drivers/scsi/NCR5380.c

   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  * For more information, please consult
  15  *
  16  * NCR 5380 Family
  17  * SCSI Protocol Controller
  18  * Databook
  19  *
  20  * NCR Microelectronics
  21  * 1635 Aeroplaza Drive
  22  * Colorado Springs, CO 80916
  23  * 1+ (719) 578-3400
  24  * 1+ (800) 334-5454
  25  */
  26
  27 /*
  28  * With contributions from Ray Van Tassle, Ingmar Baumgart,
  29  * Ronald van Cuijlenborg, Alan Cox and others.
  30  */
  31
  32 /* Ported to Atari by Roman Hodek and others. */
  33
  34 /* Adapted for the Sun 3 by Sam Creasey. */
  35
  36 /*
  37  * Design
  38  *
  39  * This is a generic 5380 driver.  To use it on a different platform,
  40  * one simply writes appropriate system specific macros (ie, data
  41  * transfer - some PC's will use the I/O bus, 68K's must use
  42  * memory mapped) and drops this file in their 'C' wrapper.
  43  *
  44  * As far as command queueing, two queues are maintained for
  45  * each 5380 in the system - commands that haven't been issued yet,
  46  * and commands that are currently executing.  This means that an
  47  * unlimited number of commands may be queued, letting
  48  * more commands propagate from the higher driver levels giving higher
  49  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
  50  * allowing multiple commands to propagate all the way to a SCSI-II device
  51  * while a command is already executing.
  52  *
  53  *
  54  * Issues specific to the NCR5380 :
  55  *
  56  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
  57  * piece of hardware that requires you to sit in a loop polling for
  58  * the REQ signal as long as you are connected.  Some devices are
  59  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
  60  * while doing long seek operations. [...] These
  61  * broken devices are the exception rather than the rule and I'd rather
  62  * spend my time optimizing for the normal case.
  63  *
  64  * Architecture :
  65  *
  66  * At the heart of the design is a coroutine, NCR5380_main,
  67  * which is started from a workqueue for each NCR5380 host in the
  68  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
  69  * removing the commands from the issue queue and calling
  70  * NCR5380_select() if a nexus is not established.
  71  *
  72  * Once a nexus is established, the NCR5380_information_transfer()
  73  * phase goes through the various phases as instructed by the target.
  74  * if the target goes into MSG IN and sends a DISCONNECT message,
  75  * the command structure is placed into the per instance disconnected
  76  * queue, and NCR5380_main tries to find more work.  If the target is
  77  * idle for too long, the system will try to sleep.
  78  *
  79  * If a command has disconnected, eventually an interrupt will trigger,
  80  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
  81  * to reestablish a nexus.  This will run main if necessary.
  82  *
  83  * On command termination, the done function will be called as
  84  * appropriate.
  85  *
  86  * SCSI pointers are maintained in the SCp field of SCSI command
  87  * structures, being 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
 131 static int do_abort(struct Scsi_Host *);
 132 static void do_reset(struct Scsi_Host *);
 133
 134 /**
 135  * initialize_SCp - init the scsi pointer field
 136  * @cmd: command block to set up
 137  *
 138  * Set up the internal fields in the SCSI command.
 139  */
 140
 141 static inline void initialize_SCp(struct scsi_cmnd *cmd)
 142 {
 143         /*
 144          * Initialize the Scsi Pointer field so that all of the commands in the
 145          * various queues are valid.
 146          */
 147
 148         if (scsi_bufflen(cmd)) {
 149                 cmd->SCp.buffer = scsi_sglist(cmd);
 150                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 151                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 152                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 153         } else {
 154                 cmd->SCp.buffer = NULL;
 155                 cmd->SCp.buffers_residual = 0;
 156                 cmd->SCp.ptr = NULL;
 157                 cmd->SCp.this_residual = 0;
 158         }
 159
 160         cmd->SCp.Status = 0;
 161         cmd->SCp.Message = 0;
 162 }
 163
 164 /**
 165  * NCR5380_poll_politely2 - wait for two chip register values
 166  * @hostdata: host private data
 167  * @reg1: 5380 register to poll
 168  * @bit1: Bitmask to check
 169  * @val1: Expected value
 170  * @reg2: Second 5380 register to poll
 171  * @bit2: Second bitmask to check
 172  * @val2: Second expected value
 173  * @wait: Time-out in jiffies
 174  *
 175  * Polls the chip in a reasonably efficient manner waiting for an
 176  * event to occur. After a short quick poll we begin to yield the CPU
 177  * (if possible). In irq contexts the time-out is arbitrarily limited.
 178  * Callers may hold locks as long as they are held in irq mode.
 179  *
 180  * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
 181  */
 182
 183 static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
 184                                   unsigned int reg1, u8 bit1, u8 val1,
 185                                   unsigned int reg2, u8 bit2, u8 val2,
 186                                   unsigned long wait)
 187 {
 188         unsigned long n = hostdata->poll_loops;
 189         unsigned long deadline = jiffies + wait;
 190
 191         do {
 192                 if ((NCR5380_read(reg1) & bit1) == val1)
 193                         return 0;
 194                 if ((NCR5380_read(reg2) & bit2) == val2)
 195                         return 0;
 196                 cpu_relax();
 197         } while (n--);
 198
 199         if (irqs_disabled() || in_interrupt())
 200                 return -ETIMEDOUT;
 201
 202         /* Repeatedly sleep for 1 ms until deadline */
 203         while (time_is_after_jiffies(deadline)) {
 204                 schedule_timeout_uninterruptible(1);
 205                 if ((NCR5380_read(reg1) & bit1) == val1)
 206                         return 0;
 207                 if ((NCR5380_read(reg2) & bit2) == val2)
 208                         return 0;
 209         }
 210
 211         return -ETIMEDOUT;
 212 }
 213
 214 #if NDEBUG
 215 static struct {
 216         unsigned char mask;
 217         const char *name;
 218 } signals[] = {
 219         {SR_DBP, "PARITY"},
 220         {SR_RST, "RST"},
 221         {SR_BSY, "BSY"},
 222         {SR_REQ, "REQ"},
 223         {SR_MSG, "MSG"},
 224         {SR_CD, "CD"},
 225         {SR_IO, "IO"},
 226         {SR_SEL, "SEL"},
 227         {0, NULL}
 228 },
 229 basrs[] = {
 230         {BASR_END_DMA_TRANSFER, "END OF DMA"},
 231         {BASR_DRQ, "DRQ"},
 232         {BASR_PARITY_ERROR, "PARITY ERROR"},
 233         {BASR_IRQ, "IRQ"},
 234         {BASR_PHASE_MATCH, "PHASE MATCH"},
 235         {BASR_BUSY_ERROR, "BUSY ERROR"},
 236         {BASR_ATN, "ATN"},
 237         {BASR_ACK, "ACK"},
 238         {0, NULL}
 239 },
 240 icrs[] = {
 241         {ICR_ASSERT_RST, "ASSERT RST"},
 242         {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
 243         {ICR_ARBITRATION_LOST, "LOST ARB."},
 244         {ICR_ASSERT_ACK, "ASSERT ACK"},
 245         {ICR_ASSERT_BSY, "ASSERT BSY"},
 246         {ICR_ASSERT_SEL, "ASSERT SEL"},
 247         {ICR_ASSERT_ATN, "ASSERT ATN"},
 248         {ICR_ASSERT_DATA, "ASSERT DATA"},
 249         {0, NULL}
 250 },
 251 mrs[] = {
 252         {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
 253         {MR_TARGET, "TARGET"},
 254         {MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
 255         {MR_ENABLE_PAR_INTR, "PARITY INTR"},
 256         {MR_ENABLE_EOP_INTR, "EOP INTR"},
 257         {MR_MONITOR_BSY, "MONITOR BSY"},
 258         {MR_DMA_MODE, "DMA MODE"},
 259         {MR_ARBITRATE, "ARBITRATE"},
 260         {0, NULL}
 261 };
 262
 263 /**
 264  * NCR5380_print - print scsi bus signals
 265  * @instance: adapter state to dump
 266  *
 267  * Print the SCSI bus signals for debugging purposes
 268  */
 269
 270 static void NCR5380_print(struct Scsi_Host *instance)
 271 {
 272         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 273         unsigned char status, data, basr, mr, icr, i;
 274
 275         data = NCR5380_read(CURRENT_SCSI_DATA_REG);
 276         status = NCR5380_read(STATUS_REG);
 277         mr = NCR5380_read(MODE_REG);
 278         icr = NCR5380_read(INITIATOR_COMMAND_REG);
 279         basr = NCR5380_read(BUS_AND_STATUS_REG);
 280
 281         printk(KERN_DEBUG "SR =   0x%02x : ", status);
 282         for (i = 0; signals[i].mask; ++i)
 283                 if (status & signals[i].mask)
 284                         printk(KERN_CONT "%s, ", signals[i].name);
 285         printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
 286         for (i = 0; basrs[i].mask; ++i)
 287                 if (basr & basrs[i].mask)
 288                         printk(KERN_CONT "%s, ", basrs[i].name);
 289         printk(KERN_CONT "\nICR =  0x%02x : ", icr);
 290         for (i = 0; icrs[i].mask; ++i)
 291                 if (icr & icrs[i].mask)
 292                         printk(KERN_CONT "%s, ", icrs[i].name);
 293         printk(KERN_CONT "\nMR =   0x%02x : ", mr);
 294         for (i = 0; mrs[i].mask; ++i)
 295                 if (mr & mrs[i].mask)
 296                         printk(KERN_CONT "%s, ", mrs[i].name);
 297         printk(KERN_CONT "\n");
 298 }
 299
 300 static struct {
 301         unsigned char value;
 302         const char *name;
 303 } phases[] = {
 304         {PHASE_DATAOUT, "DATAOUT"},
 305         {PHASE_DATAIN, "DATAIN"},
 306         {PHASE_CMDOUT, "CMDOUT"},
 307         {PHASE_STATIN, "STATIN"},
 308         {PHASE_MSGOUT, "MSGOUT"},
 309         {PHASE_MSGIN, "MSGIN"},
 310         {PHASE_UNKNOWN, "UNKNOWN"}
 311 };
 312
 313 /**
 314  * NCR5380_print_phase - show SCSI phase
 315  * @instance: adapter to dump
 316  *
 317  * Print the current SCSI phase for debugging purposes
 318  */
 319
 320 static void NCR5380_print_phase(struct Scsi_Host *instance)
 321 {
 322         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 323         unsigned char status;
 324         int i;
 325
 326         status = NCR5380_read(STATUS_REG);
 327         if (!(status & SR_REQ))
 328                 shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
 329         else {
 330                 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
 331                      (phases[i].value != (status & PHASE_MASK)); ++i)
 332                         ;
 333                 shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
 334         }
 335 }
 336 #endif
 337
 338 /**
 339  * NCR5380_info - report driver and host information
 340  * @instance: relevant scsi host instance
 341  *
 342  * For use as the host template info() handler.
