remove an NCR5380
925  *	@instance: adapter to remove
926  */
927 
928 static void NCR5380_exit(struct Scsi_Host *instance)
929 {
930 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
931 
932 	cancel_delayed_work_sync(&hostdata->coroutine);
933 }
934 
935 /**
936  *	NCR5380_queue_command 		-	queue a command
937  *	@cmd: SCSI command
938  *	@done: completion handler
939  *
940  *      cmd is added to the per instance issue_queue, with minor
941  *      twiddling done to the host specific fields of cmd.  If the
942  *      main coroutine is not running, it is restarted.
943  *
944  *	Locks: host lock taken by caller
945  */
946 
947 static int NCR5380_queue_command_lck(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
948 {
949 	struct Scsi_Host *instance = cmd->device->host;
950 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
951 	Scsi_Cmnd *tmp;
952 
953 #if (NDEBUG & NDEBUG_NO_WRITE)
954 	switch (cmd->cmnd[0]) {
955 	case WRITE_6:
956 	case WRITE_10:
957 		printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
958 		cmd->result = (DID_ERROR << 16);
959 		done(cmd);
960 		return 0;
961 	}
962 #endif				/* (NDEBUG & NDEBUG_NO_WRITE) */
963 
964 #ifdef NCR5380_STATS
965 	switch (cmd->cmnd[0]) {
966 		case WRITE:
967 		case WRITE_6:
968 		case WRITE_10:
969 			hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
970 			hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
971 			hostdata->pendingw++;
972 			break;
973 		case READ:
974 		case READ_6:
975 		case READ_10:
976 			hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
977 			hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
978 			hostdata->pendingr++;
979 			break;
980 	}
981 #endif
982 
983 	/*
984 	 * We use the host_scribble field as a pointer to the next command
985 	 * in a queue
986 	 */
987 
988 	cmd->host_scribble = NULL;
989 	cmd->scsi_done = done;
990 	cmd->result = 0;
991 
992 	/*
993 	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
994 	 * commands are added to the head of the queue since any command will
995 	 * clear the contingent allegiance condition that exists and the
996 	 * sense data is only guaranteed to be valid while the condition exists.
997 	 */
998 
999 	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1000 		LIST(cmd, hostdata->issue_queue);
1001 		cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
1002 		hostdata->issue_queue = cmd;
1003 	} else {
1004 		for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
1005 		LIST(cmd, tmp);
1006 		tmp->host_scribble = (unsigned char *) cmd;
1007 	}
1008 	dprintk(NDEBUG_QUEUES, ("scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"));
1009 
1010 	/* Run the coroutine if it isn't already running. */
1011 	/* Kick off command processing */
1012 	schedule_delayed_work(&hostdata->coroutine, 0);
1013 	return 0;
1014 }
1015 
1016 static DEF_SCSI_QCMD(NCR5380_queue_command)
1017 
1018 /**
1019  *	NCR5380_main	-	NCR state machines
1020  *
1021  *	NCR5380_main is a coroutine that runs as long as more work can
1022  *      be done on the NCR5380 host adapters in a system.  Both
1023  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1024  *      in case it is not running.
1025  *
1026  *	Locks: called as its own thread with no locks held. Takes the
1027  *	host lock and called routines may take the isa dma lock.
1028  */
1029 
1030 static void NCR5380_main(struct work_struct *work)
1031 {
1032 	struct NCR5380_hostdata *hostdata =
1033 		container_of(work, struct NCR5380_hostdata, coroutine.work);
1034 	struct Scsi_Host *instance = hostdata->host;
1035 	Scsi_Cmnd *tmp, *prev;
1036 	int done;
1037 
1038 	spin_lock_irq(instance->host_lock);
1039 	do {
1040 		/* Lock held here */
1041 		done = 1;
1042 		if (!hostdata->connected && !hostdata->selecting) {
1043 			dprintk(NDEBUG_MAIN, ("scsi%d : not connected\n", instance->host_no));
1044 			/*
1045 			 * Search through the issue_queue for a command destined
1046 			 * for a target that's not busy.
1047 			 */
1048 			for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
1049 			{
1050 				if (prev != tmp)
1051 					dprintk(NDEBUG_LISTS, ("MAIN tmp=%p   target=%d   busy=%d lun=%d\n", tmp, tmp->target, hostdata->busy[tmp->target], tmp->lun));
1052 				/*  When we find one, remove it from the issue queue. */
1053 				if (!(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))) {
1054 					if (prev) {
1055 						REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1056 						prev->host_scribble = tmp->host_scribble;
1057 					} else {
1058 						REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1059 						hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1060 					}
1061 					tmp->host_scribble = NULL;
1062 
1063 					/*
1064 					 * Attempt to establish an I_T_L nexus here.
1065 					 * On success, instance->hostdata->connected is set.
1066 					 * On failure, we must add the command back to the
1067 					 *   issue queue so we can keep trying.
1068 					 */
1069 					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));
1070 
1071 					/*
1072 					 * A successful selection is defined as one that
1073 					 * leaves us with the command connected and
1074 					 * in hostdata->connected, OR has terminated the
1075 					 * command.
1076 					 *
1077 					 * With successful commands, we fall through
1078 					 * and see if we can do an information transfer,
1079 					 * with failures we will restart.
1080 					 */
1081 					hostdata->selecting = NULL;
1082 					/* RvC: have to preset this to indicate a new command is being performed */
1083 
1084 					if (!NCR5380_select(instance, tmp,
1085 							    /*
1086 							     * REQUEST SENSE commands are issued without tagged
1087 							     * queueing, even on SCSI-II devices because the
1088 							     * contingent allegiance condition exists for the
1089 							     * entire unit.
1090 							     */
1091 							    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1092 						break;
1093 					} else {
1094 						LIST(tmp, hostdata->issue_queue);
1095 						tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1096 						hostdata->issue_queue = tmp;
1097 						done = 0;
1098 						dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no));
1099 					}
1100 					/* lock held here still */
1101 				}	/* if target/lun is not busy */
1102 			}	/* for */
1103 			/* exited locked */
1104 		}	/* if (!hostdata->connected) */
1105 		if (hostdata->selecting) {
1106 			tmp = (Scsi_Cmnd *) hostdata->selecting;
1107 			/* Selection will drop and retake the lock */
1108 			if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1109 				/* Ok ?? */
1110 			} else {
1111 				/* RvC: device failed, so we wait a long time
1112 				   this is needed for Mustek scanners, that
1113 				   do not respond to commands immediately
1114 				   after a scan */
1115 				printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1116 				LIST(tmp, hostdata->issue_queue);
1117 				tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1118 				hostdata->issue_queue = tmp;
1119 				NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1120 			}
1121 		}	/* if hostdata->selecting */
1122 		if (hostdata->connected
1123 #ifdef REAL_DMA
1124 		    && !hostdata->dmalen
1125 #endif
1126 		    && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1127 		    ) {
1128 			dprintk(NDEBUG_MAIN, ("scsi%d : main() : performing information transfer\n", instance->host_no));
1129 			NCR5380_information_transfer(instance);
1130 			dprintk(NDEBUG_MAIN, ("scsi%d : main() : done set false\n", instance->host_no));
1131 			done = 0;
1132 		} else
1133 			break;
1134 	} while (!done);
1135 
1136 	spin_unlock_irq(instance->host_lock);
1137 }
1138 
1139 #ifndef DONT_USE_INTR
1140 
1141 /**
1142  * 	NCR5380_intr	-	generic NCR5380 irq handler
1143  *	@irq: interrupt number
1144  *	@dev_id: device info
1145  *
1146  *	Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1147  *      from the disconnected queue, and restarting NCR5380_main()
1148  *      as required.
