xref: /openbmc/linux/drivers/scsi/NCR5380.c (revision 206204a1)
1 /*
2  * NCR 5380 generic driver routines.  These should make it *trivial*
3  *      to implement 5380 SCSI drivers under Linux with a non-trantor
4  *      architecture.
5  *
6  *      Note that these routines also work with NR53c400 family chips.
7  *
8  * Copyright 1993, Drew Eckhardt
9  *      Visionary Computing
10  *      (Unix and Linux consulting and custom programming)
11  *      drew@colorado.edu
12  *      +1 (303) 666-5836
13  *
14  * DISTRIBUTION RELEASE 6.
15  *
16  * For more information, please consult
17  *
18  * NCR 5380 Family
19  * SCSI Protocol Controller
20  * Databook
21  *
22  * NCR Microelectronics
23  * 1635 Aeroplaza Drive
24  * Colorado Springs, CO 80916
25  * 1+ (719) 578-3400
26  * 1+ (800) 334-5454
27  */
28 
29 /*
30  * Revision 1.10 1998/9/2	Alan Cox
31  *				(alan@lxorguk.ukuu.org.uk)
32  * Fixed up the timer lockups reported so far. Things still suck. Looking
33  * forward to 2.3 and per device request queues. Then it'll be possible to
34  * SMP thread this beast and improve life no end.
35 
36  * Revision 1.9  1997/7/27	Ronald van Cuijlenborg
37  *				(ronald.van.cuijlenborg@tip.nl or nutty@dds.nl)
38  * (hopefully) fixed and enhanced USLEEP
39  * added support for DTC3181E card (for Mustek scanner)
40  *
41 
42  * Revision 1.8			Ingmar Baumgart
43  *				(ingmar@gonzo.schwaben.de)
44  * added support for NCR53C400a card
45  *
46 
47  * Revision 1.7  1996/3/2       Ray Van Tassle (rayvt@comm.mot.com)
48  * added proc_info
49  * added support needed for DTC 3180/3280
50  * fixed a couple of bugs
51  *
52 
53  * Revision 1.5  1994/01/19  09:14:57  drew
54  * Fixed udelay() hack that was being used on DATAOUT phases
55  * instead of a proper wait for the final handshake.
56  *
57  * Revision 1.4  1994/01/19  06:44:25  drew
58  * *** empty log message ***
59  *
60  * Revision 1.3  1994/01/19  05:24:40  drew
61  * Added support for TCR LAST_BYTE_SENT bit.
62  *
63  * Revision 1.2  1994/01/15  06:14:11  drew
64  * REAL DMA support, bug fixes.
65  *
66  * Revision 1.1  1994/01/15  06:00:54  drew
67  * Initial revision
68  *
69  */
70 
71 /*
72  * Further development / testing that should be done :
73  * 1.  Cleanup the NCR5380_transfer_dma function and DMA operation complete
74  *     code so that everything does the same thing that's done at the
75  *     end of a pseudo-DMA read operation.
76  *
77  * 2.  Fix REAL_DMA (interrupt driven, polled works fine) -
78  *     basically, transfer size needs to be reduced by one
79  *     and the last byte read as is done with PSEUDO_DMA.
80  *
81  * 4.  Test SCSI-II tagged queueing (I have no devices which support
82  *      tagged queueing)
83  *
84  * 5.  Test linked command handling code after Eric is ready with
85  *      the high level code.
86  */
87 #include <scsi/scsi_dbg.h>
88 #include <scsi/scsi_transport_spi.h>
89 
90 #if (NDEBUG & NDEBUG_LISTS)
91 #define LIST(x,y) {printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); }
92 #define REMOVE(w,x,y,z) {printk("LINE:%d   Removing: %p->%p  %p->%p \n", __LINE__, (void*)(w), (void*)(x), (void*)(y), (void*)(z)); if ((x)==(y)) udelay(5); }
93 #else
94 #define LIST(x,y)
95 #define REMOVE(w,x,y,z)
96 #endif
97 
98 #ifndef notyet
99 #undef LINKED
100 #undef REAL_DMA
101 #endif
102 
103 #ifdef REAL_DMA_POLL
104 #undef READ_OVERRUNS
105 #define READ_OVERRUNS
106 #endif
107 
108 #ifdef BOARD_REQUIRES_NO_DELAY
109 #define io_recovery_delay(x)
110 #else
111 #define io_recovery_delay(x)	udelay(x)
112 #endif
113 
114 /*
115  * Design
116  *
117  * This is a generic 5380 driver.  To use it on a different platform,
118  * one simply writes appropriate system specific macros (ie, data
119  * transfer - some PC's will use the I/O bus, 68K's must use
120  * memory mapped) and drops this file in their 'C' wrapper.
121  *
122  * (Note from hch:  unfortunately it was not enough for the different
123  * m68k folks and instead of improving this driver they copied it
124  * and hacked it up for their needs.  As a consequence they lost
125  * most updates to this driver.  Maybe someone will fix all these
126  * drivers to use a common core one day..)
127  *
128  * As far as command queueing, two queues are maintained for
129  * each 5380 in the system - commands that haven't been issued yet,
130  * and commands that are currently executing.  This means that an
131  * unlimited number of commands may be queued, letting
132  * more commands propagate from the higher driver levels giving higher
133  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
134  * allowing multiple commands to propagate all the way to a SCSI-II device
135  * while a command is already executing.
136  *
137  *
138  * Issues specific to the NCR5380 :
139  *
140  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
141  * piece of hardware that requires you to sit in a loop polling for
142  * the REQ signal as long as you are connected.  Some devices are
143  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
144  * while doing long seek operations.
145  *
146  * The workaround for this is to keep track of devices that have
147  * disconnected.  If the device hasn't disconnected, for commands that
148  * should disconnect, we do something like
149  *
150  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
151  *
152  * Some tweaking of N and M needs to be done.  An algorithm based
153  * on "time to data" would give the best results as long as short time
154  * to datas (ie, on the same track) were considered, however these
155  * broken devices are the exception rather than the rule and I'd rather
156  * spend my time optimizing for the normal case.
157  *
158  * Architecture :
159  *
160  * At the heart of the design is a coroutine, NCR5380_main,
161  * which is started from a workqueue for each NCR5380 host in the
162  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
163  * removing the commands from the issue queue and calling
164  * NCR5380_select() if a nexus is not established.
165  *
166  * Once a nexus is established, the NCR5380_information_transfer()
167  * phase goes through the various phases as instructed by the target.
168  * if the target goes into MSG IN and sends a DISCONNECT message,
169  * the command structure is placed into the per instance disconnected
170  * queue, and NCR5380_main tries to find more work.  If the target is
171  * idle for too long, the system will try to sleep.
172  *
173  * If a command has disconnected, eventually an interrupt will trigger,
174  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
175  * to reestablish a nexus.  This will run main if necessary.
176  *
177  * On command termination, the done function will be called as
178  * appropriate.
179  *
180  * SCSI pointers are maintained in the SCp field of SCSI command
181  * structures, being initialized after the command is connected
182  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
183  * Note that in violation of the standard, an implicit SAVE POINTERS operation
184  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
185  */
186 
187 /*
188  * Using this file :
189  * This file a skeleton Linux SCSI driver for the NCR 5380 series
190  * of chips.  To use it, you write an architecture specific functions
191  * and macros and include this file in your driver.
192  *
193  * These macros control options :
194  * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
195  *      defined.
196  *
197  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
198  *      for commands that return with a CHECK CONDITION status.
199  *
200  * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
201  *      transceivers.
202  *
203  * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
204  *      override-configure an IRQ.
205  *
206  * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
207  *      bytes at a time.  Since interrupts are disabled by default during
208  *      these transfers, we might need this to give reasonable interrupt
209  *      service time if the transfer size gets too large.
210  *
211  * LINKED - if defined, linked commands are supported.
212  *
213  * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
214  *
215  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
216  *
217  * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
218  *      rely on phase mismatch and EOP interrupts to determine end
219  *      of phase.
220  *
221  * UNSAFE - leave interrupts enabled during pseudo-DMA transfers.  You
222  *          only really want to use this if you're having a problem with
223  *          dropped characters during high speed communications, and even
224  *          then, you're going to be better off twiddling with transfersize
225  *          in the high level code.
226  *
227  * Defaults for these will be provided although the user may want to adjust
228  * these to allocate CPU resources to the SCSI driver or "real" code.
229  *
230  * USLEEP_SLEEP - amount of time, in jiffies, to sleep
231  *
232  * USLEEP_POLL - amount of time, in jiffies, to poll
233  *
234  * These macros MUST be defined :
235  * NCR5380_local_declare() - declare any local variables needed for your
236  *      transfer routines.
237  *
238  * NCR5380_setup(instance) - initialize any local variables needed from a given
239  *      instance of the host adapter for NCR5380_{read,write,pread,pwrite}
240  *
241  * NCR5380_read(register)  - read from the specified register
242  *
243  * NCR5380_write(register, value) - write to the specific register
244  *
245  * NCR5380_implementation_fields  - additional fields needed for this
246  *      specific implementation of the NCR5380
247  *
248  * Either real DMA *or* pseudo DMA may be implemented
249  * REAL functions :
250  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
251  * Note that the DMA setup functions should return the number of bytes
252  *      that they were able to program the controller for.
253  *
254  * Also note that generic i386/PC versions of these macros are
255  *      available as NCR5380_i386_dma_write_setup,
256  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
257  *
258  * NCR5380_dma_write_setup(instance, src, count) - initialize
259  * NCR5380_dma_read_setup(instance, dst, count) - initialize
260  * NCR5380_dma_residual(instance); - residual count
261  *
262  * PSEUDO functions :
263  * NCR5380_pwrite(instance, src, count)
264  * NCR5380_pread(instance, dst, count);
265  *
266  * The generic driver is initialized by calling NCR5380_init(instance),
267  * after setting the appropriate host specific fields and ID.  If the
268  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
269  * possible) function may be used.
270  */
271 
272 static int do_abort(struct Scsi_Host *host);
273 static void do_reset(struct Scsi_Host *host);
274 
275 /*
276  *	initialize_SCp		-	init the scsi pointer field
277  *	@cmd: command block to set up
278  *
279  *	Set up the internal fields in the SCSI command.
280  */
281 
282 static __inline__ void initialize_SCp(Scsi_Cmnd * cmd)
283 {
284 	/*
285 	 * Initialize the Scsi Pointer field so that all of the commands in the
286 	 * various queues are valid.
287 	 */
288 
289 	if (scsi_bufflen(cmd)) {
290 		cmd->SCp.buffer = scsi_sglist(cmd);
291 		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
292 		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
293 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
294 	} else {
295 		cmd->SCp.buffer = NULL;
296 		cmd->SCp.buffers_residual = 0;
297 		cmd->SCp.ptr = NULL;
298 		cmd->SCp.this_residual = 0;
299 	}
300 }
301 
302 /**
303  *	NCR5380_poll_politely	-	wait for NCR5380 status bits
304  *	@instance: controller to poll
305  *	@reg: 5380 register to poll
306  *	@bit: Bitmask to check
307  *	@val: Value required to exit
308  *
309  *	Polls the NCR5380 in a reasonably efficient manner waiting for
310  *	an event to occur, after a short quick poll we begin giving the
311  *	CPU back in non IRQ contexts
312  *
313  *	Returns the value of the register or a negative error code.