 343  */
 344
 345 static const char *NCR5380_info(struct Scsi_Host *instance)
 346 {
 347         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 348
 349         return hostdata->info;
 350 }
 351
 352 /**
 353  * NCR5380_init - initialise an NCR5380
 354  * @instance: adapter to configure
 355  * @flags: control flags
 356  *
 357  * Initializes *instance and corresponding 5380 chip,
 358  * with flags OR'd into the initial flags value.
 359  *
 360  * Notes : I assume that the host, hostno, and id bits have been
 361  * set correctly. I don't care about the irq and other fields.
 362  *
 363  * Returns 0 for success
 364  */
 365
 366 static int NCR5380_init(struct Scsi_Host *instance, int flags)
 367 {
 368         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 369         int i;
 370         unsigned long deadline;
 371         unsigned long accesses_per_ms;
 372
 373         instance->max_lun = 7;
 374
 375         hostdata->host = instance;
 376         hostdata->id_mask = 1 << instance->this_id;
 377         hostdata->id_higher_mask = 0;
 378         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 379                 if (i > hostdata->id_mask)
 380                         hostdata->id_higher_mask |= i;
 381         for (i = 0; i < 8; ++i)
 382                 hostdata->busy[i] = 0;
 383         hostdata->dma_len = 0;
 384
 385         spin_lock_init(&hostdata->lock);
 386         hostdata->connected = NULL;
 387         hostdata->sensing = NULL;
 388         INIT_LIST_HEAD(&hostdata->autosense);
 389         INIT_LIST_HEAD(&hostdata->unissued);
 390         INIT_LIST_HEAD(&hostdata->disconnected);
 391
 392         hostdata->flags = flags;
 393
 394         INIT_WORK(&hostdata->main_task, NCR5380_main);
 395         hostdata->work_q = alloc_workqueue("ncr5380_%d",
 396                                 WQ_UNBOUND | WQ_MEM_RECLAIM,
 397                                 1, instance->host_no);
 398         if (!hostdata->work_q)
 399                 return -ENOMEM;
 400
 401         snprintf(hostdata->info, sizeof(hostdata->info),
 402                 "%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}",
 403                 instance->hostt->name, instance->irq, hostdata->io_port,
 404                 hostdata->base, instance->can_queue, instance->cmd_per_lun,
 405                 instance->sg_tablesize, instance->this_id,
 406                 hostdata->flags & FLAG_DMA_FIXUP     ? "DMA_FIXUP "     : "",
 407                 hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
 408                 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
 409
 410         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 411         NCR5380_write(MODE_REG, MR_BASE);
 412         NCR5380_write(TARGET_COMMAND_REG, 0);
 413         NCR5380_write(SELECT_ENABLE_REG, 0);
 414
 415         /* Calibrate register polling loop */
 416         i = 0;
 417         deadline = jiffies + 1;
 418         do {
 419                 cpu_relax();
 420         } while (time_is_after_jiffies(deadline));
 421         deadline += msecs_to_jiffies(256);
 422         do {
 423                 NCR5380_read(STATUS_REG);
 424                 ++i;
 425                 cpu_relax();
 426         } while (time_is_after_jiffies(deadline));
 427         accesses_per_ms = i / 256;
 428         hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
 429
 430         return 0;
 431 }
 432
 433 /**
 434  * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
 435  * @instance: adapter to check
 436  *
 437  * If the system crashed, it may have crashed with a connected target and
 438  * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
 439  * currently established nexus, which we know nothing about. Failing that
 440  * do a bus reset.
 441  *
 442  * Note that a bus reset will cause the chip to assert IRQ.
 443  *
 444  * Returns 0 if successful, otherwise -ENXIO.
 445  */
 446
 447 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
 448 {
 449         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 450         int pass;
 451
 452         for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
 453                 switch (pass) {
 454                 case 1:
 455                 case 3:
 456                 case 5:
 457                         shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
 458                         NCR5380_poll_politely(hostdata,
 459                                               STATUS_REG, SR_BSY, 0, 5 * HZ);
 460                         break;
 461                 case 2:
 462                         shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
 463                         do_abort(instance);
 464                         break;
 465                 case 4:
 466                         shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
 467                         do_reset(instance);
 468                         /* Wait after a reset; the SCSI standard calls for
 469                          * 250ms, we wait 500ms to be on the safe side.
 470                          * But some Toshiba CD-ROMs need ten times that.
 471                          */
 472                         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
 473                                 msleep(2500);
 474                         else
 475                                 msleep(500);
 476                         break;
 477                 case 6:
 478                         shost_printk(KERN_ERR, instance, "bus locked solid\n");
 479                         return -ENXIO;
 480                 }
 481         }
 482         return 0;
 483 }
 484
 485 /**
 486  * NCR5380_exit - remove an NCR5380
 487  * @instance: adapter to remove
 488  *
 489  * Assumes that no more work can be queued (e.g. by NCR5380_intr).
 490  */
 491
 492 static void NCR5380_exit(struct Scsi_Host *instance)
 493 {
 494         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 495
 496         cancel_work_sync(&hostdata->main_task);
 497         destroy_workqueue(hostdata->work_q);
 498 }
 499
 500 /**
 501  * complete_cmd - finish processing a command and return it to the SCSI ML
 502  * @instance: the host instance
 503  * @cmd: command to complete
 504  */
 505
 506 static void complete_cmd(struct Scsi_Host *instance,
 507                          struct scsi_cmnd *cmd)
 508 {
 509         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 510
 511         dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
 512
 513         if (hostdata->sensing == cmd) {
 514                 /* Autosense processing ends here */
 515                 if ((cmd->result & 0xff) != SAM_STAT_GOOD) {
 516                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 517                         set_host_byte(cmd, DID_ERROR);
 518                 } else
 519                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 520                 hostdata->sensing = NULL;
 521         }
 522
 523         hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
 524
 525         cmd->scsi_done(cmd);
 526 }
 527
 528 /**
 529  * NCR5380_queue_command - queue a command
 530  * @instance: the relevant SCSI adapter
 531  * @cmd: SCSI command
 532  *
 533  * cmd is added to the per-instance issue queue, with minor
 534  * twiddling done to the host specific fields of cmd.  If the
 535  * main coroutine is not running, it is restarted.
 536  */
 537
 538 static int NCR5380_queue_command(struct Scsi_Host *instance,
 539                                  struct scsi_cmnd *cmd)
 540 {
 541         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 542         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 543         unsigned long flags;
 544
 545 #if (NDEBUG & NDEBUG_NO_WRITE)
 546         switch (cmd->cmnd[0]) {
 547         case WRITE_6:
 548         case WRITE_10:
 549                 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
 550                 cmd->result = (DID_ERROR << 16);
 551                 cmd->scsi_done(cmd);
 552                 return 0;
 553         }
 554 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 555
 556         cmd->result = 0;
 557
 558         if (!NCR5380_acquire_dma_irq(instance))
 559                 return SCSI_MLQUEUE_HOST_BUSY;
 560
 561         spin_lock_irqsave(&hostdata->lock, flags);
 562
 563         /*
 564          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 565          * commands are added to the head of the queue since any command will
 566          * clear the contingent allegiance condition that exists and the
 567          * sense data is only guaranteed to be valid while the condition exists.
 568          */
 569
 570         if (cmd->cmnd[0] == REQUEST_SENSE)
 571                 list_add(&ncmd->list, &hostdata->unissued);
 572         else
 573                 list_add_tail(&ncmd->list, &hostdata->unissued);
 574
 575         spin_unlock_irqrestore(&hostdata->lock, flags);
 576
 577         dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
 578                  cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 579
 580         /* Kick off command processing */
 581         queue_work(hostdata->work_q, &hostdata->main_task);
 582         return 0;
 583 }
 584
 585 static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
 586 {
 587         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 588
 589         /* Caller does the locking needed to set & test these data atomically */
 590         if (list_empty(&hostdata->disconnected) &&
 591             list_empty(&hostdata->unissued) &&
 592             list_empty(&hostdata->autosense) &&
 593             !hostdata->connected &&
 594             !hostdata->selecting) {
 595                 NCR5380_release_dma_irq(instance);
 596         }
 597 }
 598
 599 /**
 600  * dequeue_next_cmd - dequeue a command for processing
 601  * @instance: the scsi host instance
 602  *
 603  * Priority is given to commands on the autosense queue. These commands
 604  * need autosense because of a CHECK CONDITION result.