1149  *
1150  *	Locks: takes the needed instance locks
1151  */
1152 
1153 static irqreturn_t NCR5380_intr(int dummy, void *dev_id)
1154 {
1155 	NCR5380_local_declare();
1156 	struct Scsi_Host *instance = dev_id;
1157 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1158 	int done;
1159 	unsigned char basr;
1160 	unsigned long flags;
1161 
1162 	dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n",
1163 		instance->irq));
1164 
1165 	do {
1166 		done = 1;
1167 		spin_lock_irqsave(instance->host_lock, flags);
1168 		/* Look for pending interrupts */
1169 		NCR5380_setup(instance);
1170 		basr = NCR5380_read(BUS_AND_STATUS_REG);
1171 		/* XXX dispatch to appropriate routine if found and done=0 */
1172 		if (basr & BASR_IRQ) {
1173 			NCR5380_dprint(NDEBUG_INTR, instance);
1174 			if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1175 				done = 0;
1176 				dprintk(NDEBUG_INTR, ("scsi%d : SEL interrupt\n", instance->host_no));
1177 				NCR5380_reselect(instance);
1178 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1179 			} else if (basr & BASR_PARITY_ERROR) {
1180 				dprintk(NDEBUG_INTR, ("scsi%d : PARITY interrupt\n", instance->host_no));
1181 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1182 			} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1183 				dprintk(NDEBUG_INTR, ("scsi%d : RESET interrupt\n", instance->host_no));
1184 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1185 			} else {
1186 #if defined(REAL_DMA)
1187 				/*
1188 				 * We should only get PHASE MISMATCH and EOP interrupts
1189 				 * if we have DMA enabled, so do a sanity check based on
1190 				 * the current setting of the MODE register.
1191 				 */
1192 
1193 				if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1194 					int transferred;
1195 
1196 					if (!hostdata->connected)
1197 						panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1198 
1199 					transferred = (hostdata->dmalen - NCR5380_dma_residual(instance));
1200 					hostdata->connected->SCp.this_residual -= transferred;
1201 					hostdata->connected->SCp.ptr += transferred;
1202 					hostdata->dmalen = 0;
1203 
1204 					(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1205 
1206 					/* FIXME: we need to poll briefly then defer a workqueue task ! */
1207 					NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1208 
1209 					NCR5380_write(MODE_REG, MR_BASE);
1210 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1211 				}
1212 #else
1213 				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)));
1214 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1215 #endif
1216 			}
1217 		}	/* if BASR_IRQ */
1218 		spin_unlock_irqrestore(instance->host_lock, flags);
1219 		if(!done)
1220 			schedule_delayed_work(&hostdata->coroutine, 0);
1221 	} while (!done);
1222 	return IRQ_HANDLED;
1223 }
1224 
1225 #endif
1226 
1227 /**
1228  *	collect_stats		-	collect stats on a scsi command
1229  *	@hostdata: adapter
1230  *	@cmd: command being issued
1231  *
1232  *	Update the statistical data by parsing the command in question
1233  */
1234 
1235 static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd)
1236 {
1237 #ifdef NCR5380_STATS
1238 	switch (cmd->cmnd[0]) {
1239 	case WRITE:
1240 	case WRITE_6:
1241 	case WRITE_10:
1242 		hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1243 		hostdata->pendingw--;
1244 		break;
1245 	case READ:
1246 	case READ_6:
1247 	case READ_10:
1248 		hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1249 		hostdata->pendingr--;
1250 		break;
1251 	}
1252 #endif
1253 }
1254 
1255 
1256 /*
1257  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1258  *      int tag);
1259  *
1260  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1261  *      including ARBITRATION, SELECTION, and initial message out for
1262  *      IDENTIFY and queue messages.
1263  *
1264  * Inputs : instance - instantiation of the 5380 driver on which this
1265  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1266  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1267  *      the command that is presently connected.
1268  *
1269  * Returns : -1 if selection could not execute for some reason,
1270  *      0 if selection succeeded or failed because the target
1271  *      did not respond.
1272  *
1273  * Side effects :
1274  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1275  *              with registers as they should have been on entry - ie
1276  *              SELECT_ENABLE will be set appropriately, the NCR5380
1277  *              will cease to drive any SCSI bus signals.
1278  *
1279  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1280  *              instance->connected will be set to cmd.
1281  *              SELECT interrupt will be disabled.
1282  *
1283  *      If failed (no target) : cmd->scsi_done() will be called, and the
1284  *              cmd->result host byte set to DID_BAD_TARGET.
1285  *
1286  *	Locks: caller holds hostdata lock in IRQ mode
1287  */
1288 
1289 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag)
1290 {
1291 	NCR5380_local_declare();
1292 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1293 	unsigned char tmp[3], phase;
1294 	unsigned char *data;
1295 	int len;
1296 	unsigned long timeout;
1297 	unsigned char value;
1298 	int err;
1299 	NCR5380_setup(instance);
1300 
1301 	if (hostdata->selecting)
1302 		goto part2;
1303 
1304 	hostdata->restart_select = 0;
1305 
1306 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1307 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id));
1308 
1309 	/*
1310 	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1311 	 * data bus during SELECTION.
1312 	 */
1313 
1314 	NCR5380_write(TARGET_COMMAND_REG, 0);
1315 
1316 	/*
1317 	 * Start arbitration.
1318 	 */
1319 
1320 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1321 	NCR5380_write(MODE_REG, MR_ARBITRATE);
1322 
1323 
1324 	/* We can be relaxed here, interrupts are on, we are
1325 	   in workqueue context, the birds are singing in the trees */
1326 	spin_unlock_irq(instance->host_lock);
1327 	err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1328 	spin_lock_irq(instance->host_lock);
1329 	if (err < 0) {
1330 		printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1331 		NCR5380_write(MODE_REG, MR_BASE);
1332 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1333 		goto failed;
1334 	}
1335 
1336 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : arbitration complete\n", instance->host_no));
1337 
1338 	/*
1339 	 * The arbitration delay is 2.2us, but this is a minimum and there is
1340 	 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1341 	 * the integral nature of udelay().
1342 	 *
1343 	 */
1344 
1345 	udelay(3);
1346 
1347 	/* Check for lost arbitration */
1348 	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)) {
1349 		NCR5380_write(MODE_REG, MR_BASE);
1350 		dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no));
1351 		goto failed;
1352 	}
1353 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1354 
1355 	if (!(hostdata->flags & FLAG_DTC3181E) &&
1356 	    /* RvC: DTC3181E has some trouble with this
1357 	     *      so we simply removed it. Seems to work with
1358 	     *      only Mustek scanner attached
1359 	     */
1360 	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1361 		NCR5380_write(MODE_REG, MR_BASE);
1362 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1363 		dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no));
1364 		goto failed;
1365 	}
1366 	/*
1367 	 * Again, bus clear + bus settle time is 1.2us, however, this is
1368 	 * a minimum so we'll udelay ceil(1.2)
1369 	 */
1370 
1371 	udelay(2);
1372 
1373 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : won arbitration\n", instance->host_no));
1374 
1375 	/*
1376 	 * Now that we have won arbitration, start Selection process, asserting
1377 	 * the host and target ID's on the SCSI bus.
1378 	 */
1379 
1380 	NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1381 
1382 	/*
1383 	 * Raise ATN while SEL is true before BSY goes false from arbitration,
1384 	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1385 	 * phase immediately after selection.
1386 	 */
1387 
1388 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1389 	NCR5380_write(MODE_REG, MR_BASE);
1390 
1391 	/*
1392 	 * Reselect interrupts must be turned off prior to the dropping of BSY,
1393 	 * otherwise we will trigger an interrupt.
1394 	 */
1395 	NCR5380_write(SELECT_ENABLE_REG, 0);
1396 
1397 	/*
1398 	 * The initiator shall then wait at least two deskew delays and release
1399 	 * the BSY signal.
1400 	 */
1401 	udelay(1);		/* wingel -- wait two bus deskew delay >2*45ns */
1402 
1403 	/* Reset BSY */
1404 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1405 
1406 	/*
1407 	 * Something weird happens when we cease to drive BSY - looks
1408 	 * like the board/chip is letting us do another read before the
1409 	 * appropriate propagation delay has expired, and we're confusing
1410 	 * a BSY signal from ourselves as the target's response to SELECTION.
1411 	 *
1412 	 * A small delay (the 'C++' frontend breaks the pipeline with an
1413 	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1414 	 * tighter 'C' code breaks and requires this) solves the problem -
1415 	 * the 1 us delay is arbitrary, and only used because this delay will
1416 	 * be the same on other platforms and since it works here, it should
1417 	 * work there.
