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1/*
2 * NCR 5380 generic driver routines. These should make it *trivial*
3 * to implement 5380 SCSI drivers under Linux with a non-trantor
4 * architecture.
5 *
6 * Note that these routines also work with NR53c400 family chips.
7 *
8 * Copyright 1993, Drew Eckhardt
9 * Visionary Computing
10 * (Unix and Linux consulting and custom programming)
11 * drew@colorado.edu
12 * +1 (303) 666-5836
13 *
14 * DISTRIBUTION RELEASE 6.
15 *
16 * For more information, please consult
17 *
18 * NCR 5380 Family
19 * SCSI Protocol Controller
20 * Databook
21 *
22 * NCR Microelectronics
23 * 1635 Aeroplaza Drive
24 * Colorado Springs, CO 80916
25 * 1+ (719) 578-3400
26 * 1+ (800) 334-5454
27 */
28
29/*
30 * $Log: NCR5380.c,v $
31
32 * Revision 1.10 1998/9/2 Alan Cox
33 * (alan@lxorguk.ukuu.org.uk)
34 * Fixed up the timer lockups reported so far. Things still suck. Looking
35 * forward to 2.3 and per device request queues. Then it'll be possible to
36 * SMP thread this beast and improve life no end.
37
38 * Revision 1.9 1997/7/27 Ronald van Cuijlenborg
39 * (ronald.van.cuijlenborg@tip.nl or nutty@dds.nl)
40 * (hopefully) fixed and enhanced USLEEP
41 * added support for DTC3181E card (for Mustek scanner)
42 *
43
44 * Revision 1.8 Ingmar Baumgart
45 * (ingmar@gonzo.schwaben.de)
46 * added support for NCR53C400a card
47 *
48
49 * Revision 1.7 1996/3/2 Ray Van Tassle (rayvt@comm.mot.com)
50 * added proc_info
51 * added support needed for DTC 3180/3280
52 * fixed a couple of bugs
53 *
54
55 * Revision 1.5 1994/01/19 09:14:57 drew
56 * Fixed udelay() hack that was being used on DATAOUT phases
57 * instead of a proper wait for the final handshake.
58 *
59 * Revision 1.4 1994/01/19 06:44:25 drew
60 * *** empty log message ***
61 *
62 * Revision 1.3 1994/01/19 05:24:40 drew
63 * Added support for TCR LAST_BYTE_SENT bit.
64 *
65 * Revision 1.2 1994/01/15 06:14:11 drew
66 * REAL DMA support, bug fixes.
67 *
68 * Revision 1.1 1994/01/15 06:00:54 drew
69 * Initial revision
70 *
71 */
72
73/*
74 * Further development / testing that should be done :
75 * 1. Cleanup the NCR5380_transfer_dma function and DMA operation complete
76 * code so that everything does the same thing that's done at the
77 * end of a pseudo-DMA read operation.
78 *
79 * 2. Fix REAL_DMA (interrupt driven, polled works fine) -
80 * basically, transfer size needs to be reduced by one
81 * and the last byte read as is done with PSEUDO_DMA.
82 *
83 * 4. Test SCSI-II tagged queueing (I have no devices which support
84 * tagged queueing)
85 *
86 * 5. Test linked command handling code after Eric is ready with
87 * the high level code.
88 */
89#include <scsi/scsi_dbg.h>
90#include <scsi/scsi_transport_spi.h>
91
92#ifndef NDEBUG
93#define NDEBUG 0
94#endif
95#ifndef NDEBUG_ABORT
96#define NDEBUG_ABORT 0
97#endif
98
99#if (NDEBUG & NDEBUG_LISTS)
100#define LIST(x,y) {printk("LINE:%d Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); }
101#define REMOVE(w,x,y,z) {printk("LINE:%d Removing: %p->%p %p->%p \n", __LINE__, (void*)(w), (void*)(x), (void*)(y), (void*)(z)); if ((x)==(y)) udelay(5); }
102#else
103#define LIST(x,y)
104#define REMOVE(w,x,y,z)
105#endif
106
107#ifndef notyet
108#undef LINKED
109#undef REAL_DMA
110#endif
111
112#ifdef REAL_DMA_POLL
113#undef READ_OVERRUNS
114#define READ_OVERRUNS
115#endif
116
117#ifdef BOARD_REQUIRES_NO_DELAY
118#define io_recovery_delay(x)
119#else
120#define io_recovery_delay(x) udelay(x)
121#endif
122
123/*
124 * Design
125 *
126 * This is a generic 5380 driver. To use it on a different platform,
127 * one simply writes appropriate system specific macros (ie, data
128 * transfer - some PC's will use the I/O bus, 68K's must use
129 * memory mapped) and drops this file in their 'C' wrapper.
130 *
131 * (Note from hch: unfortunately it was not enough for the different
132 * m68k folks and instead of improving this driver they copied it
133 * and hacked it up for their needs. As a consequence they lost
134 * most updates to this driver. Maybe someone will fix all these
135 * drivers to use a common core one day..)
136 *
137 * As far as command queueing, two queues are maintained for
138 * each 5380 in the system - commands that haven't been issued yet,
139 * and commands that are currently executing. This means that an
140 * unlimited number of commands may be queued, letting
141 * more commands propagate from the higher driver levels giving higher
142 * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
143 * allowing multiple commands to propagate all the way to a SCSI-II device
144 * while a command is already executing.
145 *
146 *
147 * Issues specific to the NCR5380 :
148 *
149 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
150 * piece of hardware that requires you to sit in a loop polling for
151 * the REQ signal as long as you are connected. Some devices are
152 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
153 * while doing long seek operations.
154 *
155 * The workaround for this is to keep track of devices that have
156 * disconnected. If the device hasn't disconnected, for commands that
157 * should disconnect, we do something like
158 *
159 * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
160 *
161 * Some tweaking of N and M needs to be done. An algorithm based
162 * on "time to data" would give the best results as long as short time
163 * to datas (ie, on the same track) were considered, however these
164 * broken devices are the exception rather than the rule and I'd rather
165 * spend my time optimizing for the normal case.
166 *
167 * Architecture :
168 *
169 * At the heart of the design is a coroutine, NCR5380_main,
170 * which is started from a workqueue for each NCR5380 host in the
171 * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
172 * removing the commands from the issue queue and calling
173 * NCR5380_select() if a nexus is not established.
174 *
175 * Once a nexus is established, the NCR5380_information_transfer()
176 * phase goes through the various phases as instructed by the target.
177 * if the target goes into MSG IN and sends a DISCONNECT message,
178 * the command structure is placed into the per instance disconnected
179 * queue, and NCR5380_main tries to find more work. If the target is
180 * idle for too long, the system will try to sleep.
181 *
182 * If a command has disconnected, eventually an interrupt will trigger,
183 * calling NCR5380_intr() which will in turn call NCR5380_reselect
184 * to reestablish a nexus. This will run main if necessary.
185 *
186 * On command termination, the done function will be called as
187 * appropriate.
188 *
189 * SCSI pointers are maintained in the SCp field of SCSI command
190 * structures, being initialized after the command is connected
191 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
192 * Note that in violation of the standard, an implicit SAVE POINTERS operation
193 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
194 */
195
196/*
197 * Using this file :
198 * This file a skeleton Linux SCSI driver for the NCR 5380 series
199 * of chips. To use it, you write an architecture specific functions
200 * and macros and include this file in your driver.
201 *
202 * These macros control options :
203 * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
204 * defined.
205 *
206 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
207 * for commands that return with a CHECK CONDITION status.
208 *
209 * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
210 * transceivers.
211 *
212 * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
213 * override-configure an IRQ.
214 *
215 * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
216 * bytes at a time. Since interrupts are disabled by default during
217 * these transfers, we might need this to give reasonable interrupt
218 * service time if the transfer size gets too large.
219 *
220 * LINKED - if defined, linked commands are supported.
221 *
222 * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
223 *
224 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
225 *
226 * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
227 * rely on phase mismatch and EOP interrupts to determine end
228 * of phase.
229 *
230 * UNSAFE - leave interrupts enabled during pseudo-DMA transfers. You
231 * only really want to use this if you're having a problem with
232 * dropped characters during high speed communications, and even
233 * then, you're going to be better off twiddling with transfersize
234 * in the high level code.
235 *
236 * Defaults for these will be provided although the user may want to adjust
237 * these to allocate CPU resources to the SCSI driver or "real" code.
238 *
239 * USLEEP_SLEEP - amount of time, in jiffies, to sleep
240 *
241 * USLEEP_POLL - amount of time, in jiffies, to poll
242 *
243 * These macros MUST be defined :
244 * NCR5380_local_declare() - declare any local variables needed for your
245 * transfer routines.
246 *
247 * NCR5380_setup(instance) - initialize any local variables needed from a given
248 * instance of the host adapter for NCR5380_{read,write,pread,pwrite}
249 *
250 * NCR5380_read(register) - read from the specified register
251 *
252 * NCR5380_write(register, value) - write to the specific register
253 *
254 * NCR5380_implementation_fields - additional fields needed for this
255 * specific implementation of the NCR5380
256 *
257 * Either real DMA *or* pseudo DMA may be implemented
258 * REAL functions :
259 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
260 * Note that the DMA setup functions should return the number of bytes
261 * that they were able to program the controller for.
262 *
263 * Also note that generic i386/PC versions of these macros are
264 * available as NCR5380_i386_dma_write_setup,
265 * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
266 *
267 * NCR5380_dma_write_setup(instance, src, count) - initialize
268 * NCR5380_dma_read_setup(instance, dst, count) - initialize
269 * NCR5380_dma_residual(instance); - residual count
270 *
271 * PSEUDO functions :
272 * NCR5380_pwrite(instance, src, count)
273 * NCR5380_pread(instance, dst, count);
274 *
275 * The generic driver is initialized by calling NCR5380_init(instance),
276 * after setting the appropriate host specific fields and ID. If the
277 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
278 * possible) function may be used.
279 */
280
281static int do_abort(struct Scsi_Host *host);
282static void do_reset(struct Scsi_Host *host);
283
284/*
285 * initialize_SCp - init the scsi pointer field
286 * @cmd: command block to set up
287 *
288 * Set up the internal fields in the SCSI command.
289 */
290
291static __inline__ void initialize_SCp(Scsi_Cmnd * cmd)
292{
293 /*
294 * Initialize the Scsi Pointer field so that all of the commands in the
295 * various queues are valid.
296 */
297
298 if (scsi_bufflen(cmd)) {
299 cmd->SCp.buffer = scsi_sglist(cmd);
300 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
301 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
302 cmd->SCp.this_residual = cmd->SCp.buffer->length;
303 } else {
304 cmd->SCp.buffer = NULL;
305 cmd->SCp.buffers_residual = 0;
306 cmd->SCp.ptr = NULL;
307 cmd->SCp.this_residual = 0;
308 }
309}
310
311/**
312 * NCR5380_poll_politely - wait for NCR5380 status bits
313 * @instance: controller to poll
314 * @reg: 5380 register to poll
315 * @bit: Bitmask to check
316 * @val: Value required to exit
317 *
318 * Polls the NCR5380 in a reasonably efficient manner waiting for
319 * an event to occur, after a short quick poll we begin giving the
320 * CPU back in non IRQ contexts
321 *
322 * Returns the value of the register or a negative error code.
323 */
324
325static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
326{
327 NCR5380_local_declare();
328 int n = 500; /* At about 8uS a cycle for the cpu access */
329 unsigned long end = jiffies + t;
330 int r;
331
332 NCR5380_setup(instance);
333
334 while( n-- > 0)
335 {
336 r = NCR5380_read(reg);
337 if((r & bit) == val)
338 return 0;
339 cpu_relax();
340 }
341
342 /* t time yet ? */
343 while(time_before(jiffies, end))
344 {
345 r = NCR5380_read(reg);
346 if((r & bit) == val)
347 return 0;
348 if(!in_interrupt())
349 cond_resched();
350 else
351 cpu_relax();
352 }
353 return -ETIMEDOUT;
354}
355
356static struct {
357 unsigned char value;
358 const char *name;
359} phases[] __maybe_unused = {
360 {PHASE_DATAOUT, "DATAOUT"},
361 {PHASE_DATAIN, "DATAIN"},
362 {PHASE_CMDOUT, "CMDOUT"},
363 {PHASE_STATIN, "STATIN"},
364 {PHASE_MSGOUT, "MSGOUT"},
365 {PHASE_MSGIN, "MSGIN"},
366 {PHASE_UNKNOWN, "UNKNOWN"}
367};
368
369#if NDEBUG
370static struct {
371 unsigned char mask;
372 const char *name;
373} signals[] = {
374 {SR_DBP, "PARITY"},
375 {SR_RST, "RST"},
376 {SR_BSY, "BSY"},
377 {SR_REQ, "REQ"},
378 {SR_MSG, "MSG"},
379 {SR_CD, "CD"},
380 {SR_IO, "IO"},
381 {SR_SEL, "SEL"},
382 {0, NULL}
383},
384basrs[] = {
385 {BASR_ATN, "ATN"},
386 {BASR_ACK, "ACK"},
387 {0, NULL}
388},
389icrs[] = {
390 {ICR_ASSERT_RST, "ASSERT RST"},
391 {ICR_ASSERT_ACK, "ASSERT ACK"},
392 {ICR_ASSERT_BSY, "ASSERT BSY"},
393 {ICR_ASSERT_SEL, "ASSERT SEL"},
394 {ICR_ASSERT_ATN, "ASSERT ATN"},
395 {ICR_ASSERT_DATA, "ASSERT DATA"},
396 {0, NULL}
397},
398mrs[] = {
399 {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
400 {MR_TARGET, "MODE TARGET"},
401 {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
402 {MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
403 {MR_MONITOR_BSY, "MODE MONITOR BSY"},
404 {MR_DMA_MODE, "MODE DMA"},
405 {MR_ARBITRATE, "MODE ARBITRATION"},
406 {0, NULL}
407};
408
409/**
410 * NCR5380_print - print scsi bus signals
411 * @instance: adapter state to dump
412 *
413 * Print the SCSI bus signals for debugging purposes
414 *
415 * Locks: caller holds hostdata lock (not essential)
416 */
417
418static void NCR5380_print(struct Scsi_Host *instance)
419{
420 NCR5380_local_declare();
421 unsigned char status, data, basr, mr, icr, i;
422 NCR5380_setup(instance);
423
424 data = NCR5380_read(CURRENT_SCSI_DATA_REG);
425 status = NCR5380_read(STATUS_REG);
426 mr = NCR5380_read(MODE_REG);
427 icr = NCR5380_read(INITIATOR_COMMAND_REG);
428 basr = NCR5380_read(BUS_AND_STATUS_REG);
429
430 printk("STATUS_REG: %02x ", status);
431 for (i = 0; signals[i].mask; ++i)
432 if (status & signals[i].mask)
433 printk(",%s", signals[i].name);
434 printk("\nBASR: %02x ", basr);
435 for (i = 0; basrs[i].mask; ++i)
436 if (basr & basrs[i].mask)
437 printk(",%s", basrs[i].name);
438 printk("\nICR: %02x ", icr);
439 for (i = 0; icrs[i].mask; ++i)
440 if (icr & icrs[i].mask)
441 printk(",%s", icrs[i].name);
442 printk("\nMODE: %02x ", mr);
443 for (i = 0; mrs[i].mask; ++i)
444 if (mr & mrs[i].mask)
445 printk(",%s", mrs[i].name);
446 printk("\n");
447}
448
449
450/*
451 * NCR5380_print_phase - show SCSI phase
452 * @instance: adapter to dump
453 *
454 * Print the current SCSI phase for debugging purposes
455 *
456 * Locks: none
457 */
458
459static void NCR5380_print_phase(struct Scsi_Host *instance)
460{
461 NCR5380_local_declare();
462 unsigned char status;
463 int i;
464 NCR5380_setup(instance);
465
466 status = NCR5380_read(STATUS_REG);
467 if (!(status & SR_REQ))
468 printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
469 else {
470 for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
471 printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
472 }
473}
474#endif
475
476/*
477 * These need tweaking, and would probably work best as per-device
478 * flags initialized differently for disk, tape, cd, etc devices.
479 * People with broken devices are free to experiment as to what gives
480 * the best results for them.
481 *
482 * USLEEP_SLEEP should be a minimum seek time.
483 *
484 * USLEEP_POLL should be a maximum rotational latency.
485 */
486#ifndef USLEEP_SLEEP
487/* 20 ms (reasonable hard disk speed) */
488#define USLEEP_SLEEP (20*HZ/1000)
489#endif
490/* 300 RPM (floppy speed) */
491#ifndef USLEEP_POLL
492#define USLEEP_POLL (200*HZ/1000)
493#endif
494#ifndef USLEEP_WAITLONG
495/* RvC: (reasonable time to wait on select error) */
496#define USLEEP_WAITLONG USLEEP_SLEEP
497#endif
498
499/*
500 * Function : int should_disconnect (unsigned char cmd)
501 *
502 * Purpose : decide whether a command would normally disconnect or
503 * not, since if it won't disconnect we should go to sleep.
504 *
505 * Input : cmd - opcode of SCSI command
506 *
507 * Returns : DISCONNECT_LONG if we should disconnect for a really long
508 * time (ie always, sleep, look for REQ active, sleep),
509 * DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
510 * time-to-data delay, DISCONNECT_NONE if this command would return
511 * immediately.
512 *
513 * Future sleep algorithms based on time to data can exploit
514 * something like this so they can differentiate between "normal"
515 * (ie, read, write, seek) and unusual commands (ie, * format).
516 *
517 * Note : We don't deal with commands that handle an immediate disconnect,
518 *
519 */
520
521static int should_disconnect(unsigned char cmd)
522{
523 switch (cmd) {
524 case READ_6:
525 case WRITE_6:
526 case SEEK_6:
527 case READ_10:
528 case WRITE_10:
529 case SEEK_10:
530 return DISCONNECT_TIME_TO_DATA;
531 case FORMAT_UNIT:
532 case SEARCH_HIGH:
533 case SEARCH_LOW:
534 case SEARCH_EQUAL:
535 return DISCONNECT_LONG;
536 default:
537 return DISCONNECT_NONE;
538 }
539}
540
541static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
542{
543 hostdata->time_expires = jiffies + timeout;
544 schedule_delayed_work(&hostdata->coroutine, timeout);
545}
546
547
548static int probe_irq __initdata = 0;
549
550/**
551 * probe_intr - helper for IRQ autoprobe
552 * @irq: interrupt number
553 * @dev_id: unused
554 * @regs: unused
555 *
556 * Set a flag to indicate the IRQ in question was received. This is
557 * used by the IRQ probe code.
558 */
559
560static irqreturn_t __init probe_intr(int irq, void *dev_id)
561{
562 probe_irq = irq;
563 return IRQ_HANDLED;
564}
565
566/**
567 * NCR5380_probe_irq - find the IRQ of an NCR5380
568 * @instance: NCR5380 controller
569 * @possible: bitmask of ISA IRQ lines
570 *
571 * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
572 * and then looking to see what interrupt actually turned up.
573 *
574 * Locks: none, irqs must be enabled on entry
575 */
576
577static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
578 int possible)
579{
580 NCR5380_local_declare();
581 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
582 unsigned long timeout;
583 int trying_irqs, i, mask;
584 NCR5380_setup(instance);
585
586 for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
587 if ((mask & possible) && (request_irq(i, &probe_intr, IRQF_DISABLED, "NCR-probe", NULL) == 0))
588 trying_irqs |= mask;
589
590 timeout = jiffies + (250 * HZ / 1000);
591 probe_irq = SCSI_IRQ_NONE;
592
593 /*
594 * A interrupt is triggered whenever BSY = false, SEL = true
595 * and a bit set in the SELECT_ENABLE_REG is asserted on the
596 * SCSI bus.
597 *
598 * Note that the bus is only driven when the phase control signals
599 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
600 * to zero.
601 */
602
603 NCR5380_write(TARGET_COMMAND_REG, 0);
604 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
605 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
606 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
607
608 while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
609 schedule_timeout_uninterruptible(1);
610
611 NCR5380_write(SELECT_ENABLE_REG, 0);
612 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
613
614 for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
615 if (trying_irqs & mask)
616 free_irq(i, NULL);
617
618 return probe_irq;
619}
620
621/**
622 * NCR58380_print_options - show options
623 * @instance: unused for now
624 *
625 * Called by probe code indicating the NCR5380 driver options that
626 * were selected. At some point this will switch to runtime options
627 * read from the adapter in question
628 *
629 * Locks: none
630 */
631
632static void __init __maybe_unused
633NCR5380_print_options(struct Scsi_Host *instance)
634{
635 printk(" generic options"
636#ifdef AUTOPROBE_IRQ
637 " AUTOPROBE_IRQ"
638#endif
639#ifdef AUTOSENSE
640 " AUTOSENSE"
641#endif
642#ifdef DIFFERENTIAL
643 " DIFFERENTIAL"
644#endif
645#ifdef REAL_DMA
646 " REAL DMA"
647#endif
648#ifdef REAL_DMA_POLL
649 " REAL DMA POLL"
650#endif
651#ifdef PARITY
652 " PARITY"
653#endif
654#ifdef PSEUDO_DMA
655 " PSEUDO DMA"
656#endif
657#ifdef UNSAFE
658 " UNSAFE "
659#endif
660 );
661 printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
662 printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
663 if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
664 printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
665 }
666}
667
668/**
669 * NCR5380_print_status - dump controller info
670 * @instance: controller to dump
671 *
672 * Print commands in the various queues, called from NCR5380_abort
673 * and NCR5380_debug to aid debugging.