 605  *
 606  * Returns a command pointer if a command is found for a target that is
 607  * not already busy. Otherwise returns NULL.
 608  */
 609
 610 static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
 611 {
 612         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 613         struct NCR5380_cmd *ncmd;
 614         struct scsi_cmnd *cmd;
 615
 616         if (hostdata->sensing || list_empty(&hostdata->autosense)) {
 617                 list_for_each_entry(ncmd, &hostdata->unissued, list) {
 618                         cmd = NCR5380_to_scmd(ncmd);
 619                         dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
 620                                  cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
 621
 622                         if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
 623                                 list_del(&ncmd->list);
 624                                 dsprintk(NDEBUG_QUEUES, instance,
 625                                          "dequeue: removed %p from issue queue\n", cmd);
 626                                 return cmd;
 627                         }
 628                 }
 629         } else {
 630                 /* Autosense processing begins here */
 631                 ncmd = list_first_entry(&hostdata->autosense,
 632                                         struct NCR5380_cmd, list);
 633                 list_del(&ncmd->list);
 634                 cmd = NCR5380_to_scmd(ncmd);
 635                 dsprintk(NDEBUG_QUEUES, instance,
 636                          "dequeue: removed %p from autosense queue\n", cmd);
 637                 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
 638                 hostdata->sensing = cmd;
 639                 return cmd;
 640         }
 641         return NULL;
 642 }
 643
 644 static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 645 {
 646         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 647         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 648
 649         if (hostdata->sensing == cmd) {
 650                 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 651                 list_add(&ncmd->list, &hostdata->autosense);
 652                 hostdata->sensing = NULL;
 653         } else
 654                 list_add(&ncmd->list, &hostdata->unissued);
 655 }
 656
 657 /**
 658  * NCR5380_main - NCR state machines
 659  *
 660  * NCR5380_main is a coroutine that runs as long as more work can
 661  * be done on the NCR5380 host adapters in a system.  Both
 662  * NCR5380_queue_command() and NCR5380_intr() will try to start it
 663  * in case it is not running.
 664  */
 665
 666 static void NCR5380_main(struct work_struct *work)
 667 {
 668         struct NCR5380_hostdata *hostdata =
 669                 container_of(work, struct NCR5380_hostdata, main_task);
 670         struct Scsi_Host *instance = hostdata->host;
 671         int done;
 672
 673         do {
 674                 done = 1;
 675
 676                 spin_lock_irq(&hostdata->lock);
 677                 while (!hostdata->connected && !hostdata->selecting) {
 678                         struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
 679
 680                         if (!cmd)
 681                                 break;
 682
 683                         dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
 684
 685                         /*
 686                          * Attempt to establish an I_T_L nexus here.
 687                          * On success, instance->hostdata->connected is set.
 688                          * On failure, we must add the command back to the
 689                          * issue queue so we can keep trying.
 690                          */
 691                         /*
 692                          * REQUEST SENSE commands are issued without tagged
 693                          * queueing, even on SCSI-II devices because the
 694                          * contingent allegiance condition exists for the
 695                          * entire unit.
 696                          */
 697
 698                         if (!NCR5380_select(instance, cmd)) {
 699                                 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
 700                                 maybe_release_dma_irq(instance);
 701                         } else {
 702                                 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
 703                                          "main: select failed, returning %p to queue\n", cmd);
 704                                 requeue_cmd(instance, cmd);
 705                         }
 706                 }
 707                 if (hostdata->connected && !hostdata->dma_len) {
 708                         dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
 709                         NCR5380_information_transfer(instance);
 710                         done = 0;
 711                 }
 712                 spin_unlock_irq(&hostdata->lock);
 713                 if (!done)
 714                         cond_resched();
 715         } while (!done);
 716 }
 717
 718 /*
 719  * NCR5380_dma_complete - finish DMA transfer
 720  * @instance: the scsi host instance
 721  *
 722  * Called by the interrupt handler when DMA finishes or a phase
 723  * mismatch occurs (which would end the DMA transfer).
 724  */
 725
 726 static void NCR5380_dma_complete(struct Scsi_Host *instance)
 727 {
 728         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 729         int transferred;
 730         unsigned char **data;
 731         int *count;
 732         int saved_data = 0, overrun = 0;
 733         unsigned char p;
 734
 735         if (hostdata->read_overruns) {
 736                 p = hostdata->connected->SCp.phase;
 737                 if (p & SR_IO) {
 738                         udelay(10);
 739                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
 740                              (BASR_PHASE_MATCH | BASR_ACK)) ==
 741                             (BASR_PHASE_MATCH | BASR_ACK)) {
 742                                 saved_data = NCR5380_read(INPUT_DATA_REG);
 743                                 overrun = 1;
 744                                 dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
 745                         }
 746                 }
 747         }
 748
 749 #ifdef CONFIG_SUN3
 750         if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
 751                 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
 752                        instance->host_no);
 753                 BUG();
 754         }
 755
 756         if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
 757             (BASR_PHASE_MATCH | BASR_ACK)) {
 758                 pr_err("scsi%d: BASR %02x\n", instance->host_no,
 759                        NCR5380_read(BUS_AND_STATUS_REG));
 760                 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
 761                        instance->host_no);
 762                 BUG();
 763         }
 764 #endif
 765
 766         NCR5380_write(MODE_REG, MR_BASE);
 767         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 768         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 769
 770         transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
 771         hostdata->dma_len = 0;
 772
 773         data = (unsigned char **)&hostdata->connected->SCp.ptr;
 774         count = &hostdata->connected->SCp.this_residual;
 775         *data += transferred;
 776         *count -= transferred;
 777
 778         if (hostdata->read_overruns) {
 779                 int cnt, toPIO;
 780
 781                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
 782                         cnt = toPIO = hostdata->read_overruns;
 783                         if (overrun) {
 784                                 dsprintk(NDEBUG_DMA, instance,
 785                                          "Got an input overrun, using saved byte\n");
 786                                 *(*data)++ = saved_data;
 787                                 (*count)--;
 788                                 cnt--;
 789                                 toPIO--;
 790                         }
 791                         if (toPIO > 0) {
 792                                 dsprintk(NDEBUG_DMA, instance,
 793                                          "Doing %d byte PIO to 0x%p\n", cnt, *data);
 794                                 NCR5380_transfer_pio(instance, &p, &cnt, data);
 795                                 *count -= toPIO - cnt;
 796                         }
 797                 }
 798         }
 799 }
 800
 801 /**
 802  * NCR5380_intr - generic NCR5380 irq handler
 803  * @irq: interrupt number
 804  * @dev_id: device info
 805  *
 806  * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 807  * from the disconnected queue, and restarting NCR5380_main()
 808  * as required.
 809  *
 810  * The chip can assert IRQ in any of six different conditions. The IRQ flag
 811  * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
 812  * Three of these six conditions are latched in the Bus and Status Register:
 813  * - End of DMA (cleared by ending DMA Mode)
 814  * - Parity error (cleared by reading RPIR)
 815  * - Loss of BSY (cleared by reading RPIR)
 816  * Two conditions have flag bits that are not latched:
 817  * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
 818  * - Bus reset (non-maskable)
 819  * The remaining condition has no flag bit at all:
 820  * - Selection/reselection
 821  *
 822  * Hence, establishing the cause(s) of any interrupt is partly guesswork.
 823  * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
 824  * claimed that "the design of the [DP8490] interrupt logic ensures
 825  * interrupts will not be lost (they can be on the DP5380)."
 826  * The L5380/53C80 datasheet from LOGIC Devices has more details.
 827  *
 828  * Checking for bus reset by reading RST is futile because of interrupt
 829  * latency, but a bus reset will reset chip logic. Checking for parity error
 830  * is unnecessary because that interrupt is never enabled. A Loss of BSY
 831  * condition will clear DMA Mode. We can tell when this occurs because the
 832  * the Busy Monitor interrupt is enabled together with DMA Mode.
 833  */
 834
 835 static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
 836 {
 837         struct Scsi_Host *instance = dev_id;
 838         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 839         int handled = 0;
 840         unsigned char basr;
 841         unsigned long flags;
 842
 843         spin_lock_irqsave(&hostdata->lock, flags);
 844
 845         basr = NCR5380_read(BUS_AND_STATUS_REG);
 846         if (basr & BASR_IRQ) {
 847                 unsigned char mr = NCR5380_read(MODE_REG);
 848                 unsigned char sr = NCR5380_read(STATUS_REG);
 849
 850                 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
 851                          irq, basr, sr, mr);
 852
 853                 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
 854                         /* Probably End of DMA, Phase Mismatch or Loss of BSY.
 855                          * We ack IRQ after clearing Mode Register. Workarounds
 856                          * for End of DMA errata need to happen in DMA Mode.