1418 	 *
1419 	 * wingel suggests that this could be due to failing to wait
1420 	 * one deskew delay.
1421 	 */
1422 
1423 	udelay(1);
1424 
1425 	dprintk(NDEBUG_SELECTION, ("scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd)));
1426 
1427 	/*
1428 	 * The SCSI specification calls for a 250 ms timeout for the actual
1429 	 * selection.
1430 	 */
1431 
1432 	timeout = jiffies + (250 * HZ / 1000);
1433 
1434 	/*
1435 	 * XXX very interesting - we're seeing a bounce where the BSY we
1436 	 * asserted is being reflected / still asserted (propagation delay?)
1437 	 * and it's detecting as true.  Sigh.
1438 	 */
1439 
1440 	hostdata->select_time = 0;	/* we count the clock ticks at which we polled */
1441 	hostdata->selecting = cmd;
1442 
1443 part2:
1444 	/* RvC: here we enter after a sleeping period, or immediately after
1445 	   execution of part 1
1446 	   we poll only once ech clock tick */
1447 	value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1448 
1449 	if (!value && (hostdata->select_time < HZ/4)) {
1450 		/* RvC: we still must wait for a device response */
1451 		hostdata->select_time++;	/* after 25 ticks the device has failed */
1452 		NCR5380_set_timer(hostdata, 1);
1453 		return 0;	/* RvC: we return here with hostdata->selecting set,
1454 				   to go to sleep */
1455 	}
1456 
1457 	hostdata->selecting = NULL;/* clear this pointer, because we passed the
1458 					   waiting period */
1459 	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1460 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1461 		NCR5380_reselect(instance);
1462 		printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1463 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1464 		return -1;
1465 	}
1466 	/*
1467 	 * No less than two deskew delays after the initiator detects the
1468 	 * BSY signal is true, it shall release the SEL signal and may
1469 	 * change the DATA BUS.                                     -wingel
1470 	 */
1471 
1472 	udelay(1);
1473 
1474 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1475 
1476 	if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1477 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1478 		if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1479 			printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1480 			if (hostdata->restart_select)
1481 				printk(KERN_DEBUG "\trestart select\n");
1482 			NCR5380_dprint(NDEBUG_SELECTION, instance);
1483 			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1484 			return -1;
1485 		}
1486 		cmd->result = DID_BAD_TARGET << 16;
1487 		collect_stats(hostdata, cmd);
1488 		cmd->scsi_done(cmd);
1489 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1490 		dprintk(NDEBUG_SELECTION, ("scsi%d : target did not respond within 250ms\n", instance->host_no));
1491 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1492 		return 0;
1493 	}
1494 	hostdata->targets_present |= (1 << scmd_id(cmd));
1495 
1496 	/*
1497 	 * Since we followed the SCSI spec, and raised ATN while SEL
1498 	 * was true but before BSY was false during selection, the information
1499 	 * transfer phase should be a MESSAGE OUT phase so that we can send the
1500 	 * IDENTIFY message.
1501 	 *
1502 	 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1503 	 * message (2 bytes) with a tag ID that we increment with every command
1504 	 * until it wraps back to 0.
1505 	 *
1506 	 * XXX - it turns out that there are some broken SCSI-II devices,
1507 	 *       which claim to support tagged queuing but fail when more than
1508 	 *       some number of commands are issued at once.
1509 	 */
1510 
1511 	/* Wait for start of REQ/ACK handshake */
1512 
1513 	spin_unlock_irq(instance->host_lock);
1514 	err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1515 	spin_lock_irq(instance->host_lock);
1516 
1517 	if(err) {
1518 		printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1519 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1520 		goto failed;
1521 	}
1522 
1523 	dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
1524 	tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1525 
1526 	len = 1;
1527 	cmd->tag = 0;
1528 
1529 	/* Send message(s) */
1530 	data = tmp;
1531 	phase = PHASE_MSGOUT;
1532 	NCR5380_transfer_pio(instance, &phase, &len, &data);
1533 	dprintk(NDEBUG_SELECTION, ("scsi%d : nexus established.\n", instance->host_no));
1534 	/* XXX need to handle errors here */
1535 	hostdata->connected = cmd;
1536 	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1537 
1538 	initialize_SCp(cmd);
1539 
1540 	return 0;
1541 
1542 	/* Selection failed */
1543 failed:
1544 	return -1;
1545 
1546 }
1547 
1548 /*
1549  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1550  *      unsigned char *phase, int *count, unsigned char **data)
1551  *
1552  * Purpose : transfers data in given phase using polled I/O
1553  *
1554  * Inputs : instance - instance of driver, *phase - pointer to
1555  *      what phase is expected, *count - pointer to number of
1556  *      bytes to transfer, **data - pointer to data pointer.
1557  *
1558  * Returns : -1 when different phase is entered without transferring
1559  *      maximum number of bytes, 0 if all bytes or transferred or exit
1560  *      is in same phase.
1561  *
1562  *      Also, *phase, *count, *data are modified in place.
1563  *
1564  * XXX Note : handling for bus free may be useful.
1565  */
1566 
1567 /*
1568  * Note : this code is not as quick as it could be, however it
1569  * IS 100% reliable, and for the actual data transfer where speed
1570  * counts, we will always do a pseudo DMA or DMA transfer.
1571  */
1572 
1573 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1574 	NCR5380_local_declare();
1575 	unsigned char p = *phase, tmp;
1576 	int c = *count;
1577 	unsigned char *d = *data;
1578 	/*
1579 	 *      RvC: some administrative data to process polling time
1580 	 */
1581 	int break_allowed = 0;
1582 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1583 	NCR5380_setup(instance);
1584 
1585 	if (!(p & SR_IO))
1586 		dprintk(NDEBUG_PIO, ("scsi%d : pio write %d bytes\n", instance->host_no, c));
1587 	else
1588 		dprintk(NDEBUG_PIO, ("scsi%d : pio read %d bytes\n", instance->host_no, c));
1589 
1590 	/*
1591 	 * The NCR5380 chip will only drive the SCSI bus when the
1592 	 * phase specified in the appropriate bits of the TARGET COMMAND
1593 	 * REGISTER match the STATUS REGISTER
1594 	 */
1595 
1596 	 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1597 
1598 	/* RvC: don't know if this is necessary, but other SCSI I/O is short
1599 	 *      so breaks are not necessary there
1600 	 */
1601 	if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1602 		break_allowed = 1;
1603 	}
1604 	do {
1605 		/*
1606 		 * Wait for assertion of REQ, after which the phase bits will be
1607 		 * valid
1608 		 */
1609 
1610 		/* RvC: we simply poll once, after that we stop temporarily
1611 		 *      and let the device buffer fill up
1612 		 *      if breaking is not allowed, we keep polling as long as needed
1613 		 */
1614 
1615 		/* FIXME */
1616 		while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1617 		if (!(tmp & SR_REQ)) {
1618 			/* timeout condition */
1619 			NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1620 			break;
1621 		}
1622 
1623 		dprintk(NDEBUG_HANDSHAKE, ("scsi%d : REQ detected\n", instance->host_no));
1624 
1625 		/* Check for phase mismatch */
1626 		if ((tmp & PHASE_MASK) != p) {
1627 			dprintk(NDEBUG_HANDSHAKE, ("scsi%d : phase mismatch\n", instance->host_no));
1628 			NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1629 			break;
1630 		}
1631 		/* Do actual transfer from SCSI bus to / from memory */
1632 		if (!(p & SR_IO))
1633 			NCR5380_write(OUTPUT_DATA_REG, *d);
1634 		else
1635 			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1636 
1637 		++d;
1638 
1639 		/*
1640 		 * The SCSI standard suggests that in MSGOUT phase, the initiator
1641 		 * should drop ATN on the last byte of the message phase
1642 		 * after REQ has been asserted for the handshake but before
1643 		 * the initiator raises ACK.