314  */
315 
316 static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
317 {
318 	NCR5380_local_declare();
319 	int n = 500;		/* At about 8uS a cycle for the cpu access */
320 	unsigned long end = jiffies + t;
321 	int r;
322 
323 	NCR5380_setup(instance);
324 
325 	while( n-- > 0)
326 	{
327 		r = NCR5380_read(reg);
328 		if((r & bit) == val)
329 			return 0;
330 		cpu_relax();
331 	}
332 
333 	/* t time yet ? */
334 	while(time_before(jiffies, end))
335 	{
336 		r = NCR5380_read(reg);
337 		if((r & bit) == val)
338 			return 0;
339 		if(!in_interrupt())
340 			cond_resched();
341 		else
342 			cpu_relax();
343 	}
344 	return -ETIMEDOUT;
345 }
346 
347 static struct {
348 	unsigned char value;
349 	const char *name;
350 } phases[] __maybe_unused = {
351 	{PHASE_DATAOUT, "DATAOUT"},
352 	{PHASE_DATAIN, "DATAIN"},
353 	{PHASE_CMDOUT, "CMDOUT"},
354 	{PHASE_STATIN, "STATIN"},
355 	{PHASE_MSGOUT, "MSGOUT"},
356 	{PHASE_MSGIN, "MSGIN"},
357 	{PHASE_UNKNOWN, "UNKNOWN"}
358 };
359 
360 #if NDEBUG
361 static struct {
362 	unsigned char mask;
363 	const char *name;
364 } signals[] = {
365 	{SR_DBP, "PARITY"},
366 	{SR_RST, "RST"},
367 	{SR_BSY, "BSY"},
368 	{SR_REQ, "REQ"},
369 	{SR_MSG, "MSG"},
370 	{SR_CD, "CD"},
371 	{SR_IO, "IO"},
372 	{SR_SEL, "SEL"},
373 	{0, NULL}
374 },
375 basrs[] = {
376 	{BASR_ATN, "ATN"},
377 	{BASR_ACK, "ACK"},
378 	{0, NULL}
379 },
380 icrs[] = {
381 	{ICR_ASSERT_RST, "ASSERT RST"},
382 	{ICR_ASSERT_ACK, "ASSERT ACK"},
383 	{ICR_ASSERT_BSY, "ASSERT BSY"},
384 	{ICR_ASSERT_SEL, "ASSERT SEL"},
385 	{ICR_ASSERT_ATN, "ASSERT ATN"},
386 	{ICR_ASSERT_DATA, "ASSERT DATA"},
387 	{0, NULL}
388 },
389 mrs[] = {
390 	{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
391 	{MR_TARGET, "MODE TARGET"},
392 	{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
393 	{MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
394 	{MR_MONITOR_BSY, "MODE MONITOR BSY"},
395 	{MR_DMA_MODE, "MODE DMA"},
396 	{MR_ARBITRATE, "MODE ARBITRATION"},
397 	{0, NULL}
398 };
399 
400 /**
401  *	NCR5380_print	-	print scsi bus signals
402  *	@instance:	adapter state to dump
403  *
404  *	Print the SCSI bus signals for debugging purposes
405  *
406  *	Locks: caller holds hostdata lock (not essential)
407  */
408 
409 static void NCR5380_print(struct Scsi_Host *instance)
410 {
411 	NCR5380_local_declare();
412 	unsigned char status, data, basr, mr, icr, i;
413 	NCR5380_setup(instance);
414 
415 	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
416 	status = NCR5380_read(STATUS_REG);
417 	mr = NCR5380_read(MODE_REG);
418 	icr = NCR5380_read(INITIATOR_COMMAND_REG);
419 	basr = NCR5380_read(BUS_AND_STATUS_REG);
420 
421 	printk("STATUS_REG: %02x ", status);
422 	for (i = 0; signals[i].mask; ++i)
423 		if (status & signals[i].mask)
424 			printk(",%s", signals[i].name);
425 	printk("\nBASR: %02x ", basr);
426 	for (i = 0; basrs[i].mask; ++i)
427 		if (basr & basrs[i].mask)
428 			printk(",%s", basrs[i].name);
429 	printk("\nICR: %02x ", icr);
430 	for (i = 0; icrs[i].mask; ++i)
431 		if (icr & icrs[i].mask)
432 			printk(",%s", icrs[i].name);
433 	printk("\nMODE: %02x ", mr);
434 	for (i = 0; mrs[i].mask; ++i)
435 		if (mr & mrs[i].mask)
436 			printk(",%s", mrs[i].name);
437 	printk("\n");
438 }
439 
440 
441 /*
442  *	NCR5380_print_phase	-	show SCSI phase
443  *	@instance: adapter to dump
444  *
445  * 	Print the current SCSI phase for debugging purposes
446  *
447  *	Locks: none
448  */
449 
450 static void NCR5380_print_phase(struct Scsi_Host *instance)
451 {
452 	NCR5380_local_declare();
453 	unsigned char status;
454 	int i;
455 	NCR5380_setup(instance);
456 
457 	status = NCR5380_read(STATUS_REG);
458 	if (!(status & SR_REQ))
459 		printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
460 	else {
461 		for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
462 		printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
463 	}
464 }
465 #endif
466 
467 /*
468  * These need tweaking, and would probably work best as per-device
469  * flags initialized differently for disk, tape, cd, etc devices.
470  * People with broken devices are free to experiment as to what gives
471  * the best results for them.
472  *
473  * USLEEP_SLEEP should be a minimum seek time.
474  *
475  * USLEEP_POLL should be a maximum rotational latency.
476  */
477 #ifndef USLEEP_SLEEP
478 /* 20 ms (reasonable hard disk speed) */
479 #define USLEEP_SLEEP (20*HZ/1000)
480 #endif
481 /* 300 RPM (floppy speed) */
482 #ifndef USLEEP_POLL
483 #define USLEEP_POLL (200*HZ/1000)
484 #endif
485 #ifndef USLEEP_WAITLONG
486 /* RvC: (reasonable time to wait on select error) */
487 #define USLEEP_WAITLONG USLEEP_SLEEP
488 #endif
489 
490 /*
491  * Function : int should_disconnect (unsigned char cmd)
492  *
493  * Purpose : decide whether a command would normally disconnect or
494  *      not, since if it won't disconnect we should go to sleep.
495  *
496  * Input : cmd - opcode of SCSI command
497  *
498  * Returns : DISCONNECT_LONG if we should disconnect for a really long
499  *      time (ie always, sleep, look for REQ active, sleep),
500  *      DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
501  *      time-to-data delay, DISCONNECT_NONE if this command would return
502  *      immediately.
503  *
504  *      Future sleep algorithms based on time to data can exploit
505  *      something like this so they can differentiate between "normal"
506  *      (ie, read, write, seek) and unusual commands (ie, * format).
507  *
508  * Note : We don't deal with commands that handle an immediate disconnect,
509  *
510  */
511 
512 static int should_disconnect(unsigned char cmd)
513 {
514 	switch (cmd) {
515 	case READ_6:
516 	case WRITE_6:
517 	case SEEK_6:
518 	case READ_10:
519 	case WRITE_10:
520 	case SEEK_10:
521 		return DISCONNECT_TIME_TO_DATA;
522 	case FORMAT_UNIT:
523 	case SEARCH_HIGH:
524 	case SEARCH_LOW:
525 	case SEARCH_EQUAL:
526 		return DISCONNECT_LONG;
527 	default:
528 		return DISCONNECT_NONE;
529 	}
530 }
531 
532 static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
533 {
534 	hostdata->time_expires = jiffies + timeout;
535 	schedule_delayed_work(&hostdata->coroutine, timeout);
536 }
537 
538 
539 static int probe_irq __initdata = 0;
540 
541 /**
542  *	probe_intr	-	helper for IRQ autoprobe
543  *	@irq: interrupt number
544  *	@dev_id: unused
545  *	@regs: unused
546  *
547  *	Set a flag to indicate the IRQ in question was received. This is
548  *	used by the IRQ probe code.
549  */
550 
551 static irqreturn_t __init probe_intr(int irq, void *dev_id)
552 {
553 	probe_irq = irq;
554 	return IRQ_HANDLED;
555 }
556 
557 /**
558  *	NCR5380_probe_irq	-	find the IRQ of an NCR5380
559  *	@instance: NCR5380 controller
560  *	@possible: bitmask of ISA IRQ lines
561  *
562  *	Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
563  *	and then looking to see what interrupt actually turned up.
564  *
565  *	Locks: none, irqs must be enabled on entry
566  */
567 
568 static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
569 						int possible)
570 {
571 	NCR5380_local_declare();
572 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
573 	unsigned long timeout;
574 	int trying_irqs, i, mask;
575 	NCR5380_setup(instance);
576 
577 	for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
578 		if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0))
579 			trying_irqs |= mask;
580 
581 	timeout = jiffies + (250 * HZ / 1000);
582 	probe_irq = SCSI_IRQ_NONE;
583 
584 	/*
585 	 * A interrupt is triggered whenever BSY = false, SEL = true
586 	 * and a bit set in the SELECT_ENABLE_REG is asserted on the
587 	 * SCSI bus.
588 	 *
589 	 * Note that the bus is only driven when the phase control signals
590 	 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
591 	 * to zero.
592 	 */
593 
594 	NCR5380_write(TARGET_COMMAND_REG, 0);
595 	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
596 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
597 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
598 
599 	while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
600 		schedule_timeout_uninterruptible(1);
601 
602 	NCR5380_write(SELECT_ENABLE_REG, 0);
603 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
604 
605 	for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
606 		if (trying_irqs & mask)
607 			free_irq(i, NULL);
608 
609 	return probe_irq;
610 }
611 
612 /**
613  *	NCR58380_print_options	-	show options
614  *	@instance: unused for now
615  *
616  *	Called by probe code indicating the NCR5380 driver options that
617  *	were selected. At some point this will switch to runtime options
618  *	read from the adapter in question
619  *
620  *	Locks: none
621  */
622 
623 static void __init __maybe_unused
624 NCR5380_print_options(struct Scsi_Host *instance)
625 {
626 	printk(" generic options"
627 #ifdef AUTOPROBE_IRQ
628 	       " AUTOPROBE_IRQ"
629 #endif
630 #ifdef AUTOSENSE
631 	       " AUTOSENSE"
632 #endif
633 #ifdef DIFFERENTIAL
634 	       " DIFFERENTIAL"
635 #endif
636 #ifdef REAL_DMA
637 	       " REAL DMA"
638 #endif
639 #ifdef REAL_DMA_POLL
640 	       " REAL DMA POLL"
641 #endif
642 #ifdef PARITY
643 	       " PARITY"
644 #endif
645 #ifdef PSEUDO_DMA
646 	       " PSEUDO DMA"
647 #endif
648 #ifdef UNSAFE
649 	       " UNSAFE "
650 #endif
651 	    );
652 	printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
653 	printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
654 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
655 		printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
656 	}
657 }
658 
659 /**
660  *	NCR5380_print_status 	-	dump controller info
661  *	@instance: controller to dump
662  *
663  *	Print commands in the various queues, called from NCR5380_abort
664  *	and NCR5380_debug to aid debugging.