 857                          */
 858
 859                         dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
 860
 861                         if (hostdata->connected) {
 862                                 NCR5380_dma_complete(instance);
 863                                 queue_work(hostdata->work_q, &hostdata->main_task);
 864                         } else {
 865                                 NCR5380_write(MODE_REG, MR_BASE);
 866                                 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 867                         }
 868                 } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
 869                     (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
 870                         /* Probably reselected */
 871                         NCR5380_write(SELECT_ENABLE_REG, 0);
 872                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 873
 874                         dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
 875
 876                         if (!hostdata->connected) {
 877                                 NCR5380_reselect(instance);
 878                                 queue_work(hostdata->work_q, &hostdata->main_task);
 879                         }
 880                         if (!hostdata->connected)
 881                                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 882                 } else {
 883                         /* Probably Bus Reset */
 884                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 885
 886                         dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
 887 #ifdef SUN3_SCSI_VME
 888                         dregs->csr |= CSR_DMA_ENABLE;
 889 #endif
 890                 }
 891                 handled = 1;
 892         } else {
 893                 dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
 894 #ifdef SUN3_SCSI_VME
 895                 dregs->csr |= CSR_DMA_ENABLE;
 896 #endif
 897         }
 898
 899         spin_unlock_irqrestore(&hostdata->lock, flags);
 900
 901         return IRQ_RETVAL(handled);
 902 }
 903
 904 /*
 905  * Function : int NCR5380_select(struct Scsi_Host *instance,
 906  * struct scsi_cmnd *cmd)
 907  *
 908  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
 909  * including ARBITRATION, SELECTION, and initial message out for
 910  * IDENTIFY and queue messages.
 911  *
 912  * Inputs : instance - instantiation of the 5380 driver on which this
 913  * target lives, cmd - SCSI command to execute.
 914  *
 915  * Returns cmd if selection failed but should be retried,
 916  * NULL if selection failed and should not be retried, or
 917  * NULL if selection succeeded (hostdata->connected == cmd).
 918  *
 919  * Side effects :
 920  * If bus busy, arbitration failed, etc, NCR5380_select() will exit
 921  * with registers as they should have been on entry - ie
 922  * SELECT_ENABLE will be set appropriately, the NCR5380
 923  * will cease to drive any SCSI bus signals.
 924  *
 925  * If successful : I_T_L or I_T_L_Q nexus will be established,
 926  * instance->connected will be set to cmd.
 927  * SELECT interrupt will be disabled.
 928  *
 929  * If failed (no target) : cmd->scsi_done() will be called, and the
 930  * cmd->result host byte set to DID_BAD_TARGET.
 931  */
 932
 933 static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
 934                                         struct scsi_cmnd *cmd)
 935         __releases(&hostdata->lock) __acquires(&hostdata->lock)
 936 {
 937         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 938         unsigned char tmp[3], phase;
 939         unsigned char *data;
 940         int len;
 941         int err;
 942
 943         NCR5380_dprint(NDEBUG_ARBITRATION, instance);
 944         dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
 945                  instance->this_id);
 946
 947         /*
 948          * Arbitration and selection phases are slow and involve dropping the
 949          * lock, so we have to watch out for EH. An exception handler may
 950          * change 'selecting' to NULL. This function will then return NULL
 951          * so that the caller will forget about 'cmd'. (During information
 952          * transfer phases, EH may change 'connected' to NULL.)
 953          */
 954         hostdata->selecting = cmd;
 955
 956         /*
 957          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
 958          * data bus during SELECTION.
 959          */
 960
 961         NCR5380_write(TARGET_COMMAND_REG, 0);
 962
 963         /*
 964          * Start arbitration.
 965          */
 966
 967         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
 968         NCR5380_write(MODE_REG, MR_ARBITRATE);
 969
 970         /* The chip now waits for BUS FREE phase. Then after the 800 ns
 971          * Bus Free Delay, arbitration will begin.
 972          */
 973
 974         spin_unlock_irq(&hostdata->lock);
 975         err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
 976                         INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
 977                                                ICR_ARBITRATION_PROGRESS, HZ);
 978         spin_lock_irq(&hostdata->lock);
 979         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
 980                 /* Reselection interrupt */
 981                 goto out;
 982         }
 983         if (!hostdata->selecting) {
 984                 /* Command was aborted */
 985                 NCR5380_write(MODE_REG, MR_BASE);
 986                 goto out;
 987         }
 988         if (err < 0) {
 989                 NCR5380_write(MODE_REG, MR_BASE);
 990                 shost_printk(KERN_ERR, instance,
 991                              "select: arbitration timeout\n");
 992                 goto out;
 993         }
 994         spin_unlock_irq(&hostdata->lock);
 995
 996         /* The SCSI-2 arbitration delay is 2.4 us */
 997         udelay(3);
 998
 999         /* Check for lost arbitration */
1000         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1001             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1002             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1003                 NCR5380_write(MODE_REG, MR_BASE);
1004                 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1005                 spin_lock_irq(&hostdata->lock);
1006                 goto out;
1007         }
1008
1009         /* After/during arbitration, BSY should be asserted.
1010          * IBM DPES-31080 Version S31Q works now
1011          * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1012          */
1013         NCR5380_write(INITIATOR_COMMAND_REG,
1014                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1015
1016         /*
1017          * Again, bus clear + bus settle time is 1.2us, however, this is
1018          * a minimum so we'll udelay ceil(1.2)
1019          */
1020
1021         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1022                 udelay(15);
1023         else
1024                 udelay(2);
1025
1026         spin_lock_irq(&hostdata->lock);
1027
1028         /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1029         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1030                 goto out;
1031
1032         if (!hostdata->selecting) {
1033                 NCR5380_write(MODE_REG, MR_BASE);
1034                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1035                 goto out;
1036         }
1037
1038         dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1039
1040         /*
1041          * Now that we have won arbitration, start Selection process, asserting
1042          * the host and target ID's on the SCSI bus.
1043          */
1044
1045         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1046
1047         /*
1048          * Raise ATN while SEL is true before BSY goes false from arbitration,
1049          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1050          * phase immediately after selection.
1051          */
1052
1053         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1054                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1055         NCR5380_write(MODE_REG, MR_BASE);
1056
1057         /*
1058          * Reselect interrupts must be turned off prior to the dropping of BSY,
1059          * otherwise we will trigger an interrupt.
1060          */
1061         NCR5380_write(SELECT_ENABLE_REG, 0);
1062
1063         spin_unlock_irq(&hostdata->lock);
1064
1065         /*
1066          * The initiator shall then wait at least two deskew delays and release
1067          * the BSY signal.
1068          */
1069         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1070
1071         /* Reset BSY */
1072         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1073                       ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1074
1075         /*
1076          * Something weird happens when we cease to drive BSY - looks
1077          * like the board/chip is letting us do another read before the
1078          * appropriate propagation delay has expired, and we're confusing
1079          * a BSY signal from ourselves as the target's response to SELECTION.
1080          *
1081          * A small delay (the 'C++' frontend breaks the pipeline with an
1082          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1083          * tighter 'C' code breaks and requires this) solves the problem -
1084          * the 1 us delay is arbitrary, and only used because this delay will
1085          * be the same on other platforms and since it works here, it should
1086          * work there.
1087          *
1088          * wingel suggests that this could be due to failing to wait
1089          * one deskew delay.
1090          */
1091
1092         udelay(1);
1093
1094         dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1095
1096         /*
1097          * The SCSI specification calls for a 250 ms timeout for the actual
1098          * selection.
1099          */
1100
1101         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
1102                                     msecs_to_jiffies(250));
1103
1104         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1105                 spin_lock_irq(&hostdata->lock);
1106                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1107                 NCR5380_reselect(instance);
1108                 if (!hostdata->connected)
1109                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1110                 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1111                 goto out;
1112         }
1113
1114         if (err < 0) {
1115                 spin_lock_irq(&hostdata->lock);
1116                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1117                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1118                 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1119                 if (hostdata->selecting) {
1120                         cmd->result = DID_BAD_TARGET << 16;
1121                         complete_cmd(instance, cmd);
1122                         dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n");
1123                         cmd = NULL;
1124                 }
1125                 goto out;
1126         }
1127
1128         /*
1129          * No less than two deskew delays after the initiator detects the
1130          * BSY signal is true, it shall release the SEL signal and may
1131          * change the DATA BUS.                                     -wingel
1132          */
1133
1134         udelay(1);
1135
1136         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1137
1138         /*
1139          * Since we followed the SCSI spec, and raised ATN while SEL
1140          * was true but before BSY was false during selection, the information
1141          * transfer phase should be a MESSAGE OUT phase so that we can send the
1142          * IDENTIFY message.
1143          */
1144
1145         /* Wait for start of REQ/ACK handshake */
1146
1147         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1148         spin_lock_irq(&hostdata->lock);
1149         if (err < 0) {
1150                 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1151                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1152                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1153                 goto out;
1154         }
1155         if (!hostdata->selecting) {
1156                 do_abort(instance);
1157                 goto out;
1158         }
1159
1160         dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1161                  scmd_id(cmd));
1162         tmp[0] = IDENTIFY(((instance->irq == NO_IRQ) ? 0 : 1), cmd->device->lun);
1163
1164         len = 1;
1165         data = tmp;
1166         phase = PHASE_MSGOUT;
1167         NCR5380_transfer_pio(instance, &phase, &len, &data);
1168         if (len) {
1169                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1170                 cmd->result = DID_ERROR << 16;
1171                 complete_cmd(instance, cmd);
1172                 dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
1173                 cmd = NULL;
1174                 goto out;
1175         }
1176
1177         dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1178
1179         hostdata->connected = cmd;
1180         hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1181
1182 #ifdef SUN3_SCSI_VME
1183         dregs->csr |= CSR_INTR;
1184 #endif
1185
1186         initialize_SCp(cmd);
1187
1188         cmd = NULL;
1189
1190 out:
1191         if (!hostdata->selecting)
1192                 return NULL;
1193         hostdata->selecting = NULL;
1194         return cmd;
1195 }
1196
1197 /*
1198  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1199  * unsigned char *phase, int *count, unsigned char **data)
1200  *
1201  * Purpose : transfers data in given phase using polled I/O
1202  *
1203  * Inputs : instance - instance of driver, *phase - pointer to
1204  * what phase is expected, *count - pointer to number of
1205  * bytes to transfer, **data - pointer to data pointer.