1644 		 */
1645 
1646 		if (!(p & SR_IO)) {
1647 			if (!((p & SR_MSG) && c > 1)) {
1648 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1649 				NCR5380_dprint(NDEBUG_PIO, instance);
1650 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1651 			} else {
1652 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1653 				NCR5380_dprint(NDEBUG_PIO, instance);
1654 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1655 			}
1656 		} else {
1657 			NCR5380_dprint(NDEBUG_PIO, instance);
1658 			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1659 		}
1660 
1661 		/* FIXME - if this fails bus reset ?? */
1662 		NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1663 		dprintk(NDEBUG_HANDSHAKE, ("scsi%d : req false, handshake complete\n", instance->host_no));
1664 
1665 /*
1666  * We have several special cases to consider during REQ/ACK handshaking :
1667  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1668  *      message.  ATN must be dropped as ACK is dropped.
1669  *
1670  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1671  *      message.  We must exit with ACK asserted, so that the calling
1672  *      code may raise ATN before dropping ACK to reject the message.
1673  *
1674  * 3.  ACK and ATN are clear and the target may proceed as normal.
1675  */
1676 		if (!(p == PHASE_MSGIN && c == 1)) {
1677 			if (p == PHASE_MSGOUT && c > 1)
1678 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1679 			else
1680 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1681 		}
1682 	} while (--c);
1683 
1684 	dprintk(NDEBUG_PIO, ("scsi%d : residual %d\n", instance->host_no, c));
1685 
1686 	*count = c;
1687 	*data = d;
1688 	tmp = NCR5380_read(STATUS_REG);
1689 	if (tmp & SR_REQ)
1690 		*phase = tmp & PHASE_MASK;
1691 	else
1692 		*phase = PHASE_UNKNOWN;
1693 
1694 	if (!c || (*phase == p))
1695 		return 0;
1696 	else
1697 		return -1;
1698 }
1699 
1700 /**
1701  *	do_reset	-	issue a reset command
1702  *	@host: adapter to reset
1703  *
1704  *	Issue a reset sequence to the NCR5380 and try and get the bus
1705  *	back into sane shape.
1706  *
1707  *	Locks: caller holds queue lock
1708  */
1709 
1710 static void do_reset(struct Scsi_Host *host) {
1711 	NCR5380_local_declare();
1712 	NCR5380_setup(host);
1713 
1714 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1715 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1716 	udelay(25);
1717 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1718 }
1719 
1720 /*
1721  * Function : do_abort (Scsi_Host *host)
1722  *
1723  * Purpose : abort the currently established nexus.  Should only be
1724  *      called from a routine which can drop into a
1725  *
1726  * Returns : 0 on success, -1 on failure.
1727  *
1728  * Locks: queue lock held by caller
1729  *	FIXME: sort this out and get new_eh running
1730  */
1731 
1732 static int do_abort(struct Scsi_Host *host) {
1733 	NCR5380_local_declare();
1734 	unsigned char *msgptr, phase, tmp;
1735 	int len;
1736 	int rc;
1737 	NCR5380_setup(host);
1738 
1739 
1740 	/* Request message out phase */
1741 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1742 
1743 	/*
1744 	 * Wait for the target to indicate a valid phase by asserting
1745 	 * REQ.  Once this happens, we'll have either a MSGOUT phase
1746 	 * and can immediately send the ABORT message, or we'll have some
1747 	 * other phase and will have to source/sink data.
1748 	 *
1749 	 * We really don't care what value was on the bus or what value
1750 	 * the target sees, so we just handshake.
1751 	 */
1752 
1753 	rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1754 
1755 	if(rc < 0)
1756 		return -1;
1757 
1758 	tmp = (unsigned char)rc;
1759 
1760 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1761 
1762 	if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1763 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1764 		rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1765 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1766 		if(rc == -1)
1767 			return -1;
1768 	}
1769 	tmp = ABORT;
1770 	msgptr = &tmp;
1771 	len = 1;
1772 	phase = PHASE_MSGOUT;
1773 	NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1774 
1775 	/*
1776 	 * If we got here, and the command completed successfully,
1777 	 * we're about to go into bus free state.
1778 	 */
1779 
1780 	return len ? -1 : 0;
1781 }
1782 
1783 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1784 /*
1785  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1786  *      unsigned char *phase, int *count, unsigned char **data)
1787  *
1788  * Purpose : transfers data in given phase using either real
1789  *      or pseudo DMA.
1790  *
1791  * Inputs : instance - instance of driver, *phase - pointer to
1792  *      what phase is expected, *count - pointer to number of
1793  *      bytes to transfer, **data - pointer to data pointer.
1794  *
1795  * Returns : -1 when different phase is entered without transferring
1796  *      maximum number of bytes, 0 if all bytes or transferred or exit
1797  *      is in same phase.
1798  *
1799  *      Also, *phase, *count, *data are modified in place.
1800  *
1801  *	Locks: io_request lock held by caller
1802  */
1803 
1804 
1805 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1806 	NCR5380_local_declare();
1807 	register int c = *count;
1808 	register unsigned char p = *phase;
1809 	register unsigned char *d = *data;
1810 	unsigned char tmp;
1811 	int foo;
1812 #if defined(REAL_DMA_POLL)
1813 	int cnt, toPIO;
1814 	unsigned char saved_data = 0, overrun = 0, residue;
1815 #endif
1816 
1817 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1818 
1819 	NCR5380_setup(instance);
1820 
1821 	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1822 		*phase = tmp;
1823 		return -1;
1824 	}
1825 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1826 #ifdef READ_OVERRUNS
1827 	if (p & SR_IO) {
1828 		c -= 2;
1829 	}
1830 #endif
1831 	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));
1832 	hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1833 #endif
1834 
1835 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1836 
1837 #ifdef REAL_DMA
1838 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1839 #elif defined(REAL_DMA_POLL)
1840 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1841 #else
1842 	/*
1843 	 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1844 	 * were not disabled for the duration of a single DMA transfer, from
1845 	 * before the setting of DMA mode to after transfer of the last byte.
1846 	 */
1847 
1848 #if defined(PSEUDO_DMA) && defined(UNSAFE)
1849 	spin_unlock_irq(instance->host_lock);
1850 #endif
1851 	/* KLL May need eop and parity in 53c400 */
1852 	if (hostdata->flags & FLAG_NCR53C400)
1853 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE |
1854 				MR_ENABLE_PAR_CHECK | MR_ENABLE_PAR_INTR |
1855 				MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1856 	else
1857 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1858 #endif				/* def REAL_DMA */
1859 
1860 	dprintk(NDEBUG_DMA, ("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)));
1861 
1862 	/*
1863 	 *	On the PAS16 at least I/O recovery delays are not needed here.
1864 	 *	Everyone else seems to want them.
1865 	 */
1866 
1867 	if (p & SR_IO) {
1868 		io_recovery_delay(1);
1869 		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1870 	} else {
1871 		io_recovery_delay(1);
1872 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1873 		io_recovery_delay(1);
1874 		NCR5380_write(START_DMA_SEND_REG, 0);
1875 		io_recovery_delay(1);
1876 	}
1877 
1878 #if defined(REAL_DMA_POLL)
1879 	do {
1880 		tmp = NCR5380_read(BUS_AND_STATUS_REG);
1881 	} while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1882 
1883 /*
1884    At this point, either we've completed DMA, or we have a phase mismatch,
1885    or we've unexpectedly lost BUSY (which is a real error).
1886 
1887    For write DMAs, we want to wait until the last byte has been
1888    transferred out over the bus before we turn off DMA mode.  Alas, there
1889    seems to be no terribly good way of doing this on a 5380 under all
1890    conditions.  For non-scatter-gather operations, we can wait until REQ
1891    and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1892    are nastier, since the device will be expecting more data than we
1893    are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1894    could test LAST BIT SENT to assure transfer (I imagine this is precisely
1895    why this signal was added to the newer chips) but on the older 538[01]
1896    this signal does not exist.  The workaround for this lack is a watchdog;
1897    we bail out of the wait-loop after a modest amount of wait-time if
1898    the usual exit conditions are not met.  Not a terribly clean or
1899    correct solution :-%
1900 
1901    Reads are equally tricky due to a nasty characteristic of the NCR5380.
1902    If the chip is in DMA mode for an READ, it will respond to a target's
1903    REQ by latching the SCSI data into the INPUT DATA register and asserting
1904    ACK, even if it has _already_ been notified by the DMA controller that
1905    the current DMA transfer has completed!  If the NCR5380 is then taken
1906    out of DMA mode, this already-acknowledged byte is lost.