665  *
666  *	Locks: called functions disable irqs
667  */
668 
669 static void NCR5380_print_status(struct Scsi_Host *instance)
670 {
671 	NCR5380_dprint(NDEBUG_ANY, instance);
672 	NCR5380_dprint_phase(NDEBUG_ANY, instance);
673 }
674 
675 /******************************************/
676 /*
677  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
678  *
679  * *buffer: I/O buffer
680  * **start: if inout == FALSE pointer into buffer where user read should start
681  * offset: current offset
682  * length: length of buffer
683  * hostno: Scsi_Host host_no
684  * inout: TRUE - user is writing; FALSE - user is reading
685  *
686  * Return the number of bytes read from or written
687  */
688 
689 static int __maybe_unused NCR5380_write_info(struct Scsi_Host *instance,
690 	char *buffer, int length)
691 {
692 #ifdef DTC_PUBLIC_RELEASE
693 	dtc_wmaxi = dtc_maxi = 0;
694 #endif
695 #ifdef PAS16_PUBLIC_RELEASE
696 	pas_wmaxi = pas_maxi = 0;
697 #endif
698 	return (-ENOSYS);	/* Currently this is a no-op */
699 }
700 
701 #undef SPRINTF
702 #define SPRINTF(args...) seq_printf(m, ## args)
703 static
704 void lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, struct seq_file *m);
705 static
706 void lprint_command(unsigned char *cmd, struct seq_file *m);
707 static
708 void lprint_opcode(int opcode, struct seq_file *m);
709 
710 static int __maybe_unused NCR5380_show_info(struct seq_file *m,
711 	struct Scsi_Host *instance)
712 {
713 	struct NCR5380_hostdata *hostdata;
714 	Scsi_Cmnd *ptr;
715 
716 	hostdata = (struct NCR5380_hostdata *) instance->hostdata;
717 
718 	SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
719 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
720 		SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
721 #ifdef DTC_PUBLIC_RELEASE
722 	SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
723 #endif
724 #ifdef T128_PUBLIC_RELEASE
725 	SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
726 #endif
727 #ifdef GENERIC_NCR5380_PUBLIC_RELEASE
728 	SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
729 #endif
730 #ifdef PAS16_PUBLIC_RELEASE
731 	SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
732 #endif
733 
734 	SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
735 	SPRINTF("io_port: %04x      ", (int) instance->io_port);
736 	if (instance->irq == SCSI_IRQ_NONE)
737 		SPRINTF("IRQ: None.\n");
738 	else
739 		SPRINTF("IRQ: %d.\n", instance->irq);
740 
741 #ifdef DTC_PUBLIC_RELEASE
742 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
743 #endif
744 #ifdef PAS16_PUBLIC_RELEASE
745 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
746 #endif
747 	spin_lock_irq(instance->host_lock);
748 	if (!hostdata->connected)
749 		SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
750 	else
751 		lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, m);
752 	SPRINTF("scsi%d: issue_queue\n", instance->host_no);
753 	for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
754 		lprint_Scsi_Cmnd(ptr, m);
755 
756 	SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
757 	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
758 		lprint_Scsi_Cmnd(ptr, m);
759 	spin_unlock_irq(instance->host_lock);
760 	return 0;
761 }
762 
763 static void lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, struct seq_file *m)
764 {
765 	SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
766 	SPRINTF("        command = ");
767 	lprint_command(cmd->cmnd, m);
768 }
769 
770 static void lprint_command(unsigned char *command, struct seq_file *m)
771 {
772 	int i, s;
773 	lprint_opcode(command[0], m);
774 	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
775 		SPRINTF("%02x ", command[i]);
776 	SPRINTF("\n");
777 }
778 
779 static void lprint_opcode(int opcode, struct seq_file *m)
780 {
781 	SPRINTF("%2d (0x%02x)", opcode, opcode);
782 }
783 
784 
785 /**
786  *	NCR5380_init	-	initialise an NCR5380
787  *	@instance: adapter to configure
788  *	@flags: control flags
789  *
790  *	Initializes *instance and corresponding 5380 chip,
791  *      with flags OR'd into the initial flags value.
792  *
793  *	Notes : I assume that the host, hostno, and id bits have been
794  *      set correctly.  I don't care about the irq and other fields.
795  *
796  *	Returns 0 for success
797  *
798  *	Locks: interrupts must be enabled when we are called
799  */
800 
801 static int NCR5380_init(struct Scsi_Host *instance, int flags)
802 {
803 	NCR5380_local_declare();
804 	int i, pass;
805 	unsigned long timeout;
806 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
807 
808 	if(in_interrupt())
809 		printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
810 	/*
811 	 * On NCR53C400 boards, NCR5380 registers are mapped 8 past
812 	 * the base address.
813 	 */
814 
815 #ifdef NCR53C400
816 	if (flags & FLAG_NCR53C400)
817 		instance->NCR5380_instance_name += NCR53C400_address_adjust;
818 #endif
819 
820 	NCR5380_setup(instance);
821 
822 	hostdata->aborted = 0;
823 	hostdata->id_mask = 1 << instance->this_id;
824 	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
825 		if (i > hostdata->id_mask)
826 			hostdata->id_higher_mask |= i;
827 	for (i = 0; i < 8; ++i)
828 		hostdata->busy[i] = 0;
829 #ifdef REAL_DMA
830 	hostdata->dmalen = 0;
831 #endif
832 	hostdata->targets_present = 0;
833 	hostdata->connected = NULL;
834 	hostdata->issue_queue = NULL;
835 	hostdata->disconnected_queue = NULL;
836 
837 	INIT_DELAYED_WORK(&hostdata->coroutine, NCR5380_main);
838 
839 #ifdef NCR5380_STATS
840 	for (i = 0; i < 8; ++i) {
841 		hostdata->time_read[i] = 0;
842 		hostdata->time_write[i] = 0;
843 		hostdata->bytes_read[i] = 0;
844 		hostdata->bytes_write[i] = 0;
845 	}
846 	hostdata->timebase = 0;
847 	hostdata->pendingw = 0;
848 	hostdata->pendingr = 0;
849 #endif
850 
851 	/* The CHECK code seems to break the 53C400. Will check it later maybe */
852 	if (flags & FLAG_NCR53C400)
853 		hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
854 	else
855 		hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
856 
857 	hostdata->host = instance;
858 	hostdata->time_expires = 0;
859 
860 #ifndef AUTOSENSE
861 	if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
862 		    printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
863 		    	   "         be incorrectly cleared.\n", instance->host_no);
864 #endif				/* def AUTOSENSE */
865 
866 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
867 	NCR5380_write(MODE_REG, MR_BASE);
868 	NCR5380_write(TARGET_COMMAND_REG, 0);
869 	NCR5380_write(SELECT_ENABLE_REG, 0);
870 
871 #ifdef NCR53C400
872 	if (hostdata->flags & FLAG_NCR53C400) {
873 		NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
874 	}
875 #endif
876 
877 	/*
878 	 * Detect and correct bus wedge problems.
879 	 *
880 	 * If the system crashed, it may have crashed in a state
881 	 * where a SCSI command was still executing, and the
882 	 * SCSI bus is not in a BUS FREE STATE.
883 	 *
884 	 * If this is the case, we'll try to abort the currently
885 	 * established nexus which we know nothing about, and that
886 	 * failing, do a hard reset of the SCSI bus
887 	 */
888 
889 	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
890 		switch (pass) {
891 		case 1:
892 		case 3:
893 		case 5:
894 			printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
895 			timeout = jiffies + 5 * HZ;
896 			NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
897 			break;
898 		case 2:
899 			printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
900 			do_abort(instance);
901 			break;
902 		case 4:
903 			printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
904 			do_reset(instance);
905 			break;
906 		case 6:
907 			printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
908 			return -ENXIO;
909 		}
910 	}
911 	return 0;
912 }
913 
914 /**
915  *	NCR5380_exit	-	remove an NCR5380
916  *	@instance: adapter to remove
917  */
918 
919 static void NCR5380_exit(struct Scsi_Host *instance)
920 {
921 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
922 
923 	cancel_delayed_work_sync(&hostdata->coroutine);
924 }
925 
926 /**
927  *	NCR5380_queue_command 		-	queue a command
928  *	@cmd: SCSI command
929  *	@done: completion handler
930  *
931  *      cmd is added to the per instance issue_queue, with minor
932  *      twiddling done to the host specific fields of cmd.  If the
933  *      main coroutine is not running, it is restarted.
934  *
935  *	Locks: host lock taken by caller
936  */
937 
938 static int NCR5380_queue_command_lck(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
939 {
940 	struct Scsi_Host *instance = cmd->device->host;
941 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
942 	Scsi_Cmnd *tmp;
943 
944 #if (NDEBUG & NDEBUG_NO_WRITE)
945 	switch (cmd->cmnd[0]) {
946 	case WRITE_6:
947 	case WRITE_10:
948 		printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
949 		cmd->result = (DID_ERROR << 16);
950 		done(cmd);
951 		return 0;
952 	}
953 #endif				/* (NDEBUG & NDEBUG_NO_WRITE) */
954 
955 #ifdef NCR5380_STATS
956 	switch (cmd->cmnd[0]) {
957 		case WRITE:
958 		case WRITE_6:
959 		case WRITE_10:
960 			hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
961 			hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
962 			hostdata->pendingw++;
963 			break;
964 		case READ:
965 		case READ_6:
966 		case READ_10:
967 			hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
968 			hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
969 			hostdata->pendingr++;
970 			break;
971 	}
972 #endif
973 
974 	/*
975 	 * We use the host_scribble field as a pointer to the next command
976 	 * in a queue
977 	 */
978 
979 	cmd->host_scribble = NULL;
980 	cmd->scsi_done = done;
981 	cmd->result = 0;
982 
983 	/*
984 	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
985 	 * commands are added to the head of the queue since any command will
986 	 * clear the contingent allegiance condition that exists and the
987 	 * sense data is only guaranteed to be valid while the condition exists.
988 	 */
989 
990 	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
991 		LIST(cmd, hostdata->issue_queue);
992 		cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
993 		hostdata->issue_queue = cmd;
994 	} else {
995 		for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
996 		LIST(cmd, tmp);
997 		tmp->host_scribble = (unsigned char *) cmd;
998 	}
999 	dprintk(NDEBUG_QUEUES, "scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
1000 
1001 	/* Run the coroutine if it isn't already running. */
1002 	/* Kick off command processing */
1003 	schedule_delayed_work(&hostdata->coroutine, 0);
1004 	return 0;
1005 }
1006 
1007 static DEF_SCSI_QCMD(NCR5380_queue_command)
1008 
1009 /**
1010  *	NCR5380_main	-	NCR state machines
1011  *
1012  *	NCR5380_main is a coroutine that runs as long as more work can
1013  *      be done on the NCR5380 host adapters in a system.  Both
1014  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1015  *      in case it is not running.
1016  *
1017  *	Locks: called as its own thread with no locks held. Takes the
1018  *	host lock and called routines may take the isa dma lock.
1019  */
1020 
1021 static void NCR5380_main(struct work_struct *work)
1022 {
1023 	struct NCR5380_hostdata *hostdata =
1024 		container_of(work, struct NCR5380_hostdata, coroutine.work);
1025 	struct Scsi_Host *instance = hostdata->host;
1026 	Scsi_Cmnd *tmp, *prev;
1027 	int done;
1028 
1029 	spin_lock_irq(instance->host_lock);
1030 	do {
1031 		/* Lock held here */
1032 		done = 1;
1033 		if (!hostdata->connected && !hostdata->selecting) {
1034 			dprintk(NDEBUG_MAIN, "scsi%d : not connected\n", instance->host_no);
1035 			/*
1036 			 * Search through the issue_queue for a command destined
1037 			 * for a target that's not busy.
1038 			 */
1039 			for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
1040 			{
1041 				if (prev != tmp)
1042 					dprintk(NDEBUG_LISTS, "MAIN tmp=%p   target=%d   busy=%d lun=%d\n", tmp, tmp->device->id, hostdata->busy[tmp->device->id], tmp->device->lun);
1043 				/*  When we find one, remove it from the issue queue. */
1044 				if (!(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))) {
1045 					if (prev) {
1046 						REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1047 						prev->host_scribble = tmp->host_scribble;
1048 					} else {
1049 						REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1050 						hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1051 					}
1052 					tmp->host_scribble = NULL;
1053 
1054 					/*
1055 					 * Attempt to establish an I_T_L nexus here.
1056 					 * On success, instance->hostdata->connected is set.
1057 					 * On failure, we must add the command back to the
1058 					 *   issue queue so we can keep trying.
1059 					 */
1060 					dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, "scsi%d : main() : command for target %d lun %d removed from issue_queue\n", instance->host_no, tmp->device->id, tmp->device->lun);
1061 
1062 					/*
1063 					 * A successful selection is defined as one that
1064 					 * leaves us with the command connected and
1065 					 * in hostdata->connected, OR has terminated the
1066 					 * command.
1067 					 *
1068 					 * With successful commands, we fall through
1069 					 * and see if we can do an information transfer,
1070 					 * with failures we will restart.
1071 					 */
1072 					hostdata->selecting = NULL;
1073 					/* RvC: have to preset this to indicate a new command is being performed */
1074 
1075 					if (!NCR5380_select(instance, tmp,
1076 							    /*
1077 							     * REQUEST SENSE commands are issued without tagged
1078 							     * queueing, even on SCSI-II devices because the
1079 							     * contingent allegiance condition exists for the
1080 							     * entire unit.