1206  *
1207  * Returns : -1 when different phase is entered without transferring
1208  * maximum number of bytes, 0 if all bytes are transferred or exit
1209  * is in same phase.
1210  *
1211  * Also, *phase, *count, *data are modified in place.
1212  *
1213  * XXX Note : handling for bus free may be useful.
1214  */
1215
1216 /*
1217  * Note : this code is not as quick as it could be, however it
1218  * IS 100% reliable, and for the actual data transfer where speed
1219  * counts, we will always do a pseudo DMA or DMA transfer.
1220  */
1221
1222 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1223                                 unsigned char *phase, int *count,
1224                                 unsigned char **data)
1225 {
1226         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1227         unsigned char p = *phase, tmp;
1228         int c = *count;
1229         unsigned char *d = *data;
1230
1231         /*
1232          * The NCR5380 chip will only drive the SCSI bus when the
1233          * phase specified in the appropriate bits of the TARGET COMMAND
1234          * REGISTER match the STATUS REGISTER
1235          */
1236
1237         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1238
1239         do {
1240                 /*
1241                  * Wait for assertion of REQ, after which the phase bits will be
1242                  * valid
1243                  */
1244
1245                 if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1246                         break;
1247
1248                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1249
1250                 /* Check for phase mismatch */
1251                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1252                         dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1253                         NCR5380_dprint_phase(NDEBUG_PIO, instance);
1254                         break;
1255                 }
1256
1257                 /* Do actual transfer from SCSI bus to / from memory */
1258                 if (!(p & SR_IO))
1259                         NCR5380_write(OUTPUT_DATA_REG, *d);
1260                 else
1261                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1262
1263                 ++d;
1264
1265                 /*
1266                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1267                  * should drop ATN on the last byte of the message phase
1268                  * after REQ has been asserted for the handshake but before
1269                  * the initiator raises ACK.
1270                  */
1271
1272                 if (!(p & SR_IO)) {
1273                         if (!((p & SR_MSG) && c > 1)) {
1274                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1275                                 NCR5380_dprint(NDEBUG_PIO, instance);
1276                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1277                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1278                         } else {
1279                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1280                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1281                                 NCR5380_dprint(NDEBUG_PIO, instance);
1282                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1283                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1284                         }
1285                 } else {
1286                         NCR5380_dprint(NDEBUG_PIO, instance);
1287                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1288                 }
1289
1290                 if (NCR5380_poll_politely(hostdata,
1291                                           STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1292                         break;
1293
1294                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1295
1296 /*
1297  * We have several special cases to consider during REQ/ACK handshaking :
1298  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1299  * message.  ATN must be dropped as ACK is dropped.
1300  *
1301  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1302  * message.  We must exit with ACK asserted, so that the calling
1303  * code may raise ATN before dropping ACK to reject the message.
1304  *
1305  * 3.  ACK and ATN are clear and the target may proceed as normal.
1306  */
1307                 if (!(p == PHASE_MSGIN && c == 1)) {
1308                         if (p == PHASE_MSGOUT && c > 1)
1309                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1310                         else
1311                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1312                 }
1313         } while (--c);
1314
1315         dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1316
1317         *count = c;
1318         *data = d;
1319         tmp = NCR5380_read(STATUS_REG);
1320         /* The phase read from the bus is valid if either REQ is (already)
1321          * asserted or if ACK hasn't been released yet. The latter applies if
1322          * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1323          */
1324         if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1325                 *phase = tmp & PHASE_MASK;
1326         else
1327                 *phase = PHASE_UNKNOWN;
1328
1329         if (!c || (*phase == p))
1330                 return 0;
1331         else
1332                 return -1;
1333 }
1334
1335 /**
1336  * do_reset - issue a reset command
1337  * @instance: adapter to reset
1338  *
1339  * Issue a reset sequence to the NCR5380 and try and get the bus
1340  * back into sane shape.
1341  *
1342  * This clears the reset interrupt flag because there may be no handler for
1343  * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1344  * been installed. And when in EH we may have released the ST DMA interrupt.
1345  */
1346
1347 static void do_reset(struct Scsi_Host *instance)
1348 {
1349         struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
1350         unsigned long flags;
1351
1352         local_irq_save(flags);
1353         NCR5380_write(TARGET_COMMAND_REG,
1354                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1355         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1356         udelay(50);
1357         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1358         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1359         local_irq_restore(flags);
1360 }
1361
1362 /**
1363  * do_abort - abort the currently established nexus by going to
1364  * MESSAGE OUT phase and sending an ABORT message.
1365  * @instance: relevant scsi host instance
1366  *
1367  * Returns 0 on success, -1 on failure.
1368  */
1369
1370 static int do_abort(struct Scsi_Host *instance)
1371 {
1372         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1373         unsigned char *msgptr, phase, tmp;
1374         int len;
1375         int rc;
1376
1377         /* Request message out phase */
1378         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1379
1380         /*
1381          * Wait for the target to indicate a valid phase by asserting
1382          * REQ.  Once this happens, we'll have either a MSGOUT phase
1383          * and can immediately send the ABORT message, or we'll have some
1384          * other phase and will have to source/sink data.
1385          *
1386          * We really don't care what value was on the bus or what value
1387          * the target sees, so we just handshake.
1388          */
1389
1390         rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1391         if (rc < 0)
1392                 goto timeout;
1393
1394         tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1395
1396         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1397
1398         if (tmp != PHASE_MSGOUT) {
1399                 NCR5380_write(INITIATOR_COMMAND_REG,
1400                               ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1401                 rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
1402                 if (rc < 0)
1403                         goto timeout;
1404                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1405         }
1406
1407         tmp = ABORT;
1408         msgptr = &tmp;
1409         len = 1;
1410         phase = PHASE_MSGOUT;
1411         NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1412
1413         /*
1414          * If we got here, and the command completed successfully,
1415          * we're about to go into bus free state.
1416          */
1417
1418         return len ? -1 : 0;
1419
1420 timeout:
1421         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1422         return -1;
1423 }
1424
1425 /*
1426  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1427  * unsigned char *phase, int *count, unsigned char **data)
1428  *
1429  * Purpose : transfers data in given phase using either real
1430  * or pseudo DMA.
1431  *
1432  * Inputs : instance - instance of driver, *phase - pointer to
1433  * what phase is expected, *count - pointer to number of
1434  * bytes to transfer, **data - pointer to data pointer.
1435  *
1436  * Returns : -1 when different phase is entered without transferring
1437  * maximum number of bytes, 0 if all bytes or transferred or exit
1438  * is in same phase.
1439  *
1440  * Also, *phase, *count, *data are modified in place.
1441  */
1442
1443
1444 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1445                                 unsigned char *phase, int *count,
1446                                 unsigned char **data)
1447 {
1448         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1449         int c = *count;
1450         unsigned char p = *phase;
1451         unsigned char *d = *data;
1452         unsigned char tmp;
1453         int result = 0;
1454
1455         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1456                 *phase = tmp;
1457                 return -1;
1458         }
1459
1460         hostdata->connected->SCp.phase = p;
1461
1462         if (p & SR_IO) {
1463                 if (hostdata->read_overruns)
1464                         c -= hostdata->read_overruns;
1465                 else if (hostdata->flags & FLAG_DMA_FIXUP)
1466                         --c;
1467         }
1468
1469         dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1470                  (p & SR_IO) ? "receive" : "send", c, d);
1471
1472 #ifdef CONFIG_SUN3
1473         /* send start chain */
1474         sun3scsi_dma_start(c, *data);
1475 #endif
1476
1477         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1478         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1479                                 MR_ENABLE_EOP_INTR);
1480
1481         if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1482                 /* On the Medusa, it is a must to initialize the DMA before
1483                  * starting the NCR. This is also the cleaner way for the TT.
1484                  */
1485                 if (p & SR_IO)
1486                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1487                 else
1488                         result = NCR5380_dma_send_setup(hostdata, d, c);
1489         }
1490
1491         /*
1492          * On the PAS16 at least I/O recovery delays are not needed here.
1493          * Everyone else seems to want them.
1494          */
1495
1496         if (p & SR_IO) {
1497                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1498                 NCR5380_io_delay(1);
1499                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1500         } else {
1501                 NCR5380_io_delay(1);
1502                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1503                 NCR5380_io_delay(1);
1504                 NCR5380_write(START_DMA_SEND_REG, 0);
1505                 NCR5380_io_delay(1);
1506         }
1507
1508 #ifdef CONFIG_SUN3
1509 #ifdef SUN3_SCSI_VME
1510         dregs->csr |= CSR_DMA_ENABLE;
1511 #endif
1512         sun3_dma_active = 1;
1513 #endif
1514
1515         if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1516                 /* On the Falcon, the DMA setup must be done after the last
1517                  * NCR access, else the DMA setup gets trashed!