674 *
675 * Locks: called functions disable irqs
676 */
677
678static void NCR5380_print_status(struct Scsi_Host *instance)
679{
680 NCR5380_dprint(NDEBUG_ANY, instance);
681 NCR5380_dprint_phase(NDEBUG_ANY, instance);
682}
683
684/******************************************/
685/*
686 * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
687 *
688 * *buffer: I/O buffer
689 * **start: if inout == FALSE pointer into buffer where user read should start
690 * offset: current offset
691 * length: length of buffer
692 * hostno: Scsi_Host host_no
693 * inout: TRUE - user is writing; FALSE - user is reading
694 *
695 * Return the number of bytes read from or written
696 */
697
698#undef SPRINTF
699#define SPRINTF(args...) do { if(pos < buffer + length-80) pos += sprintf(pos, ## args); } while(0)
700static
701char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length);
702static
703char *lprint_command(unsigned char *cmd, char *pos, char *buffer, int len);
704static
705char *lprint_opcode(int opcode, char *pos, char *buffer, int length);
706
707static int __maybe_unused NCR5380_proc_info(struct Scsi_Host *instance,
708 char *buffer, char **start, off_t offset, int length, int inout)
709{
710 char *pos = buffer;
711 struct NCR5380_hostdata *hostdata;
712 Scsi_Cmnd *ptr;
713
714 hostdata = (struct NCR5380_hostdata *) instance->hostdata;
715
716 if (inout) { /* Has data been written to the file ? */
717#ifdef DTC_PUBLIC_RELEASE
718 dtc_wmaxi = dtc_maxi = 0;
719#endif
720#ifdef PAS16_PUBLIC_RELEASE
721 pas_wmaxi = pas_maxi = 0;
722#endif
723 return (-ENOSYS); /* Currently this is a no-op */
724 }
725 SPRINTF("NCR5380 core release=%d. ", NCR5380_PUBLIC_RELEASE);
726 if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
727 SPRINTF("ncr53c400 release=%d. ", NCR53C400_PUBLIC_RELEASE);
728#ifdef DTC_PUBLIC_RELEASE
729 SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
730#endif
731#ifdef T128_PUBLIC_RELEASE
732 SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
733#endif
734#ifdef GENERIC_NCR5380_PUBLIC_RELEASE
735 SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
736#endif
737#ifdef PAS16_PUBLIC_RELEASE
738 SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
739#endif
740
741 SPRINTF("\nBase Addr: 0x%05lX ", (long) instance->base);
742 SPRINTF("io_port: %04x ", (int) instance->io_port);
743 if (instance->irq == SCSI_IRQ_NONE)
744 SPRINTF("IRQ: None.\n");
745 else
746 SPRINTF("IRQ: %d.\n", instance->irq);
747
748#ifdef DTC_PUBLIC_RELEASE
749 SPRINTF("Highwater I/O busy_spin_counts -- write: %d read: %d\n", dtc_wmaxi, dtc_maxi);
750#endif
751#ifdef PAS16_PUBLIC_RELEASE
752 SPRINTF("Highwater I/O busy_spin_counts -- write: %d read: %d\n", pas_wmaxi, pas_maxi);
753#endif
754 spin_lock_irq(instance->host_lock);
755 if (!hostdata->connected)
756 SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
757 else
758 pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, pos, buffer, length);
759 SPRINTF("scsi%d: issue_queue\n", instance->host_no);
760 for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
761 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
762
763 SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
764 for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
765 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
766 spin_unlock_irq(instance->host_lock);
767
768 *start = buffer;
769 if (pos - buffer < offset)
770 return 0;
771 else if (pos - buffer - offset < length)
772 return pos - buffer - offset;
773 return length;
774}
775
776static char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length)
777{
778 SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
779 SPRINTF(" command = ");
780 pos = lprint_command(cmd->cmnd, pos, buffer, length);
781 return (pos);
782}
783
784static char *lprint_command(unsigned char *command, char *pos, char *buffer, int length)
785{
786 int i, s;
787 pos = lprint_opcode(command[0], pos, buffer, length);
788 for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
789 SPRINTF("%02x ", command[i]);
790 SPRINTF("\n");
791 return (pos);
792}
793
794static char *lprint_opcode(int opcode, char *pos, char *buffer, int length)
795{
796 SPRINTF("%2d (0x%02x)", opcode, opcode);
797 return (pos);
798}
799
800
801/**
802 * NCR5380_init - initialise an NCR5380
803 * @instance: adapter to configure
804 * @flags: control flags
805 *
806 * Initializes *instance and corresponding 5380 chip,
807 * with flags OR'd into the initial flags value.
808 *
809 * Notes : I assume that the host, hostno, and id bits have been
810 * set correctly. I don't care about the irq and other fields.
811 *
812 * Returns 0 for success
813 *
814 * Locks: interrupts must be enabled when we are called
815 */
816
817static int __devinit NCR5380_init(struct Scsi_Host *instance, int flags)
818{
819 NCR5380_local_declare();
820 int i, pass;
821 unsigned long timeout;
822 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
823
824 if(in_interrupt())
825 printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
826 /*
827 * On NCR53C400 boards, NCR5380 registers are mapped 8 past
828 * the base address.
829 */
830
831#ifdef NCR53C400
832 if (flags & FLAG_NCR53C400)
833 instance->NCR5380_instance_name += NCR53C400_address_adjust;
834#endif
835
836 NCR5380_setup(instance);
837
838 hostdata->aborted = 0;
839 hostdata->id_mask = 1 << instance->this_id;
840 for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
841 if (i > hostdata->id_mask)
842 hostdata->id_higher_mask |= i;
843 for (i = 0; i < 8; ++i)
844 hostdata->busy[i] = 0;
845#ifdef REAL_DMA
846 hostdata->dmalen = 0;
847#endif
848 hostdata->targets_present = 0;
849 hostdata->connected = NULL;
850 hostdata->issue_queue = NULL;
851 hostdata->disconnected_queue = NULL;
852
853 INIT_DELAYED_WORK(&hostdata->coroutine, NCR5380_main);
854
855#ifdef NCR5380_STATS
856 for (i = 0; i < 8; ++i) {
857 hostdata->time_read[i] = 0;
858 hostdata->time_write[i] = 0;
859 hostdata->bytes_read[i] = 0;
860 hostdata->bytes_write[i] = 0;
861 }
862 hostdata->timebase = 0;
863 hostdata->pendingw = 0;
864 hostdata->pendingr = 0;
865#endif
866
867 /* The CHECK code seems to break the 53C400. Will check it later maybe */
868 if (flags & FLAG_NCR53C400)
869 hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
870 else
871 hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
872
873 hostdata->host = instance;
874 hostdata->time_expires = 0;
875
876#ifndef AUTOSENSE
877 if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
878 printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" " without AUTOSENSE option, contingent allegiance conditions may\n"
879 " be incorrectly cleared.\n", instance->host_no);
880#endif /* def AUTOSENSE */
881
882 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
883 NCR5380_write(MODE_REG, MR_BASE);
884 NCR5380_write(TARGET_COMMAND_REG, 0);
885 NCR5380_write(SELECT_ENABLE_REG, 0);
886
887#ifdef NCR53C400
888 if (hostdata->flags & FLAG_NCR53C400) {
889 NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
890 }
891#endif
892
893 /*
894 * Detect and correct bus wedge problems.
895 *
896 * If the system crashed, it may have crashed in a state
897 * where a SCSI command was still executing, and the
898 * SCSI bus is not in a BUS FREE STATE.
899 *
900 * If this is the case, we'll try to abort the currently
901 * established nexus which we know nothing about, and that
902 * failing, do a hard reset of the SCSI bus
903 */
904
905 for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
906 switch (pass) {
907 case 1:
908 case 3:
909 case 5:
910 printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
911 timeout = jiffies + 5 * HZ;
912 NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
913 break;
914 case 2:
915 printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
916 do_abort(instance);
917 break;
918 case 4:
919 printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
920 do_reset(instance);
921 break;
922 case 6:
923 printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
924 return -ENXIO;
925 }
926 }
927 return 0;
928}
929
930/**
931 * NCR5380_exit - remove an NCR5380
932 * @instance: adapter to remove
933 */
934
935static void NCR5380_exit(struct Scsi_Host *instance)
936{
937 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
938
939 cancel_delayed_work_sync(&hostdata->coroutine);
940}
941
942/**
943 * NCR5380_queue_command - queue a command
944 * @cmd: SCSI command
945 * @done: completion handler
946 *
947 * cmd is added to the per instance issue_queue, with minor
948 * twiddling done to the host specific fields of cmd. If the
949 * main coroutine is not running, it is restarted.
950 *
951 * Locks: host lock taken by caller
952 */
953
954static int NCR5380_queue_command_lck(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
955{
956 struct Scsi_Host *instance = cmd->device->host;
957 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
958 Scsi_Cmnd *tmp;
959
960#if (NDEBUG & NDEBUG_NO_WRITE)
961 switch (cmd->cmnd[0]) {
962 case WRITE_6:
963 case WRITE_10:
964 printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
965 cmd->result = (DID_ERROR << 16);
966 done(cmd);
967 return 0;
968 }
969#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
970
971#ifdef NCR5380_STATS
972 switch (cmd->cmnd[0]) {
973 case WRITE:
974 case WRITE_6:
975 case WRITE_10:
976 hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
977 hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
978 hostdata->pendingw++;
979 break;
980 case READ:
981 case READ_6:
982 case READ_10:
983 hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
984 hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
985 hostdata->pendingr++;
986 break;
987 }
988#endif
989
990 /*
991 * We use the host_scribble field as a pointer to the next command
992 * in a queue
993 */
994
995 cmd->host_scribble = NULL;
996 cmd->scsi_done = done;
997 cmd->result = 0;
998
999 /*
1000 * Insert the cmd into the issue queue. Note that REQUEST SENSE
1001 * commands are added to the head of the queue since any command will
1002 * clear the contingent allegiance condition that exists and the
1003 * sense data is only guaranteed to be valid while the condition exists.
1004 */
1005
1006 if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1007 LIST(cmd, hostdata->issue_queue);
1008 cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
1009 hostdata->issue_queue = cmd;
1010 } else {
1011 for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
1012 LIST(cmd, tmp);
1013 tmp->host_scribble = (unsigned char *) cmd;
1014 }
1015 dprintk(NDEBUG_QUEUES, ("scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"));
1016
1017 /* Run the coroutine if it isn't already running. */
1018 /* Kick off command processing */
1019 schedule_delayed_work(&hostdata->coroutine, 0);
1020 return 0;
1021}
1022
1023static DEF_SCSI_QCMD(NCR5380_queue_command)
1024
1025/**
1026 * NCR5380_main - NCR state machines
1027 *
1028 * NCR5380_main is a coroutine that runs as long as more work can
1029 * be done on the NCR5380 host adapters in a system. Both
1030 * NCR5380_queue_command() and NCR5380_intr() will try to start it
1031 * in case it is not running.
1032 *
1033 * Locks: called as its own thread with no locks held. Takes the
1034 * host lock and called routines may take the isa dma lock.
1035 */
1036
1037static void NCR5380_main(struct work_struct *work)
1038{
1039 struct NCR5380_hostdata *hostdata =
1040 container_of(work, struct NCR5380_hostdata, coroutine.work);
1041 struct Scsi_Host *instance = hostdata->host;
1042 Scsi_Cmnd *tmp, *prev;
1043 int done;
1044
1045 spin_lock_irq(instance->host_lock);
1046 do {
1047 /* Lock held here */
1048 done = 1;
1049 if (!hostdata->connected && !hostdata->selecting) {
1050 dprintk(NDEBUG_MAIN, ("scsi%d : not connected\n", instance->host_no));
1051 /*
1052 * Search through the issue_queue for a command destined
1053 * for a target that's not busy.
1054 */
1055 for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
1056 {
1057 if (prev != tmp)
1058 dprintk(NDEBUG_LISTS, ("MAIN tmp=%p target=%d busy=%d lun=%d\n", tmp, tmp->target, hostdata->busy[tmp->target], tmp->lun));
1059 /* When we find one, remove it from the issue queue. */
1060 if (!(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))) {
1061 if (prev) {
1062 REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1063 prev->host_scribble = tmp->host_scribble;
1064 } else {
1065 REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1066 hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1067 }
1068 tmp->host_scribble = NULL;
1069
1070 /*
1071 * Attempt to establish an I_T_L nexus here.
1072 * On success, instance->hostdata->connected is set.
1073 * On failure, we must add the command back to the
1074 * issue queue so we can keep trying.
1075 */
1076 dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main() : command for target %d lun %d removed from issue_queue\n", instance->host_no, tmp->target, tmp->lun));
1077
1078 /*
1079 * A successful selection is defined as one that
1080 * leaves us with the command connected and
1081 * in hostdata->connected, OR has terminated the
1082 * command.
1083 *
1084 * With successful commands, we fall through
1085 * and see if we can do an information transfer,
1086 * with failures we will restart.
1087 */
1088 hostdata->selecting = NULL;
1089 /* RvC: have to preset this to indicate a new command is being performed */
1090
1091 if (!NCR5380_select(instance, tmp,
1092 /*
1093 * REQUEST SENSE commands are issued without tagged
1094 * queueing, even on SCSI-II devices because the
1095 * contingent allegiance condition exists for the
1096 * entire unit.
1097 */
1098 (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1099 break;
1100 } else {
1101 LIST(tmp, hostdata->issue_queue);
1102 tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1103 hostdata->issue_queue = tmp;
1104 done = 0;
1105 dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no));
1106 }
1107 /* lock held here still */
1108 } /* if target/lun is not busy */
1109 } /* for */
1110 /* exited locked */
1111 } /* if (!hostdata->connected) */
1112 if (hostdata->selecting) {
1113 tmp = (Scsi_Cmnd *) hostdata->selecting;
1114 /* Selection will drop and retake the lock */
1115 if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1116 /* Ok ?? */
1117 } else {
1118 /* RvC: device failed, so we wait a long time
1119 this is needed for Mustek scanners, that
1120 do not respond to commands immediately
1121 after a scan */
1122 printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1123 LIST(tmp, hostdata->issue_queue);
1124 tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1125 hostdata->issue_queue = tmp;
1126 NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1127 }
1128 } /* if hostdata->selecting */
1129 if (hostdata->connected
1130#ifdef REAL_DMA
1131 && !hostdata->dmalen
1132#endif
1133 && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1134 ) {
1135 dprintk(NDEBUG_MAIN, ("scsi%d : main() : performing information transfer\n", instance->host_no));
1136 NCR5380_information_transfer(instance);
1137 dprintk(NDEBUG_MAIN, ("scsi%d : main() : done set false\n", instance->host_no));
1138 done = 0;
1139 } else
1140 break;
1141 } while (!done);
1142
1143 spin_unlock_irq(instance->host_lock);
1144}
1145
1146#ifndef DONT_USE_INTR
1147
1148/**
1149 * NCR5380_intr - generic NCR5380 irq handler
1150 * @irq: interrupt number
1151 * @dev_id: device info
1152 *
1153 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1154 * from the disconnected queue, and restarting NCR5380_main()
1155 * as required.
1156 *
1157 * Locks: takes the needed instance locks
1158 */
1159
1160static irqreturn_t NCR5380_intr(int dummy, void *dev_id)
1161{
1162 NCR5380_local_declare();
1163 struct Scsi_Host *instance = dev_id;
1164 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1165 int done;
1166 unsigned char basr;
1167 unsigned long flags;
1168
1169 dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n",
1170 instance->irq));
1171
1172 do {
1173 done = 1;
1174 spin_lock_irqsave(instance->host_lock, flags);
1175 /* Look for pending interrupts */
1176 NCR5380_setup(instance);
1177 basr = NCR5380_read(BUS_AND_STATUS_REG);
1178 /* XXX dispatch to appropriate routine if found and done=0 */
1179 if (basr & BASR_IRQ) {
1180 NCR5380_dprint(NDEBUG_INTR, instance);
1181 if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1182 done = 0;
1183 dprintk(NDEBUG_INTR, ("scsi%d : SEL interrupt\n", instance->host_no));
1184 NCR5380_reselect(instance);
1185 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1186 } else if (basr & BASR_PARITY_ERROR) {
1187 dprintk(NDEBUG_INTR, ("scsi%d : PARITY interrupt\n", instance->host_no));
1188 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1189 } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1190 dprintk(NDEBUG_INTR, ("scsi%d : RESET interrupt\n", instance->host_no));
1191 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1192 } else {
1193#if defined(REAL_DMA)
1194 /*
1195 * We should only get PHASE MISMATCH and EOP interrupts
1196 * if we have DMA enabled, so do a sanity check based on
1197 * the current setting of the MODE register.
1198 */
1199
1200 if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1201 int transferred;
1202
1203 if (!hostdata->connected)
1204 panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1205
1206 transferred = (hostdata->dmalen - NCR5380_dma_residual(instance));
1207 hostdata->connected->SCp.this_residual -= transferred;
1208 hostdata->connected->SCp.ptr += transferred;
1209 hostdata->dmalen = 0;
1210
1211 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1212
1213 /* FIXME: we need to poll briefly then defer a workqueue task ! */
1214 NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1215
1216 NCR5380_write(MODE_REG, MR_BASE);
1217 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1218 }
1219#else
1220 dprintk(NDEBUG_INTR, ("scsi : unknown interrupt, BASR 0x%X, MR 0x%X, SR 0x%x\n", basr, NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG)));
1221 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1222#endif
1223 }
1224 } /* if BASR_IRQ */
1225 spin_unlock_irqrestore(instance->host_lock, flags);
1226 if(!done)
1227 schedule_delayed_work(&hostdata->coroutine, 0);
1228 } while (!done);
1229 return IRQ_HANDLED;
1230}
1231
1232#endif
1233
1234/**
1235 * collect_stats - collect stats on a scsi command
1236 * @hostdata: adapter
1237 * @cmd: command being issued
1238 *
1239 * Update the statistical data by parsing the command in question
1240 */
1241
1242static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd)
1243{
1244#ifdef NCR5380_STATS
1245 switch (cmd->cmnd[0]) {
1246 case WRITE:
1247 case WRITE_6:
1248 case WRITE_10:
1249 hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1250 hostdata->pendingw--;
1251 break;
1252 case READ:
1253 case READ_6:
1254 case READ_10:
1255 hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1256 hostdata->pendingr--;
1257 break;
1258 }
1259#endif
1260}
1261
1262
1263/*
1264 * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1265 * int tag);
1266 *
1267 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1268 * including ARBITRATION, SELECTION, and initial message out for
1269 * IDENTIFY and queue messages.
1270 *
1271 * Inputs : instance - instantiation of the 5380 driver on which this
1272 * target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1273 * new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1274 * the command that is presently connected.
1275 *
1276 * Returns : -1 if selection could not execute for some reason,
1277 * 0 if selection succeeded or failed because the target
1278 * did not respond.
1279 *
1280 * Side effects :
1281 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
1282 * with registers as they should have been on entry - ie
1283 * SELECT_ENABLE will be set appropriately, the NCR5380
1284 * will cease to drive any SCSI bus signals.
1285 *
1286 * If successful : I_T_L or I_T_L_Q nexus will be established,
1287 * instance->connected will be set to cmd.
1288 * SELECT interrupt will be disabled.
1289 *
1290 * If failed (no target) : cmd->scsi_done() will be called, and the
1291 * cmd->result host byte set to DID_BAD_TARGET.
1292 *
1293 * Locks: caller holds hostdata lock in IRQ mode
1294 */
1295
1296static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag)
1297{
1298 NCR5380_local_declare();
1299 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1300 unsigned char tmp[3], phase;
1301 unsigned char *data;
1302 int len;
1303 unsigned long timeout;
1304 unsigned char value;
1305 int err;
1306 NCR5380_setup(instance);
1307
1308 if (hostdata->selecting)
1309 goto part2;
1310
1311 hostdata->restart_select = 0;
1312
1313 NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1314 dprintk(NDEBUG_ARBITRATION, ("scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id));
1315
1316 /*
1317 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1318 * data bus during SELECTION.
1319 */
1320
1321 NCR5380_write(TARGET_COMMAND_REG, 0);
1322
1323 /*
1324 * Start arbitration.