1081 							     */
1082 							    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1083 						break;
1084 					} else {
1085 						LIST(tmp, hostdata->issue_queue);
1086 						tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1087 						hostdata->issue_queue = tmp;
1088 						done = 0;
1089 						dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, "scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no);
1090 					}
1091 					/* lock held here still */
1092 				}	/* if target/lun is not busy */
1093 			}	/* for */
1094 			/* exited locked */
1095 		}	/* if (!hostdata->connected) */
1096 		if (hostdata->selecting) {
1097 			tmp = (Scsi_Cmnd *) hostdata->selecting;
1098 			/* Selection will drop and retake the lock */
1099 			if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1100 				/* Ok ?? */
1101 			} else {
1102 				/* RvC: device failed, so we wait a long time
1103 				   this is needed for Mustek scanners, that
1104 				   do not respond to commands immediately
1105 				   after a scan */
1106 				printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1107 				LIST(tmp, hostdata->issue_queue);
1108 				tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1109 				hostdata->issue_queue = tmp;
1110 				NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1111 			}
1112 		}	/* if hostdata->selecting */
1113 		if (hostdata->connected
1114 #ifdef REAL_DMA
1115 		    && !hostdata->dmalen
1116 #endif
1117 		    && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1118 		    ) {
1119 			dprintk(NDEBUG_MAIN, "scsi%d : main() : performing information transfer\n", instance->host_no);
1120 			NCR5380_information_transfer(instance);
1121 			dprintk(NDEBUG_MAIN, "scsi%d : main() : done set false\n", instance->host_no);
1122 			done = 0;
1123 		} else
1124 			break;
1125 	} while (!done);
1126 
1127 	spin_unlock_irq(instance->host_lock);
1128 }
1129 
1130 #ifndef DONT_USE_INTR
1131 
1132 /**
1133  * 	NCR5380_intr	-	generic NCR5380 irq handler
1134  *	@irq: interrupt number
1135  *	@dev_id: device info
1136  *
1137  *	Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1138  *      from the disconnected queue, and restarting NCR5380_main()
1139  *      as required.
1140  *
1141  *	Locks: takes the needed instance locks
1142  */
1143 
1144 static irqreturn_t NCR5380_intr(int dummy, void *dev_id)
1145 {
1146 	NCR5380_local_declare();
1147 	struct Scsi_Host *instance = dev_id;
1148 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1149 	int done;
1150 	unsigned char basr;
1151 	unsigned long flags;
1152 
1153 	dprintk(NDEBUG_INTR, "scsi : NCR5380 irq %d triggered\n",
1154 		instance->irq);
1155 
1156 	do {
1157 		done = 1;
1158 		spin_lock_irqsave(instance->host_lock, flags);
1159 		/* Look for pending interrupts */
1160 		NCR5380_setup(instance);
1161 		basr = NCR5380_read(BUS_AND_STATUS_REG);
1162 		/* XXX dispatch to appropriate routine if found and done=0 */
1163 		if (basr & BASR_IRQ) {
1164 			NCR5380_dprint(NDEBUG_INTR, instance);
1165 			if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1166 				done = 0;
1167 				dprintk(NDEBUG_INTR, "scsi%d : SEL interrupt\n", instance->host_no);
1168 				NCR5380_reselect(instance);
1169 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1170 			} else if (basr & BASR_PARITY_ERROR) {
1171 				dprintk(NDEBUG_INTR, "scsi%d : PARITY interrupt\n", instance->host_no);
1172 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1173 			} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1174 				dprintk(NDEBUG_INTR, "scsi%d : RESET interrupt\n", instance->host_no);
1175 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1176 			} else {
1177 #if defined(REAL_DMA)
1178 				/*
1179 				 * We should only get PHASE MISMATCH and EOP interrupts
1180 				 * if we have DMA enabled, so do a sanity check based on
1181 				 * the current setting of the MODE register.
1182 				 */
1183 
1184 				if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1185 					int transferred;
1186 
1187 					if (!hostdata->connected)
1188 						panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1189 
1190 					transferred = (hostdata->dmalen - NCR5380_dma_residual(instance));
1191 					hostdata->connected->SCp.this_residual -= transferred;
1192 					hostdata->connected->SCp.ptr += transferred;
1193 					hostdata->dmalen = 0;
1194 
1195 					(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1196 
1197 					/* FIXME: we need to poll briefly then defer a workqueue task ! */
1198 					NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1199 
1200 					NCR5380_write(MODE_REG, MR_BASE);
1201 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1202 				}
1203 #else
1204 				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));
1205 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1206 #endif
1207 			}
1208 		}	/* if BASR_IRQ */
1209 		spin_unlock_irqrestore(instance->host_lock, flags);
1210 		if(!done)
1211 			schedule_delayed_work(&hostdata->coroutine, 0);
1212 	} while (!done);
1213 	return IRQ_HANDLED;
1214 }
1215 
1216 #endif
1217 
1218 /**
1219  *	collect_stats		-	collect stats on a scsi command
1220  *	@hostdata: adapter
1221  *	@cmd: command being issued
1222  *
1223  *	Update the statistical data by parsing the command in question
1224  */
1225 
1226 static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd)
1227 {
1228 #ifdef NCR5380_STATS
1229 	switch (cmd->cmnd[0]) {
1230 	case WRITE:
1231 	case WRITE_6:
1232 	case WRITE_10:
1233 		hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1234 		hostdata->pendingw--;
1235 		break;
1236 	case READ:
1237 	case READ_6:
1238 	case READ_10:
1239 		hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1240 		hostdata->pendingr--;
1241 		break;
1242 	}
1243 #endif
1244 }
1245 
1246 
1247 /*
1248  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1249  *      int tag);
1250  *
1251  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1252  *      including ARBITRATION, SELECTION, and initial message out for
1253  *      IDENTIFY and queue messages.
1254  *
1255  * Inputs : instance - instantiation of the 5380 driver on which this
1256  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1257  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1258  *      the command that is presently connected.
1259  *
1260  * Returns : -1 if selection could not execute for some reason,
1261  *      0 if selection succeeded or failed because the target
1262  *      did not respond.
1263  *
1264  * Side effects :
1265  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1266  *              with registers as they should have been on entry - ie
1267  *              SELECT_ENABLE will be set appropriately, the NCR5380
1268  *              will cease to drive any SCSI bus signals.
1269  *
1270  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1271  *              instance->connected will be set to cmd.
1272  *              SELECT interrupt will be disabled.
1273  *
1274  *      If failed (no target) : cmd->scsi_done() will be called, and the
1275  *              cmd->result host byte set to DID_BAD_TARGET.
1276  *
1277  *	Locks: caller holds hostdata lock in IRQ mode
1278  */
1279 
1280 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag)
1281 {
1282 	NCR5380_local_declare();
1283 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1284 	unsigned char tmp[3], phase;
1285 	unsigned char *data;
1286 	int len;
1287 	unsigned long timeout;
1288 	unsigned char value;
1289 	int err;
1290 	NCR5380_setup(instance);
1291 
1292 	if (hostdata->selecting)
1293 		goto part2;
1294 
1295 	hostdata->restart_select = 0;
1296 
1297 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1298 	dprintk(NDEBUG_ARBITRATION, "scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id);
1299 
1300 	/*
1301 	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1302 	 * data bus during SELECTION.
1303 	 */
1304 
1305 	NCR5380_write(TARGET_COMMAND_REG, 0);
1306 
1307 	/*
1308 	 * Start arbitration.
1309 	 */
1310 
1311 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1312 	NCR5380_write(MODE_REG, MR_ARBITRATE);
1313 
1314 
1315 	/* We can be relaxed here, interrupts are on, we are
1316 	   in workqueue context, the birds are singing in the trees */
1317 	spin_unlock_irq(instance->host_lock);
1318 	err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1319 	spin_lock_irq(instance->host_lock);
1320 	if (err < 0) {
1321 		printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1322 		NCR5380_write(MODE_REG, MR_BASE);
1323 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1324 		goto failed;
1325 	}
1326 
1327 	dprintk(NDEBUG_ARBITRATION, "scsi%d : arbitration complete\n", instance->host_no);
1328 
1329 	/*
1330 	 * The arbitration delay is 2.2us, but this is a minimum and there is
1331 	 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1332 	 * the integral nature of udelay().
1333 	 *
1334 	 */
1335 
1336 	udelay(3);
1337 
1338 	/* Check for lost arbitration */
1339 	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)) {
1340 		NCR5380_write(MODE_REG, MR_BASE);
1341 		dprintk(NDEBUG_ARBITRATION, "scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no);
1342 		goto failed;
1343 	}
1344 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1345 
1346 	if (!(hostdata->flags & FLAG_DTC3181E) &&
1347 	    /* RvC: DTC3181E has some trouble with this
1348 	     *      so we simply removed it. Seems to work with
1349 	     *      only Mustek scanner attached
1350 	     */
1351 	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1352 		NCR5380_write(MODE_REG, MR_BASE);
1353 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1354 		dprintk(NDEBUG_ARBITRATION, "scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no);
1355 		goto failed;
1356 	}
1357 	/*
1358 	 * Again, bus clear + bus settle time is 1.2us, however, this is
1359 	 * a minimum so we'll udelay ceil(1.2)
1360 	 */
1361 
1362 	udelay(2);
1363 
1364 	dprintk(NDEBUG_ARBITRATION, "scsi%d : won arbitration\n", instance->host_no);
1365 
1366 	/*
1367 	 * Now that we have won arbitration, start Selection process, asserting
1368 	 * the host and target ID's on the SCSI bus.
1369 	 */
1370 
1371 	NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1372 
1373 	/*
1374 	 * Raise ATN while SEL is true before BSY goes false from arbitration,
1375 	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1376 	 * phase immediately after selection.
1377 	 */
1378 
1379 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1380 	NCR5380_write(MODE_REG, MR_BASE);
1381 
1382 	/*
1383 	 * Reselect interrupts must be turned off prior to the dropping of BSY,
1384 	 * otherwise we will trigger an interrupt.
1385 	 */
1386 	NCR5380_write(SELECT_ENABLE_REG, 0);
1387 
1388 	/*
1389 	 * The initiator shall then wait at least two deskew delays and release
1390 	 * the BSY signal.
1391 	 */
1392 	udelay(1);		/* wingel -- wait two bus deskew delay >2*45ns */
1393 
1394 	/* Reset BSY */
1395 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1396 
1397 	/*
1398 	 * Something weird happens when we cease to drive BSY - looks
1399 	 * like the board/chip is letting us do another read before the
1400 	 * appropriate propagation delay has expired, and we're confusing
1401 	 * a BSY signal from ourselves as the target's response to SELECTION.
1402 	 *
1403 	 * A small delay (the 'C++' frontend breaks the pipeline with an
1404 	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1405 	 * tighter 'C' code breaks and requires this) solves the problem -
1406 	 * the 1 us delay is arbitrary, and only used because this delay will
1407 	 * be the same on other platforms and since it works here, it should
1408 	 * work there.
1409 	 *
1410 	 * wingel suggests that this could be due to failing to wait
1411 	 * one deskew delay.
1412 	 */
1413 
1414 	udelay(1);
1415 
1416 	dprintk(NDEBUG_SELECTION, "scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd));
1417 
1418 	/*
1419 	 * The SCSI specification calls for a 250 ms timeout for the actual
1420 	 * selection.
1421 	 */
1422 
1423 	timeout = jiffies + (250 * HZ / 1000);
1424 
1425 	/*
1426 	 * XXX very interesting - we're seeing a bounce where the BSY we
1427 	 * asserted is being reflected / still asserted (propagation delay?)
1428 	 * and it's detecting as true.  Sigh.