1907 
1908    This is not a problem for "one DMA transfer per command" reads, because
1909    the situation will never arise... either all of the data is DMA'ed
1910    properly, or the target switches to MESSAGE IN phase to signal a
1911    disconnection (either operation bringing the DMA to a clean halt).
1912    However, in order to handle scatter-reads, we must work around the
1913    problem.  The chosen fix is to DMA N-2 bytes, then check for the
1914    condition before taking the NCR5380 out of DMA mode.  One or two extra
1915    bytes are transferred via PIO as necessary to fill out the original
1916    request.
1917  */
1918 
1919 	if (p & SR_IO) {
1920 #ifdef READ_OVERRUNS
1921 		udelay(10);
1922 		if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1923 			saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1924 			overrun = 1;
1925 		}
1926 #endif
1927 	} else {
1928 		int limit = 100;
1929 		while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1930 			if (!(tmp & BASR_PHASE_MATCH))
1931 				break;
1932 			if (--limit < 0)
1933 				break;
1934 		}
1935 	}
1936 
1937 	dprintk(NDEBUG_DMA, ("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG)));
1938 
1939 	NCR5380_write(MODE_REG, MR_BASE);
1940 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1941 
1942 	residue = NCR5380_dma_residual(instance);
1943 	c -= residue;
1944 	*count -= c;
1945 	*data += c;
1946 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1947 
1948 #ifdef READ_OVERRUNS
1949 	if (*phase == p && (p & SR_IO) && residue == 0) {
1950 		if (overrun) {
1951 			dprintk(NDEBUG_DMA, ("Got an input overrun, using saved byte\n"));
1952 			**data = saved_data;
1953 			*data += 1;
1954 			*count -= 1;
1955 			cnt = toPIO = 1;
1956 		} else {
1957 			printk("No overrun??\n");
1958 			cnt = toPIO = 2;
1959 		}
1960 		dprintk(NDEBUG_DMA, ("Doing %d-byte PIO to 0x%X\n", cnt, *data));
1961 		NCR5380_transfer_pio(instance, phase, &cnt, data);
1962 		*count -= toPIO - cnt;
1963 	}
1964 #endif
1965 
1966 	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)));
1967 	return 0;
1968 
1969 #elif defined(REAL_DMA)
1970 	return 0;
1971 #else				/* defined(REAL_DMA_POLL) */
1972 	if (p & SR_IO) {
1973 #ifdef DMA_WORKS_RIGHT
1974 		foo = NCR5380_pread(instance, d, c);
1975 #else
1976 		int diff = 1;
1977 		if (hostdata->flags & FLAG_NCR53C400) {
1978 			diff = 0;
1979 		}
1980 		if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1981 			/*
1982 			 * We can't disable DMA mode after successfully transferring
1983 			 * what we plan to be the last byte, since that would open up
1984 			 * a race condition where if the target asserted REQ before
1985 			 * we got the DMA mode reset, the NCR5380 would have latched
1986 			 * an additional byte into the INPUT DATA register and we'd
1987 			 * have dropped it.
1988 			 *
1989 			 * The workaround was to transfer one fewer bytes than we
1990 			 * intended to with the pseudo-DMA read function, wait for
1991 			 * the chip to latch the last byte, read it, and then disable
1992 			 * pseudo-DMA mode.
1993 			 *
1994 			 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1995 			 * REQ is deasserted when ACK is asserted, and not reasserted
1996 			 * until ACK goes false.  Since the NCR5380 won't lower ACK
1997 			 * until DACK is asserted, which won't happen unless we twiddle
1998 			 * the DMA port or we take the NCR5380 out of DMA mode, we
1999 			 * can guarantee that we won't handshake another extra
2000 			 * byte.
2001 			 */
2002 
2003 			if (!(hostdata->flags & FLAG_NCR53C400)) {
2004 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
2005 				/* Wait for clean handshake */
2006 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2007 				d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2008 			}
2009 		}
2010 #endif
2011 	} else {
2012 #ifdef DMA_WORKS_RIGHT
2013 		foo = NCR5380_pwrite(instance, d, c);
2014 #else
2015 		int timeout;
2016 		dprintk(NDEBUG_C400_PWRITE, ("About to pwrite %d bytes\n", c));
2017 		if (!(foo = NCR5380_pwrite(instance, d, c))) {
2018 			/*
2019 			 * Wait for the last byte to be sent.  If REQ is being asserted for
2020 			 * the byte we're interested, we'll ACK it and it will go false.
2021 			 */
2022 			if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2023 				timeout = 20000;
2024 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2025 
2026 				if (!timeout)
2027 					dprintk(NDEBUG_LAST_BYTE_SENT, ("scsi%d : timed out on last byte\n", instance->host_no));
2028 
2029 				if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2030 					hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2031 					if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2032 						hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2033 						dprintk(NDEBUG_LAST_WRITE_SENT, ("scsi%d : last bit sent works\n", instance->host_no));
2034 					}
2035 				}
2036 			} else {
2037 				dprintk(NDEBUG_C400_PWRITE, ("Waiting for LASTBYTE\n"));
2038 				while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2039 				dprintk(NDEBUG_C400_PWRITE, ("Got LASTBYTE\n"));
2040 			}
2041 		}
2042 #endif
2043 	}
2044 	NCR5380_write(MODE_REG, MR_BASE);
2045 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2046 
2047 	if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2048 		dprintk(NDEBUG_C400_PWRITE, ("53C400w: Checking for IRQ\n"));
2049 		if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2050 			dprintk(NDEBUG_C400_PWRITE, ("53C400w:    got it, reading reset interrupt reg\n"));
2051 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2052 		} else {
2053 			printk("53C400w:    IRQ NOT THERE!\n");
2054 		}
2055 	}
2056 	*data = d + c;
2057 	*count = 0;
2058 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2059 #if defined(PSEUDO_DMA) && defined(UNSAFE)
2060 	spin_lock_irq(instance->host_lock);
2061 #endif				/* defined(REAL_DMA_POLL) */
2062 	return foo;
2063 #endif				/* def REAL_DMA */
2064 }
2065 #endif				/* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2066 
2067 /*
2068  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2069  *
2070  * Purpose : run through the various SCSI phases and do as the target
2071  *      directs us to.  Operates on the currently connected command,
2072  *      instance->connected.
2073  *
2074  * Inputs : instance, instance for which we are doing commands
2075  *
2076  * Side effects : SCSI things happen, the disconnected queue will be
2077  *      modified if a command disconnects, *instance->connected will
2078  *      change.
2079  *
2080  * XXX Note : we need to watch for bus free or a reset condition here
2081  *      to recover from an unexpected bus free condition.
2082  *
2083  * Locks: io_request_lock held by caller in IRQ mode
2084  */
2085 
2086 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2087 	NCR5380_local_declare();
2088 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2089 	unsigned char msgout = NOP;
2090 	int sink = 0;
2091 	int len;
2092 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2093 	int transfersize;
2094 #endif
2095 	unsigned char *data;
2096 	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2097 	Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2098 	/* RvC: we need to set the end of the polling time */
2099 	unsigned long poll_time = jiffies + USLEEP_POLL;
2100 
2101 	NCR5380_setup(instance);
2102 
2103 	while (1) {
2104 		tmp = NCR5380_read(STATUS_REG);
2105 		/* We only have a valid SCSI phase when REQ is asserted */
2106 		if (tmp & SR_REQ) {
2107 			phase = (tmp & PHASE_MASK);
2108 			if (phase != old_phase) {
2109 				old_phase = phase;
2110 				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2111 			}
2112 			if (sink && (phase != PHASE_MSGOUT)) {
2113 				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2114 
2115 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2116 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2117 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2118 				sink = 0;
2119 				continue;
2120 			}
2121 			switch (phase) {
2122 			case PHASE_DATAIN:
2123 			case PHASE_DATAOUT:
2124 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2125 				printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2126 				sink = 1;
2127 				do_abort(instance);
2128 				cmd->result = DID_ERROR << 16;
2129 				cmd->scsi_done(cmd);
2130 				return;
2131 #endif
2132 				/*
2133 				 * If there is no room left in the current buffer in the
2134 				 * scatter-gather list, move onto the next one.