1325 */
1326
1327 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1328 NCR5380_write(MODE_REG, MR_ARBITRATE);
1329
1330
1331 /* We can be relaxed here, interrupts are on, we are
1332 in workqueue context, the birds are singing in the trees */
1333 spin_unlock_irq(instance->host_lock);
1334 err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1335 spin_lock_irq(instance->host_lock);
1336 if (err < 0) {
1337 printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1338 NCR5380_write(MODE_REG, MR_BASE);
1339 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1340 goto failed;
1341 }
1342
1343 dprintk(NDEBUG_ARBITRATION, ("scsi%d : arbitration complete\n", instance->host_no));
1344
1345 /*
1346 * The arbitration delay is 2.2us, but this is a minimum and there is
1347 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1348 * the integral nature of udelay().
1349 *
1350 */
1351
1352 udelay(3);
1353
1354 /* Check for lost arbitration */
1355 if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1356 NCR5380_write(MODE_REG, MR_BASE);
1357 dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no));
1358 goto failed;
1359 }
1360 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1361
1362 if (!(hostdata->flags & FLAG_DTC3181E) &&
1363 /* RvC: DTC3181E has some trouble with this
1364 * so we simply removed it. Seems to work with
1365 * only Mustek scanner attached
1366 */
1367 (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1368 NCR5380_write(MODE_REG, MR_BASE);
1369 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1370 dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no));
1371 goto failed;
1372 }
1373 /*
1374 * Again, bus clear + bus settle time is 1.2us, however, this is
1375 * a minimum so we'll udelay ceil(1.2)
1376 */
1377
1378 udelay(2);
1379
1380 dprintk(NDEBUG_ARBITRATION, ("scsi%d : won arbitration\n", instance->host_no));
1381
1382 /*
1383 * Now that we have won arbitration, start Selection process, asserting
1384 * the host and target ID's on the SCSI bus.
1385 */
1386
1387 NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1388
1389 /*
1390 * Raise ATN while SEL is true before BSY goes false from arbitration,
1391 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1392 * phase immediately after selection.
1393 */
1394
1395 NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1396 NCR5380_write(MODE_REG, MR_BASE);
1397
1398 /*
1399 * Reselect interrupts must be turned off prior to the dropping of BSY,
1400 * otherwise we will trigger an interrupt.
1401 */
1402 NCR5380_write(SELECT_ENABLE_REG, 0);
1403
1404 /*
1405 * The initiator shall then wait at least two deskew delays and release
1406 * the BSY signal.
1407 */
1408 udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
1409
1410 /* Reset BSY */
1411 NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1412
1413 /*
1414 * Something weird happens when we cease to drive BSY - looks
1415 * like the board/chip is letting us do another read before the
1416 * appropriate propagation delay has expired, and we're confusing
1417 * a BSY signal from ourselves as the target's response to SELECTION.
1418 *
1419 * A small delay (the 'C++' frontend breaks the pipeline with an
1420 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1421 * tighter 'C' code breaks and requires this) solves the problem -
1422 * the 1 us delay is arbitrary, and only used because this delay will
1423 * be the same on other platforms and since it works here, it should
1424 * work there.
1425 *
1426 * wingel suggests that this could be due to failing to wait
1427 * one deskew delay.
1428 */
1429
1430 udelay(1);
1431
1432 dprintk(NDEBUG_SELECTION, ("scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd)));
1433
1434 /*
1435 * The SCSI specification calls for a 250 ms timeout for the actual
1436 * selection.
1437 */
1438
1439 timeout = jiffies + (250 * HZ / 1000);
1440
1441 /*
1442 * XXX very interesting - we're seeing a bounce where the BSY we
1443 * asserted is being reflected / still asserted (propagation delay?)
1444 * and it's detecting as true. Sigh.
1445 */
1446
1447 hostdata->select_time = 0; /* we count the clock ticks at which we polled */
1448 hostdata->selecting = cmd;
1449
1450part2:
1451 /* RvC: here we enter after a sleeping period, or immediately after
1452 execution of part 1
1453 we poll only once ech clock tick */
1454 value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1455
1456 if (!value && (hostdata->select_time < HZ/4)) {
1457 /* RvC: we still must wait for a device response */
1458 hostdata->select_time++; /* after 25 ticks the device has failed */
1459 NCR5380_set_timer(hostdata, 1);
1460 return 0; /* RvC: we return here with hostdata->selecting set,
1461 to go to sleep */
1462 }
1463
1464 hostdata->selecting = NULL;/* clear this pointer, because we passed the
1465 waiting period */
1466 if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1467 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1468 NCR5380_reselect(instance);
1469 printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1470 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1471 return -1;
1472 }
1473 /*
1474 * No less than two deskew delays after the initiator detects the
1475 * BSY signal is true, it shall release the SEL signal and may
1476 * change the DATA BUS. -wingel
1477 */
1478
1479 udelay(1);
1480
1481 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1482
1483 if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1484 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1485 if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1486 printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1487 if (hostdata->restart_select)
1488 printk(KERN_DEBUG "\trestart select\n");
1489 NCR5380_dprint(NDEBUG_SELECTION, instance);
1490 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1491 return -1;
1492 }
1493 cmd->result = DID_BAD_TARGET << 16;
1494 collect_stats(hostdata, cmd);
1495 cmd->scsi_done(cmd);
1496 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1497 dprintk(NDEBUG_SELECTION, ("scsi%d : target did not respond within 250ms\n", instance->host_no));
1498 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1499 return 0;
1500 }
1501 hostdata->targets_present |= (1 << scmd_id(cmd));
1502
1503 /*
1504 * Since we followed the SCSI spec, and raised ATN while SEL
1505 * was true but before BSY was false during selection, the information
1506 * transfer phase should be a MESSAGE OUT phase so that we can send the
1507 * IDENTIFY message.
1508 *
1509 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1510 * message (2 bytes) with a tag ID that we increment with every command
1511 * until it wraps back to 0.
1512 *
1513 * XXX - it turns out that there are some broken SCSI-II devices,
1514 * which claim to support tagged queuing but fail when more than
1515 * some number of commands are issued at once.
1516 */
1517
1518 /* Wait for start of REQ/ACK handshake */
1519
1520 spin_unlock_irq(instance->host_lock);
1521 err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1522 spin_lock_irq(instance->host_lock);
1523
1524 if(err) {
1525 printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1526 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1527 goto failed;
1528 }
1529
1530 dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
1531 tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1532
1533 len = 1;
1534 cmd->tag = 0;
1535
1536 /* Send message(s) */
1537 data = tmp;
1538 phase = PHASE_MSGOUT;
1539 NCR5380_transfer_pio(instance, &phase, &len, &data);
1540 dprintk(NDEBUG_SELECTION, ("scsi%d : nexus established.\n", instance->host_no));
1541 /* XXX need to handle errors here */
1542 hostdata->connected = cmd;
1543 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1544
1545 initialize_SCp(cmd);
1546
1547 return 0;
1548
1549 /* Selection failed */
1550failed:
1551 return -1;
1552
1553}
1554
1555/*
1556 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1557 * unsigned char *phase, int *count, unsigned char **data)
1558 *
1559 * Purpose : transfers data in given phase using polled I/O
1560 *
1561 * Inputs : instance - instance of driver, *phase - pointer to
1562 * what phase is expected, *count - pointer to number of
1563 * bytes to transfer, **data - pointer to data pointer.
1564 *
1565 * Returns : -1 when different phase is entered without transferring
1566 * maximum number of bytes, 0 if all bytes or transferred or exit
1567 * is in same phase.
1568 *
1569 * Also, *phase, *count, *data are modified in place.
1570 *
1571 * XXX Note : handling for bus free may be useful.
1572 */
1573
1574/*
1575 * Note : this code is not as quick as it could be, however it
1576 * IS 100% reliable, and for the actual data transfer where speed
1577 * counts, we will always do a pseudo DMA or DMA transfer.
1578 */
1579
1580static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1581 NCR5380_local_declare();
1582 unsigned char p = *phase, tmp;
1583 int c = *count;
1584 unsigned char *d = *data;
1585 /*
1586 * RvC: some administrative data to process polling time
1587 */
1588 int break_allowed = 0;
1589 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1590 NCR5380_setup(instance);
1591
1592 if (!(p & SR_IO))
1593 dprintk(NDEBUG_PIO, ("scsi%d : pio write %d bytes\n", instance->host_no, c));
1594 else
1595 dprintk(NDEBUG_PIO, ("scsi%d : pio read %d bytes\n", instance->host_no, c));
1596
1597 /*
1598 * The NCR5380 chip will only drive the SCSI bus when the
1599 * phase specified in the appropriate bits of the TARGET COMMAND
1600 * REGISTER match the STATUS REGISTER
1601 */
1602
1603 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1604
1605 /* RvC: don't know if this is necessary, but other SCSI I/O is short
1606 * so breaks are not necessary there
1607 */
1608 if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1609 break_allowed = 1;
1610 }
1611 do {
1612 /*
1613 * Wait for assertion of REQ, after which the phase bits will be
1614 * valid
1615 */
1616
1617 /* RvC: we simply poll once, after that we stop temporarily
1618 * and let the device buffer fill up
1619 * if breaking is not allowed, we keep polling as long as needed
1620 */
1621
1622 /* FIXME */
1623 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1624 if (!(tmp & SR_REQ)) {
1625 /* timeout condition */
1626 NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1627 break;
1628 }
1629
1630 dprintk(NDEBUG_HANDSHAKE, ("scsi%d : REQ detected\n", instance->host_no));
1631
1632 /* Check for phase mismatch */
1633 if ((tmp & PHASE_MASK) != p) {
1634 dprintk(NDEBUG_HANDSHAKE, ("scsi%d : phase mismatch\n", instance->host_no));
1635 NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1636 break;
1637 }
1638 /* Do actual transfer from SCSI bus to / from memory */
1639 if (!(p & SR_IO))
1640 NCR5380_write(OUTPUT_DATA_REG, *d);
1641 else
1642 *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1643
1644 ++d;
1645
1646 /*
1647 * The SCSI standard suggests that in MSGOUT phase, the initiator
1648 * should drop ATN on the last byte of the message phase
1649 * after REQ has been asserted for the handshake but before
1650 * the initiator raises ACK.
1651 */
1652
1653 if (!(p & SR_IO)) {
1654 if (!((p & SR_MSG) && c > 1)) {
1655 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1656 NCR5380_dprint(NDEBUG_PIO, instance);
1657 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1658 } else {
1659 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1660 NCR5380_dprint(NDEBUG_PIO, instance);
1661 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1662 }
1663 } else {
1664 NCR5380_dprint(NDEBUG_PIO, instance);
1665 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1666 }
1667
1668 /* FIXME - if this fails bus reset ?? */
1669 NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1670 dprintk(NDEBUG_HANDSHAKE, ("scsi%d : req false, handshake complete\n", instance->host_no));
1671
1672/*
1673 * We have several special cases to consider during REQ/ACK handshaking :
1674 * 1. We were in MSGOUT phase, and we are on the last byte of the
1675 * message. ATN must be dropped as ACK is dropped.
1676 *
1677 * 2. We are in a MSGIN phase, and we are on the last byte of the
1678 * message. We must exit with ACK asserted, so that the calling
1679 * code may raise ATN before dropping ACK to reject the message.
1680 *
1681 * 3. ACK and ATN are clear and the target may proceed as normal.
1682 */
1683 if (!(p == PHASE_MSGIN && c == 1)) {
1684 if (p == PHASE_MSGOUT && c > 1)
1685 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1686 else
1687 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1688 }
1689 } while (--c);
1690
1691 dprintk(NDEBUG_PIO, ("scsi%d : residual %d\n", instance->host_no, c));
1692
1693 *count = c;
1694 *data = d;
1695 tmp = NCR5380_read(STATUS_REG);
1696 if (tmp & SR_REQ)
1697 *phase = tmp & PHASE_MASK;
1698 else
1699 *phase = PHASE_UNKNOWN;
1700
1701 if (!c || (*phase == p))
1702 return 0;
1703 else
1704 return -1;
1705}
1706
1707/**
1708 * do_reset - issue a reset command
1709 * @host: adapter to reset
1710 *
1711 * Issue a reset sequence to the NCR5380 and try and get the bus
1712 * back into sane shape.
1713 *
1714 * Locks: caller holds queue lock
1715 */
1716
1717static void do_reset(struct Scsi_Host *host) {
1718 NCR5380_local_declare();
1719 NCR5380_setup(host);
1720
1721 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1722 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1723 udelay(25);
1724 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1725}
1726
1727/*
1728 * Function : do_abort (Scsi_Host *host)
1729 *
1730 * Purpose : abort the currently established nexus. Should only be
1731 * called from a routine which can drop into a
1732 *
1733 * Returns : 0 on success, -1 on failure.
1734 *
1735 * Locks: queue lock held by caller
1736 * FIXME: sort this out and get new_eh running
1737 */
1738
1739static int do_abort(struct Scsi_Host *host) {
1740 NCR5380_local_declare();
1741 unsigned char *msgptr, phase, tmp;
1742 int len;
1743 int rc;
1744 NCR5380_setup(host);
1745
1746
1747 /* Request message out phase */
1748 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1749
1750 /*
1751 * Wait for the target to indicate a valid phase by asserting
1752 * REQ. Once this happens, we'll have either a MSGOUT phase
1753 * and can immediately send the ABORT message, or we'll have some
1754 * other phase and will have to source/sink data.
1755 *
1756 * We really don't care what value was on the bus or what value
1757 * the target sees, so we just handshake.
1758 */
1759
1760 rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1761
1762 if(rc < 0)
1763 return -1;
1764
1765 tmp = (unsigned char)rc;
1766
1767 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1768
1769 if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1770 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1771 rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1772 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1773 if(rc == -1)
1774 return -1;
1775 }
1776 tmp = ABORT;
1777 msgptr = &tmp;
1778 len = 1;
1779 phase = PHASE_MSGOUT;
1780 NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1781
1782 /*
1783 * If we got here, and the command completed successfully,
1784 * we're about to go into bus free state.
1785 */
1786
1787 return len ? -1 : 0;
1788}
1789
1790#if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1791/*
1792 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1793 * unsigned char *phase, int *count, unsigned char **data)
1794 *
1795 * Purpose : transfers data in given phase using either real
1796 * or pseudo DMA.
1797 *
1798 * Inputs : instance - instance of driver, *phase - pointer to
1799 * what phase is expected, *count - pointer to number of
1800 * bytes to transfer, **data - pointer to data pointer.
1801 *
1802 * Returns : -1 when different phase is entered without transferring
1803 * maximum number of bytes, 0 if all bytes or transferred or exit
1804 * is in same phase.
1805 *
1806 * Also, *phase, *count, *data are modified in place.
1807 *
1808 * Locks: io_request lock held by caller
1809 */
1810
1811
1812static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1813 NCR5380_local_declare();
1814 register int c = *count;
1815 register unsigned char p = *phase;
1816 register unsigned char *d = *data;
1817 unsigned char tmp;
1818 int foo;
1819#if defined(REAL_DMA_POLL)
1820 int cnt, toPIO;
1821 unsigned char saved_data = 0, overrun = 0, residue;
1822#endif
1823
1824 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1825
1826 NCR5380_setup(instance);
1827
1828 if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1829 *phase = tmp;
1830 return -1;
1831 }
1832#if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1833#ifdef READ_OVERRUNS
1834 if (p & SR_IO) {
1835 c -= 2;
1836 }
1837#endif
1838 dprintk(NDEBUG_DMA, ("scsi%d : initializing DMA channel %d for %s, %d bytes %s %0x\n", instance->host_no, instance->dma_channel, (p & SR_IO) ? "reading" : "writing", c, (p & SR_IO) ? "to" : "from", (unsigned) d));
1839 hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1840#endif
1841
1842 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1843
1844#ifdef REAL_DMA
1845 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1846#elif defined(REAL_DMA_POLL)
1847 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1848#else
1849 /*
1850 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1851 * were not disabled for the duration of a single DMA transfer, from
1852 * before the setting of DMA mode to after transfer of the last byte.
1853 */
1854
1855#if defined(PSEUDO_DMA) && defined(UNSAFE)
1856 spin_unlock_irq(instance->host_lock);
1857#endif
1858 /* KLL May need eop and parity in 53c400 */
1859 if (hostdata->flags & FLAG_NCR53C400)
1860 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE |
1861 MR_ENABLE_PAR_CHECK | MR_ENABLE_PAR_INTR |
1862 MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1863 else
1864 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1865#endif /* def REAL_DMA */
1866
1867 dprintk(NDEBUG_DMA, ("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)));
1868
1869 /*
1870 * On the PAS16 at least I/O recovery delays are not needed here.
1871 * Everyone else seems to want them.
1872 */
1873
1874 if (p & SR_IO) {
1875 io_recovery_delay(1);
1876 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1877 } else {
1878 io_recovery_delay(1);
1879 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1880 io_recovery_delay(1);
1881 NCR5380_write(START_DMA_SEND_REG, 0);
1882 io_recovery_delay(1);
1883 }
1884
1885#if defined(REAL_DMA_POLL)
1886 do {
1887 tmp = NCR5380_read(BUS_AND_STATUS_REG);
1888 } while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1889
1890/*
1891 At this point, either we've completed DMA, or we have a phase mismatch,
1892 or we've unexpectedly lost BUSY (which is a real error).
1893
1894 For write DMAs, we want to wait until the last byte has been
1895 transferred out over the bus before we turn off DMA mode. Alas, there
1896 seems to be no terribly good way of doing this on a 5380 under all
1897 conditions. For non-scatter-gather operations, we can wait until REQ
1898 and ACK both go false, or until a phase mismatch occurs. Gather-writes
1899 are nastier, since the device will be expecting more data than we
1900 are prepared to send it, and REQ will remain asserted. On a 53C8[01] we
1901 could test LAST BIT SENT to assure transfer (I imagine this is precisely
1902 why this signal was added to the newer chips) but on the older 538[01]
1903 this signal does not exist. The workaround for this lack is a watchdog;
1904 we bail out of the wait-loop after a modest amount of wait-time if
1905 the usual exit conditions are not met. Not a terribly clean or
1906 correct solution :-%
1907
1908 Reads are equally tricky due to a nasty characteristic of the NCR5380.
1909 If the chip is in DMA mode for an READ, it will respond to a target's
1910 REQ by latching the SCSI data into the INPUT DATA register and asserting
1911 ACK, even if it has _already_ been notified by the DMA controller that
1912 the current DMA transfer has completed! If the NCR5380 is then taken
1913 out of DMA mode, this already-acknowledged byte is lost.
1914
1915 This is not a problem for "one DMA transfer per command" reads, because
1916 the situation will never arise... either all of the data is DMA'ed
1917 properly, or the target switches to MESSAGE IN phase to signal a
1918 disconnection (either operation bringing the DMA to a clean halt).
1919 However, in order to handle scatter-reads, we must work around the
1920 problem. The chosen fix is to DMA N-2 bytes, then check for the
1921 condition before taking the NCR5380 out of DMA mode. One or two extra
1922 bytes are transferred via PIO as necessary to fill out the original
1923 request.
1924 */
1925
1926 if (p & SR_IO) {
1927#ifdef READ_OVERRUNS
1928 udelay(10);
1929 if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1930 saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1931 overrun = 1;
1932 }
1933#endif
1934 } else {
1935 int limit = 100;
1936 while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1937 if (!(tmp & BASR_PHASE_MATCH))
1938 break;
1939 if (--limit < 0)
1940 break;
1941 }
1942 }
1943
1944 dprintk(NDEBUG_DMA, ("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG)));
1945
1946 NCR5380_write(MODE_REG, MR_BASE);
1947 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1948
1949 residue = NCR5380_dma_residual(instance);
1950 c -= residue;
1951 *count -= c;
1952 *data += c;
1953 *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1954
1955#ifdef READ_OVERRUNS
1956 if (*phase == p && (p & SR_IO) && residue == 0) {
1957 if (overrun) {
1958 dprintk(NDEBUG_DMA, ("Got an input overrun, using saved byte\n"));
1959 **data = saved_data;
1960 *data += 1;
1961 *count -= 1;
1962 cnt = toPIO = 1;
1963 } else {
1964 printk("No overrun??\n");
1965 cnt = toPIO = 2;
1966 }
1967 dprintk(NDEBUG_DMA, ("Doing %d-byte PIO to 0x%X\n", cnt, *data));
1968 NCR5380_transfer_pio(instance, phase, &cnt, data);
1969 *count -= toPIO - cnt;
1970 }
1971#endif
1972
1973 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)));
1974 return 0;
1975
1976#elif defined(REAL_DMA)
1977 return 0;
1978#else /* defined(REAL_DMA_POLL) */
1979 if (p & SR_IO) {
1980#ifdef DMA_WORKS_RIGHT
1981 foo = NCR5380_pread(instance, d, c);
1982#else
1983 int diff = 1;
1984 if (hostdata->flags & FLAG_NCR53C400) {
1985 diff = 0;
1986 }
1987 if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1988 /*
1989 * We can't disable DMA mode after successfully transferring
1990 * what we plan to be the last byte, since that would open up
1991 * a race condition where if the target asserted REQ before
1992 * we got the DMA mode reset, the NCR5380 would have latched
1993 * an additional byte into the INPUT DATA register and we'd
1994 * have dropped it.