1429 	 */
1430 
1431 	hostdata->select_time = 0;	/* we count the clock ticks at which we polled */
1432 	hostdata->selecting = cmd;
1433 
1434 part2:
1435 	/* RvC: here we enter after a sleeping period, or immediately after
1436 	   execution of part 1
1437 	   we poll only once ech clock tick */
1438 	value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1439 
1440 	if (!value && (hostdata->select_time < HZ/4)) {
1441 		/* RvC: we still must wait for a device response */
1442 		hostdata->select_time++;	/* after 25 ticks the device has failed */
1443 		NCR5380_set_timer(hostdata, 1);
1444 		return 0;	/* RvC: we return here with hostdata->selecting set,
1445 				   to go to sleep */
1446 	}
1447 
1448 	hostdata->selecting = NULL;/* clear this pointer, because we passed the
1449 					   waiting period */
1450 	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1451 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1452 		NCR5380_reselect(instance);
1453 		printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1454 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1455 		return -1;
1456 	}
1457 	/*
1458 	 * No less than two deskew delays after the initiator detects the
1459 	 * BSY signal is true, it shall release the SEL signal and may
1460 	 * change the DATA BUS.                                     -wingel
1461 	 */
1462 
1463 	udelay(1);
1464 
1465 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1466 
1467 	if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1468 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1469 		if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1470 			printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1471 			if (hostdata->restart_select)
1472 				printk(KERN_DEBUG "\trestart select\n");
1473 			NCR5380_dprint(NDEBUG_SELECTION, instance);
1474 			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1475 			return -1;
1476 		}
1477 		cmd->result = DID_BAD_TARGET << 16;
1478 		collect_stats(hostdata, cmd);
1479 		cmd->scsi_done(cmd);
1480 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1481 		dprintk(NDEBUG_SELECTION, "scsi%d : target did not respond within 250ms\n", instance->host_no);
1482 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1483 		return 0;
1484 	}
1485 	hostdata->targets_present |= (1 << scmd_id(cmd));
1486 
1487 	/*
1488 	 * Since we followed the SCSI spec, and raised ATN while SEL
1489 	 * was true but before BSY was false during selection, the information
1490 	 * transfer phase should be a MESSAGE OUT phase so that we can send the
1491 	 * IDENTIFY message.
1492 	 *
1493 	 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1494 	 * message (2 bytes) with a tag ID that we increment with every command
1495 	 * until it wraps back to 0.
1496 	 *
1497 	 * XXX - it turns out that there are some broken SCSI-II devices,
1498 	 *       which claim to support tagged queuing but fail when more than
1499 	 *       some number of commands are issued at once.
1500 	 */
1501 
1502 	/* Wait for start of REQ/ACK handshake */
1503 
1504 	spin_unlock_irq(instance->host_lock);
1505 	err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1506 	spin_lock_irq(instance->host_lock);
1507 
1508 	if(err) {
1509 		printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1510 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1511 		goto failed;
1512 	}
1513 
1514 	dprintk(NDEBUG_SELECTION, "scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id);
1515 	tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1516 
1517 	len = 1;
1518 	cmd->tag = 0;
1519 
1520 	/* Send message(s) */
1521 	data = tmp;
1522 	phase = PHASE_MSGOUT;
1523 	NCR5380_transfer_pio(instance, &phase, &len, &data);
1524 	dprintk(NDEBUG_SELECTION, "scsi%d : nexus established.\n", instance->host_no);
1525 	/* XXX need to handle errors here */
1526 	hostdata->connected = cmd;
1527 	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1528 
1529 	initialize_SCp(cmd);
1530 
1531 	return 0;
1532 
1533 	/* Selection failed */
1534 failed:
1535 	return -1;
1536 
1537 }
1538 
1539 /*
1540  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1541  *      unsigned char *phase, int *count, unsigned char **data)
1542  *
1543  * Purpose : transfers data in given phase using polled I/O
1544  *
1545  * Inputs : instance - instance of driver, *phase - pointer to
1546  *      what phase is expected, *count - pointer to number of
1547  *      bytes to transfer, **data - pointer to data pointer.
1548  *
1549  * Returns : -1 when different phase is entered without transferring
1550  *      maximum number of bytes, 0 if all bytes or transferred or exit
1551  *      is in same phase.
1552  *
1553  *      Also, *phase, *count, *data are modified in place.
1554  *
1555  * XXX Note : handling for bus free may be useful.
1556  */
1557 
1558 /*
1559  * Note : this code is not as quick as it could be, however it
1560  * IS 100% reliable, and for the actual data transfer where speed
1561  * counts, we will always do a pseudo DMA or DMA transfer.
1562  */
1563 
1564 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1565 	NCR5380_local_declare();
1566 	unsigned char p = *phase, tmp;
1567 	int c = *count;
1568 	unsigned char *d = *data;
1569 	/*
1570 	 *      RvC: some administrative data to process polling time
1571 	 */
1572 	int break_allowed = 0;
1573 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1574 	NCR5380_setup(instance);
1575 
1576 	if (!(p & SR_IO))
1577 		dprintk(NDEBUG_PIO, "scsi%d : pio write %d bytes\n", instance->host_no, c);
1578 	else
1579 		dprintk(NDEBUG_PIO, "scsi%d : pio read %d bytes\n", instance->host_no, c);
1580 
1581 	/*
1582 	 * The NCR5380 chip will only drive the SCSI bus when the
1583 	 * phase specified in the appropriate bits of the TARGET COMMAND
1584 	 * REGISTER match the STATUS REGISTER
1585 	 */
1586 
1587 	 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1588 
1589 	/* RvC: don't know if this is necessary, but other SCSI I/O is short
1590 	 *      so breaks are not necessary there
1591 	 */
1592 	if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1593 		break_allowed = 1;
1594 	}
1595 	do {
1596 		/*
1597 		 * Wait for assertion of REQ, after which the phase bits will be
1598 		 * valid
1599 		 */
1600 
1601 		/* RvC: we simply poll once, after that we stop temporarily
1602 		 *      and let the device buffer fill up
1603 		 *      if breaking is not allowed, we keep polling as long as needed
1604 		 */
1605 
1606 		/* FIXME */
1607 		while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1608 		if (!(tmp & SR_REQ)) {
1609 			/* timeout condition */
1610 			NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1611 			break;
1612 		}
1613 
1614 		dprintk(NDEBUG_HANDSHAKE, "scsi%d : REQ detected\n", instance->host_no);
1615 
1616 		/* Check for phase mismatch */
1617 		if ((tmp & PHASE_MASK) != p) {
1618 			dprintk(NDEBUG_HANDSHAKE, "scsi%d : phase mismatch\n", instance->host_no);
1619 			NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1620 			break;
1621 		}
1622 		/* Do actual transfer from SCSI bus to / from memory */
1623 		if (!(p & SR_IO))
1624 			NCR5380_write(OUTPUT_DATA_REG, *d);
1625 		else
1626 			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1627 
1628 		++d;
1629 
1630 		/*
1631 		 * The SCSI standard suggests that in MSGOUT phase, the initiator
1632 		 * should drop ATN on the last byte of the message phase
1633 		 * after REQ has been asserted for the handshake but before
1634 		 * the initiator raises ACK.
1635 		 */
1636 
1637 		if (!(p & SR_IO)) {
1638 			if (!((p & SR_MSG) && c > 1)) {
1639 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1640 				NCR5380_dprint(NDEBUG_PIO, instance);
1641 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1642 			} else {
1643 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1644 				NCR5380_dprint(NDEBUG_PIO, instance);
1645 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1646 			}
1647 		} else {
1648 			NCR5380_dprint(NDEBUG_PIO, instance);
1649 			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1650 		}
1651 
1652 		/* FIXME - if this fails bus reset ?? */
1653 		NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1654 		dprintk(NDEBUG_HANDSHAKE, "scsi%d : req false, handshake complete\n", instance->host_no);
1655 
1656 /*
1657  * We have several special cases to consider during REQ/ACK handshaking :
1658  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1659  *      message.  ATN must be dropped as ACK is dropped.
1660  *
1661  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1662  *      message.  We must exit with ACK asserted, so that the calling
1663  *      code may raise ATN before dropping ACK to reject the message.
1664  *
1665  * 3.  ACK and ATN are clear and the target may proceed as normal.
1666  */
1667 		if (!(p == PHASE_MSGIN && c == 1)) {
1668 			if (p == PHASE_MSGOUT && c > 1)
1669 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1670 			else
1671 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1672 		}
1673 	} while (--c);
1674 
1675 	dprintk(NDEBUG_PIO, "scsi%d : residual %d\n", instance->host_no, c);
1676 
1677 	*count = c;
1678 	*data = d;
1679 	tmp = NCR5380_read(STATUS_REG);
1680 	if (tmp & SR_REQ)
1681 		*phase = tmp & PHASE_MASK;
1682 	else
1683 		*phase = PHASE_UNKNOWN;
1684 
1685 	if (!c || (*phase == p))
1686 		return 0;
1687 	else
1688 		return -1;
1689 }
1690 
1691 /**
1692  *	do_reset	-	issue a reset command
1693  *	@host: adapter to reset
1694  *
1695  *	Issue a reset sequence to the NCR5380 and try and get the bus
1696  *	back into sane shape.
1697  *
1698  *	Locks: caller holds queue lock
1699  */
1700 
1701 static void do_reset(struct Scsi_Host *host) {
1702 	NCR5380_local_declare();
1703 	NCR5380_setup(host);
1704 
1705 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1706 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1707 	udelay(25);
1708 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1709 }
1710 
1711 /*
1712  * Function : do_abort (Scsi_Host *host)
1713  *
1714  * Purpose : abort the currently established nexus.  Should only be
1715  *      called from a routine which can drop into a
1716  *
1717  * Returns : 0 on success, -1 on failure.
1718  *
1719  * Locks: queue lock held by caller
1720  *	FIXME: sort this out and get new_eh running
1721  */
1722 
1723 static int do_abort(struct Scsi_Host *host) {
1724 	NCR5380_local_declare();
1725 	unsigned char *msgptr, phase, tmp;
1726 	int len;
1727 	int rc;
1728 	NCR5380_setup(host);
1729 
1730 
1731 	/* Request message out phase */
1732 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1733 
1734 	/*
1735 	 * Wait for the target to indicate a valid phase by asserting
1736 	 * REQ.  Once this happens, we'll have either a MSGOUT phase
1737 	 * and can immediately send the ABORT message, or we'll have some
1738 	 * other phase and will have to source/sink data.
1739 	 *
1740 	 * We really don't care what value was on the bus or what value
1741 	 * the target sees, so we just handshake.
1742 	 */
1743 
1744 	rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1745 
1746 	if(rc < 0)
1747 		return -1;
1748 
1749 	tmp = (unsigned char)rc;
1750 
1751 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1752 
1753 	if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1754 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1755 		rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1756 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1757 		if(rc == -1)
1758 			return -1;
1759 	}
1760 	tmp = ABORT;
1761 	msgptr = &tmp;
1762 	len = 1;
1763 	phase = PHASE_MSGOUT;
1764 	NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1765 
1766 	/*
1767 	 * If we got here, and the command completed successfully,
1768 	 * we're about to go into bus free state.
1769 	 */
1770 
1771 	return len ? -1 : 0;
1772 }
1773 
1774 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1775 /*
1776  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1777  *      unsigned char *phase, int *count, unsigned char **data)
1778  *
1779  * Purpose : transfers data in given phase using either real
1780  *      or pseudo DMA.
1781  *
1782  * Inputs : instance - instance of driver, *phase - pointer to
1783  *      what phase is expected, *count - pointer to number of
1784  *      bytes to transfer, **data - pointer to data pointer.
1785  *
1786  * Returns : -1 when different phase is entered without transferring
1787  *      maximum number of bytes, 0 if all bytes or transferred or exit
1788  *      is in same phase.
1789  *
1790  *      Also, *phase, *count, *data are modified in place.