2135 				 */
2136 
2137 				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2138 					++cmd->SCp.buffer;
2139 					--cmd->SCp.buffers_residual;
2140 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
2141 					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2142 					dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
2143 				}
2144 				/*
2145 				 * The preferred transfer method is going to be
2146 				 * PSEUDO-DMA for systems that are strictly PIO,
2147 				 * since we can let the hardware do the handshaking.
2148 				 *
2149 				 * For this to work, we need to know the transfersize
2150 				 * ahead of time, since the pseudo-DMA code will sit
2151 				 * in an unconditional loop.
2152 				 */
2153 
2154 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2155 				/* KLL
2156 				 * PSEUDO_DMA is defined here. If this is the g_NCR5380
2157 				 * driver then it will always be defined, so the
2158 				 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2159 				 * NCR5380 case.  I think this is a fairly clean solution.
2160 				 * We supplement these 2 if's with the flag.
2161 				 */
2162 #ifdef NCR5380_dma_xfer_len
2163 				if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2164 #else
2165 				transfersize = cmd->transfersize;
2166 
2167 #ifdef LIMIT_TRANSFERSIZE	/* If we have problems with interrupt service */
2168 				if (transfersize > 512)
2169 					transfersize = 512;
2170 #endif				/* LIMIT_TRANSFERSIZE */
2171 
2172 				if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2173 					/* Limit transfers to 32K, for xx400 & xx406
2174 					 * pseudoDMA that transfers in 128 bytes blocks. */
2175 					if (transfersize > 32 * 1024)
2176 						transfersize = 32 * 1024;
2177 #endif
2178 					len = transfersize;
2179 					if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2180 						/*
2181 						 * If the watchdog timer fires, all future accesses to this
2182 						 * device will use the polled-IO.
2183 						 */
2184 						scmd_printk(KERN_INFO, cmd,
2185 							    "switching to slow handshake\n");
2186 						cmd->device->borken = 1;
2187 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2188 						sink = 1;
2189 						do_abort(instance);
2190 						cmd->result = DID_ERROR << 16;
2191 						cmd->scsi_done(cmd);
2192 						/* XXX - need to source or sink data here, as appropriate */
2193 					} else
2194 						cmd->SCp.this_residual -= transfersize - len;
2195 				} else
2196 #endif				/* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2197 					NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2198 							     &cmd->SCp.ptr);
2199 				break;
2200 			case PHASE_MSGIN:
2201 				len = 1;
2202 				data = &tmp;
2203 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2204 				cmd->SCp.Message = tmp;
2205 
2206 				switch (tmp) {
2207 					/*
2208 					 * Linking lets us reduce the time required to get the
2209 					 * next command out to the device, hopefully this will
2210 					 * mean we don't waste another revolution due to the delays
2211 					 * required by ARBITRATION and another SELECTION.
2212 					 *
2213 					 * In the current implementation proposal, low level drivers
2214 					 * merely have to start the next command, pointed to by
2215 					 * next_link, done() is called as with unlinked commands.
2216 					 */
2217 #ifdef LINKED
2218 				case LINKED_CMD_COMPLETE:
2219 				case LINKED_FLG_CMD_COMPLETE:
2220 					/* Accept message by clearing ACK */
2221 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2222 					dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun));
2223 					/*
2224 					 * Sanity check : A linked command should only terminate with
2225 					 * one of these messages if there are more linked commands
2226 					 * available.
2227 					 */
2228 					if (!cmd->next_link) {
2229 						printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2230 						sink = 1;
2231 						do_abort(instance);
2232 						return;
2233 					}
2234 					initialize_SCp(cmd->next_link);
2235 					/* The next command is still part of this process */
2236 					cmd->next_link->tag = cmd->tag;
2237 					cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2238 					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));
2239 					collect_stats(hostdata, cmd);
2240 					cmd->scsi_done(cmd);
2241 					cmd = hostdata->connected;
2242 					break;
2243 #endif				/* def LINKED */
2244 				case ABORT:
2245 				case COMMAND_COMPLETE:
2246 					/* Accept message by clearing ACK */
2247 					sink = 1;
2248 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2249 					hostdata->connected = NULL;
2250 					dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun));
2251 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2252 
2253 					/*
2254 					 * I'm not sure what the correct thing to do here is :
2255 					 *
2256 					 * If the command that just executed is NOT a request
2257 					 * sense, the obvious thing to do is to set the result
2258 					 * code to the values of the stored parameters.
2259 					 *
2260 					 * If it was a REQUEST SENSE command, we need some way
2261 					 * to differentiate between the failure code of the original
2262 					 * and the failure code of the REQUEST sense - the obvious
2263 					 * case is success, where we fall through and leave the result
2264 					 * code unchanged.
2265 					 *
2266 					 * The non-obvious place is where the REQUEST SENSE failed
2267 					 */
2268 
2269 					if (cmd->cmnd[0] != REQUEST_SENSE)
2270 						cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2271 					else if (status_byte(cmd->SCp.Status) != GOOD)
2272 						cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2273 
2274 #ifdef AUTOSENSE
2275 					if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2276 						hostdata->ses.cmd_len) {
2277 						scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2278 						hostdata->ses.cmd_len = 0 ;
2279 					}
2280 
2281 					if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2282 						scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2283 
2284 						dprintk(NDEBUG_AUTOSENSE, ("scsi%d : performing request sense\n", instance->host_no));
2285 
2286 						LIST(cmd, hostdata->issue_queue);
2287 						cmd->host_scribble = (unsigned char *)
2288 						    hostdata->issue_queue;
2289 						hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2290 						dprintk(NDEBUG_QUEUES, ("scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no));
2291 					} else
2292 #endif				/* def AUTOSENSE */
2293 					{
2294 						collect_stats(hostdata, cmd);
2295 						cmd->scsi_done(cmd);
2296 					}
2297 
2298 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2299 					/*
2300 					 * Restore phase bits to 0 so an interrupted selection,
2301 					 * arbitration can resume.
2302 					 */
2303 					NCR5380_write(TARGET_COMMAND_REG, 0);
2304 
2305 					while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2306 						barrier();
2307 					return;
2308 				case MESSAGE_REJECT:
2309 					/* Accept message by clearing ACK */
2310 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2311 					switch (hostdata->last_message) {
2312 					case HEAD_OF_QUEUE_TAG:
2313 					case ORDERED_QUEUE_TAG:
2314 					case SIMPLE_QUEUE_TAG:
2315 						cmd->device->simple_tags = 0;
2316 						hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2317 						break;
2318 					default:
2319 						break;
2320 					}
2321 				case DISCONNECT:{
2322 						/* Accept message by clearing ACK */
2323 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2324 						cmd->device->disconnect = 1;
2325 						LIST(cmd, hostdata->disconnected_queue);
2326 						cmd->host_scribble = (unsigned char *)
2327 						    hostdata->disconnected_queue;
2328 						hostdata->connected = NULL;
2329 						hostdata->disconnected_queue = cmd;
2330 						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));
2331 						/*
2332 						 * Restore phase bits to 0 so an interrupted selection,
2333 						 * arbitration can resume.
2334 						 */
2335 						NCR5380_write(TARGET_COMMAND_REG, 0);
2336 
2337 						/* Enable reselect interrupts */
2338 						NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2339 						/* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2340 						/* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2341 						while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2342 							barrier();
2343 						return;
2344 					}
2345 					/*
2346 					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2347 					 * operation, in violation of the SCSI spec so we can safely
2348 					 * ignore SAVE/RESTORE pointers calls.
2349 					 *
2350 					 * Unfortunately, some disks violate the SCSI spec and
2351 					 * don't issue the required SAVE_POINTERS message before
2352 					 * disconnecting, and we have to break spec to remain
2353 					 * compatible.