1995 *
1996 * The workaround was to transfer one fewer bytes than we
1997 * intended to with the pseudo-DMA read function, wait for
1998 * the chip to latch the last byte, read it, and then disable
1999 * pseudo-DMA mode.
2000 *
2001 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
2002 * REQ is deasserted when ACK is asserted, and not reasserted
2003 * until ACK goes false. Since the NCR5380 won't lower ACK
2004 * until DACK is asserted, which won't happen unless we twiddle
2005 * the DMA port or we take the NCR5380 out of DMA mode, we
2006 * can guarantee that we won't handshake another extra
2007 * byte.
2008 */
2009
2010 if (!(hostdata->flags & FLAG_NCR53C400)) {
2011 while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
2012 /* Wait for clean handshake */
2013 while (NCR5380_read(STATUS_REG) & SR_REQ);
2014 d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2015 }
2016 }
2017#endif
2018 } else {
2019#ifdef DMA_WORKS_RIGHT
2020 foo = NCR5380_pwrite(instance, d, c);
2021#else
2022 int timeout;
2023 dprintk(NDEBUG_C400_PWRITE, ("About to pwrite %d bytes\n", c));
2024 if (!(foo = NCR5380_pwrite(instance, d, c))) {
2025 /*
2026 * Wait for the last byte to be sent. If REQ is being asserted for
2027 * the byte we're interested, we'll ACK it and it will go false.
2028 */
2029 if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2030 timeout = 20000;
2031 while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2032
2033 if (!timeout)
2034 dprintk(NDEBUG_LAST_BYTE_SENT, ("scsi%d : timed out on last byte\n", instance->host_no));
2035
2036 if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2037 hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2038 if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2039 hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2040 dprintk(NDEBUG_LAST_WRITE_SENT, ("scsi%d : last bit sent works\n", instance->host_no));
2041 }
2042 }
2043 } else {
2044 dprintk(NDEBUG_C400_PWRITE, ("Waiting for LASTBYTE\n"));
2045 while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2046 dprintk(NDEBUG_C400_PWRITE, ("Got LASTBYTE\n"));
2047 }
2048 }
2049#endif
2050 }
2051 NCR5380_write(MODE_REG, MR_BASE);
2052 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2053
2054 if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2055 dprintk(NDEBUG_C400_PWRITE, ("53C400w: Checking for IRQ\n"));
2056 if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2057 dprintk(NDEBUG_C400_PWRITE, ("53C400w: got it, reading reset interrupt reg\n"));
2058 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2059 } else {
2060 printk("53C400w: IRQ NOT THERE!\n");
2061 }
2062 }
2063 *data = d + c;
2064 *count = 0;
2065 *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2066#if defined(PSEUDO_DMA) && defined(UNSAFE)
2067 spin_lock_irq(instance->host_lock);
2068#endif /* defined(REAL_DMA_POLL) */
2069 return foo;
2070#endif /* def REAL_DMA */
2071}
2072#endif /* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2073
2074/*
2075 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2076 *
2077 * Purpose : run through the various SCSI phases and do as the target
2078 * directs us to. Operates on the currently connected command,
2079 * instance->connected.
2080 *
2081 * Inputs : instance, instance for which we are doing commands
2082 *
2083 * Side effects : SCSI things happen, the disconnected queue will be
2084 * modified if a command disconnects, *instance->connected will
2085 * change.
2086 *
2087 * XXX Note : we need to watch for bus free or a reset condition here
2088 * to recover from an unexpected bus free condition.
2089 *
2090 * Locks: io_request_lock held by caller in IRQ mode
2091 */
2092
2093static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2094 NCR5380_local_declare();
2095 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2096 unsigned char msgout = NOP;
2097 int sink = 0;
2098 int len;
2099#if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2100 int transfersize;
2101#endif
2102 unsigned char *data;
2103 unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2104 Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2105 /* RvC: we need to set the end of the polling time */
2106 unsigned long poll_time = jiffies + USLEEP_POLL;
2107
2108 NCR5380_setup(instance);
2109
2110 while (1) {
2111 tmp = NCR5380_read(STATUS_REG);
2112 /* We only have a valid SCSI phase when REQ is asserted */
2113 if (tmp & SR_REQ) {
2114 phase = (tmp & PHASE_MASK);
2115 if (phase != old_phase) {
2116 old_phase = phase;
2117 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2118 }
2119 if (sink && (phase != PHASE_MSGOUT)) {
2120 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2121
2122 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2123 while (NCR5380_read(STATUS_REG) & SR_REQ);
2124 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2125 sink = 0;
2126 continue;
2127 }
2128 switch (phase) {
2129 case PHASE_DATAIN:
2130 case PHASE_DATAOUT:
2131#if (NDEBUG & NDEBUG_NO_DATAOUT)
2132 printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2133 sink = 1;
2134 do_abort(instance);
2135 cmd->result = DID_ERROR << 16;
2136 cmd->scsi_done(cmd);
2137 return;
2138#endif
2139 /*
2140 * If there is no room left in the current buffer in the
2141 * scatter-gather list, move onto the next one.
2142 */
2143
2144 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2145 ++cmd->SCp.buffer;
2146 --cmd->SCp.buffers_residual;
2147 cmd->SCp.this_residual = cmd->SCp.buffer->length;
2148 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2149 dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
2150 }
2151 /*
2152 * The preferred transfer method is going to be
2153 * PSEUDO-DMA for systems that are strictly PIO,
2154 * since we can let the hardware do the handshaking.
2155 *
2156 * For this to work, we need to know the transfersize
2157 * ahead of time, since the pseudo-DMA code will sit
2158 * in an unconditional loop.
2159 */
2160
2161#if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2162 /* KLL
2163 * PSEUDO_DMA is defined here. If this is the g_NCR5380
2164 * driver then it will always be defined, so the
2165 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2166 * NCR5380 case. I think this is a fairly clean solution.
2167 * We supplement these 2 if's with the flag.
2168 */
2169#ifdef NCR5380_dma_xfer_len
2170 if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2171#else
2172 transfersize = cmd->transfersize;
2173
2174#ifdef LIMIT_TRANSFERSIZE /* If we have problems with interrupt service */
2175 if (transfersize > 512)
2176 transfersize = 512;
2177#endif /* LIMIT_TRANSFERSIZE */
2178
2179 if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2180 /* Limit transfers to 32K, for xx400 & xx406
2181 * pseudoDMA that transfers in 128 bytes blocks. */
2182 if (transfersize > 32 * 1024)
2183 transfersize = 32 * 1024;
2184#endif
2185 len = transfersize;
2186 if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2187 /*
2188 * If the watchdog timer fires, all future accesses to this
2189 * device will use the polled-IO.
2190 */
2191 scmd_printk(KERN_INFO, cmd,
2192 "switching to slow handshake\n");
2193 cmd->device->borken = 1;
2194 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2195 sink = 1;
2196 do_abort(instance);
2197 cmd->result = DID_ERROR << 16;
2198 cmd->scsi_done(cmd);
2199 /* XXX - need to source or sink data here, as appropriate */
2200 } else
2201 cmd->SCp.this_residual -= transfersize - len;
2202 } else
2203#endif /* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2204 NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2205 &cmd->SCp.ptr);
2206 break;
2207 case PHASE_MSGIN:
2208 len = 1;
2209 data = &tmp;
2210 NCR5380_transfer_pio(instance, &phase, &len, &data);
2211 cmd->SCp.Message = tmp;
2212
2213 switch (tmp) {
2214 /*
2215 * Linking lets us reduce the time required to get the
2216 * next command out to the device, hopefully this will
2217 * mean we don't waste another revolution due to the delays
2218 * required by ARBITRATION and another SELECTION.
2219 *
2220 * In the current implementation proposal, low level drivers
2221 * merely have to start the next command, pointed to by
2222 * next_link, done() is called as with unlinked commands.
2223 */
2224#ifdef LINKED
2225 case LINKED_CMD_COMPLETE:
2226 case LINKED_FLG_CMD_COMPLETE:
2227 /* Accept message by clearing ACK */
2228 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2229 dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun));
2230 /*
2231 * Sanity check : A linked command should only terminate with
2232 * one of these messages if there are more linked commands
2233 * available.
2234 */
2235 if (!cmd->next_link) {
2236 printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2237 sink = 1;
2238 do_abort(instance);
2239 return;
2240 }
2241 initialize_SCp(cmd->next_link);
2242 /* The next command is still part of this process */
2243 cmd->next_link->tag = cmd->tag;
2244 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2245 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));
2246 collect_stats(hostdata, cmd);
2247 cmd->scsi_done(cmd);
2248 cmd = hostdata->connected;
2249 break;
2250#endif /* def LINKED */
2251 case ABORT:
2252 case COMMAND_COMPLETE:
2253 /* Accept message by clearing ACK */
2254 sink = 1;
2255 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2256 hostdata->connected = NULL;
2257 dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun));
2258 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2259
2260 /*
2261 * I'm not sure what the correct thing to do here is :
2262 *
2263 * If the command that just executed is NOT a request
2264 * sense, the obvious thing to do is to set the result
2265 * code to the values of the stored parameters.
2266 *
2267 * If it was a REQUEST SENSE command, we need some way
2268 * to differentiate between the failure code of the original
2269 * and the failure code of the REQUEST sense - the obvious
2270 * case is success, where we fall through and leave the result
2271 * code unchanged.
2272 *
2273 * The non-obvious place is where the REQUEST SENSE failed
2274 */
2275
2276 if (cmd->cmnd[0] != REQUEST_SENSE)
2277 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2278 else if (status_byte(cmd->SCp.Status) != GOOD)
2279 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2280
2281#ifdef AUTOSENSE
2282 if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2283 hostdata->ses.cmd_len) {
2284 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2285 hostdata->ses.cmd_len = 0 ;
2286 }
2287
2288 if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2289 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2290
2291 dprintk(NDEBUG_AUTOSENSE, ("scsi%d : performing request sense\n", instance->host_no));
2292
2293 LIST(cmd, hostdata->issue_queue);
2294 cmd->host_scribble = (unsigned char *)
2295 hostdata->issue_queue;
2296 hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2297 dprintk(NDEBUG_QUEUES, ("scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no));
2298 } else
2299#endif /* def AUTOSENSE */
2300 {
2301 collect_stats(hostdata, cmd);
2302 cmd->scsi_done(cmd);
2303 }
2304
2305 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2306 /*
2307 * Restore phase bits to 0 so an interrupted selection,
2308 * arbitration can resume.
2309 */
2310 NCR5380_write(TARGET_COMMAND_REG, 0);
2311
2312 while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2313 barrier();
2314 return;
2315 case MESSAGE_REJECT:
2316 /* Accept message by clearing ACK */
2317 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2318 switch (hostdata->last_message) {
2319 case HEAD_OF_QUEUE_TAG:
2320 case ORDERED_QUEUE_TAG:
2321 case SIMPLE_QUEUE_TAG:
2322 cmd->device->simple_tags = 0;
2323 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2324 break;
2325 default:
2326 break;
2327 }
2328 case DISCONNECT:{
2329 /* Accept message by clearing ACK */
2330 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2331 cmd->device->disconnect = 1;
2332 LIST(cmd, hostdata->disconnected_queue);
2333 cmd->host_scribble = (unsigned char *)
2334 hostdata->disconnected_queue;
2335 hostdata->connected = NULL;
2336 hostdata->disconnected_queue = cmd;
2337 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));
2338 /*
2339 * Restore phase bits to 0 so an interrupted selection,
2340 * arbitration can resume.
2341 */
2342 NCR5380_write(TARGET_COMMAND_REG, 0);
2343
2344 /* Enable reselect interrupts */
2345 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2346 /* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2347 /* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2348 while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2349 barrier();
2350 return;
2351 }
2352 /*
2353 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2354 * operation, in violation of the SCSI spec so we can safely
2355 * ignore SAVE/RESTORE pointers calls.
2356 *
2357 * Unfortunately, some disks violate the SCSI spec and
2358 * don't issue the required SAVE_POINTERS message before
2359 * disconnecting, and we have to break spec to remain
2360 * compatible.
2361 */
2362 case SAVE_POINTERS:
2363 case RESTORE_POINTERS:
2364 /* Accept message by clearing ACK */
2365 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2366 break;
2367 case EXTENDED_MESSAGE:
2368/*
2369 * Extended messages are sent in the following format :
2370 * Byte
2371 * 0 EXTENDED_MESSAGE == 1
2372 * 1 length (includes one byte for code, doesn't
2373 * include first two bytes)
2374 * 2 code
2375 * 3..length+1 arguments
2376 *
2377 * Start the extended message buffer with the EXTENDED_MESSAGE
2378 * byte, since spi_print_msg() wants the whole thing.
2379 */
2380 extended_msg[0] = EXTENDED_MESSAGE;
2381 /* Accept first byte by clearing ACK */
2382 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2383 dprintk(NDEBUG_EXTENDED, ("scsi%d : receiving extended message\n", instance->host_no));
2384
2385 len = 2;
2386 data = extended_msg + 1;
2387 phase = PHASE_MSGIN;
2388 NCR5380_transfer_pio(instance, &phase, &len, &data);
2389
2390 dprintk(NDEBUG_EXTENDED, ("scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]));
2391
2392 if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2393 /* Accept third byte by clearing ACK */
2394 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2395 len = extended_msg[1] - 1;
2396 data = extended_msg + 3;
2397 phase = PHASE_MSGIN;
2398
2399 NCR5380_transfer_pio(instance, &phase, &len, &data);
2400 dprintk(NDEBUG_EXTENDED, ("scsi%d : message received, residual %d\n", instance->host_no, len));
2401
2402 switch (extended_msg[2]) {
2403 case EXTENDED_SDTR:
2404 case EXTENDED_WDTR:
2405 case EXTENDED_MODIFY_DATA_POINTER:
2406 case EXTENDED_EXTENDED_IDENTIFY:
2407 tmp = 0;
2408 }
2409 } else if (len) {
2410 printk("scsi%d: error receiving extended message\n", instance->host_no);
2411 tmp = 0;
2412 } else {
2413 printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2414 tmp = 0;
2415 }
2416 /* Fall through to reject message */
2417
2418 /*
2419 * If we get something weird that we aren't expecting,
2420 * reject it.
2421 */
2422 default:
2423 if (!tmp) {
2424 printk("scsi%d: rejecting message ", instance->host_no);
2425 spi_print_msg(extended_msg);
2426 printk("\n");
2427 } else if (tmp != EXTENDED_MESSAGE)
2428 scmd_printk(KERN_INFO, cmd,
2429 "rejecting unknown message %02x\n",tmp);
2430 else
2431 scmd_printk(KERN_INFO, cmd,
2432 "rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2433
2434 msgout = MESSAGE_REJECT;
2435 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2436 break;
2437 } /* switch (tmp) */
2438 break;
2439 case PHASE_MSGOUT:
2440 len = 1;
2441 data = &msgout;
2442 hostdata->last_message = msgout;
2443 NCR5380_transfer_pio(instance, &phase, &len, &data);
2444 if (msgout == ABORT) {
2445 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2446 hostdata->connected = NULL;
2447 cmd->result = DID_ERROR << 16;
2448 collect_stats(hostdata, cmd);
2449 cmd->scsi_done(cmd);
2450 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2451 return;
2452 }
2453 msgout = NOP;
2454 break;
2455 case PHASE_CMDOUT:
2456 len = cmd->cmd_len;
2457 data = cmd->cmnd;
2458 /*
2459 * XXX for performance reasons, on machines with a
2460 * PSEUDO-DMA architecture we should probably
2461 * use the dma transfer function.
2462 */
2463 NCR5380_transfer_pio(instance, &phase, &len, &data);
2464 if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2465 NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2466 dprintk(NDEBUG_USLEEP, ("scsi%d : issued command, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2467 return;
2468 }
2469 break;
2470 case PHASE_STATIN:
2471 len = 1;
2472 data = &tmp;
2473 NCR5380_transfer_pio(instance, &phase, &len, &data);
2474 cmd->SCp.Status = tmp;
2475 break;
2476 default:
2477 printk("scsi%d : unknown phase\n", instance->host_no);
2478 NCR5380_dprint(NDEBUG_ALL, instance);
2479 } /* switch(phase) */
2480 } /* if (tmp * SR_REQ) */
2481 else {
2482 /* RvC: go to sleep if polling time expired
2483 */
2484 if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2485 NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2486 dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2487 return;
2488 }
2489 }
2490 } /* while (1) */
2491}
2492
2493/*
2494 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2495 *
2496 * Purpose : does reselection, initializing the instance->connected
2497 * field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2498 * nexus has been reestablished,
2499 *
2500 * Inputs : instance - this instance of the NCR5380.
2501 *
2502 * Locks: io_request_lock held by caller if IRQ driven
2503 */
2504
2505static void NCR5380_reselect(struct Scsi_Host *instance) {
2506 NCR5380_local_declare();
2507 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2508 instance->hostdata;
2509 unsigned char target_mask;
2510 unsigned char lun, phase;
2511 int len;
2512 unsigned char msg[3];
2513 unsigned char *data;
2514 Scsi_Cmnd *tmp = NULL, *prev;
2515 int abort = 0;
2516 NCR5380_setup(instance);
2517
2518 /*
2519 * Disable arbitration, etc. since the host adapter obviously
2520 * lost, and tell an interrupted NCR5380_select() to restart.
2521 */
2522
2523 NCR5380_write(MODE_REG, MR_BASE);
2524 hostdata->restart_select = 1;
2525
2526 target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2527 dprintk(NDEBUG_SELECTION, ("scsi%d : reselect\n", instance->host_no));
2528
2529 /*
2530 * At this point, we have detected that our SCSI ID is on the bus,
2531 * SEL is true and BSY was false for at least one bus settle delay
2532 * (400 ns).
2533 *
2534 * We must assert BSY ourselves, until the target drops the SEL
2535 * signal.
2536 */
2537
2538 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2539
2540 /* FIXME: timeout too long, must fail to workqueue */
2541 if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2542 abort = 1;
2543
2544 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2545
2546 /*
2547 * Wait for target to go into MSGIN.
2548 * FIXME: timeout needed and fail to work queeu
2549 */
2550
2551 if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2552 abort = 1;
2553
2554 len = 1;
2555 data = msg;
2556 phase = PHASE_MSGIN;
2557 NCR5380_transfer_pio(instance, &phase, &len, &data);
2558
2559 if (!(msg[0] & 0x80)) {
2560 printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2561 spi_print_msg(msg);
2562 abort = 1;
2563 } else {
2564 /* Accept message by clearing ACK */
2565 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2566 lun = (msg[0] & 0x07);
2567
2568 /*
2569 * We need to add code for SCSI-II to track which devices have
2570 * I_T_L_Q nexuses established, and which have simple I_T_L
2571 * nexuses so we can chose to do additional data transfer.
2572 */
2573
2574 /*
2575 * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
2576 * just reestablished, and remove it from the disconnected queue.
2577 */
2578
2579
2580 for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2581 if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2582 ) {
2583 if (prev) {
2584 REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2585 prev->host_scribble = tmp->host_scribble;
2586 } else {
2587 REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2588 hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2589 }
2590 tmp->host_scribble = NULL;
2591 break;
2592 }
2593 if (!tmp) {
2594 printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2595 /*
2596 * Since we have an established nexus that we can't do anything with,
2597 * we must abort it.
2598 */
2599 abort = 1;
2600 }
2601 }
2602
2603 if (abort) {
2604 do_abort(instance);
2605 } else {
2606 hostdata->connected = tmp;
2607 dprintk(NDEBUG_RESELECTION, ("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->target, tmp->lun, tmp->tag));
2608 }
2609}
2610
2611/*
2612 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2613 *
2614 * Purpose : called by interrupt handler when DMA finishes or a phase
2615 * mismatch occurs (which would finish the DMA transfer).
2616 *
2617 * Inputs : instance - this instance of the NCR5380.
2618 *
2619 * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2620 * nexus has been reestablished, on failure NULL is returned.
2621 */
2622
2623#ifdef REAL_DMA
2624static void NCR5380_dma_complete(NCR5380_instance * instance) {
2625 NCR5380_local_declare();
2626 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2627 int transferred;
2628 NCR5380_setup(instance);
2629
2630 /*
2631 * XXX this might not be right.
2632 *
2633 * Wait for final byte to transfer, ie wait for ACK to go false.
