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: &phase,
1779 count: &len, data: (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, cmd: 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, cmd: 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}
2412

source code of linux/drivers/scsi/NCR5380.c