2354 					 */
2355 				case SAVE_POINTERS:
2356 				case RESTORE_POINTERS:
2357 					/* Accept message by clearing ACK */
2358 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2359 					break;
2360 				case EXTENDED_MESSAGE:
2361 /*
2362  * Extended messages are sent in the following format :
2363  * Byte
2364  * 0            EXTENDED_MESSAGE == 1
2365  * 1            length (includes one byte for code, doesn't
2366  *              include first two bytes)
2367  * 2            code
2368  * 3..length+1  arguments
2369  *
2370  * Start the extended message buffer with the EXTENDED_MESSAGE
2371  * byte, since spi_print_msg() wants the whole thing.
2372  */
2373 					extended_msg[0] = EXTENDED_MESSAGE;
2374 					/* Accept first byte by clearing ACK */
2375 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2376 					dprintk(NDEBUG_EXTENDED, ("scsi%d : receiving extended message\n", instance->host_no));
2377 
2378 					len = 2;
2379 					data = extended_msg + 1;
2380 					phase = PHASE_MSGIN;
2381 					NCR5380_transfer_pio(instance, &phase, &len, &data);
2382 
2383 					dprintk(NDEBUG_EXTENDED, ("scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]));
2384 
2385 					if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2386 						/* Accept third byte by clearing ACK */
2387 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2388 						len = extended_msg[1] - 1;
2389 						data = extended_msg + 3;
2390 						phase = PHASE_MSGIN;
2391 
2392 						NCR5380_transfer_pio(instance, &phase, &len, &data);
2393 						dprintk(NDEBUG_EXTENDED, ("scsi%d : message received, residual %d\n", instance->host_no, len));
2394 
2395 						switch (extended_msg[2]) {
2396 						case EXTENDED_SDTR:
2397 						case EXTENDED_WDTR:
2398 						case EXTENDED_MODIFY_DATA_POINTER:
2399 						case EXTENDED_EXTENDED_IDENTIFY:
2400 							tmp = 0;
2401 						}
2402 					} else if (len) {
2403 						printk("scsi%d: error receiving extended message\n", instance->host_no);
2404 						tmp = 0;
2405 					} else {
2406 						printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2407 						tmp = 0;
2408 					}
2409 					/* Fall through to reject message */
2410 
2411 					/*
2412 					 * If we get something weird that we aren't expecting,
2413 					 * reject it.
2414 					 */
2415 				default:
2416 					if (!tmp) {
2417 						printk("scsi%d: rejecting message ", instance->host_no);
2418 						spi_print_msg(extended_msg);
2419 						printk("\n");
2420 					} else if (tmp != EXTENDED_MESSAGE)
2421 						scmd_printk(KERN_INFO, cmd,
2422 							"rejecting unknown message %02x\n",tmp);
2423 					else
2424 						scmd_printk(KERN_INFO, cmd,
2425 							"rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2426 
2427 					msgout = MESSAGE_REJECT;
2428 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2429 					break;
2430 				}	/* switch (tmp) */
2431 				break;
2432 			case PHASE_MSGOUT:
2433 				len = 1;
2434 				data = &msgout;
2435 				hostdata->last_message = msgout;
2436 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2437 				if (msgout == ABORT) {
2438 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2439 					hostdata->connected = NULL;
2440 					cmd->result = DID_ERROR << 16;
2441 					collect_stats(hostdata, cmd);
2442 					cmd->scsi_done(cmd);
2443 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2444 					return;
2445 				}
2446 				msgout = NOP;
2447 				break;
2448 			case PHASE_CMDOUT:
2449 				len = cmd->cmd_len;
2450 				data = cmd->cmnd;
2451 				/*
2452 				 * XXX for performance reasons, on machines with a
2453 				 * PSEUDO-DMA architecture we should probably
2454 				 * use the dma transfer function.
2455 				 */
2456 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2457 				if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2458 					NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2459 					dprintk(NDEBUG_USLEEP, ("scsi%d : issued command, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2460 					return;
2461 				}
2462 				break;
2463 			case PHASE_STATIN:
2464 				len = 1;
2465 				data = &tmp;
2466 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2467 				cmd->SCp.Status = tmp;
2468 				break;
2469 			default:
2470 				printk("scsi%d : unknown phase\n", instance->host_no);
2471 				NCR5380_dprint(NDEBUG_ALL, instance);
2472 			}	/* switch(phase) */
2473 		}		/* if (tmp * SR_REQ) */
2474 		else {
2475 			/* RvC: go to sleep if polling time expired
2476 			 */
2477 			if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2478 				NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2479 				dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2480 				return;
2481 			}
2482 		}
2483 	}			/* while (1) */
2484 }
2485 
2486 /*
2487  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2488  *
2489  * Purpose : does reselection, initializing the instance->connected
2490  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2491  *      nexus has been reestablished,
2492  *
2493  * Inputs : instance - this instance of the NCR5380.
2494  *
2495  * Locks: io_request_lock held by caller if IRQ driven
2496  */
2497 
2498 static void NCR5380_reselect(struct Scsi_Host *instance) {
2499 	NCR5380_local_declare();
2500 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2501 	 instance->hostdata;
2502 	unsigned char target_mask;
2503 	unsigned char lun, phase;
2504 	int len;
2505 	unsigned char msg[3];
2506 	unsigned char *data;
2507 	Scsi_Cmnd *tmp = NULL, *prev;
2508 	int abort = 0;
2509 	NCR5380_setup(instance);
2510 
2511 	/*
2512 	 * Disable arbitration, etc. since the host adapter obviously
2513 	 * lost, and tell an interrupted NCR5380_select() to restart.
2514 	 */
2515 
2516 	NCR5380_write(MODE_REG, MR_BASE);
2517 	hostdata->restart_select = 1;
2518 
2519 	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2520 	dprintk(NDEBUG_SELECTION, ("scsi%d : reselect\n", instance->host_no));
2521 
2522 	/*
2523 	 * At this point, we have detected that our SCSI ID is on the bus,
2524 	 * SEL is true and BSY was false for at least one bus settle delay
2525 	 * (400 ns).
2526 	 *
2527 	 * We must assert BSY ourselves, until the target drops the SEL
2528 	 * signal.
2529 	 */
2530 
2531 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2532 
2533 	/* FIXME: timeout too long, must fail to workqueue */
2534 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2535 		abort = 1;
2536 
2537 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2538 
2539 	/*
2540 	 * Wait for target to go into MSGIN.
2541 	 * FIXME: timeout needed and fail to work queeu
2542 	 */
2543 
2544 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2545 		abort = 1;
2546 
2547 	len = 1;
2548 	data = msg;
2549 	phase = PHASE_MSGIN;
2550 	NCR5380_transfer_pio(instance, &phase, &len, &data);
2551 
2552 	if (!(msg[0] & 0x80)) {
2553 		printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2554 		spi_print_msg(msg);
2555 		abort = 1;
2556 	} else {
2557 		/* Accept message by clearing ACK */
2558 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2559 		lun = (msg[0] & 0x07);
2560 
2561 		/*
2562 		 * We need to add code for SCSI-II to track which devices have
2563 		 * I_T_L_Q nexuses established, and which have simple I_T_L
2564 		 * nexuses so we can chose to do additional data transfer.
2565 		 */
2566 
2567 		/*
2568 		 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2569 		 * just reestablished, and remove it from the disconnected queue.
2570 		 */
2571 
2572 
2573 		for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2574 			if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2575 			    ) {
2576 				if (prev) {
2577 					REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2578 					prev->host_scribble = tmp->host_scribble;
2579 				} else {
2580 					REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2581 					hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2582 				}
2583 				tmp->host_scribble = NULL;
2584 				break;
2585 			}
2586 		if (!tmp) {
2587 			printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2588 			/*
2589 			 * Since we have an established nexus that we can't do anything with,
2590 			 * we must abort it.
2591 			 */
2592 			abort = 1;
2593 		}
2594 	}
2595 
2596 	if (abort) {
2597 		do_abort(instance);
2598 	} else {
2599 		hostdata->connected = tmp;
2600 		dprintk(NDEBUG_RESELECTION, ("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->target, tmp->lun, tmp->tag));
2601 	}
2602 }
2603 
2604 /*
2605  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2606  *
2607  * Purpose : called by interrupt handler when DMA finishes or a phase
2608  *      mismatch occurs (which would finish the DMA transfer).
2609  *
2610  * Inputs : instance - this instance of the NCR5380.