2634 *
2635 * We should use the Last Byte Sent bit, unfortunately this is
2636 * not available on the 5380/5381 (only the various CMOS chips)
2637 *
2638 * FIXME: timeout, and need to handle long timeout/irq case
2639 */
2640
2641 NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2642
2643 NCR5380_write(MODE_REG, MR_BASE);
2644 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2645
2646 /*
2647 * The only places we should see a phase mismatch and have to send
2648 * data from the same set of pointers will be the data transfer
2649 * phases. So, residual, requested length are only important here.
2650 */
2651
2652 if (!(hostdata->connected->SCp.phase & SR_CD)) {
2653 transferred = instance->dmalen - NCR5380_dma_residual();
2654 hostdata->connected->SCp.this_residual -= transferred;
2655 hostdata->connected->SCp.ptr += transferred;
2656 }
2657}
2658#endif /* def REAL_DMA */
2659
2660/*
2661 * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2662 *
2663 * Purpose : abort a command
2664 *
2665 * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2666 * host byte of the result field to, if zero DID_ABORTED is
2667 * used.
2668 *
2669 * Returns : 0 - success, -1 on failure.
2670 *
2671 * XXX - there is no way to abort the command that is currently
2672 * connected, you have to wait for it to complete. If this is
2673 * a problem, we could implement longjmp() / setjmp(), setjmp()
2674 * called where the loop started in NCR5380_main().
2675 *
2676 * Locks: host lock taken by caller
2677 */
2678
2679static int NCR5380_abort(Scsi_Cmnd * cmd) {
2680 NCR5380_local_declare();
2681 struct Scsi_Host *instance = cmd->device->host;
2682 struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2683 Scsi_Cmnd *tmp, **prev;
2684
2685 printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2686 scsi_print_command(cmd);
2687
2688 NCR5380_print_status(instance);
2689
2690 NCR5380_setup(instance);
2691
2692 dprintk(NDEBUG_ABORT, ("scsi%d : abort called\n", instance->host_no));
2693 dprintk(NDEBUG_ABORT, (" basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)));
2694
2695#if 0
2696/*
2697 * Case 1 : If the command is the currently executing command,
2698 * we'll set the aborted flag and return control so that
2699 * information transfer routine can exit cleanly.
2700 */
2701
2702 if (hostdata->connected == cmd) {
2703 dprintk(NDEBUG_ABORT, ("scsi%d : aborting connected command\n", instance->host_no));
2704 hostdata->aborted = 1;
2705/*
2706 * We should perform BSY checking, and make sure we haven't slipped
2707 * into BUS FREE.
2708 */
2709
2710 NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2711/*
2712 * Since we can't change phases until we've completed the current
2713 * handshake, we have to source or sink a byte of data if the current
2714 * phase is not MSGOUT.
2715 */
2716
2717/*
2718 * Return control to the executing NCR drive so we can clear the
2719 * aborted flag and get back into our main loop.
2720 */
2721
2722 return 0;
2723 }
2724#endif
2725
2726/*
2727 * Case 2 : If the command hasn't been issued yet, we simply remove it
2728 * from the issue queue.
2729 */
2730
2731 dprintk(NDEBUG_ABORT, ("scsi%d : abort going into loop.\n", instance->host_no));
2732 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)
2733 if (cmd == tmp) {
2734 REMOVE(5, *prev, tmp, tmp->host_scribble);
2735 (*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2736 tmp->host_scribble = NULL;
2737 tmp->result = DID_ABORT << 16;
2738 dprintk(NDEBUG_ABORT, ("scsi%d : abort removed command from issue queue.\n", instance->host_no));
2739 tmp->scsi_done(tmp);
2740 return SUCCESS;
2741 }
2742#if (NDEBUG & NDEBUG_ABORT)
2743 /* KLL */
2744 else if (prev == tmp)
2745 printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2746#endif
2747
2748/*
2749 * Case 3 : If any commands are connected, we're going to fail the abort
2750 * and let the high level SCSI driver retry at a later time or
2751 * issue a reset.
2752 *
2753 * Timeouts, and therefore aborted commands, will be highly unlikely
2754 * and handling them cleanly in this situation would make the common
2755 * case of noresets less efficient, and would pollute our code. So,
2756 * we fail.
2757 */
2758
2759 if (hostdata->connected) {
2760 dprintk(NDEBUG_ABORT, ("scsi%d : abort failed, command connected.\n", instance->host_no));
2761 return FAILED;
2762 }
2763/*
2764 * Case 4: If the command is currently disconnected from the bus, and
2765 * there are no connected commands, we reconnect the I_T_L or
2766 * I_T_L_Q nexus associated with it, go into message out, and send
2767 * an abort message.
2768 *
2769 * This case is especially ugly. In order to reestablish the nexus, we
2770 * need to call NCR5380_select(). The easiest way to implement this
2771 * function was to abort if the bus was busy, and let the interrupt
2772 * handler triggered on the SEL for reselect take care of lost arbitrations
2773 * where necessary, meaning interrupts need to be enabled.
2774 *
2775 * When interrupts are enabled, the queues may change - so we
2776 * can't remove it from the disconnected queue before selecting it
2777 * because that could cause a failure in hashing the nexus if that
2778 * device reselected.
2779 *
2780 * Since the queues may change, we can't use the pointers from when we
2781 * first locate it.
2782 *
2783 * So, we must first locate the command, and if NCR5380_select()
2784 * succeeds, then issue the abort, relocate the command and remove
2785 * it from the disconnected queue.
2786 */
2787
2788 for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2789 if (cmd == tmp) {
2790 dprintk(NDEBUG_ABORT, ("scsi%d : aborting disconnected command.\n", instance->host_no));
2791
2792 if (NCR5380_select(instance, cmd, (int) cmd->tag))
2793 return FAILED;
2794 dprintk(NDEBUG_ABORT, ("scsi%d : nexus reestablished.\n", instance->host_no));
2795
2796 do_abort(instance);
2797
2798 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)
2799 if (cmd == tmp) {
2800 REMOVE(5, *prev, tmp, tmp->host_scribble);
2801 *prev = (Scsi_Cmnd *) tmp->host_scribble;
2802 tmp->host_scribble = NULL;
2803 tmp->result = DID_ABORT << 16;
2804 tmp->scsi_done(tmp);
2805 return SUCCESS;
2806 }
2807 }
2808/*
2809 * Case 5 : If we reached this point, the command was not found in any of
2810 * the queues.
2811 *
2812 * We probably reached this point because of an unlikely race condition
2813 * between the command completing successfully and the abortion code,
2814 * so we won't panic, but we will notify the user in case something really
2815 * broke.
2816 */
2817 printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2818 " before abortion\n", instance->host_no);
2819 return FAILED;
2820}
2821
2822
2823/*
2824 * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2825 *
2826 * Purpose : reset the SCSI bus.
2827 *
2828 * Returns : SUCCESS
2829 *
2830 * Locks: host lock taken by caller
2831 */
2832
2833static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2834{
2835 struct Scsi_Host *instance = cmd->device->host;
2836
2837 NCR5380_local_declare();
2838 NCR5380_setup(instance);
2839 NCR5380_print_status(instance);
2840
2841 spin_lock_irq(instance->host_lock);
2842 do_reset(instance);
2843 spin_unlock_irq(instance->host_lock);
2844
2845 return SUCCESS;
2846}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * NCR 5380 generic driver routines. These should make it *trivial*
4 * to implement 5380 SCSI drivers under Linux with a non-trantor
5 * architecture.
6 *
7 * Note that these routines also work with NR53c400 family chips.
8 *
9 * Copyright 1993, Drew Eckhardt
10 * Visionary Computing
11 * (Unix and Linux consulting and custom programming)
12 * drew@colorado.edu
13 * +1 (303) 666-5836
14 *
15 * For more information, please consult
16 *
17 * NCR 5380 Family
18 * SCSI Protocol Controller
19 * Databook
20 *
21 * NCR Microelectronics
22 * 1635 Aeroplaza Drive
23 * Colorado Springs, CO 80916
24 * 1+ (719) 578-3400
25 * 1+ (800) 334-5454
26 */
27
28/*
29 * With contributions from Ray Van Tassle, Ingmar Baumgart,
30 * Ronald van Cuijlenborg, Alan Cox and others.
31 */
32
33/* Ported to Atari by Roman Hodek and others. */
34
35/* Adapted for the Sun 3 by Sam Creasey. */
36
37/*
38 * Design
39 *
40 * This is a generic 5380 driver. To use it on a different platform,
41 * one simply writes appropriate system specific macros (ie, data
42 * transfer - some PC's will use the I/O bus, 68K's must use
43 * memory mapped) and drops this file in their 'C' wrapper.
44 *
45 * As far as command queueing, two queues are maintained for
46 * each 5380 in the system - commands that haven't been issued yet,
47 * and commands that are currently executing. This means that an
48 * unlimited number of commands may be queued, letting
49 * more commands propagate from the higher driver levels giving higher
50 * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
51 * allowing multiple commands to propagate all the way to a SCSI-II device
52 * while a command is already executing.
53 *
54 *
55 * Issues specific to the NCR5380 :
56 *
57 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
58 * piece of hardware that requires you to sit in a loop polling for
59 * the REQ signal as long as you are connected. Some devices are
60 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
61 * while doing long seek operations. [...] These
62 * broken devices are the exception rather than the rule and I'd rather
63 * spend my time optimizing for the normal case.
64 *
65 * Architecture :
66 *
67 * At the heart of the design is a coroutine, NCR5380_main,
68 * which is started from a workqueue for each NCR5380 host in the
69 * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
70 * removing the commands from the issue queue and calling
71 * NCR5380_select() if a nexus is not established.
72 *
73 * Once a nexus is established, the NCR5380_information_transfer()
74 * phase goes through the various phases as instructed by the target.
75 * if the target goes into MSG IN and sends a DISCONNECT message,
76 * the command structure is placed into the per instance disconnected
77 * queue, and NCR5380_main tries to find more work. If the target is
78 * idle for too long, the system will try to sleep.
79 *
80 * If a command has disconnected, eventually an interrupt will trigger,
81 * calling NCR5380_intr() which will in turn call NCR5380_reselect
82 * to reestablish a nexus. This will run main if necessary.
83 *
84 * On command termination, the done function will be called as
85 * appropriate.
86 *
87 * The command data pointer is initialized after the command is connected
88 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
89 * Note that in violation of the standard, an implicit SAVE POINTERS operation
90 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
91 */
92
93/*
94 * Using this file :
95 * This file a skeleton Linux SCSI driver for the NCR 5380 series
96 * of chips. To use it, you write an architecture specific functions
97 * and macros and include this file in your driver.
98 *
99 * These macros MUST be defined :
100 *
101 * NCR5380_read(register) - read from the specified register
102 *
103 * NCR5380_write(register, value) - write to the specific register
104 *
105 * NCR5380_implementation_fields - additional fields needed for this
106 * specific implementation of the NCR5380
107 *
108 * Either real DMA *or* pseudo DMA may be implemented
109 *
110 * NCR5380_dma_xfer_len - determine size of DMA/PDMA transfer
111 * NCR5380_dma_send_setup - execute DMA/PDMA from memory to 5380
112 * NCR5380_dma_recv_setup - execute DMA/PDMA from 5380 to memory
113 * NCR5380_dma_residual - residual byte count
114 *
115 * The generic driver is initialized by calling NCR5380_init(instance),
116 * after setting the appropriate host specific fields and ID.
117 */
118
119#ifndef NCR5380_io_delay
120#define NCR5380_io_delay(x)
121#endif
122
123#ifndef NCR5380_acquire_dma_irq
124#define NCR5380_acquire_dma_irq(x) (1)
125#endif
126
127#ifndef NCR5380_release_dma_irq
128#define NCR5380_release_dma_irq(x)
129#endif
130
131static unsigned int disconnect_mask = ~0;
132module_param(disconnect_mask, int, 0444);
133
134static int do_abort(struct Scsi_Host *, unsigned int);
135static void do_reset(struct Scsi_Host *);
136static void bus_reset_cleanup(struct Scsi_Host *);
137
138/**
139 * initialize_SCp - init the scsi pointer field
140 * @cmd: command block to set up
141 *
142 * Set up the internal fields in the SCSI command.
143 */
144
145static inline void initialize_SCp(struct scsi_cmnd *cmd)
146{
147 struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(cmd);
148
149 if (scsi_bufflen(cmd)) {
150 ncmd->buffer = scsi_sglist(cmd);
151 ncmd->ptr = sg_virt(ncmd->buffer);
152 ncmd->this_residual = ncmd->buffer->length;
153 } else {
154 ncmd->buffer = NULL;
155 ncmd->ptr = NULL;
156 ncmd->this_residual = 0;
157 }
158
159 ncmd->status = 0;
160 ncmd->message = 0;
161}
162
163static inline void advance_sg_buffer(struct NCR5380_cmd *ncmd)
164{
165 struct scatterlist *s = ncmd->buffer;
166
167 if (!ncmd->this_residual && s && !sg_is_last(s)) {
168 ncmd->buffer = sg_next(s);
169 ncmd->ptr = sg_virt(ncmd->buffer);
170 ncmd->this_residual = ncmd->buffer->length;
171 }
172}
173
174static inline void set_resid_from_SCp(struct scsi_cmnd *cmd)
175{
176 struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(cmd);
177 int resid = ncmd->this_residual;
178 struct scatterlist *s = ncmd->buffer;
179
180 if (s)
181 while (!sg_is_last(s)) {
182 s = sg_next(s);
183 resid += s->length;
184 }
185 scsi_set_resid(cmd, resid);
186}
187
188/**
189 * NCR5380_poll_politely2 - wait for two chip register values
190 * @hostdata: host private data
191 * @reg1: 5380 register to poll
192 * @bit1: Bitmask to check
193 * @val1: Expected value
194 * @reg2: Second 5380 register to poll
195 * @bit2: Second bitmask to check
196 * @val2: Second expected value
197 * @wait: Time-out in jiffies, 0 if sleeping is not allowed
198 *
199 * Polls the chip in a reasonably efficient manner waiting for an
200 * event to occur. After a short quick poll we begin to yield the CPU
201 * (if possible). In irq contexts the time-out is arbitrarily limited.
202 * Callers may hold locks as long as they are held in irq mode.
203 *
204 * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
205 */
206
207static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
208 unsigned int reg1, u8 bit1, u8 val1,
209 unsigned int reg2, u8 bit2, u8 val2,
210 unsigned long wait)
211{
212 unsigned long n = hostdata->poll_loops;
213 unsigned long deadline = jiffies + wait;
214
215 do {
216 if ((NCR5380_read(reg1) & bit1) == val1)
217 return 0;
218 if ((NCR5380_read(reg2) & bit2) == val2)
219 return 0;
220 cpu_relax();
221 } while (n--);
222
223 if (!wait)
224 return -ETIMEDOUT;
225
226 /* Repeatedly sleep for 1 ms until deadline */
227 while (time_is_after_jiffies(deadline)) {
228 schedule_timeout_uninterruptible(1);
229 if ((NCR5380_read(reg1) & bit1) == val1)
230 return 0;
231 if ((NCR5380_read(reg2) & bit2) == val2)
232 return 0;
233 }
234
235 return -ETIMEDOUT;
236}
237
238#if NDEBUG
239static struct {
240 unsigned char mask;
241 const char *name;
242} signals[] = {
243 {SR_DBP, "PARITY"},
244 {SR_RST, "RST"},
245 {SR_BSY, "BSY"},
246 {SR_REQ, "REQ"},
247 {SR_MSG, "MSG"},
248 {SR_CD, "CD"},
249 {SR_IO, "IO"},
250 {SR_SEL, "SEL"},
251 {0, NULL}
252},
253basrs[] = {
254 {BASR_END_DMA_TRANSFER, "END OF DMA"},
255 {BASR_DRQ, "DRQ"},
256 {BASR_PARITY_ERROR, "PARITY ERROR"},
257 {BASR_IRQ, "IRQ"},
258 {BASR_PHASE_MATCH, "PHASE MATCH"},
259 {BASR_BUSY_ERROR, "BUSY ERROR"},
260 {BASR_ATN, "ATN"},
261 {BASR_ACK, "ACK"},
262 {0, NULL}
263},
264icrs[] = {
265 {ICR_ASSERT_RST, "ASSERT RST"},
266 {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
267 {ICR_ARBITRATION_LOST, "LOST ARB."},
268 {ICR_ASSERT_ACK, "ASSERT ACK"},
269 {ICR_ASSERT_BSY, "ASSERT BSY"},
270 {ICR_ASSERT_SEL, "ASSERT SEL"},
271 {ICR_ASSERT_ATN, "ASSERT ATN"},
272 {ICR_ASSERT_DATA, "ASSERT DATA"},
273 {0, NULL}
274},
275mrs[] = {
276 {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
277 {MR_TARGET, "TARGET"},
278 {MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
279 {MR_ENABLE_PAR_INTR, "PARITY INTR"},
280 {MR_ENABLE_EOP_INTR, "EOP INTR"},
281 {MR_MONITOR_BSY, "MONITOR BSY"},
282 {MR_DMA_MODE, "DMA MODE"},
283 {MR_ARBITRATE, "ARBITRATE"},
284 {0, NULL}
285};
286
287/**
288 * NCR5380_print - print scsi bus signals
289 * @instance: adapter state to dump
290 *
291 * Print the SCSI bus signals for debugging purposes
292 */
293
294static void NCR5380_print(struct Scsi_Host *instance)
295{
296 struct NCR5380_hostdata *hostdata = shost_priv(instance);
297 unsigned char status, basr, mr, icr, i;
298
299 status = NCR5380_read(STATUS_REG);
300 mr = NCR5380_read(MODE_REG);
301 icr = NCR5380_read(INITIATOR_COMMAND_REG);
302 basr = NCR5380_read(BUS_AND_STATUS_REG);
303
304 printk(KERN_DEBUG "SR = 0x%02x : ", status);
305 for (i = 0; signals[i].mask; ++i)
306 if (status & signals[i].mask)
307 printk(KERN_CONT "%s, ", signals[i].name);
308 printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
309 for (i = 0; basrs[i].mask; ++i)
310 if (basr & basrs[i].mask)
311 printk(KERN_CONT "%s, ", basrs[i].name);
312 printk(KERN_CONT "\nICR = 0x%02x : ", icr);
313 for (i = 0; icrs[i].mask; ++i)
314 if (icr & icrs[i].mask)
315 printk(KERN_CONT "%s, ", icrs[i].name);
316 printk(KERN_CONT "\nMR = 0x%02x : ", mr);
317 for (i = 0; mrs[i].mask; ++i)
318 if (mr & mrs[i].mask)
319 printk(KERN_CONT "%s, ", mrs[i].name);
320 printk(KERN_CONT "\n");
321}
322
323static struct {
324 unsigned char value;
325 const char *name;
326} phases[] = {
327 {PHASE_DATAOUT, "DATAOUT"},
328 {PHASE_DATAIN, "DATAIN"},
329 {PHASE_CMDOUT, "CMDOUT"},
330 {PHASE_STATIN, "STATIN"},
331 {PHASE_MSGOUT, "MSGOUT"},
332 {PHASE_MSGIN, "MSGIN"},
333 {PHASE_UNKNOWN, "UNKNOWN"}
334};
335
336/**
337 * NCR5380_print_phase - show SCSI phase
338 * @instance: adapter to dump
339 *
340 * Print the current SCSI phase for debugging purposes
341 */
342
343static void NCR5380_print_phase(struct Scsi_Host *instance)
344{
345 struct NCR5380_hostdata *hostdata = shost_priv(instance);
346 unsigned char status;
347 int i;
348
349 status = NCR5380_read(STATUS_REG);
350 if (!(status & SR_REQ))
351 shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
352 else {
353 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
354 (phases[i].value != (status & PHASE_MASK)); ++i)
355 ;
356 shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
357 }
358}
359#endif
360
361/**
362 * NCR5380_info - report driver and host information
363 * @instance: relevant scsi host instance
364 *
365 * For use as the host template info() handler.
366 */
367
368static const char *NCR5380_info(struct Scsi_Host *instance)
369{
370 struct NCR5380_hostdata *hostdata = shost_priv(instance);
371
372 return hostdata->info;
373}
374
375/**
376 * NCR5380_init - initialise an NCR5380
377 * @instance: adapter to configure
378 * @flags: control flags
379 *
380 * Initializes *instance and corresponding 5380 chip,
381 * with flags OR'd into the initial flags value.
382 *
383 * Notes : I assume that the host, hostno, and id bits have been
384 * set correctly. I don't care about the irq and other fields.