1791  *
1792  *	Locks: io_request lock held by caller
1793  */
1794 
1795 
1796 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1797 	NCR5380_local_declare();
1798 	register int c = *count;
1799 	register unsigned char p = *phase;
1800 	register unsigned char *d = *data;
1801 	unsigned char tmp;
1802 	int foo;
1803 #if defined(REAL_DMA_POLL)
1804 	int cnt, toPIO;
1805 	unsigned char saved_data = 0, overrun = 0, residue;
1806 #endif
1807 
1808 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1809 
1810 	NCR5380_setup(instance);
1811 
1812 	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1813 		*phase = tmp;
1814 		return -1;
1815 	}
1816 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1817 #ifdef READ_OVERRUNS
1818 	if (p & SR_IO) {
1819 		c -= 2;
1820 	}
1821 #endif
1822 	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);
1823 	hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1824 #endif
1825 
1826 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1827 
1828 #ifdef REAL_DMA
1829 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1830 #elif defined(REAL_DMA_POLL)
1831 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1832 #else
1833 	/*
1834 	 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1835 	 * were not disabled for the duration of a single DMA transfer, from
1836 	 * before the setting of DMA mode to after transfer of the last byte.
1837 	 */
1838 
1839 #if defined(PSEUDO_DMA) && defined(UNSAFE)
1840 	spin_unlock_irq(instance->host_lock);
1841 #endif
1842 	/* KLL May need eop and parity in 53c400 */
1843 	if (hostdata->flags & FLAG_NCR53C400)
1844 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE |
1845 				MR_ENABLE_PAR_CHECK | MR_ENABLE_PAR_INTR |
1846 				MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1847 	else
1848 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1849 #endif				/* def REAL_DMA */
1850 
1851 	dprintk(NDEBUG_DMA, "scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG));
1852 
1853 	/*
1854 	 *	On the PAS16 at least I/O recovery delays are not needed here.
1855 	 *	Everyone else seems to want them.
1856 	 */
1857 
1858 	if (p & SR_IO) {
1859 		io_recovery_delay(1);
1860 		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1861 	} else {
1862 		io_recovery_delay(1);
1863 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1864 		io_recovery_delay(1);
1865 		NCR5380_write(START_DMA_SEND_REG, 0);
1866 		io_recovery_delay(1);
1867 	}
1868 
1869 #if defined(REAL_DMA_POLL)
1870 	do {
1871 		tmp = NCR5380_read(BUS_AND_STATUS_REG);
1872 	} while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1873 
1874 /*
1875    At this point, either we've completed DMA, or we have a phase mismatch,
1876    or we've unexpectedly lost BUSY (which is a real error).
1877 
1878    For write DMAs, we want to wait until the last byte has been
1879    transferred out over the bus before we turn off DMA mode.  Alas, there
1880    seems to be no terribly good way of doing this on a 5380 under all
1881    conditions.  For non-scatter-gather operations, we can wait until REQ
1882    and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1883    are nastier, since the device will be expecting more data than we
1884    are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1885    could test LAST BIT SENT to assure transfer (I imagine this is precisely
1886    why this signal was added to the newer chips) but on the older 538[01]
1887    this signal does not exist.  The workaround for this lack is a watchdog;
1888    we bail out of the wait-loop after a modest amount of wait-time if
1889    the usual exit conditions are not met.  Not a terribly clean or
1890    correct solution :-%
1891 
1892    Reads are equally tricky due to a nasty characteristic of the NCR5380.
1893    If the chip is in DMA mode for an READ, it will respond to a target's
1894    REQ by latching the SCSI data into the INPUT DATA register and asserting
1895    ACK, even if it has _already_ been notified by the DMA controller that
1896    the current DMA transfer has completed!  If the NCR5380 is then taken
1897    out of DMA mode, this already-acknowledged byte is lost.
1898 
1899    This is not a problem for "one DMA transfer per command" reads, because
1900    the situation will never arise... either all of the data is DMA'ed
1901    properly, or the target switches to MESSAGE IN phase to signal a
1902    disconnection (either operation bringing the DMA to a clean halt).
1903    However, in order to handle scatter-reads, we must work around the
1904    problem.  The chosen fix is to DMA N-2 bytes, then check for the
1905    condition before taking the NCR5380 out of DMA mode.  One or two extra
1906    bytes are transferred via PIO as necessary to fill out the original
1907    request.
1908  */
1909 
1910 	if (p & SR_IO) {
1911 #ifdef READ_OVERRUNS
1912 		udelay(10);
1913 		if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1914 			saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1915 			overrun = 1;
1916 		}
1917 #endif
1918 	} else {
1919 		int limit = 100;
1920 		while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1921 			if (!(tmp & BASR_PHASE_MATCH))
1922 				break;
1923 			if (--limit < 0)
1924 				break;
1925 		}
1926 	}
1927 
1928 	dprintk(NDEBUG_DMA, "scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG));
1929 
1930 	NCR5380_write(MODE_REG, MR_BASE);
1931 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1932 
1933 	residue = NCR5380_dma_residual(instance);
1934 	c -= residue;
1935 	*count -= c;
1936 	*data += c;
1937 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1938 
1939 #ifdef READ_OVERRUNS
1940 	if (*phase == p && (p & SR_IO) && residue == 0) {
1941 		if (overrun) {
1942 			dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1943 			**data = saved_data;
1944 			*data += 1;
1945 			*count -= 1;
1946 			cnt = toPIO = 1;
1947 		} else {
1948 			printk("No overrun??\n");
1949 			cnt = toPIO = 2;
1950 		}
1951 		dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%X\n", cnt, *data);
1952 		NCR5380_transfer_pio(instance, phase, &cnt, data);
1953 		*count -= toPIO - cnt;
1954 	}
1955 #endif
1956 
1957 	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));
1958 	return 0;
1959 
1960 #elif defined(REAL_DMA)
1961 	return 0;
1962 #else				/* defined(REAL_DMA_POLL) */
1963 	if (p & SR_IO) {
1964 #ifdef DMA_WORKS_RIGHT
1965 		foo = NCR5380_pread(instance, d, c);
1966 #else
1967 		int diff = 1;
1968 		if (hostdata->flags & FLAG_NCR53C400) {
1969 			diff = 0;
1970 		}
1971 		if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1972 			/*
1973 			 * We can't disable DMA mode after successfully transferring
1974 			 * what we plan to be the last byte, since that would open up
1975 			 * a race condition where if the target asserted REQ before
1976 			 * we got the DMA mode reset, the NCR5380 would have latched
1977 			 * an additional byte into the INPUT DATA register and we'd
1978 			 * have dropped it.
1979 			 *
1980 			 * The workaround was to transfer one fewer bytes than we
1981 			 * intended to with the pseudo-DMA read function, wait for
1982 			 * the chip to latch the last byte, read it, and then disable
1983 			 * pseudo-DMA mode.
1984 			 *
1985 			 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1986 			 * REQ is deasserted when ACK is asserted, and not reasserted
1987 			 * until ACK goes false.  Since the NCR5380 won't lower ACK
1988 			 * until DACK is asserted, which won't happen unless we twiddle
1989 			 * the DMA port or we take the NCR5380 out of DMA mode, we
1990 			 * can guarantee that we won't handshake another extra
1991 			 * byte.
1992 			 */
1993 
1994 			if (!(hostdata->flags & FLAG_NCR53C400)) {
1995 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
1996 				/* Wait for clean handshake */
1997 				while (NCR5380_read(STATUS_REG) & SR_REQ);
1998 				d[c - 1] = NCR5380_read(INPUT_DATA_REG);
1999 			}
2000 		}
2001 #endif
2002 	} else {
2003 #ifdef DMA_WORKS_RIGHT
2004 		foo = NCR5380_pwrite(instance, d, c);
2005 #else
2006 		int timeout;
2007 		dprintk(NDEBUG_C400_PWRITE, "About to pwrite %d bytes\n", c);
2008 		if (!(foo = NCR5380_pwrite(instance, d, c))) {
2009 			/*
2010 			 * Wait for the last byte to be sent.  If REQ is being asserted for
2011 			 * the byte we're interested, we'll ACK it and it will go false.
2012 			 */
2013 			if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2014 				timeout = 20000;
2015 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2016 
2017 				if (!timeout)
2018 					dprintk(NDEBUG_LAST_BYTE_SENT, "scsi%d : timed out on last byte\n", instance->host_no);
2019 
2020 				if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2021 					hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2022 					if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2023 						hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2024 						dprintk(NDEBUG_LAST_BYTE_SENT, "scsi%d : last byte sent works\n", instance->host_no);
2025 					}
2026 				}
2027 			} else {
2028 				dprintk(NDEBUG_C400_PWRITE, "Waiting for LASTBYTE\n");
2029 				while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2030 				dprintk(NDEBUG_C400_PWRITE, "Got LASTBYTE\n");
2031 			}
2032 		}
2033 #endif
2034 	}
2035 	NCR5380_write(MODE_REG, MR_BASE);
2036 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2037 
2038 	if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2039 		dprintk(NDEBUG_C400_PWRITE, "53C400w: Checking for IRQ\n");
2040 		if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2041 			dprintk(NDEBUG_C400_PWRITE, "53C400w:    got it, reading reset interrupt reg\n");
2042 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2043 		} else {
2044 			printk("53C400w:    IRQ NOT THERE!\n");
2045 		}
2046 	}
2047 	*data = d + c;
2048 	*count = 0;
2049 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2050 #if defined(PSEUDO_DMA) && defined(UNSAFE)
2051 	spin_lock_irq(instance->host_lock);
2052 #endif				/* defined(REAL_DMA_POLL) */
2053 	return foo;
2054 #endif				/* def REAL_DMA */
2055 }
2056 #endif				/* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2057 
2058 /*
2059  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2060  *
2061  * Purpose : run through the various SCSI phases and do as the target
2062  *      directs us to.  Operates on the currently connected command,
2063  *      instance->connected.
2064  *
2065  * Inputs : instance, instance for which we are doing commands
2066  *
2067  * Side effects : SCSI things happen, the disconnected queue will be
2068  *      modified if a command disconnects, *instance->connected will
2069  *      change.
2070  *
2071  * XXX Note : we need to watch for bus free or a reset condition here
2072  *      to recover from an unexpected bus free condition.
2073  *
2074  * Locks: io_request_lock held by caller in IRQ mode
2075  */
2076 
2077 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2078 	NCR5380_local_declare();
2079 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2080 	unsigned char msgout = NOP;
2081 	int sink = 0;
2082 	int len;
2083 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2084 	int transfersize;
2085 #endif
2086 	unsigned char *data;
2087 	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2088 	Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2089 	/* RvC: we need to set the end of the polling time */
2090 	unsigned long poll_time = jiffies + USLEEP_POLL;
2091 
2092 	NCR5380_setup(instance);
2093 
2094 	while (1) {
2095 		tmp = NCR5380_read(STATUS_REG);
2096 		/* We only have a valid SCSI phase when REQ is asserted */
2097 		if (tmp & SR_REQ) {
2098 			phase = (tmp & PHASE_MASK);
2099 			if (phase != old_phase) {
2100 				old_phase = phase;
2101 				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2102 			}
2103 			if (sink && (phase != PHASE_MSGOUT)) {
2104 				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2105 
2106 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2107 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2108 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2109 				sink = 0;
2110 				continue;
2111 			}
2112 			switch (phase) {
2113 			case PHASE_DATAIN:
2114 			case PHASE_DATAOUT:
2115 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2116 				printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2117 				sink = 1;
2118 				do_abort(instance);
2119 				cmd->result = DID_ERROR << 16;
2120 				cmd->scsi_done(cmd);
2121 				return;
2122 #endif
2123 				/*
2124 				 * If there is no room left in the current buffer in the
2125 				 * scatter-gather list, move onto the next one.
2126 				 */
2127 
2128 				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2129 					++cmd->SCp.buffer;
2130 					--cmd->SCp.buffers_residual;
2131 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
2132 					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2133 					dprintk(NDEBUG_INFORMATION, "scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual);
2134 				}
2135 				/*
2136 				 * The preferred transfer method is going to be
2137 				 * PSEUDO-DMA for systems that are strictly PIO,
2138 				 * since we can let the hardware do the handshaking.