1518                  */
1519                 if (p & SR_IO)
1520                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1521                 else
1522                         result = NCR5380_dma_send_setup(hostdata, d, c);
1523         }
1524
1525         /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
1526         if (result < 0)
1527                 return result;
1528
1529         /* For real DMA, result is the byte count. DMA interrupt is expected. */
1530         if (result > 0) {
1531                 hostdata->dma_len = result;
1532                 return 0;
1533         }
1534
1535         /* The result is zero iff pseudo DMA send/receive was completed. */
1536         hostdata->dma_len = c;
1537
1538 /*
1539  * A note regarding the DMA errata workarounds for early NMOS silicon.
1540  *
1541  * For DMA sends, we want to wait until the last byte has been
1542  * transferred out over the bus before we turn off DMA mode.  Alas, there
1543  * seems to be no terribly good way of doing this on a 5380 under all
1544  * conditions.  For non-scatter-gather operations, we can wait until REQ
1545  * and ACK both go false, or until a phase mismatch occurs.  Gather-sends
1546  * are nastier, since the device will be expecting more data than we
1547  * are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1548  * could test Last Byte Sent to assure transfer (I imagine this is precisely
1549  * why this signal was added to the newer chips) but on the older 538[01]
1550  * this signal does not exist.  The workaround for this lack is a watchdog;
1551  * we bail out of the wait-loop after a modest amount of wait-time if
1552  * the usual exit conditions are not met.  Not a terribly clean or
1553  * correct solution :-%
1554  *
1555  * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1556  * If the chip is in DMA receive mode, it will respond to a target's
1557  * REQ by latching the SCSI data into the INPUT DATA register and asserting
1558  * ACK, even if it has _already_ been notified by the DMA controller that
1559  * the current DMA transfer has completed!  If the NCR5380 is then taken
1560  * out of DMA mode, this already-acknowledged byte is lost. This is
1561  * not a problem for "one DMA transfer per READ command", because
1562  * the situation will never arise... either all of the data is DMA'ed
1563  * properly, or the target switches to MESSAGE IN phase to signal a
1564  * disconnection (either operation bringing the DMA to a clean halt).
1565  * However, in order to handle scatter-receive, we must work around the
1566  * problem.  The chosen fix is to DMA fewer bytes, then check for the
1567  * condition before taking the NCR5380 out of DMA mode.  One or two extra
1568  * bytes are transferred via PIO as necessary to fill out the original
1569  * request.
1570  */
1571
1572         if (hostdata->flags & FLAG_DMA_FIXUP) {
1573                 if (p & SR_IO) {
1574                         /*
1575                          * The workaround was to transfer fewer bytes than we
1576                          * intended to with the pseudo-DMA read function, wait for
1577                          * the chip to latch the last byte, read it, and then disable
1578                          * pseudo-DMA mode.
1579                          *
1580                          * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1581                          * REQ is deasserted when ACK is asserted, and not reasserted
1582                          * until ACK goes false.  Since the NCR5380 won't lower ACK
1583                          * until DACK is asserted, which won't happen unless we twiddle
1584                          * the DMA port or we take the NCR5380 out of DMA mode, we
1585                          * can guarantee that we won't handshake another extra
1586                          * byte.
1587                          */
1588
1589                         if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
1590                                                   BASR_DRQ, BASR_DRQ, HZ) < 0) {
1591                                 result = -1;
1592                                 shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1593                         }
1594                         if (NCR5380_poll_politely(hostdata, STATUS_REG,
1595                                                   SR_REQ, 0, HZ) < 0) {
1596                                 result = -1;
1597                                 shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1598                         }
1599                         d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
1600                 } else {
1601                         /*
1602                          * Wait for the last byte to be sent.  If REQ is being asserted for
1603                          * the byte we're interested, we'll ACK it and it will go false.
1604                          */
1605                         if (NCR5380_poll_politely2(hostdata,
1606                              BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1607                              BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
1608                                 result = -1;
1609                                 shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1610                         }
1611                 }
1612         }
1613
1614         NCR5380_dma_complete(instance);
1615         return result;
1616 }
1617
1618 /*
1619  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1620  *
1621  * Purpose : run through the various SCSI phases and do as the target
1622  * directs us to.  Operates on the currently connected command,
1623  * instance->connected.
1624  *
1625  * Inputs : instance, instance for which we are doing commands
1626  *
1627  * Side effects : SCSI things happen, the disconnected queue will be
1628  * modified if a command disconnects, *instance->connected will
1629  * change.
1630  *
1631  * XXX Note : we need to watch for bus free or a reset condition here
1632  * to recover from an unexpected bus free condition.
1633  */
1634
1635 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1636         __releases(&hostdata->lock) __acquires(&hostdata->lock)
1637 {
1638         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1639         unsigned char msgout = NOP;
1640         int sink = 0;
1641         int len;
1642         int transfersize;
1643         unsigned char *data;
1644         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1645         struct scsi_cmnd *cmd;
1646
1647 #ifdef SUN3_SCSI_VME
1648         dregs->csr |= CSR_INTR;
1649 #endif
1650
1651         while ((cmd = hostdata->connected)) {
1652                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1653
1654                 tmp = NCR5380_read(STATUS_REG);
1655                 /* We only have a valid SCSI phase when REQ is asserted */
1656                 if (tmp & SR_REQ) {
1657                         phase = (tmp & PHASE_MASK);
1658                         if (phase != old_phase) {
1659                                 old_phase = phase;
1660                                 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1661                         }
1662 #ifdef CONFIG_SUN3
1663                         if (phase == PHASE_CMDOUT &&
1664                             sun3_dma_setup_done != cmd) {
1665                                 int count;
1666
1667                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1668                                         ++cmd->SCp.buffer;
1669                                         --cmd->SCp.buffers_residual;
1670                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
1671                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1672                                 }
1673
1674                                 count = sun3scsi_dma_xfer_len(hostdata, cmd);
1675
1676                                 if (count > 0) {
1677                                         if (rq_data_dir(cmd->request))
1678                                                 sun3scsi_dma_send_setup(hostdata,
1679                                                                         cmd->SCp.ptr, count);
1680                                         else
1681                                                 sun3scsi_dma_recv_setup(hostdata,
1682                                                                         cmd->SCp.ptr, count);
1683                                         sun3_dma_setup_done = cmd;
1684                                 }
1685 #ifdef SUN3_SCSI_VME
1686                                 dregs->csr |= CSR_INTR;
1687 #endif
1688                         }
1689 #endif /* CONFIG_SUN3 */
1690
1691                         if (sink && (phase != PHASE_MSGOUT)) {
1692                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1693
1694                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1695                                               ICR_ASSERT_ACK);
1696                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1697                                         ;
1698                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1699                                               ICR_ASSERT_ATN);
1700                                 sink = 0;
1701                                 continue;
1702                         }
1703
1704                         switch (phase) {
1705                         case PHASE_DATAOUT:
1706 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1707                                 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1708                                 sink = 1;
1709                                 do_abort(instance);
1710                                 cmd->result = DID_ERROR << 16;
1711                                 complete_cmd(instance, cmd);
1712                                 hostdata->connected = NULL;
1713                                 return;
1714 #endif
1715                         case PHASE_DATAIN:
1716                                 /*
1717                                  * If there is no room left in the current buffer in the
1718                                  * scatter-gather list, move onto the next one.
1719                                  */
1720
1721                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1722                                         ++cmd->SCp.buffer;
1723                                         --cmd->SCp.buffers_residual;
1724                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
1725                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1726                                         dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
1727                                                  cmd->SCp.this_residual,
1728                                                  cmd->SCp.buffers_residual);
1729                                 }
1730
1731                                 /*
1732                                  * The preferred transfer method is going to be
1733                                  * PSEUDO-DMA for systems that are strictly PIO,
1734                                  * since we can let the hardware do the handshaking.
1735                                  *
1736                                  * For this to work, we need to know the transfersize
1737                                  * ahead of time, since the pseudo-DMA code will sit
1738                                  * in an unconditional loop.
1739                                  */
1740
1741                                 transfersize = 0;
1742                                 if (!cmd->device->borken)
1743                                         transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
1744
1745                                 if (transfersize > 0) {
1746                                         len = transfersize;
1747                                         if (NCR5380_transfer_dma(instance, &phase,
1748                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
1749                                                 /*
1750                                                  * If the watchdog timer fires, all future
1751                                                  * accesses to this device will use the
1752                                                  * polled-IO.
1753                                                  */
1754                                                 scmd_printk(KERN_INFO, cmd,
1755                                                         "switching to slow handshake\n");
1756                                                 cmd->device->borken = 1;
1757                                                 sink = 1;
1758                                                 do_abort(instance);
1759                                                 cmd->result = DID_ERROR << 16;
1760                                                 /* XXX - need to source or sink data here, as appropriate */
1761                                         }
1762                                 } else {
1763                                         /* Transfer a small chunk so that the
1764                                          * irq mode lock is not held too long.