385 *
386 * Returns 0 for success
387 */
388
389static int NCR5380_init(struct Scsi_Host *instance, int flags)
390{
391 struct NCR5380_hostdata *hostdata = shost_priv(instance);
392 int i;
393 unsigned long deadline;
394 unsigned long accesses_per_ms;
395
396 instance->max_lun = 7;
397
398 hostdata->host = instance;
399 hostdata->id_mask = 1 << instance->this_id;
400 hostdata->id_higher_mask = 0;
401 for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
402 if (i > hostdata->id_mask)
403 hostdata->id_higher_mask |= i;
404 for (i = 0; i < 8; ++i)
405 hostdata->busy[i] = 0;
406 hostdata->dma_len = 0;
407
408 spin_lock_init(&hostdata->lock);
409 hostdata->connected = NULL;
410 hostdata->sensing = NULL;
411 INIT_LIST_HEAD(&hostdata->autosense);
412 INIT_LIST_HEAD(&hostdata->unissued);
413 INIT_LIST_HEAD(&hostdata->disconnected);
414
415 hostdata->flags = flags;
416
417 INIT_WORK(&hostdata->main_task, NCR5380_main);
418 hostdata->work_q = alloc_workqueue("ncr5380_%d",
419 WQ_UNBOUND | WQ_MEM_RECLAIM,
420 0, instance->host_no);
421 if (!hostdata->work_q)
422 return -ENOMEM;
423
424 snprintf(hostdata->info, sizeof(hostdata->info),
425 "%s, irq %d, io_port 0x%lx, base 0x%lx, can_queue %d, cmd_per_lun %d, sg_tablesize %d, this_id %d, flags { %s%s%s}",
426 instance->hostt->name, instance->irq, hostdata->io_port,
427 hostdata->base, instance->can_queue, instance->cmd_per_lun,
428 instance->sg_tablesize, instance->this_id,
429 hostdata->flags & FLAG_DMA_FIXUP ? "DMA_FIXUP " : "",
430 hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
431 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
432
433 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
434 NCR5380_write(MODE_REG, MR_BASE);
435 NCR5380_write(TARGET_COMMAND_REG, 0);
436 NCR5380_write(SELECT_ENABLE_REG, 0);
437
438 /* Calibrate register polling loop */
439 i = 0;
440 deadline = jiffies + 1;
441 do {
442 cpu_relax();
443 } while (time_is_after_jiffies(deadline));
444 deadline += msecs_to_jiffies(256);
445 do {
446 NCR5380_read(STATUS_REG);
447 ++i;
448 cpu_relax();
449 } while (time_is_after_jiffies(deadline));
450 accesses_per_ms = i / 256;
451 hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
452
453 return 0;
454}
455
456/**
457 * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
458 * @instance: adapter to check
459 *
460 * If the system crashed, it may have crashed with a connected target and
461 * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
462 * currently established nexus, which we know nothing about. Failing that
463 * do a bus reset.
464 *
465 * Note that a bus reset will cause the chip to assert IRQ.
466 *
467 * Returns 0 if successful, otherwise -ENXIO.
468 */
469
470static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
471{
472 struct NCR5380_hostdata *hostdata = shost_priv(instance);
473 int pass;
474
475 for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
476 switch (pass) {
477 case 1:
478 case 3:
479 case 5:
480 shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
481 NCR5380_poll_politely(hostdata,
482 STATUS_REG, SR_BSY, 0, 5 * HZ);
483 break;
484 case 2:
485 shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
486 do_abort(instance, 1);
487 break;
488 case 4:
489 shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
490 do_reset(instance);
491 /* Wait after a reset; the SCSI standard calls for
492 * 250ms, we wait 500ms to be on the safe side.
493 * But some Toshiba CD-ROMs need ten times that.
494 */
495 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
496 msleep(2500);
497 else
498 msleep(500);
499 break;
500 case 6:
501 shost_printk(KERN_ERR, instance, "bus locked solid\n");
502 return -ENXIO;
503 }
504 }
505 return 0;
506}
507
508/**
509 * NCR5380_exit - remove an NCR5380
510 * @instance: adapter to remove
511 *
512 * Assumes that no more work can be queued (e.g. by NCR5380_intr).
513 */
514
515static void NCR5380_exit(struct Scsi_Host *instance)
516{
517 struct NCR5380_hostdata *hostdata = shost_priv(instance);
518
519 cancel_work_sync(&hostdata->main_task);
520 destroy_workqueue(hostdata->work_q);
521}
522
523/**
524 * complete_cmd - finish processing a command and return it to the SCSI ML
525 * @instance: the host instance
526 * @cmd: command to complete
527 */
528
529static void complete_cmd(struct Scsi_Host *instance,
530 struct scsi_cmnd *cmd)
531{
532 struct NCR5380_hostdata *hostdata = shost_priv(instance);
533
534 dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
535
536 if (hostdata->sensing == cmd) {
537 /* Autosense processing ends here */
538 if (get_status_byte(cmd) != SAM_STAT_GOOD) {
539 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
540 } else {
541 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
542 set_status_byte(cmd, SAM_STAT_CHECK_CONDITION);
543 }
544 hostdata->sensing = NULL;
545 }
546
547 scsi_done(cmd);
548}
549
550/**
551 * NCR5380_queue_command - queue a command
552 * @instance: the relevant SCSI adapter
553 * @cmd: SCSI command
554 *
555 * cmd is added to the per-instance issue queue, with minor
556 * twiddling done to the host specific fields of cmd. If the
557 * main coroutine is not running, it is restarted.
558 */
559
560static int NCR5380_queue_command(struct Scsi_Host *instance,
561 struct scsi_cmnd *cmd)
562{
563 struct NCR5380_hostdata *hostdata = shost_priv(instance);
564 struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(cmd);
565 unsigned long flags;
566
567#if (NDEBUG & NDEBUG_NO_WRITE)
568 switch (cmd->cmnd[0]) {
569 case WRITE_6:
570 case WRITE_10:
571 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
572 cmd->result = (DID_ERROR << 16);
573 scsi_done(cmd);
574 return 0;
575 }
576#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
577
578 cmd->result = 0;
579
580 spin_lock_irqsave(&hostdata->lock, flags);
581
582 if (!NCR5380_acquire_dma_irq(instance)) {
583 spin_unlock_irqrestore(&hostdata->lock, flags);
584
585 return SCSI_MLQUEUE_HOST_BUSY;
586 }
587
588 /*
589 * Insert the cmd into the issue queue. Note that REQUEST SENSE
590 * commands are added to the head of the queue since any command will
591 * clear the contingent allegiance condition that exists and the
592 * sense data is only guaranteed to be valid while the condition exists.
593 */
594
595 if (cmd->cmnd[0] == REQUEST_SENSE)
596 list_add(&ncmd->list, &hostdata->unissued);
597 else
598 list_add_tail(&ncmd->list, &hostdata->unissued);
599
600 spin_unlock_irqrestore(&hostdata->lock, flags);
601
602 dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
603 cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
604
605 /* Kick off command processing */
606 queue_work(hostdata->work_q, &hostdata->main_task);
607 return 0;
608}
609
610static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
611{
612 struct NCR5380_hostdata *hostdata = shost_priv(instance);
613
614 /* Caller does the locking needed to set & test these data atomically */
615 if (list_empty(&hostdata->disconnected) &&
616 list_empty(&hostdata->unissued) &&
617 list_empty(&hostdata->autosense) &&
618 !hostdata->connected &&
619 !hostdata->selecting) {
620 NCR5380_release_dma_irq(instance);
621 }
622}
623
624/**
625 * dequeue_next_cmd - dequeue a command for processing
626 * @instance: the scsi host instance
627 *
628 * Priority is given to commands on the autosense queue. These commands
629 * need autosense because of a CHECK CONDITION result.
630 *
631 * Returns a command pointer if a command is found for a target that is
632 * not already busy. Otherwise returns NULL.
633 */
634
635static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
636{
637 struct NCR5380_hostdata *hostdata = shost_priv(instance);
638 struct NCR5380_cmd *ncmd;
639 struct scsi_cmnd *cmd;
640
641 if (hostdata->sensing || list_empty(&hostdata->autosense)) {
642 list_for_each_entry(ncmd, &hostdata->unissued, list) {
643 cmd = NCR5380_to_scmd(ncmd);
644 dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
645 cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
646
647 if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
648 list_del(&ncmd->list);
649 dsprintk(NDEBUG_QUEUES, instance,
650 "dequeue: removed %p from issue queue\n", cmd);
651 return cmd;
652 }
653 }
654 } else {
655 /* Autosense processing begins here */
656 ncmd = list_first_entry(&hostdata->autosense,
657 struct NCR5380_cmd, list);
658 list_del(&ncmd->list);
659 cmd = NCR5380_to_scmd(ncmd);
660 dsprintk(NDEBUG_QUEUES, instance,
661 "dequeue: removed %p from autosense queue\n", cmd);
662 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
663 hostdata->sensing = cmd;
664 return cmd;
665 }
666 return NULL;
667}
668
669static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
670{
671 struct NCR5380_hostdata *hostdata = shost_priv(instance);
672 struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(cmd);
673
674 if (hostdata->sensing == cmd) {
675 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
676 list_add(&ncmd->list, &hostdata->autosense);
677 hostdata->sensing = NULL;
678 } else
679 list_add(&ncmd->list, &hostdata->unissued);
680}
681
682/**
683 * NCR5380_main - NCR state machines
684 *
685 * NCR5380_main is a coroutine that runs as long as more work can
686 * be done on the NCR5380 host adapters in a system. Both
687 * NCR5380_queue_command() and NCR5380_intr() will try to start it
688 * in case it is not running.
689 */
690
691static void NCR5380_main(struct work_struct *work)
692{
693 struct NCR5380_hostdata *hostdata =
694 container_of(work, struct NCR5380_hostdata, main_task);
695 struct Scsi_Host *instance = hostdata->host;
696 int done;
697
698 do {
699 done = 1;
700
701 spin_lock_irq(&hostdata->lock);
702 while (!hostdata->connected && !hostdata->selecting) {
703 struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
704
705 if (!cmd)
706 break;
707
708 dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
709
710 /*
711 * Attempt to establish an I_T_L nexus here.
712 * On success, instance->hostdata->connected is set.
713 * On failure, we must add the command back to the
714 * issue queue so we can keep trying.
715 */
716 /*
717 * REQUEST SENSE commands are issued without tagged
718 * queueing, even on SCSI-II devices because the
719 * contingent allegiance condition exists for the
720 * entire unit.
721 */
722
723 if (!NCR5380_select(instance, cmd)) {
724 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
725 } else {
726 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
727 "main: select failed, returning %p to queue\n", cmd);
728 requeue_cmd(instance, cmd);
729 }
730 }
731 if (hostdata->connected && !hostdata->dma_len) {
732 dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
733 NCR5380_information_transfer(instance);
734 done = 0;
735 }
736 if (!hostdata->connected) {
737 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
738 maybe_release_dma_irq(instance);
739 }
740 spin_unlock_irq(&hostdata->lock);
741 if (!done)
742 cond_resched();
743 } while (!done);
744}
745
746/*
747 * NCR5380_dma_complete - finish DMA transfer
748 * @instance: the scsi host instance
749 *
750 * Called by the interrupt handler when DMA finishes or a phase
751 * mismatch occurs (which would end the DMA transfer).
752 */
753
754static void NCR5380_dma_complete(struct Scsi_Host *instance)
755{
756 struct NCR5380_hostdata *hostdata = shost_priv(instance);
757 struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(hostdata->connected);
758 int transferred;
759 unsigned char **data;
760 int *count;
761 int saved_data = 0, overrun = 0;
762 unsigned char p;
763
764 if (hostdata->read_overruns) {
765 p = ncmd->phase;
766 if (p & SR_IO) {
767 udelay(10);
768 if ((NCR5380_read(BUS_AND_STATUS_REG) &
769 (BASR_PHASE_MATCH | BASR_ACK)) ==
770 (BASR_PHASE_MATCH | BASR_ACK)) {
771 saved_data = NCR5380_read(INPUT_DATA_REG);
772 overrun = 1;
773 dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
774 }
775 }
776 }
777
778#ifdef CONFIG_SUN3
779 if (sun3scsi_dma_finish(hostdata->connected->sc_data_direction)) {
780 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
781 instance->host_no);
782 BUG();
783 }
784
785 if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
786 (BASR_PHASE_MATCH | BASR_ACK)) {
787 pr_err("scsi%d: BASR %02x\n", instance->host_no,
788 NCR5380_read(BUS_AND_STATUS_REG));
789 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
790 instance->host_no);
791 BUG();
792 }
793#endif
794
795 NCR5380_write(MODE_REG, MR_BASE);
796 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
797 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
798
799 transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
800 hostdata->dma_len = 0;
801
802 data = (unsigned char **)&ncmd->ptr;
803 count = &ncmd->this_residual;
804 *data += transferred;
805 *count -= transferred;
806
807 if (hostdata->read_overruns) {
808 int cnt, toPIO;
809
810 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
811 cnt = toPIO = hostdata->read_overruns;
812 if (overrun) {
813 dsprintk(NDEBUG_DMA, instance,
814 "Got an input overrun, using saved byte\n");
815 *(*data)++ = saved_data;
816 (*count)--;
817 cnt--;
818 toPIO--;
819 }
820 if (toPIO > 0) {
821 dsprintk(NDEBUG_DMA, instance,
822 "Doing %d byte PIO to 0x%p\n", cnt, *data);
823 NCR5380_transfer_pio(instance, &p, &cnt, data, 0);
824 *count -= toPIO - cnt;
825 }
826 }
827 }
828}
829
830/**
831 * NCR5380_intr - generic NCR5380 irq handler
832 * @irq: interrupt number
833 * @dev_id: device info
834 *
835 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
836 * from the disconnected queue, and restarting NCR5380_main()
837 * as required.
838 *
839 * The chip can assert IRQ in any of six different conditions. The IRQ flag
840 * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
841 * Three of these six conditions are latched in the Bus and Status Register:
842 * - End of DMA (cleared by ending DMA Mode)
843 * - Parity error (cleared by reading RPIR)
844 * - Loss of BSY (cleared by reading RPIR)
845 * Two conditions have flag bits that are not latched:
846 * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
847 * - Bus reset (non-maskable)
848 * The remaining condition has no flag bit at all:
849 * - Selection/reselection
850 *
851 * Hence, establishing the cause(s) of any interrupt is partly guesswork.
852 * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
853 * claimed that "the design of the [DP8490] interrupt logic ensures
854 * interrupts will not be lost (they can be on the DP5380)."
855 * The L5380/53C80 datasheet from LOGIC Devices has more details.
856 *
857 * Checking for bus reset by reading RST is futile because of interrupt
858 * latency, but a bus reset will reset chip logic. Checking for parity error
859 * is unnecessary because that interrupt is never enabled. A Loss of BSY
860 * condition will clear DMA Mode. We can tell when this occurs because the
861 * Busy Monitor interrupt is enabled together with DMA Mode.
862 */
863
864static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
865{
866 struct Scsi_Host *instance = dev_id;
867 struct NCR5380_hostdata *hostdata = shost_priv(instance);
868 int handled = 0;
869 unsigned char basr;
870 unsigned long flags;
871
872 spin_lock_irqsave(&hostdata->lock, flags);
873
874 basr = NCR5380_read(BUS_AND_STATUS_REG);
875 if (basr & BASR_IRQ) {
876 unsigned char mr = NCR5380_read(MODE_REG);
877 unsigned char sr = NCR5380_read(STATUS_REG);
878
879 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
880 irq, basr, sr, mr);
881
882 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
883 /* Probably End of DMA, Phase Mismatch or Loss of BSY.
884 * We ack IRQ after clearing Mode Register. Workarounds
885 * for End of DMA errata need to happen in DMA Mode.
886 */
887
888 dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
889
890 if (hostdata->connected) {
891 NCR5380_dma_complete(instance);
892 queue_work(hostdata->work_q, &hostdata->main_task);
893 } else {
894 NCR5380_write(MODE_REG, MR_BASE);
895 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
896 }
897 } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
898 (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
899 /* Probably reselected */
900 NCR5380_write(SELECT_ENABLE_REG, 0);
901 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
902
903 dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
904
905 if (!hostdata->connected) {
906 NCR5380_reselect(instance);
907 queue_work(hostdata->work_q, &hostdata->main_task);
908 }
909 if (!hostdata->connected)
910 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
911 } else {
912 /* Probably Bus Reset */
913 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
914
915 if (sr & SR_RST) {
916 /* Certainly Bus Reset */
917 shost_printk(KERN_WARNING, instance,
918 "bus reset interrupt\n");
919 bus_reset_cleanup(instance);
920 } else {
921 dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
922 }
923#ifdef SUN3_SCSI_VME
924 dregs->csr |= CSR_DMA_ENABLE;
925#endif
926 }
927 handled = 1;
928 } else {
929 dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
930#ifdef SUN3_SCSI_VME
931 dregs->csr |= CSR_DMA_ENABLE;
932#endif
933 }
934
935 spin_unlock_irqrestore(&hostdata->lock, flags);
936
937 return IRQ_RETVAL(handled);
938}
939
940/**
941 * NCR5380_select - attempt arbitration and selection for a given command
942 * @instance: the Scsi_Host instance
943 * @cmd: the scsi_cmnd to execute
944 *
945 * This routine establishes an I_T_L nexus for a SCSI command. This involves
946 * ARBITRATION, SELECTION and MESSAGE OUT phases and an IDENTIFY message.
947 *
948 * Returns true if the operation should be retried.
949 * Returns false if it should not be retried.
950 *
951 * Side effects :
952 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
953 * with registers as they should have been on entry - ie
954 * SELECT_ENABLE will be set appropriately, the NCR5380
955 * will cease to drive any SCSI bus signals.
956 *
957 * If successful : the I_T_L nexus will be established, and
958 * hostdata->connected will be set to cmd.
959 * SELECT interrupt will be disabled.
960 *
961 * If failed (no target) : scsi_done() will be called, and the
962 * cmd->result host byte set to DID_BAD_TARGET.
963 */
964
965static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
966 __releases(&hostdata->lock) __acquires(&hostdata->lock)
967{
968 struct NCR5380_hostdata *hostdata = shost_priv(instance);
969 unsigned char tmp[3], phase;
970 unsigned char *data;
971 int len;
972 int err;
973 bool ret = true;
974 bool can_disconnect = instance->irq != NO_IRQ &&
975 cmd->cmnd[0] != REQUEST_SENSE &&
976 (disconnect_mask & BIT(scmd_id(cmd)));
977
978 NCR5380_dprint(NDEBUG_ARBITRATION, instance);
979 dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
980 instance->this_id);
981
982 /*
983 * Arbitration and selection phases are slow and involve dropping the
984 * lock, so we have to watch out for EH. An exception handler may
985 * change 'selecting' to NULL. This function will then return false
986 * so that the caller will forget about 'cmd'. (During information
987 * transfer phases, EH may change 'connected' to NULL.)
988 */
989 hostdata->selecting = cmd;
990
991 /*
992 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
993 * data bus during SELECTION.
994 */
995
996 NCR5380_write(TARGET_COMMAND_REG, 0);
997
998 /*
999 * Start arbitration.
1000 */
1001
1002 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1003 NCR5380_write(MODE_REG, MR_ARBITRATE);
1004
1005 /* The chip now waits for BUS FREE phase. Then after the 800 ns
1006 * Bus Free Delay, arbitration will begin.
1007 */
1008
1009 spin_unlock_irq(&hostdata->lock);
1010 err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
1011 INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
1012 ICR_ARBITRATION_PROGRESS, HZ);
1013 spin_lock_irq(&hostdata->lock);
1014 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
1015 /* Reselection interrupt */
1016 goto out;
1017 }
1018 if (!hostdata->selecting) {
1019 /* Command was aborted */
1020 NCR5380_write(MODE_REG, MR_BASE);
1021 return false;
1022 }
1023 if (err < 0) {
1024 NCR5380_write(MODE_REG, MR_BASE);
1025 shost_printk(KERN_ERR, instance,
1026 "select: arbitration timeout\n");
1027 goto out;
1028 }
1029 spin_unlock_irq(&hostdata->lock);
1030
1031 /* The SCSI-2 arbitration delay is 2.4 us */
1032 udelay(3);
1033
1034 /* Check for lost arbitration */
1035 if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1036 (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1037 (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1038 NCR5380_write(MODE_REG, MR_BASE);
1039 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1040 spin_lock_irq(&hostdata->lock);
1041 goto out;
1042 }
1043
1044 /* After/during arbitration, BSY should be asserted.
1045 * IBM DPES-31080 Version S31Q works now
1046 * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1047 */
1048 NCR5380_write(INITIATOR_COMMAND_REG,
1049 ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1050
1051 /*
1052 * Again, bus clear + bus settle time is 1.2us, however, this is
1053 * a minimum so we'll udelay ceil(1.2)
1054 */
1055
1056 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1057 udelay(15);
1058 else
1059 udelay(2);
1060
1061 spin_lock_irq(&hostdata->lock);
1062
1063 /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1064 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1065 goto out;
1066
1067 if (!hostdata->selecting) {
1068 NCR5380_write(MODE_REG, MR_BASE);
1069 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1070 return false;
1071 }
1072
1073 dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1074
1075 /*
1076 * Now that we have won arbitration, start Selection process, asserting
1077 * the host and target ID's on the SCSI bus.