2139 				 *
2140 				 * For this to work, we need to know the transfersize
2141 				 * ahead of time, since the pseudo-DMA code will sit
2142 				 * in an unconditional loop.
2143 				 */
2144 
2145 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2146 				/* KLL
2147 				 * PSEUDO_DMA is defined here. If this is the g_NCR5380
2148 				 * driver then it will always be defined, so the
2149 				 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2150 				 * NCR5380 case.  I think this is a fairly clean solution.
2151 				 * We supplement these 2 if's with the flag.
2152 				 */
2153 #ifdef NCR5380_dma_xfer_len
2154 				if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2155 #else
2156 				transfersize = cmd->transfersize;
2157 
2158 #ifdef LIMIT_TRANSFERSIZE	/* If we have problems with interrupt service */
2159 				if (transfersize > 512)
2160 					transfersize = 512;
2161 #endif				/* LIMIT_TRANSFERSIZE */
2162 
2163 				if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2164 					/* Limit transfers to 32K, for xx400 & xx406
2165 					 * pseudoDMA that transfers in 128 bytes blocks. */
2166 					if (transfersize > 32 * 1024)
2167 						transfersize = 32 * 1024;
2168 #endif
2169 					len = transfersize;
2170 					if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2171 						/*
2172 						 * If the watchdog timer fires, all future accesses to this
2173 						 * device will use the polled-IO.
2174 						 */
2175 						scmd_printk(KERN_INFO, cmd,
2176 							    "switching to slow handshake\n");
2177 						cmd->device->borken = 1;
2178 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2179 						sink = 1;
2180 						do_abort(instance);
2181 						cmd->result = DID_ERROR << 16;
2182 						cmd->scsi_done(cmd);
2183 						/* XXX - need to source or sink data here, as appropriate */
2184 					} else
2185 						cmd->SCp.this_residual -= transfersize - len;
2186 				} else
2187 #endif				/* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2188 					NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2189 							     &cmd->SCp.ptr);
2190 				break;
2191 			case PHASE_MSGIN:
2192 				len = 1;
2193 				data = &tmp;
2194 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2195 				cmd->SCp.Message = tmp;
2196 
2197 				switch (tmp) {
2198 					/*
2199 					 * Linking lets us reduce the time required to get the
2200 					 * next command out to the device, hopefully this will
2201 					 * mean we don't waste another revolution due to the delays
2202 					 * required by ARBITRATION and another SELECTION.
2203 					 *
2204 					 * In the current implementation proposal, low level drivers
2205 					 * merely have to start the next command, pointed to by
2206 					 * next_link, done() is called as with unlinked commands.
2207 					 */
2208 #ifdef LINKED
2209 				case LINKED_CMD_COMPLETE:
2210 				case LINKED_FLG_CMD_COMPLETE:
2211 					/* Accept message by clearing ACK */
2212 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2213 					dprintk(NDEBUG_LINKED, "scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun);
2214 					/*
2215 					 * Sanity check : A linked command should only terminate with
2216 					 * one of these messages if there are more linked commands
2217 					 * available.
2218 					 */
2219 					if (!cmd->next_link) {
2220 						printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2221 						sink = 1;
2222 						do_abort(instance);
2223 						return;
2224 					}
2225 					initialize_SCp(cmd->next_link);
2226 					/* The next command is still part of this process */
2227 					cmd->next_link->tag = cmd->tag;
2228 					cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2229 					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);
2230 					collect_stats(hostdata, cmd);
2231 					cmd->scsi_done(cmd);
2232 					cmd = hostdata->connected;
2233 					break;
2234 #endif				/* def LINKED */
2235 				case ABORT:
2236 				case COMMAND_COMPLETE:
2237 					/* Accept message by clearing ACK */
2238 					sink = 1;
2239 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2240 					hostdata->connected = NULL;
2241 					dprintk(NDEBUG_QUEUES, "scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun);
2242 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2243 
2244 					/*
2245 					 * I'm not sure what the correct thing to do here is :
2246 					 *
2247 					 * If the command that just executed is NOT a request
2248 					 * sense, the obvious thing to do is to set the result
2249 					 * code to the values of the stored parameters.
2250 					 *
2251 					 * If it was a REQUEST SENSE command, we need some way
2252 					 * to differentiate between the failure code of the original
2253 					 * and the failure code of the REQUEST sense - the obvious
2254 					 * case is success, where we fall through and leave the result
2255 					 * code unchanged.
2256 					 *
2257 					 * The non-obvious place is where the REQUEST SENSE failed
2258 					 */
2259 
2260 					if (cmd->cmnd[0] != REQUEST_SENSE)
2261 						cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2262 					else if (status_byte(cmd->SCp.Status) != GOOD)
2263 						cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2264 
2265 #ifdef AUTOSENSE
2266 					if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2267 						hostdata->ses.cmd_len) {
2268 						scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2269 						hostdata->ses.cmd_len = 0 ;
2270 					}
2271 
2272 					if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2273 						scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2274 
2275 						dprintk(NDEBUG_AUTOSENSE, "scsi%d : performing request sense\n", instance->host_no);
2276 
2277 						LIST(cmd, hostdata->issue_queue);
2278 						cmd->host_scribble = (unsigned char *)
2279 						    hostdata->issue_queue;
2280 						hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2281 						dprintk(NDEBUG_QUEUES, "scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no);
2282 					} else
2283 #endif				/* def AUTOSENSE */
2284 					{
2285 						collect_stats(hostdata, cmd);
2286 						cmd->scsi_done(cmd);
2287 					}
2288 
2289 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2290 					/*
2291 					 * Restore phase bits to 0 so an interrupted selection,
2292 					 * arbitration can resume.
2293 					 */
2294 					NCR5380_write(TARGET_COMMAND_REG, 0);
2295 
2296 					while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2297 						barrier();
2298 					return;
2299 				case MESSAGE_REJECT:
2300 					/* Accept message by clearing ACK */
2301 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2302 					switch (hostdata->last_message) {
2303 					case HEAD_OF_QUEUE_TAG:
2304 					case ORDERED_QUEUE_TAG:
2305 					case SIMPLE_QUEUE_TAG:
2306 						cmd->device->simple_tags = 0;
2307 						hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2308 						break;
2309 					default:
2310 						break;
2311 					}
2312 				case DISCONNECT:{
2313 						/* Accept message by clearing ACK */
2314 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2315 						cmd->device->disconnect = 1;
2316 						LIST(cmd, hostdata->disconnected_queue);
2317 						cmd->host_scribble = (unsigned char *)
2318 						    hostdata->disconnected_queue;
2319 						hostdata->connected = NULL;
2320 						hostdata->disconnected_queue = cmd;
2321 						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);
2322 						/*
2323 						 * Restore phase bits to 0 so an interrupted selection,
2324 						 * arbitration can resume.
2325 						 */
2326 						NCR5380_write(TARGET_COMMAND_REG, 0);
2327 
2328 						/* Enable reselect interrupts */
2329 						NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2330 						/* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2331 						/* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2332 						while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2333 							barrier();
2334 						return;
2335 					}
2336 					/*
2337 					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2338 					 * operation, in violation of the SCSI spec so we can safely
2339 					 * ignore SAVE/RESTORE pointers calls.
2340 					 *
2341 					 * Unfortunately, some disks violate the SCSI spec and
2342 					 * don't issue the required SAVE_POINTERS message before
2343 					 * disconnecting, and we have to break spec to remain
2344 					 * compatible.
2345 					 */
2346 				case SAVE_POINTERS:
2347 				case RESTORE_POINTERS:
2348 					/* Accept message by clearing ACK */
2349 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2350 					break;
2351 				case EXTENDED_MESSAGE:
2352 /*
2353  * Extended messages are sent in the following format :
2354  * Byte
2355  * 0            EXTENDED_MESSAGE == 1
2356  * 1            length (includes one byte for code, doesn't
2357  *              include first two bytes)
2358  * 2            code
2359  * 3..length+1  arguments
2360  *
2361  * Start the extended message buffer with the EXTENDED_MESSAGE
2362  * byte, since spi_print_msg() wants the whole thing.
2363  */
2364 					extended_msg[0] = EXTENDED_MESSAGE;
2365 					/* Accept first byte by clearing ACK */
2366 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2367 					dprintk(NDEBUG_EXTENDED, "scsi%d : receiving extended message\n", instance->host_no);
2368 
2369 					len = 2;
2370 					data = extended_msg + 1;
2371 					phase = PHASE_MSGIN;
2372 					NCR5380_transfer_pio(instance, &phase, &len, &data);
2373 
2374 					dprintk(NDEBUG_EXTENDED, "scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]);
2375 
2376 					if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2377 						/* Accept third byte by clearing ACK */
2378 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2379 						len = extended_msg[1] - 1;
2380 						data = extended_msg + 3;
2381 						phase = PHASE_MSGIN;
2382 
2383 						NCR5380_transfer_pio(instance, &phase, &len, &data);
2384 						dprintk(NDEBUG_EXTENDED, "scsi%d : message received, residual %d\n", instance->host_no, len);
2385 
2386 						switch (extended_msg[2]) {
2387 						case EXTENDED_SDTR:
2388 						case EXTENDED_WDTR:
2389 						case EXTENDED_MODIFY_DATA_POINTER:
2390 						case EXTENDED_EXTENDED_IDENTIFY:
2391 							tmp = 0;
2392 						}
2393 					} else if (len) {
2394 						printk("scsi%d: error receiving extended message\n", instance->host_no);
2395 						tmp = 0;
2396 					} else {
2397 						printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2398 						tmp = 0;
2399 					}
2400 					/* Fall through to reject message */
2401 
2402 					/*
2403 					 * If we get something weird that we aren't expecting,
2404 					 * reject it.
2405 					 */
2406 				default:
2407 					if (!tmp) {
2408 						printk("scsi%d: rejecting message ", instance->host_no);
2409 						spi_print_msg(extended_msg);
2410 						printk("\n");
2411 					} else if (tmp != EXTENDED_MESSAGE)
2412 						scmd_printk(KERN_INFO, cmd,
2413 							"rejecting unknown message %02x\n",tmp);
2414 					else
2415 						scmd_printk(KERN_INFO, cmd,
2416 							"rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2417 
2418 					msgout = MESSAGE_REJECT;
2419 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2420 					break;
2421 				}	/* switch (tmp) */
2422 				break;
2423 			case PHASE_MSGOUT:
2424 				len = 1;
2425 				data = &msgout;
2426 				hostdata->last_message = msgout;
2427 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2428 				if (msgout == ABORT) {
2429 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2430 					hostdata->connected = NULL;
2431 					cmd->result = DID_ERROR << 16;
2432 					collect_stats(hostdata, cmd);
2433 					cmd->scsi_done(cmd);
2434 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2435 					return;
2436 				}
2437 				msgout = NOP;
2438 				break;
2439 			case PHASE_CMDOUT:
2440 				len = cmd->cmd_len;
2441 				data = cmd->cmnd;
2442 				/*
2443 				 * XXX for performance reasons, on machines with a
2444 				 * PSEUDO-DMA architecture we should probably
2445 				 * use the dma transfer function.
2446 				 */
2447 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2448 				if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2449 					NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2450 					dprintk(NDEBUG_USLEEP, "scsi%d : issued command, sleeping until %lu\n", instance->host_no, hostdata->time_expires);
2451 					return;
2452 				}
2453 				break;
2454 			case PHASE_STATIN:
2455 				len = 1;
2456 				data = &tmp;
2457 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2458 				cmd->SCp.Status = tmp;
2459 				break;
2460 			default:
2461 				printk("scsi%d : unknown phase\n", instance->host_no);
2462 				NCR5380_dprint(NDEBUG_ANY, instance);
2463 			}	/* switch(phase) */
2464 		}		/* if (tmp * SR_REQ) */
2465 		else {
2466 			/* RvC: go to sleep if polling time expired
2467 			 */
2468 			if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2469 				NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2470 				dprintk(NDEBUG_USLEEP, "scsi%d : poll timed out, sleeping until %lu\n", instance->host_no, hostdata->time_expires);
2471 				return;
2472 			}
2473 		}
2474 	}			/* while (1) */
2475 }
2476 
2477 /*
2478  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2479  *
2480  * Purpose : does reselection, initializing the instance->connected
2481  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2482  *      nexus has been reestablished,
2483  *
2484  * Inputs : instance - this instance of the NCR5380.