1765                                          */
1766                                         transfersize = min(cmd->SCp.this_residual,
1767                                                            NCR5380_PIO_CHUNK_SIZE);
1768                                         len = transfersize;
1769                                         NCR5380_transfer_pio(instance, &phase, &len,
1770                                                              (unsigned char **)&cmd->SCp.ptr);
1771                                         cmd->SCp.this_residual -= transfersize - len;
1772                                 }
1773 #ifdef CONFIG_SUN3
1774                                 if (sun3_dma_setup_done == cmd)
1775                                         sun3_dma_setup_done = NULL;
1776 #endif
1777                                 return;
1778                         case PHASE_MSGIN:
1779                                 len = 1;
1780                                 data = &tmp;
1781                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1782                                 cmd->SCp.Message = tmp;
1783
1784                                 switch (tmp) {
1785                                 case ABORT:
1786                                 case COMMAND_COMPLETE:
1787                                         /* Accept message by clearing ACK */
1788                                         sink = 1;
1789                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1790                                         dsprintk(NDEBUG_QUEUES, instance,
1791                                                  "COMMAND COMPLETE %p target %d lun %llu\n",
1792                                                  cmd, scmd_id(cmd), cmd->device->lun);
1793
1794                                         hostdata->connected = NULL;
1795
1796                                         cmd->result &= ~0xffff;
1797                                         cmd->result |= cmd->SCp.Status;
1798                                         cmd->result |= cmd->SCp.Message << 8;
1799
1800                                         if (cmd->cmnd[0] == REQUEST_SENSE)
1801                                                 complete_cmd(instance, cmd);
1802                                         else {
1803                                                 if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1804                                                     cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1805                                                         dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1806                                                                  cmd);
1807                                                         list_add_tail(&ncmd->list,
1808                                                                       &hostdata->autosense);
1809                                                 } else
1810                                                         complete_cmd(instance, cmd);
1811                                         }
1812
1813                                         /*
1814                                          * Restore phase bits to 0 so an interrupted selection,
1815                                          * arbitration can resume.
1816                                          */
1817                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1818
1819                                         /* Enable reselect interrupts */
1820                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1821
1822                                         maybe_release_dma_irq(instance);
1823                                         return;
1824                                 case MESSAGE_REJECT:
1825                                         /* Accept message by clearing ACK */
1826                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1827                                         switch (hostdata->last_message) {
1828                                         case HEAD_OF_QUEUE_TAG:
1829                                         case ORDERED_QUEUE_TAG:
1830                                         case SIMPLE_QUEUE_TAG:
1831                                                 cmd->device->simple_tags = 0;
1832                                                 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1833                                                 break;
1834                                         default:
1835                                                 break;
1836                                         }
1837                                         break;
1838                                 case DISCONNECT:
1839                                         /* Accept message by clearing ACK */
1840                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1841                                         hostdata->connected = NULL;
1842                                         list_add(&ncmd->list, &hostdata->disconnected);
1843                                         dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1844                                                  instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1845                                                  cmd, scmd_id(cmd), cmd->device->lun);
1846
1847                                         /*
1848                                          * Restore phase bits to 0 so an interrupted selection,
1849                                          * arbitration can resume.
1850                                          */
1851                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1852
1853                                         /* Enable reselect interrupts */
1854                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1855 #ifdef SUN3_SCSI_VME
1856                                         dregs->csr |= CSR_DMA_ENABLE;
1857 #endif
1858                                         return;
1859                                         /*
1860                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1861                                          * operation, in violation of the SCSI spec so we can safely
1862                                          * ignore SAVE/RESTORE pointers calls.
1863                                          *
1864                                          * Unfortunately, some disks violate the SCSI spec and
1865                                          * don't issue the required SAVE_POINTERS message before
1866                                          * disconnecting, and we have to break spec to remain
1867                                          * compatible.
1868                                          */
1869                                 case SAVE_POINTERS:
1870                                 case RESTORE_POINTERS:
1871                                         /* Accept message by clearing ACK */
1872                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1873                                         break;
1874                                 case EXTENDED_MESSAGE:
1875                                         /*
1876                                          * Start the message buffer with the EXTENDED_MESSAGE
1877                                          * byte, since spi_print_msg() wants the whole thing.
1878                                          */
1879                                         extended_msg[0] = EXTENDED_MESSAGE;
1880                                         /* Accept first byte by clearing ACK */
1881                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1882
1883                                         spin_unlock_irq(&hostdata->lock);
1884
1885                                         dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1886
1887                                         len = 2;
1888                                         data = extended_msg + 1;
1889                                         phase = PHASE_MSGIN;
1890                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
1891                                         dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1892                                                  (int)extended_msg[1],
1893                                                  (int)extended_msg[2]);
1894
1895                                         if (!len && extended_msg[1] > 0 &&
1896                                             extended_msg[1] <= sizeof(extended_msg) - 2) {
1897                                                 /* Accept third byte by clearing ACK */
1898                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1899                                                 len = extended_msg[1] - 1;
1900                                                 data = extended_msg + 3;
1901                                                 phase = PHASE_MSGIN;
1902
1903                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1904                                                 dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
1905                                                          len);
1906
1907                                                 switch (extended_msg[2]) {
1908                                                 case EXTENDED_SDTR:
1909                                                 case EXTENDED_WDTR:
1910                                                 case EXTENDED_MODIFY_DATA_POINTER:
1911                                                 case EXTENDED_EXTENDED_IDENTIFY:
1912                                                         tmp = 0;
1913                                                 }
1914                                         } else if (len) {
1915                                                 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1916                                                 tmp = 0;
1917                                         } else {
1918                                                 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
1919                                                              extended_msg[2], extended_msg[1]);
1920                                                 tmp = 0;
1921                                         }
1922
1923                                         spin_lock_irq(&hostdata->lock);
1924                                         if (!hostdata->connected)
1925                                                 return;
1926
1927                                         /* Fall through to reject message */
1928
1929                                         /*
1930                                          * If we get something weird that we aren't expecting,
1931                                          * reject it.
1932                                          */
1933                                 default:
1934                                         if (!tmp) {
1935                                                 shost_printk(KERN_ERR, instance, "rejecting message ");
1936                                                 spi_print_msg(extended_msg);
1937                                                 printk("\n");
1938                                         } else if (tmp != EXTENDED_MESSAGE)
1939                                                 scmd_printk(KERN_INFO, cmd,
1940                                                             "rejecting unknown message %02x\n",
1941                                                             tmp);
1942                                         else
1943                                                 scmd_printk(KERN_INFO, cmd,
1944                                                             "rejecting unknown extended message code %02x, length %d\n",
1945                                                             extended_msg[1], extended_msg[0]);
1946
1947                                         msgout = MESSAGE_REJECT;
1948                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1949                                         break;
1950                                 } /* switch (tmp) */
1951                                 break;
1952                         case PHASE_MSGOUT:
1953                                 len = 1;
1954                                 data = &msgout;
1955                                 hostdata->last_message = msgout;
1956                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1957                                 if (msgout == ABORT) {
1958                                         hostdata->connected = NULL;
1959                                         cmd->result = DID_ERROR << 16;
1960                                         complete_cmd(instance, cmd);
1961                                         maybe_release_dma_irq(instance);
1962                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1963                                         return;
1964                                 }
1965                                 msgout = NOP;
1966                                 break;
1967                         case PHASE_CMDOUT:
1968                                 len = cmd->cmd_len;
1969                                 data = cmd->cmnd;
1970                                 /*
1971                                  * XXX for performance reasons, on machines with a
1972                                  * PSEUDO-DMA architecture we should probably
1973                                  * use the dma transfer function.
1974                                  */
1975                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1976                                 break;
1977                         case PHASE_STATIN:
1978                                 len = 1;
1979                                 data = &tmp;
1980                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1981                                 cmd->SCp.Status = tmp;
1982                                 break;
1983                         default:
1984                                 shost_printk(KERN_ERR, instance, "unknown phase\n");
1985                                 NCR5380_dprint(NDEBUG_ANY, instance);
1986                         } /* switch(phase) */
1987                 } else {
1988                         spin_unlock_irq(&hostdata->lock);
1989                         NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1990                         spin_lock_irq(&hostdata->lock);
1991                 }
1992         }
1993 }
1994
1995 /*
1996  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
1997  *
1998  * Purpose : does reselection, initializing the instance->connected
1999  * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2000  * nexus has been reestablished,
2001  *
2002  * Inputs : instance - this instance of the NCR5380.
2003  */
2004
2005 static void NCR5380_reselect(struct Scsi_Host *instance)
2006 {
2007         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2008         unsigned char target_mask;
2009         unsigned char lun;
2010         unsigned char msg[3];
2011         struct NCR5380_cmd *ncmd;
2012         struct scsi_cmnd *tmp;
2013
2014         /*
2015          * Disable arbitration, etc. since the host adapter obviously
2016          * lost, and tell an interrupted NCR5380_select() to restart.
2017          */
2018
2019         NCR5380_write(MODE_REG, MR_BASE);
2020
2021         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2022
2023         dsprintk(NDEBUG_RESELECTION, instance, "reselect\n");
2024
2025         /*
2026          * At this point, we have detected that our SCSI ID is on the bus,
2027          * SEL is true and BSY was false for at least one bus settle delay
2028          * (400 ns).
2029          *
2030          * We must assert BSY ourselves, until the target drops the SEL
2031          * signal.
2032          */
2033
2034         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2035         if (NCR5380_poll_politely(hostdata,
2036                                   STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2037                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2038                 return;
2039         }
2040         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2041
2042         /*
2043          * Wait for target to go into MSGIN.