1078 */
1079
1080 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1081
1082 /*
1083 * Raise ATN while SEL is true before BSY goes false from arbitration,
1084 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1085 * phase immediately after selection.
1086 */
1087
1088 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1089 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1090 NCR5380_write(MODE_REG, MR_BASE);
1091
1092 /*
1093 * Reselect interrupts must be turned off prior to the dropping of BSY,
1094 * otherwise we will trigger an interrupt.
1095 */
1096 NCR5380_write(SELECT_ENABLE_REG, 0);
1097
1098 spin_unlock_irq(&hostdata->lock);
1099
1100 /*
1101 * The initiator shall then wait at least two deskew delays and release
1102 * the BSY signal.
1103 */
1104 udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
1105
1106 /* Reset BSY */
1107 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1108 ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1109
1110 /*
1111 * Something weird happens when we cease to drive BSY - looks
1112 * like the board/chip is letting us do another read before the
1113 * appropriate propagation delay has expired, and we're confusing
1114 * a BSY signal from ourselves as the target's response to SELECTION.
1115 *
1116 * A small delay (the 'C++' frontend breaks the pipeline with an
1117 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1118 * tighter 'C' code breaks and requires this) solves the problem -
1119 * the 1 us delay is arbitrary, and only used because this delay will
1120 * be the same on other platforms and since it works here, it should
1121 * work there.
1122 *
1123 * wingel suggests that this could be due to failing to wait
1124 * one deskew delay.
1125 */
1126
1127 udelay(1);
1128
1129 dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1130
1131 /*
1132 * The SCSI specification calls for a 250 ms timeout for the actual
1133 * selection.
1134 */
1135
1136 err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
1137 msecs_to_jiffies(250));
1138
1139 if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1140 spin_lock_irq(&hostdata->lock);
1141 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1142 NCR5380_reselect(instance);
1143 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1144 goto out;
1145 }
1146
1147 if (err < 0) {
1148 spin_lock_irq(&hostdata->lock);
1149 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1150
1151 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1152 if (!hostdata->selecting)
1153 return false;
1154
1155 cmd->result = DID_BAD_TARGET << 16;
1156 complete_cmd(instance, cmd);
1157 dsprintk(NDEBUG_SELECTION, instance,
1158 "target did not respond within 250ms\n");
1159 ret = false;
1160 goto out;
1161 }
1162
1163 /*
1164 * No less than two deskew delays after the initiator detects the
1165 * BSY signal is true, it shall release the SEL signal and may
1166 * change the DATA BUS. -wingel
1167 */
1168
1169 udelay(1);
1170
1171 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1172
1173 /*
1174 * Since we followed the SCSI spec, and raised ATN while SEL
1175 * was true but before BSY was false during selection, the information
1176 * transfer phase should be a MESSAGE OUT phase so that we can send the
1177 * IDENTIFY message.
1178 */
1179
1180 /* Wait for start of REQ/ACK handshake */
1181
1182 err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1183 spin_lock_irq(&hostdata->lock);
1184 if (err < 0) {
1185 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1186 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1187 goto out;
1188 }
1189 if (!hostdata->selecting) {
1190 do_abort(instance, 0);
1191 return false;
1192 }
1193
1194 dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1195 scmd_id(cmd));
1196 tmp[0] = IDENTIFY(can_disconnect, cmd->device->lun);
1197
1198 len = 1;
1199 data = tmp;
1200 phase = PHASE_MSGOUT;
1201 NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
1202 if (len) {
1203 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1204 cmd->result = DID_ERROR << 16;
1205 complete_cmd(instance, cmd);
1206 dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
1207 ret = false;
1208 goto out;
1209 }
1210
1211 dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1212
1213 hostdata->connected = cmd;
1214 hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1215
1216#ifdef SUN3_SCSI_VME
1217 dregs->csr |= CSR_INTR;
1218#endif
1219
1220 initialize_SCp(cmd);
1221
1222 ret = false;
1223
1224out:
1225 if (!hostdata->selecting)
1226 return false;
1227 hostdata->selecting = NULL;
1228 return ret;
1229}
1230
1231/*
1232 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1233 * unsigned char *phase, int *count, unsigned char **data)
1234 *
1235 * Purpose : transfers data in given phase using polled I/O
1236 *
1237 * Inputs : instance - instance of driver, *phase - pointer to
1238 * what phase is expected, *count - pointer to number of
1239 * bytes to transfer, **data - pointer to data pointer,
1240 * can_sleep - 1 or 0 when sleeping is permitted or not, respectively.
1241 *
1242 * Returns : -1 when different phase is entered without transferring
1243 * maximum number of bytes, 0 if all bytes are transferred or exit
1244 * is in same phase.
1245 *
1246 * Also, *phase, *count, *data are modified in place.
1247 *
1248 * XXX Note : handling for bus free may be useful.
1249 */
1250
1251/*
1252 * Note : this code is not as quick as it could be, however it
1253 * IS 100% reliable, and for the actual data transfer where speed
1254 * counts, we will always do a pseudo DMA or DMA transfer.
1255 */
1256
1257static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1258 unsigned char *phase, int *count,
1259 unsigned char **data, unsigned int can_sleep)
1260{
1261 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1262 unsigned char p = *phase, tmp;
1263 int c = *count;
1264 unsigned char *d = *data;
1265
1266 /*
1267 * The NCR5380 chip will only drive the SCSI bus when the
1268 * phase specified in the appropriate bits of the TARGET COMMAND
1269 * REGISTER match the STATUS REGISTER
1270 */
1271
1272 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1273
1274 do {
1275 /*
1276 * Wait for assertion of REQ, after which the phase bits will be
1277 * valid
1278 */
1279
1280 if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,
1281 HZ * can_sleep) < 0)
1282 break;
1283
1284 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1285
1286 /* Check for phase mismatch */
1287 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1288 dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1289 NCR5380_dprint_phase(NDEBUG_PIO, instance);
1290 break;
1291 }
1292
1293 /* Do actual transfer from SCSI bus to / from memory */
1294 if (!(p & SR_IO))
1295 NCR5380_write(OUTPUT_DATA_REG, *d);
1296 else
1297 *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1298
1299 ++d;
1300
1301 /*
1302 * The SCSI standard suggests that in MSGOUT phase, the initiator
1303 * should drop ATN on the last byte of the message phase
1304 * after REQ has been asserted for the handshake but before
1305 * the initiator raises ACK.
1306 */
1307
1308 if (!(p & SR_IO)) {
1309 if (!((p & SR_MSG) && c > 1)) {
1310 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1311 NCR5380_dprint(NDEBUG_PIO, instance);
1312 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1313 ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1314 } else {
1315 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1316 ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1317 NCR5380_dprint(NDEBUG_PIO, instance);
1318 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1319 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1320 }
1321 } else {
1322 NCR5380_dprint(NDEBUG_PIO, instance);
1323 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1324 }
1325
1326 if (NCR5380_poll_politely(hostdata,
1327 STATUS_REG, SR_REQ, 0, 5 * HZ * can_sleep) < 0)
1328 break;
1329
1330 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1331
1332/*
1333 * We have several special cases to consider during REQ/ACK handshaking :
1334 * 1. We were in MSGOUT phase, and we are on the last byte of the
1335 * message. ATN must be dropped as ACK is dropped.
1336 *
1337 * 2. We are in a MSGIN phase, and we are on the last byte of the
1338 * message. We must exit with ACK asserted, so that the calling
1339 * code may raise ATN before dropping ACK to reject the message.
1340 *
1341 * 3. ACK and ATN are clear and the target may proceed as normal.
1342 */
1343 if (!(p == PHASE_MSGIN && c == 1)) {
1344 if (p == PHASE_MSGOUT && c > 1)
1345 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1346 else
1347 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1348 }
1349 } while (--c);
1350
1351 dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1352
1353 *count = c;
1354 *data = d;
1355 tmp = NCR5380_read(STATUS_REG);
1356 /* The phase read from the bus is valid if either REQ is (already)
1357 * asserted or if ACK hasn't been released yet. The latter applies if
1358 * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1359 */
1360 if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1361 *phase = tmp & PHASE_MASK;
1362 else
1363 *phase = PHASE_UNKNOWN;
1364
1365 if (!c || (*phase == p))
1366 return 0;
1367 else
1368 return -1;
1369}
1370
1371/**
1372 * do_reset - issue a reset command
1373 * @instance: adapter to reset
1374 *
1375 * Issue a reset sequence to the NCR5380 and try and get the bus
1376 * back into sane shape.
1377 *
1378 * This clears the reset interrupt flag because there may be no handler for
1379 * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1380 * been installed. And when in EH we may have released the ST DMA interrupt.
1381 */
1382
1383static void do_reset(struct Scsi_Host *instance)
1384{
1385 struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
1386 unsigned long flags;
1387
1388 local_irq_save(flags);
1389 NCR5380_write(TARGET_COMMAND_REG,
1390 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1391 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1392 udelay(50);
1393 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1394 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1395 local_irq_restore(flags);
1396}
1397
1398/**
1399 * do_abort - abort the currently established nexus by going to
1400 * MESSAGE OUT phase and sending an ABORT message.
1401 * @instance: relevant scsi host instance
1402 * @can_sleep: 1 or 0 when sleeping is permitted or not, respectively
1403 *
1404 * Returns 0 on success, negative error code on failure.
1405 */
1406
1407static int do_abort(struct Scsi_Host *instance, unsigned int can_sleep)
1408{
1409 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1410 unsigned char *msgptr, phase, tmp;
1411 int len;
1412 int rc;
1413
1414 /* Request message out phase */
1415 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1416
1417 /*
1418 * Wait for the target to indicate a valid phase by asserting
1419 * REQ. Once this happens, we'll have either a MSGOUT phase
1420 * and can immediately send the ABORT message, or we'll have some
1421 * other phase and will have to source/sink data.
1422 *
1423 * We really don't care what value was on the bus or what value
1424 * the target sees, so we just handshake.
1425 */
1426
1427 rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,
1428 10 * HZ * can_sleep);
1429 if (rc < 0)
1430 goto out;
1431
1432 tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1433
1434 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1435
1436 if (tmp != PHASE_MSGOUT) {
1437 NCR5380_write(INITIATOR_COMMAND_REG,
1438 ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1439 rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0,
1440 3 * HZ * can_sleep);
1441 if (rc < 0)
1442 goto out;
1443 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1444 }
1445
1446 tmp = ABORT;
1447 msgptr = &tmp;
1448 len = 1;
1449 phase = PHASE_MSGOUT;
1450 NCR5380_transfer_pio(instance, &phase, &len, &msgptr, can_sleep);
1451 if (len)
1452 rc = -ENXIO;
1453
1454 /*
1455 * If we got here, and the command completed successfully,
1456 * we're about to go into bus free state.
1457 */
1458
1459out:
1460 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1461 return rc;
1462}
1463
1464/*
1465 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1466 * unsigned char *phase, int *count, unsigned char **data)
1467 *
1468 * Purpose : transfers data in given phase using either real
1469 * or pseudo DMA.
1470 *
1471 * Inputs : instance - instance of driver, *phase - pointer to
1472 * what phase is expected, *count - pointer to number of
1473 * bytes to transfer, **data - pointer to data pointer.
1474 *
1475 * Returns : -1 when different phase is entered without transferring
1476 * maximum number of bytes, 0 if all bytes or transferred or exit
1477 * is in same phase.
1478 *
1479 * Also, *phase, *count, *data are modified in place.
1480 */
1481
1482
1483static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1484 unsigned char *phase, int *count,
1485 unsigned char **data)
1486{
1487 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1488 int c = *count;
1489 unsigned char p = *phase;
1490 unsigned char *d = *data;
1491 unsigned char tmp;
1492 int result = 0;
1493
1494 if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1495 *phase = tmp;
1496 return -1;
1497 }
1498
1499 NCR5380_to_ncmd(hostdata->connected)->phase = p;
1500
1501 if (p & SR_IO) {
1502 if (hostdata->read_overruns)
1503 c -= hostdata->read_overruns;
1504 else if (hostdata->flags & FLAG_DMA_FIXUP)
1505 --c;
1506 }
1507
1508 dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1509 (p & SR_IO) ? "receive" : "send", c, d);
1510
1511#ifdef CONFIG_SUN3
1512 /* send start chain */
1513 sun3scsi_dma_start(c, *data);
1514#endif
1515
1516 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1517 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1518 MR_ENABLE_EOP_INTR);
1519
1520 if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1521 /* On the Medusa, it is a must to initialize the DMA before
1522 * starting the NCR. This is also the cleaner way for the TT.
1523 */
1524 if (p & SR_IO)
1525 result = NCR5380_dma_recv_setup(hostdata, d, c);
1526 else
1527 result = NCR5380_dma_send_setup(hostdata, d, c);
1528 }
1529
1530 /*
1531 * On the PAS16 at least I/O recovery delays are not needed here.
1532 * Everyone else seems to want them.
1533 */
1534
1535 if (p & SR_IO) {
1536 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1537 NCR5380_io_delay(1);
1538 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1539 } else {
1540 NCR5380_io_delay(1);
1541 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1542 NCR5380_io_delay(1);
1543 NCR5380_write(START_DMA_SEND_REG, 0);
1544 NCR5380_io_delay(1);
1545 }
1546
1547#ifdef CONFIG_SUN3
1548#ifdef SUN3_SCSI_VME
1549 dregs->csr |= CSR_DMA_ENABLE;
1550#endif
1551 sun3_dma_active = 1;
1552#endif
1553
1554 if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1555 /* On the Falcon, the DMA setup must be done after the last
1556 * NCR access, else the DMA setup gets trashed!
1557 */
1558 if (p & SR_IO)
1559 result = NCR5380_dma_recv_setup(hostdata, d, c);
1560 else
1561 result = NCR5380_dma_send_setup(hostdata, d, c);
1562 }
1563
1564 /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
1565 if (result < 0)
1566 return result;
1567
1568 /* For real DMA, result is the byte count. DMA interrupt is expected. */
1569 if (result > 0) {
1570 hostdata->dma_len = result;
1571 return 0;
1572 }
1573
1574 /* The result is zero iff pseudo DMA send/receive was completed. */
1575 hostdata->dma_len = c;
1576
1577/*
1578 * A note regarding the DMA errata workarounds for early NMOS silicon.
1579 *
1580 * For DMA sends, we want to wait until the last byte has been
1581 * transferred out over the bus before we turn off DMA mode. Alas, there
1582 * seems to be no terribly good way of doing this on a 5380 under all
1583 * conditions. For non-scatter-gather operations, we can wait until REQ
1584 * and ACK both go false, or until a phase mismatch occurs. Gather-sends
1585 * are nastier, since the device will be expecting more data than we
1586 * are prepared to send it, and REQ will remain asserted. On a 53C8[01] we
1587 * could test Last Byte Sent to assure transfer (I imagine this is precisely
1588 * why this signal was added to the newer chips) but on the older 538[01]
1589 * this signal does not exist. The workaround for this lack is a watchdog;
1590 * we bail out of the wait-loop after a modest amount of wait-time if
1591 * the usual exit conditions are not met. Not a terribly clean or
1592 * correct solution :-%
1593 *
1594 * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1595 * If the chip is in DMA receive mode, it will respond to a target's
1596 * REQ by latching the SCSI data into the INPUT DATA register and asserting
1597 * ACK, even if it has _already_ been notified by the DMA controller that
1598 * the current DMA transfer has completed! If the NCR5380 is then taken
1599 * out of DMA mode, this already-acknowledged byte is lost. This is
1600 * not a problem for "one DMA transfer per READ command", because
1601 * the situation will never arise... either all of the data is DMA'ed
1602 * properly, or the target switches to MESSAGE IN phase to signal a
1603 * disconnection (either operation bringing the DMA to a clean halt).
1604 * However, in order to handle scatter-receive, we must work around the
1605 * problem. The chosen fix is to DMA fewer bytes, then check for the
1606 * condition before taking the NCR5380 out of DMA mode. One or two extra
1607 * bytes are transferred via PIO as necessary to fill out the original
1608 * request.
1609 */
1610
1611 if (hostdata->flags & FLAG_DMA_FIXUP) {
1612 if (p & SR_IO) {
1613 /*
1614 * The workaround was to transfer fewer bytes than we
1615 * intended to with the pseudo-DMA read function, wait for
1616 * the chip to latch the last byte, read it, and then disable
1617 * pseudo-DMA mode.
1618 *
1619 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1620 * REQ is deasserted when ACK is asserted, and not reasserted
1621 * until ACK goes false. Since the NCR5380 won't lower ACK
1622 * until DACK is asserted, which won't happen unless we twiddle
1623 * the DMA port or we take the NCR5380 out of DMA mode, we
1624 * can guarantee that we won't handshake another extra
1625 * byte.
1626 */
1627
1628 if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
1629 BASR_DRQ, BASR_DRQ, 0) < 0) {
1630 result = -1;
1631 shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1632 }
1633 if (NCR5380_poll_politely(hostdata, STATUS_REG,
1634 SR_REQ, 0, 0) < 0) {
1635 result = -1;
1636 shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1637 }
1638 d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
1639 } else {
1640 /*
1641 * Wait for the last byte to be sent. If REQ is being asserted for
1642 * the byte we're interested, we'll ACK it and it will go false.
1643 */
1644 if (NCR5380_poll_politely2(hostdata,
1645 BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1646 BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, 0) < 0) {
1647 result = -1;
1648 shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1649 }
1650 }
1651 }
1652
1653 NCR5380_dma_complete(instance);
1654 return result;
1655}
1656
1657/*
1658 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1659 *
1660 * Purpose : run through the various SCSI phases and do as the target
1661 * directs us to. Operates on the currently connected command,
1662 * instance->connected.
1663 *
1664 * Inputs : instance, instance for which we are doing commands
1665 *
1666 * Side effects : SCSI things happen, the disconnected queue will be
1667 * modified if a command disconnects, *instance->connected will
1668 * change.
1669 *
1670 * XXX Note : we need to watch for bus free or a reset condition here
1671 * to recover from an unexpected bus free condition.
1672 */
1673
1674static void NCR5380_information_transfer(struct Scsi_Host *instance)
1675 __releases(&hostdata->lock) __acquires(&hostdata->lock)
1676{
1677 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1678 unsigned char msgout = NOP;
1679 int sink = 0;
1680 int len;
1681 int transfersize;
1682 unsigned char *data;
1683 unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1684 struct scsi_cmnd *cmd;
1685
1686#ifdef SUN3_SCSI_VME
1687 dregs->csr |= CSR_INTR;
1688#endif
1689
1690 while ((cmd = hostdata->connected)) {
1691 struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(cmd);
1692
1693 tmp = NCR5380_read(STATUS_REG);
1694 /* We only have a valid SCSI phase when REQ is asserted */
1695 if (tmp & SR_REQ) {
1696 phase = (tmp & PHASE_MASK);
1697 if (phase != old_phase) {
1698 old_phase = phase;
1699 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1700 }
1701#ifdef CONFIG_SUN3
1702 if (phase == PHASE_CMDOUT &&
1703 sun3_dma_setup_done != cmd) {
1704 int count;
1705
1706 advance_sg_buffer(ncmd);
1707
1708 count = sun3scsi_dma_xfer_len(hostdata, cmd);
1709
1710 if (count > 0) {
1711 if (cmd->sc_data_direction == DMA_TO_DEVICE)
1712 sun3scsi_dma_send_setup(hostdata,
1713 ncmd->ptr, count);
1714 else
1715 sun3scsi_dma_recv_setup(hostdata,
1716 ncmd->ptr, count);
1717 sun3_dma_setup_done = cmd;
1718 }
1719#ifdef SUN3_SCSI_VME
1720 dregs->csr |= CSR_INTR;
1721#endif
1722 }
1723#endif /* CONFIG_SUN3 */
1724
1725 if (sink && (phase != PHASE_MSGOUT)) {
1726 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1727
1728 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1729 ICR_ASSERT_ACK);
1730 while (NCR5380_read(STATUS_REG) & SR_REQ)
1731 ;
1732 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1733 ICR_ASSERT_ATN);
1734 sink = 0;
1735 continue;
1736 }
1737
1738 switch (phase) {
1739 case PHASE_DATAOUT:
1740#if (NDEBUG & NDEBUG_NO_DATAOUT)
1741 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1742 sink = 1;
1743 do_abort(instance, 0);
1744 cmd->result = DID_ERROR << 16;
1745 complete_cmd(instance, cmd);
1746 hostdata->connected = NULL;
1747 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1748 return;
1749#endif
1750 case PHASE_DATAIN:
1751 /*
1752 * If there is no room left in the current buffer in the
1753 * scatter-gather list, move onto the next one.