2485  *
2486  * Locks: io_request_lock held by caller if IRQ driven
2487  */
2488 
2489 static void NCR5380_reselect(struct Scsi_Host *instance) {
2490 	NCR5380_local_declare();
2491 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2492 	 instance->hostdata;
2493 	unsigned char target_mask;
2494 	unsigned char lun, phase;
2495 	int len;
2496 	unsigned char msg[3];
2497 	unsigned char *data;
2498 	Scsi_Cmnd *tmp = NULL, *prev;
2499 	int abort = 0;
2500 	NCR5380_setup(instance);
2501 
2502 	/*
2503 	 * Disable arbitration, etc. since the host adapter obviously
2504 	 * lost, and tell an interrupted NCR5380_select() to restart.
2505 	 */
2506 
2507 	NCR5380_write(MODE_REG, MR_BASE);
2508 	hostdata->restart_select = 1;
2509 
2510 	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2511 	dprintk(NDEBUG_SELECTION, "scsi%d : reselect\n", instance->host_no);
2512 
2513 	/*
2514 	 * At this point, we have detected that our SCSI ID is on the bus,
2515 	 * SEL is true and BSY was false for at least one bus settle delay
2516 	 * (400 ns).
2517 	 *
2518 	 * We must assert BSY ourselves, until the target drops the SEL
2519 	 * signal.
2520 	 */
2521 
2522 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2523 
2524 	/* FIXME: timeout too long, must fail to workqueue */
2525 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2526 		abort = 1;
2527 
2528 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2529 
2530 	/*
2531 	 * Wait for target to go into MSGIN.
2532 	 * FIXME: timeout needed and fail to work queeu
2533 	 */
2534 
2535 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2536 		abort = 1;
2537 
2538 	len = 1;
2539 	data = msg;
2540 	phase = PHASE_MSGIN;
2541 	NCR5380_transfer_pio(instance, &phase, &len, &data);
2542 
2543 	if (!(msg[0] & 0x80)) {
2544 		printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2545 		spi_print_msg(msg);
2546 		abort = 1;
2547 	} else {
2548 		/* Accept message by clearing ACK */
2549 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2550 		lun = (msg[0] & 0x07);
2551 
2552 		/*
2553 		 * We need to add code for SCSI-II to track which devices have
2554 		 * I_T_L_Q nexuses established, and which have simple I_T_L
2555 		 * nexuses so we can chose to do additional data transfer.
2556 		 */
2557 
2558 		/*
2559 		 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2560 		 * just reestablished, and remove it from the disconnected queue.
2561 		 */
2562 
2563 
2564 		for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2565 			if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2566 			    ) {
2567 				if (prev) {
2568 					REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2569 					prev->host_scribble = tmp->host_scribble;
2570 				} else {
2571 					REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2572 					hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2573 				}
2574 				tmp->host_scribble = NULL;
2575 				break;
2576 			}
2577 		if (!tmp) {
2578 			printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2579 			/*
2580 			 * Since we have an established nexus that we can't do anything with,
2581 			 * we must abort it.
2582 			 */
2583 			abort = 1;
2584 		}
2585 	}
2586 
2587 	if (abort) {
2588 		do_abort(instance);
2589 	} else {
2590 		hostdata->connected = tmp;
2591 		dprintk(NDEBUG_RESELECTION, "scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->device->id, tmp->device->lun, tmp->tag);
2592 	}
2593 }
2594 
2595 /*
2596  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2597  *
2598  * Purpose : called by interrupt handler when DMA finishes or a phase
2599  *      mismatch occurs (which would finish the DMA transfer).
2600  *
2601  * Inputs : instance - this instance of the NCR5380.
2602  *
2603  * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2604  *      nexus has been reestablished, on failure NULL is returned.
2605  */
2606 
2607 #ifdef REAL_DMA
2608 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2609 	NCR5380_local_declare();
2610 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2611 	int transferred;
2612 	NCR5380_setup(instance);
2613 
2614 	/*
2615 	 * XXX this might not be right.
2616 	 *
2617 	 * Wait for final byte to transfer, ie wait for ACK to go false.
2618 	 *
2619 	 * We should use the Last Byte Sent bit, unfortunately this is
2620 	 * not available on the 5380/5381 (only the various CMOS chips)
2621 	 *
2622 	 * FIXME: timeout, and need to handle long timeout/irq case
2623 	 */
2624 
2625 	NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2626 
2627 	NCR5380_write(MODE_REG, MR_BASE);
2628 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2629 
2630 	/*
2631 	 * The only places we should see a phase mismatch and have to send
2632 	 * data from the same set of pointers will be the data transfer
2633 	 * phases.  So, residual, requested length are only important here.
2634 	 */
2635 
2636 	if (!(hostdata->connected->SCp.phase & SR_CD)) {
2637 		transferred = instance->dmalen - NCR5380_dma_residual();
2638 		hostdata->connected->SCp.this_residual -= transferred;
2639 		hostdata->connected->SCp.ptr += transferred;
2640 	}
2641 }
2642 #endif				/* def REAL_DMA */
2643 
2644 /*
2645  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2646  *
2647  * Purpose : abort a command
2648  *
2649  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2650  *      host byte of the result field to, if zero DID_ABORTED is
2651  *      used.
2652  *
2653  * Returns : 0 - success, -1 on failure.
2654  *
2655  *	XXX - there is no way to abort the command that is currently
2656  *	connected, you have to wait for it to complete.  If this is
2657  *	a problem, we could implement longjmp() / setjmp(), setjmp()
2658  *	called where the loop started in NCR5380_main().
2659  *
2660  * Locks: host lock taken by caller
2661  */
2662 
2663 static int NCR5380_abort(Scsi_Cmnd * cmd) {
2664 	NCR5380_local_declare();
2665 	struct Scsi_Host *instance = cmd->device->host;
2666 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2667 	Scsi_Cmnd *tmp, **prev;
2668 
2669 	printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2670 	scsi_print_command(cmd);
2671 
2672 	NCR5380_print_status(instance);
2673 
2674 	NCR5380_setup(instance);
2675 
2676 	dprintk(NDEBUG_ABORT, "scsi%d : abort called\n", instance->host_no);
2677 	dprintk(NDEBUG_ABORT, "        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG));
2678 
2679 #if 0
2680 /*
2681  * Case 1 : If the command is the currently executing command,
2682  * we'll set the aborted flag and return control so that
2683  * information transfer routine can exit cleanly.
2684  */
2685 
2686 	if (hostdata->connected == cmd) {
2687 		dprintk(NDEBUG_ABORT, "scsi%d : aborting connected command\n", instance->host_no);
2688 		hostdata->aborted = 1;
2689 /*
2690  * We should perform BSY checking, and make sure we haven't slipped
2691  * into BUS FREE.
2692  */
2693 
2694 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2695 /*
2696  * Since we can't change phases until we've completed the current
2697  * handshake, we have to source or sink a byte of data if the current
2698  * phase is not MSGOUT.
2699  */
2700 
2701 /*
2702  * Return control to the executing NCR drive so we can clear the
2703  * aborted flag and get back into our main loop.
2704  */
2705 
2706 		return 0;
2707 	}
2708 #endif
2709 
2710 /*
2711  * Case 2 : If the command hasn't been issued yet, we simply remove it
2712  *          from the issue queue.
2713  */
2714 
2715 	dprintk(NDEBUG_ABORT, "scsi%d : abort going into loop.\n", instance->host_no);
2716 	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)
2717 		if (cmd == tmp) {
2718 			REMOVE(5, *prev, tmp, tmp->host_scribble);
2719 			(*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2720 			tmp->host_scribble = NULL;
2721 			tmp->result = DID_ABORT << 16;
2722 			dprintk(NDEBUG_ABORT, "scsi%d : abort removed command from issue queue.\n", instance->host_no);
2723 			tmp->scsi_done(tmp);
2724 			return SUCCESS;
2725 		}
2726 #if (NDEBUG  & NDEBUG_ABORT)
2727 	/* KLL */
2728 		else if (prev == tmp)
2729 			printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2730 #endif
2731 
2732 /*
2733  * Case 3 : If any commands are connected, we're going to fail the abort
2734  *          and let the high level SCSI driver retry at a later time or
2735  *          issue a reset.
2736  *
2737  *          Timeouts, and therefore aborted commands, will be highly unlikely
2738  *          and handling them cleanly in this situation would make the common
2739  *          case of noresets less efficient, and would pollute our code.  So,
2740  *          we fail.
2741  */
2742 
2743 	if (hostdata->connected) {
2744 		dprintk(NDEBUG_ABORT, "scsi%d : abort failed, command connected.\n", instance->host_no);
2745 		return FAILED;
2746 	}
2747 /*
2748  * Case 4: If the command is currently disconnected from the bus, and
2749  *      there are no connected commands, we reconnect the I_T_L or
2750  *      I_T_L_Q nexus associated with it, go into message out, and send
2751  *      an abort message.
2752  *
2753  * This case is especially ugly. In order to reestablish the nexus, we
2754  * need to call NCR5380_select().  The easiest way to implement this
2755  * function was to abort if the bus was busy, and let the interrupt
2756  * handler triggered on the SEL for reselect take care of lost arbitrations
2757  * where necessary, meaning interrupts need to be enabled.
2758  *
2759  * When interrupts are enabled, the queues may change - so we
2760  * can't remove it from the disconnected queue before selecting it
2761  * because that could cause a failure in hashing the nexus if that
2762  * device reselected.
2763  *
2764  * Since the queues may change, we can't use the pointers from when we
2765  * first locate it.
2766  *
2767  * So, we must first locate the command, and if NCR5380_select()
2768  * succeeds, then issue the abort, relocate the command and remove
2769  * it from the disconnected queue.
2770  */
2771 
2772 	for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2773 		if (cmd == tmp) {
2774 			dprintk(NDEBUG_ABORT, "scsi%d : aborting disconnected command.\n", instance->host_no);
2775 
2776 			if (NCR5380_select(instance, cmd, (int) cmd->tag))
2777 				return FAILED;
2778 			dprintk(NDEBUG_ABORT, "scsi%d : nexus reestablished.\n", instance->host_no);
2779 
2780 			do_abort(instance);
2781 
2782 			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)
2783 				if (cmd == tmp) {
2784 					REMOVE(5, *prev, tmp, tmp->host_scribble);
2785 					*prev = (Scsi_Cmnd *) tmp->host_scribble;
2786 					tmp->host_scribble = NULL;
2787 					tmp->result = DID_ABORT << 16;
2788 					tmp->scsi_done(tmp);
2789 					return SUCCESS;
2790 				}
2791 		}
2792 /*
2793  * Case 5 : If we reached this point, the command was not found in any of
2794  *          the queues.
2795  *
2796  * We probably reached this point because of an unlikely race condition
2797  * between the command completing successfully and the abortion code,
2798  * so we won't panic, but we will notify the user in case something really
2799  * broke.
2800  */
2801 	printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2802 			"         before abortion\n", instance->host_no);
2803 	return FAILED;
2804 }
2805 
2806 
2807 /*
2808  * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2809  *
2810  * Purpose : reset the SCSI bus.
2811  *
2812  * Returns : SUCCESS
2813  *
2814  * Locks: host lock taken by caller
2815  */
2816 
2817 static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2818 {
2819 	struct Scsi_Host *instance = cmd->device->host;
2820 
2821 	NCR5380_local_declare();
2822 	NCR5380_setup(instance);
2823 	NCR5380_print_status(instance);
2824 
2825 	spin_lock_irq(instance->host_lock);
2826 	do_reset(instance);
2827 	spin_unlock_irq(instance->host_lock);
2828 
2829 	return SUCCESS;
2830 }
2831