2611  *
2612  * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2613  *      nexus has been reestablished, on failure NULL is returned.
2614  */
2615 
2616 #ifdef REAL_DMA
2617 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2618 	NCR5380_local_declare();
2619 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2620 	int transferred;
2621 	NCR5380_setup(instance);
2622 
2623 	/*
2624 	 * XXX this might not be right.
2625 	 *
2626 	 * Wait for final byte to transfer, ie wait for ACK to go false.
2627 	 *
2628 	 * We should use the Last Byte Sent bit, unfortunately this is
2629 	 * not available on the 5380/5381 (only the various CMOS chips)
2630 	 *
2631 	 * FIXME: timeout, and need to handle long timeout/irq case
2632 	 */
2633 
2634 	NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2635 
2636 	NCR5380_write(MODE_REG, MR_BASE);
2637 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2638 
2639 	/*
2640 	 * The only places we should see a phase mismatch and have to send
2641 	 * data from the same set of pointers will be the data transfer
2642 	 * phases.  So, residual, requested length are only important here.
2643 	 */
2644 
2645 	if (!(hostdata->connected->SCp.phase & SR_CD)) {
2646 		transferred = instance->dmalen - NCR5380_dma_residual();
2647 		hostdata->connected->SCp.this_residual -= transferred;
2648 		hostdata->connected->SCp.ptr += transferred;
2649 	}
2650 }
2651 #endif				/* def REAL_DMA */
2652 
2653 /*
2654  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2655  *
2656  * Purpose : abort a command
2657  *
2658  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2659  *      host byte of the result field to, if zero DID_ABORTED is
2660  *      used.
2661  *
2662  * Returns : 0 - success, -1 on failure.
2663  *
2664  *	XXX - there is no way to abort the command that is currently
2665  *	connected, you have to wait for it to complete.  If this is
2666  *	a problem, we could implement longjmp() / setjmp(), setjmp()
2667  *	called where the loop started in NCR5380_main().
2668  *
2669  * Locks: host lock taken by caller
2670  */
2671 
2672 static int NCR5380_abort(Scsi_Cmnd * cmd) {
2673 	NCR5380_local_declare();
2674 	struct Scsi_Host *instance = cmd->device->host;
2675 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2676 	Scsi_Cmnd *tmp, **prev;
2677 
2678 	printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2679 	scsi_print_command(cmd);
2680 
2681 	NCR5380_print_status(instance);
2682 
2683 	NCR5380_setup(instance);
2684 
2685 	dprintk(NDEBUG_ABORT, ("scsi%d : abort called\n", instance->host_no));
2686 	dprintk(NDEBUG_ABORT, ("        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)));
2687 
2688 #if 0
2689 /*
2690  * Case 1 : If the command is the currently executing command,
2691  * we'll set the aborted flag and return control so that
2692  * information transfer routine can exit cleanly.
2693  */
2694 
2695 	if (hostdata->connected == cmd) {
2696 		dprintk(NDEBUG_ABORT, ("scsi%d : aborting connected command\n", instance->host_no));
2697 		hostdata->aborted = 1;
2698 /*
2699  * We should perform BSY checking, and make sure we haven't slipped
2700  * into BUS FREE.
2701  */
2702 
2703 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2704 /*
2705  * Since we can't change phases until we've completed the current
2706  * handshake, we have to source or sink a byte of data if the current
2707  * phase is not MSGOUT.
2708  */
2709 
2710 /*
2711  * Return control to the executing NCR drive so we can clear the
2712  * aborted flag and get back into our main loop.
2713  */
2714 
2715 		return 0;
2716 	}
2717 #endif
2718 
2719 /*
2720  * Case 2 : If the command hasn't been issued yet, we simply remove it
2721  *          from the issue queue.
2722  */
2723 
2724 	dprintk(NDEBUG_ABORT, ("scsi%d : abort going into loop.\n", instance->host_no));
2725 	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)
2726 		if (cmd == tmp) {
2727 			REMOVE(5, *prev, tmp, tmp->host_scribble);
2728 			(*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2729 			tmp->host_scribble = NULL;
2730 			tmp->result = DID_ABORT << 16;
2731 			dprintk(NDEBUG_ABORT, ("scsi%d : abort removed command from issue queue.\n", instance->host_no));
2732 			tmp->scsi_done(tmp);
2733 			return SUCCESS;
2734 		}
2735 #if (NDEBUG  & NDEBUG_ABORT)
2736 	/* KLL */
2737 		else if (prev == tmp)
2738 			printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2739 #endif
2740 
2741 /*
2742  * Case 3 : If any commands are connected, we're going to fail the abort
2743  *          and let the high level SCSI driver retry at a later time or
2744  *          issue a reset.
2745  *
2746  *          Timeouts, and therefore aborted commands, will be highly unlikely
2747  *          and handling them cleanly in this situation would make the common
2748  *          case of noresets less efficient, and would pollute our code.  So,
2749  *          we fail.
2750  */
2751 
2752 	if (hostdata->connected) {
2753 		dprintk(NDEBUG_ABORT, ("scsi%d : abort failed, command connected.\n", instance->host_no));
2754 		return FAILED;
2755 	}
2756 /*
2757  * Case 4: If the command is currently disconnected from the bus, and
2758  *      there are no connected commands, we reconnect the I_T_L or
2759  *      I_T_L_Q nexus associated with it, go into message out, and send
2760  *      an abort message.
2761  *
2762  * This case is especially ugly. In order to reestablish the nexus, we
2763  * need to call NCR5380_select().  The easiest way to implement this
2764  * function was to abort if the bus was busy, and let the interrupt
2765  * handler triggered on the SEL for reselect take care of lost arbitrations
2766  * where necessary, meaning interrupts need to be enabled.
2767  *
2768  * When interrupts are enabled, the queues may change - so we
2769  * can't remove it from the disconnected queue before selecting it
2770  * because that could cause a failure in hashing the nexus if that
2771  * device reselected.
2772  *
2773  * Since the queues may change, we can't use the pointers from when we
2774  * first locate it.
2775  *
2776  * So, we must first locate the command, and if NCR5380_select()
2777  * succeeds, then issue the abort, relocate the command and remove
2778  * it from the disconnected queue.
2779  */
2780 
2781 	for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2782 		if (cmd == tmp) {
2783 			dprintk(NDEBUG_ABORT, ("scsi%d : aborting disconnected command.\n", instance->host_no));
2784 
2785 			if (NCR5380_select(instance, cmd, (int) cmd->tag))
2786 				return FAILED;
2787 			dprintk(NDEBUG_ABORT, ("scsi%d : nexus reestablished.\n", instance->host_no));
2788 
2789 			do_abort(instance);
2790 
2791 			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)
2792 				if (cmd == tmp) {
2793 					REMOVE(5, *prev, tmp, tmp->host_scribble);
2794 					*prev = (Scsi_Cmnd *) tmp->host_scribble;
2795 					tmp->host_scribble = NULL;
2796 					tmp->result = DID_ABORT << 16;
2797 					tmp->scsi_done(tmp);
2798 					return SUCCESS;
2799 				}
2800 		}
2801 /*
2802  * Case 5 : If we reached this point, the command was not found in any of
2803  *          the queues.
2804  *
2805  * We probably reached this point because of an unlikely race condition
2806  * between the command completing successfully and the abortion code,
2807  * so we won't panic, but we will notify the user in case something really
2808  * broke.
2809  */
2810 	printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2811 			"         before abortion\n", instance->host_no);
2812 	return FAILED;
2813 }
2814 
2815 
2816 /*
2817  * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2818  *
2819  * Purpose : reset the SCSI bus.
2820  *
2821  * Returns : SUCCESS
2822  *
2823  * Locks: host lock taken by caller
2824  */
2825 
2826 static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2827 {
2828 	struct Scsi_Host *instance = cmd->device->host;
2829 
2830 	NCR5380_local_declare();
2831 	NCR5380_setup(instance);
2832 	NCR5380_print_status(instance);
2833 
2834 	spin_lock_irq(instance->host_lock);
2835 	do_reset(instance);
2836 	spin_unlock_irq(instance->host_lock);
2837 
2838 	return SUCCESS;
2839 }
2840