1754 */
1755
1756 advance_sg_buffer(ncmd);
1757 dsprintk(NDEBUG_INFORMATION, instance,
1758 "this residual %d, sg ents %d\n",
1759 ncmd->this_residual,
1760 sg_nents(ncmd->buffer));
1761
1762 /*
1763 * The preferred transfer method is going to be
1764 * PSEUDO-DMA for systems that are strictly PIO,
1765 * since we can let the hardware do the handshaking.
1766 *
1767 * For this to work, we need to know the transfersize
1768 * ahead of time, since the pseudo-DMA code will sit
1769 * in an unconditional loop.
1770 */
1771
1772 transfersize = 0;
1773 if (!cmd->device->borken)
1774 transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
1775
1776 if (transfersize > 0) {
1777 len = transfersize;
1778 if (NCR5380_transfer_dma(instance, &phase,
1779 &len, (unsigned char **)&ncmd->ptr)) {
1780 /*
1781 * If the watchdog timer fires, all future
1782 * accesses to this device will use the
1783 * polled-IO.
1784 */
1785 scmd_printk(KERN_INFO, cmd,
1786 "switching to slow handshake\n");
1787 cmd->device->borken = 1;
1788 do_reset(instance);
1789 bus_reset_cleanup(instance);
1790 }
1791 } else {
1792 /* Transfer a small chunk so that the
1793 * irq mode lock is not held too long.
1794 */
1795 transfersize = min(ncmd->this_residual,
1796 NCR5380_PIO_CHUNK_SIZE);
1797 len = transfersize;
1798 NCR5380_transfer_pio(instance, &phase, &len,
1799 (unsigned char **)&ncmd->ptr,
1800 0);
1801 ncmd->this_residual -= transfersize - len;
1802 }
1803#ifdef CONFIG_SUN3
1804 if (sun3_dma_setup_done == cmd)
1805 sun3_dma_setup_done = NULL;
1806#endif
1807 return;
1808 case PHASE_MSGIN:
1809 len = 1;
1810 data = &tmp;
1811 NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
1812 ncmd->message = tmp;
1813
1814 switch (tmp) {
1815 case ABORT:
1816 set_host_byte(cmd, DID_ABORT);
1817 fallthrough;
1818 case COMMAND_COMPLETE:
1819 /* Accept message by clearing ACK */
1820 sink = 1;
1821 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1822 dsprintk(NDEBUG_QUEUES, instance,
1823 "COMMAND COMPLETE %p target %d lun %llu\n",
1824 cmd, scmd_id(cmd), cmd->device->lun);
1825
1826 hostdata->connected = NULL;
1827 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1828
1829 set_status_byte(cmd, ncmd->status);
1830
1831 set_resid_from_SCp(cmd);
1832
1833 if (cmd->cmnd[0] == REQUEST_SENSE)
1834 complete_cmd(instance, cmd);
1835 else {
1836 if (ncmd->status == SAM_STAT_CHECK_CONDITION ||
1837 ncmd->status == SAM_STAT_COMMAND_TERMINATED) {
1838 dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1839 cmd);
1840 list_add_tail(&ncmd->list,
1841 &hostdata->autosense);
1842 } else
1843 complete_cmd(instance, cmd);
1844 }
1845
1846 /*
1847 * Restore phase bits to 0 so an interrupted selection,
1848 * arbitration can resume.
1849 */
1850 NCR5380_write(TARGET_COMMAND_REG, 0);
1851
1852 return;
1853 case MESSAGE_REJECT:
1854 /* Accept message by clearing ACK */
1855 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1856 switch (hostdata->last_message) {
1857 case HEAD_OF_QUEUE_TAG:
1858 case ORDERED_QUEUE_TAG:
1859 case SIMPLE_QUEUE_TAG:
1860 cmd->device->simple_tags = 0;
1861 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1862 break;
1863 default:
1864 break;
1865 }
1866 break;
1867 case DISCONNECT:
1868 /* Accept message by clearing ACK */
1869 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1870 hostdata->connected = NULL;
1871 list_add(&ncmd->list, &hostdata->disconnected);
1872 dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1873 instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1874 cmd, scmd_id(cmd), cmd->device->lun);
1875
1876 /*
1877 * Restore phase bits to 0 so an interrupted selection,
1878 * arbitration can resume.
1879 */
1880 NCR5380_write(TARGET_COMMAND_REG, 0);
1881
1882#ifdef SUN3_SCSI_VME
1883 dregs->csr |= CSR_DMA_ENABLE;
1884#endif
1885 return;
1886 /*
1887 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1888 * operation, in violation of the SCSI spec so we can safely
1889 * ignore SAVE/RESTORE pointers calls.
1890 *
1891 * Unfortunately, some disks violate the SCSI spec and
1892 * don't issue the required SAVE_POINTERS message before
1893 * disconnecting, and we have to break spec to remain
1894 * compatible.
1895 */
1896 case SAVE_POINTERS:
1897 case RESTORE_POINTERS:
1898 /* Accept message by clearing ACK */
1899 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1900 break;
1901 case EXTENDED_MESSAGE:
1902 /*
1903 * Start the message buffer with the EXTENDED_MESSAGE
1904 * byte, since spi_print_msg() wants the whole thing.
1905 */
1906 extended_msg[0] = EXTENDED_MESSAGE;
1907 /* Accept first byte by clearing ACK */
1908 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1909
1910 spin_unlock_irq(&hostdata->lock);
1911
1912 dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1913
1914 len = 2;
1915 data = extended_msg + 1;
1916 phase = PHASE_MSGIN;
1917 NCR5380_transfer_pio(instance, &phase, &len, &data, 1);
1918 dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1919 (int)extended_msg[1],
1920 (int)extended_msg[2]);
1921
1922 if (!len && extended_msg[1] > 0 &&
1923 extended_msg[1] <= sizeof(extended_msg) - 2) {
1924 /* Accept third byte by clearing ACK */
1925 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1926 len = extended_msg[1] - 1;
1927 data = extended_msg + 3;
1928 phase = PHASE_MSGIN;
1929
1930 NCR5380_transfer_pio(instance, &phase, &len, &data, 1);
1931 dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
1932 len);
1933
1934 switch (extended_msg[2]) {
1935 case EXTENDED_SDTR:
1936 case EXTENDED_WDTR:
1937 tmp = 0;
1938 }
1939 } else if (len) {
1940 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1941 tmp = 0;
1942 } else {
1943 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
1944 extended_msg[2], extended_msg[1]);
1945 tmp = 0;
1946 }
1947
1948 spin_lock_irq(&hostdata->lock);
1949 if (!hostdata->connected)
1950 return;
1951
1952 /* Reject message */
1953 fallthrough;
1954 default:
1955 /*
1956 * If we get something weird that we aren't expecting,
1957 * log it.
1958 */
1959 if (tmp == EXTENDED_MESSAGE)
1960 scmd_printk(KERN_INFO, cmd,
1961 "rejecting unknown extended message code %02x, length %d\n",
1962 extended_msg[2], extended_msg[1]);
1963 else if (tmp)
1964 scmd_printk(KERN_INFO, cmd,
1965 "rejecting unknown message code %02x\n",
1966 tmp);
1967
1968 msgout = MESSAGE_REJECT;
1969 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1970 break;
1971 } /* switch (tmp) */
1972 break;
1973 case PHASE_MSGOUT:
1974 len = 1;
1975 data = &msgout;
1976 hostdata->last_message = msgout;
1977 NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
1978 if (msgout == ABORT) {
1979 hostdata->connected = NULL;
1980 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1981 cmd->result = DID_ERROR << 16;
1982 complete_cmd(instance, cmd);
1983 return;
1984 }
1985 msgout = NOP;
1986 break;
1987 case PHASE_CMDOUT:
1988 len = cmd->cmd_len;
1989 data = cmd->cmnd;
1990 /*
1991 * XXX for performance reasons, on machines with a
1992 * PSEUDO-DMA architecture we should probably
1993 * use the dma transfer function.
1994 */
1995 NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
1996 break;
1997 case PHASE_STATIN:
1998 len = 1;
1999 data = &tmp;
2000 NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
2001 ncmd->status = tmp;
2002 break;
2003 default:
2004 shost_printk(KERN_ERR, instance, "unknown phase\n");
2005 NCR5380_dprint(NDEBUG_ANY, instance);
2006 } /* switch(phase) */
2007 } else {
2008 spin_unlock_irq(&hostdata->lock);
2009 NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
2010 spin_lock_irq(&hostdata->lock);
2011 }
2012 }
2013}
2014
2015/*
2016 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2017 *
2018 * Purpose : does reselection, initializing the instance->connected
2019 * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2020 * nexus has been reestablished,
2021 *
2022 * Inputs : instance - this instance of the NCR5380.
2023 */
2024
2025static void NCR5380_reselect(struct Scsi_Host *instance)
2026{
2027 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2028 unsigned char target_mask;
2029 unsigned char lun;
2030 unsigned char msg[3];
2031 struct NCR5380_cmd *ncmd;
2032 struct scsi_cmnd *tmp;
2033
2034 /*
2035 * Disable arbitration, etc. since the host adapter obviously
2036 * lost, and tell an interrupted NCR5380_select() to restart.
2037 */
2038
2039 NCR5380_write(MODE_REG, MR_BASE);
2040
2041 target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2042 if (!target_mask || target_mask & (target_mask - 1)) {
2043 shost_printk(KERN_WARNING, instance,
2044 "reselect: bad target_mask 0x%02x\n", target_mask);
2045 return;
2046 }
2047
2048 /*
2049 * At this point, we have detected that our SCSI ID is on the bus,
2050 * SEL is true and BSY was false for at least one bus settle delay
2051 * (400 ns).
2052 *
2053 * We must assert BSY ourselves, until the target drops the SEL
2054 * signal.
2055 */
2056
2057 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2058 if (NCR5380_poll_politely(hostdata,
2059 STATUS_REG, SR_SEL, 0, 0) < 0) {
2060 shost_printk(KERN_ERR, instance, "reselect: !SEL timeout\n");
2061 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2062 return;
2063 }
2064 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2065
2066 /*
2067 * Wait for target to go into MSGIN.
2068 */
2069
2070 if (NCR5380_poll_politely(hostdata,
2071 STATUS_REG, SR_REQ, SR_REQ, 0) < 0) {
2072 if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
2073 /* BUS FREE phase */
2074 return;
2075 shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
2076 do_abort(instance, 0);
2077 return;
2078 }
2079
2080#ifdef CONFIG_SUN3
2081 /* acknowledge toggle to MSGIN */
2082 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2083
2084 /* peek at the byte without really hitting the bus */
2085 msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2086#else
2087 {
2088 int len = 1;
2089 unsigned char *data = msg;
2090 unsigned char phase = PHASE_MSGIN;
2091
2092 NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
2093
2094 if (len) {
2095 do_abort(instance, 0);
2096 return;
2097 }
2098 }
2099#endif /* CONFIG_SUN3 */
2100
2101 if (!(msg[0] & 0x80)) {
2102 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2103 spi_print_msg(msg);
2104 printk("\n");
2105 do_abort(instance, 0);
2106 return;
2107 }
2108 lun = msg[0] & 0x07;
2109
2110 /*
2111 * We need to add code for SCSI-II to track which devices have
2112 * I_T_L_Q nexuses established, and which have simple I_T_L
2113 * nexuses so we can chose to do additional data transfer.
2114 */
2115
2116 /*
2117 * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
2118 * just reestablished, and remove it from the disconnected queue.
2119 */
2120
2121 tmp = NULL;
2122 list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2123 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2124
2125 if (target_mask == (1 << scmd_id(cmd)) &&
2126 lun == (u8)cmd->device->lun) {
2127 list_del(&ncmd->list);
2128 tmp = cmd;
2129 break;
2130 }
2131 }
2132
2133 if (tmp) {
2134 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2135 "reselect: removed %p from disconnected queue\n", tmp);
2136 } else {
2137 int target = ffs(target_mask) - 1;
2138
2139 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2140 target_mask, lun);
2141 /*
2142 * Since we have an established nexus that we can't do anything
2143 * with, we must abort it.
2144 */
2145 if (do_abort(instance, 0) == 0)
2146 hostdata->busy[target] &= ~(1 << lun);
2147 return;
2148 }
2149
2150#ifdef CONFIG_SUN3
2151 if (sun3_dma_setup_done != tmp) {
2152 int count;
2153
2154 advance_sg_buffer(ncmd);
2155
2156 count = sun3scsi_dma_xfer_len(hostdata, tmp);
2157
2158 if (count > 0) {
2159 if (tmp->sc_data_direction == DMA_TO_DEVICE)
2160 sun3scsi_dma_send_setup(hostdata,
2161 ncmd->ptr, count);
2162 else
2163 sun3scsi_dma_recv_setup(hostdata,
2164 ncmd->ptr, count);
2165 sun3_dma_setup_done = tmp;
2166 }
2167 }
2168
2169 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2170#endif /* CONFIG_SUN3 */
2171
2172 /* Accept message by clearing ACK */
2173 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2174
2175 hostdata->connected = tmp;
2176 dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
2177 scmd_id(tmp), tmp->device->lun);
2178}
2179
2180/**
2181 * list_find_cmd - test for presence of a command in a linked list
2182 * @haystack: list of commands
2183 * @needle: command to search for
2184 */
2185
2186static bool list_find_cmd(struct list_head *haystack,
2187 struct scsi_cmnd *needle)
2188{
2189 struct NCR5380_cmd *ncmd;
2190
2191 list_for_each_entry(ncmd, haystack, list)
2192 if (NCR5380_to_scmd(ncmd) == needle)
2193 return true;
2194 return false;
2195}
2196
2197/**
2198 * list_remove_cmd - remove a command from linked list
2199 * @haystack: list of commands
2200 * @needle: command to remove
2201 */
2202
2203static bool list_del_cmd(struct list_head *haystack,
2204 struct scsi_cmnd *needle)
2205{
2206 if (list_find_cmd(haystack, needle)) {
2207 struct NCR5380_cmd *ncmd = NCR5380_to_ncmd(needle);
2208
2209 list_del(&ncmd->list);
2210 return true;
2211 }
2212 return false;
2213}
2214
2215/**
2216 * NCR5380_abort - scsi host eh_abort_handler() method
2217 * @cmd: the command to be aborted
2218 *
2219 * Try to abort a given command by removing it from queues and/or sending
2220 * the target an abort message. This may not succeed in causing a target
2221 * to abort the command. Nonetheless, the low-level driver must forget about
2222 * the command because the mid-layer reclaims it and it may be re-issued.
2223 *
2224 * The normal path taken by a command is as follows. For EH we trace this
2225 * same path to locate and abort the command.
2226 *
2227 * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2228 * [disconnected -> connected ->]...
2229 * [autosense -> connected ->] done
2230 *
2231 * If cmd was not found at all then presumably it has already been completed,
2232 * in which case return SUCCESS to try to avoid further EH measures.
2233 *
2234 * If the command has not completed yet, we must not fail to find it.
2235 * We have no option but to forget the aborted command (even if it still
2236 * lacks sense data). The mid-layer may re-issue a command that is in error
2237 * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2238 * this driver are such that a command can appear on one queue only.
2239 *
2240 * The lock protects driver data structures, but EH handlers also use it
2241 * to serialize their own execution and prevent their own re-entry.
2242 */
2243
2244static int NCR5380_abort(struct scsi_cmnd *cmd)
2245{
2246 struct Scsi_Host *instance = cmd->device->host;
2247 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2248 unsigned long flags;
2249 int result = SUCCESS;
2250
2251 spin_lock_irqsave(&hostdata->lock, flags);
2252
2253#if (NDEBUG & NDEBUG_ANY)
2254 scmd_printk(KERN_INFO, cmd, __func__);
2255#endif
2256 NCR5380_dprint(NDEBUG_ANY, instance);
2257 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2258
2259 if (list_del_cmd(&hostdata->unissued, cmd)) {
2260 dsprintk(NDEBUG_ABORT, instance,
2261 "abort: removed %p from issue queue\n", cmd);
2262 cmd->result = DID_ABORT << 16;
2263 scsi_done(cmd); /* No tag or busy flag to worry about */
2264 goto out;
2265 }
2266
2267 if (hostdata->selecting == cmd) {
2268 dsprintk(NDEBUG_ABORT, instance,
2269 "abort: cmd %p == selecting\n", cmd);
2270 hostdata->selecting = NULL;
2271 cmd->result = DID_ABORT << 16;
2272 complete_cmd(instance, cmd);
2273 goto out;
2274 }
2275
2276 if (list_del_cmd(&hostdata->disconnected, cmd)) {
2277 dsprintk(NDEBUG_ABORT, instance,
2278 "abort: removed %p from disconnected list\n", cmd);
2279 /* Can't call NCR5380_select() and send ABORT because that
2280 * means releasing the lock. Need a bus reset.
2281 */
2282 set_host_byte(cmd, DID_ERROR);
2283 complete_cmd(instance, cmd);
2284 result = FAILED;
2285 goto out;
2286 }
2287
2288 if (hostdata->connected == cmd) {
2289 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2290 hostdata->connected = NULL;
2291 hostdata->dma_len = 0;
2292 if (do_abort(instance, 0) < 0) {
2293 set_host_byte(cmd, DID_ERROR);
2294 complete_cmd(instance, cmd);
2295 result = FAILED;
2296 goto out;
2297 }
2298 set_host_byte(cmd, DID_ABORT);
2299 complete_cmd(instance, cmd);
2300 goto out;
2301 }
2302
2303 if (list_del_cmd(&hostdata->autosense, cmd)) {
2304 dsprintk(NDEBUG_ABORT, instance,
2305 "abort: removed %p from sense queue\n", cmd);
2306 complete_cmd(instance, cmd);
2307 }
2308
2309out:
2310 if (result == FAILED)
2311 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2312 else {
2313 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
2314 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2315 }
2316
2317 queue_work(hostdata->work_q, &hostdata->main_task);
2318 spin_unlock_irqrestore(&hostdata->lock, flags);
2319
2320 return result;
2321}
2322
2323
2324static void bus_reset_cleanup(struct Scsi_Host *instance)
2325{
2326 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2327 int i;
2328 struct NCR5380_cmd *ncmd;
2329
2330 /* reset NCR registers */
2331 NCR5380_write(MODE_REG, MR_BASE);
2332 NCR5380_write(TARGET_COMMAND_REG, 0);
2333 NCR5380_write(SELECT_ENABLE_REG, 0);
2334
2335 /* After the reset, there are no more connected or disconnected commands
2336 * and no busy units; so clear the low-level status here to avoid
2337 * conflicts when the mid-level code tries to wake up the affected
2338 * commands!
2339 */
2340
2341 if (hostdata->selecting) {
2342 hostdata->selecting->result = DID_RESET << 16;
2343 complete_cmd(instance, hostdata->selecting);
2344 hostdata->selecting = NULL;
2345 }
2346
2347 list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2348 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2349
2350 set_host_byte(cmd, DID_RESET);
2351 complete_cmd(instance, cmd);
2352 }
2353 INIT_LIST_HEAD(&hostdata->disconnected);
2354
2355 list_for_each_entry(ncmd, &hostdata->autosense, list) {
2356 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2357
2358 scsi_done(cmd);
2359 }
2360 INIT_LIST_HEAD(&hostdata->autosense);
2361
2362 if (hostdata->connected) {
2363 set_host_byte(hostdata->connected, DID_RESET);
2364 complete_cmd(instance, hostdata->connected);
2365 hostdata->connected = NULL;
2366 }
2367
2368 for (i = 0; i < 8; ++i)
2369 hostdata->busy[i] = 0;
2370 hostdata->dma_len = 0;
2371
2372 queue_work(hostdata->work_q, &hostdata->main_task);
2373}
2374
2375/**
2376 * NCR5380_host_reset - reset the SCSI host
2377 * @cmd: SCSI command undergoing EH
2378 *
2379 * Returns SUCCESS
2380 */
2381
2382static int NCR5380_host_reset(struct scsi_cmnd *cmd)
2383{
2384 struct Scsi_Host *instance = cmd->device->host;
2385 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2386 unsigned long flags;
2387 struct NCR5380_cmd *ncmd;
2388
2389 spin_lock_irqsave(&hostdata->lock, flags);
2390
2391#if (NDEBUG & NDEBUG_ANY)
2392 shost_printk(KERN_INFO, instance, __func__);
2393#endif
2394 NCR5380_dprint(NDEBUG_ANY, instance);
2395 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2396
2397 list_for_each_entry(ncmd, &hostdata->unissued, list) {
2398 struct scsi_cmnd *scmd = NCR5380_to_scmd(ncmd);
2399
2400 scmd->result = DID_RESET << 16;
2401 scsi_done(scmd);
2402 }
2403 INIT_LIST_HEAD(&hostdata->unissued);
2404
2405 do_reset(instance);
2406 bus_reset_cleanup(instance);
2407
2408 spin_unlock_irqrestore(&hostdata->lock, flags);
2409
2410 return SUCCESS;
2411}