2044          */
2045
2046         if (NCR5380_poll_politely(hostdata,
2047                                   STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2048                 do_abort(instance);
2049                 return;
2050         }
2051
2052 #ifdef CONFIG_SUN3
2053         /* acknowledge toggle to MSGIN */
2054         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2055
2056         /* peek at the byte without really hitting the bus */
2057         msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2058 #else
2059         {
2060                 int len = 1;
2061                 unsigned char *data = msg;
2062                 unsigned char phase = PHASE_MSGIN;
2063
2064                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2065
2066                 if (len) {
2067                         do_abort(instance);
2068                         return;
2069                 }
2070         }
2071 #endif /* CONFIG_SUN3 */
2072
2073         if (!(msg[0] & 0x80)) {
2074                 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2075                 spi_print_msg(msg);
2076                 printk("\n");
2077                 do_abort(instance);
2078                 return;
2079         }
2080         lun = msg[0] & 0x07;
2081
2082         /*
2083          * We need to add code for SCSI-II to track which devices have
2084          * I_T_L_Q nexuses established, and which have simple I_T_L
2085          * nexuses so we can chose to do additional data transfer.
2086          */
2087
2088         /*
2089          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2090          * just reestablished, and remove it from the disconnected queue.
2091          */
2092
2093         tmp = NULL;
2094         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2095                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2096
2097                 if (target_mask == (1 << scmd_id(cmd)) &&
2098                     lun == (u8)cmd->device->lun) {
2099                         list_del(&ncmd->list);
2100                         tmp = cmd;
2101                         break;
2102                 }
2103         }
2104
2105         if (tmp) {
2106                 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2107                          "reselect: removed %p from disconnected queue\n", tmp);
2108         } else {
2109                 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2110                              target_mask, lun);
2111                 /*
2112                  * Since we have an established nexus that we can't do anything
2113                  * with, we must abort it.
2114                  */
2115                 do_abort(instance);
2116                 return;
2117         }
2118
2119 #ifdef CONFIG_SUN3
2120         if (sun3_dma_setup_done != tmp) {
2121                 int count;
2122
2123                 if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
2124                         ++tmp->SCp.buffer;
2125                         --tmp->SCp.buffers_residual;
2126                         tmp->SCp.this_residual = tmp->SCp.buffer->length;
2127                         tmp->SCp.ptr = sg_virt(tmp->SCp.buffer);
2128                 }
2129
2130                 count = sun3scsi_dma_xfer_len(hostdata, tmp);
2131
2132                 if (count > 0) {
2133                         if (rq_data_dir(tmp->request))
2134                                 sun3scsi_dma_send_setup(hostdata,
2135                                                         tmp->SCp.ptr, count);
2136                         else
2137                                 sun3scsi_dma_recv_setup(hostdata,
2138                                                         tmp->SCp.ptr, count);
2139                         sun3_dma_setup_done = tmp;
2140                 }
2141         }
2142
2143         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2144 #endif /* CONFIG_SUN3 */
2145
2146         /* Accept message by clearing ACK */
2147         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2148
2149         hostdata->connected = tmp;
2150         dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
2151                  scmd_id(tmp), tmp->device->lun);
2152 }
2153
2154 /**
2155  * list_find_cmd - test for presence of a command in a linked list
2156  * @haystack: list of commands
2157  * @needle: command to search for
2158  */
2159
2160 static bool list_find_cmd(struct list_head *haystack,
2161                           struct scsi_cmnd *needle)
2162 {
2163         struct NCR5380_cmd *ncmd;
2164
2165         list_for_each_entry(ncmd, haystack, list)
2166                 if (NCR5380_to_scmd(ncmd) == needle)
2167                         return true;
2168         return false;
2169 }
2170
2171 /**
2172  * list_remove_cmd - remove a command from linked list
2173  * @haystack: list of commands
2174  * @needle: command to remove
2175  */
2176
2177 static bool list_del_cmd(struct list_head *haystack,
2178                          struct scsi_cmnd *needle)
2179 {
2180         if (list_find_cmd(haystack, needle)) {
2181                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2182
2183                 list_del(&ncmd->list);
2184                 return true;
2185         }
2186         return false;
2187 }
2188
2189 /**
2190  * NCR5380_abort - scsi host eh_abort_handler() method
2191  * @cmd: the command to be aborted
2192  *
2193  * Try to abort a given command by removing it from queues and/or sending
2194  * the target an abort message. This may not succeed in causing a target
2195  * to abort the command. Nonetheless, the low-level driver must forget about
2196  * the command because the mid-layer reclaims it and it may be re-issued.
2197  *
2198  * The normal path taken by a command is as follows. For EH we trace this
2199  * same path to locate and abort the command.
2200  *
2201  * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2202  * [disconnected -> connected ->]...
2203  * [autosense -> connected ->] done
2204  *
2205  * If cmd was not found at all then presumably it has already been completed,
2206  * in which case return SUCCESS to try to avoid further EH measures.
2207  *
2208  * If the command has not completed yet, we must not fail to find it.
2209  * We have no option but to forget the aborted command (even if it still
2210  * lacks sense data). The mid-layer may re-issue a command that is in error
2211  * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2212  * this driver are such that a command can appear on one queue only.
2213  *
2214  * The lock protects driver data structures, but EH handlers also use it
2215  * to serialize their own execution and prevent their own re-entry.
2216  */
2217
2218 static int NCR5380_abort(struct scsi_cmnd *cmd)
2219 {
2220         struct Scsi_Host *instance = cmd->device->host;
2221         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2222         unsigned long flags;
2223         int result = SUCCESS;
2224
2225         spin_lock_irqsave(&hostdata->lock, flags);
2226
2227 #if (NDEBUG & NDEBUG_ANY)
2228         scmd_printk(KERN_INFO, cmd, __func__);
2229 #endif
2230         NCR5380_dprint(NDEBUG_ANY, instance);
2231         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2232
2233         if (list_del_cmd(&hostdata->unissued, cmd)) {
2234                 dsprintk(NDEBUG_ABORT, instance,
2235                          "abort: removed %p from issue queue\n", cmd);
2236                 cmd->result = DID_ABORT << 16;
2237                 cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2238                 goto out;
2239         }
2240
2241         if (hostdata->selecting == cmd) {
2242                 dsprintk(NDEBUG_ABORT, instance,
2243                          "abort: cmd %p == selecting\n", cmd);
2244                 hostdata->selecting = NULL;
2245                 cmd->result = DID_ABORT << 16;
2246                 complete_cmd(instance, cmd);
2247                 goto out;
2248         }
2249
2250         if (list_del_cmd(&hostdata->disconnected, cmd)) {
2251                 dsprintk(NDEBUG_ABORT, instance,
2252                          "abort: removed %p from disconnected list\n", cmd);
2253                 /* Can't call NCR5380_select() and send ABORT because that
2254                  * means releasing the lock. Need a bus reset.
2255                  */
2256                 set_host_byte(cmd, DID_ERROR);
2257                 complete_cmd(instance, cmd);
2258                 result = FAILED;
2259                 goto out;
2260         }
2261
2262         if (hostdata->connected == cmd) {
2263                 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2264                 hostdata->connected = NULL;
2265                 hostdata->dma_len = 0;
2266                 if (do_abort(instance)) {
2267                         set_host_byte(cmd, DID_ERROR);
2268                         complete_cmd(instance, cmd);
2269                         result = FAILED;
2270                         goto out;
2271                 }
2272                 set_host_byte(cmd, DID_ABORT);
2273                 complete_cmd(instance, cmd);
2274                 goto out;
2275         }
2276
2277         if (list_del_cmd(&hostdata->autosense, cmd)) {
2278                 dsprintk(NDEBUG_ABORT, instance,
2279                          "abort: removed %p from sense queue\n", cmd);
2280                 set_host_byte(cmd, DID_ERROR);
2281                 complete_cmd(instance, cmd);
2282         }
2283
2284 out:
2285         if (result == FAILED)
2286                 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2287         else
2288                 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2289
2290         queue_work(hostdata->work_q, &hostdata->main_task);
2291         maybe_release_dma_irq(instance);
2292         spin_unlock_irqrestore(&hostdata->lock, flags);
2293
2294         return result;
2295 }
2296
2297
2298 /**
2299  * NCR5380_bus_reset - reset the SCSI bus
2300  * @cmd: SCSI command undergoing EH
2301  *
2302  * Returns SUCCESS
2303  */
2304
2305 static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
2306 {
2307         struct Scsi_Host *instance = cmd->device->host;
2308         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2309         int i;
2310         unsigned long flags;
2311         struct NCR5380_cmd *ncmd;
2312
2313         spin_lock_irqsave(&hostdata->lock, flags);
2314
2315 #if (NDEBUG & NDEBUG_ANY)
2316         scmd_printk(KERN_INFO, cmd, __func__);
2317 #endif
2318         NCR5380_dprint(NDEBUG_ANY, instance);
2319         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2320
2321         do_reset(instance);
2322
2323         /* reset NCR registers */
2324         NCR5380_write(MODE_REG, MR_BASE);
2325         NCR5380_write(TARGET_COMMAND_REG, 0);
2326         NCR5380_write(SELECT_ENABLE_REG, 0);
2327
2328         /* After the reset, there are no more connected or disconnected commands
2329          * and no busy units; so clear the low-level status here to avoid
2330          * conflicts when the mid-level code tries to wake up the affected
2331          * commands!
2332          */
2333
2334         if (list_del_cmd(&hostdata->unissued, cmd)) {
2335                 cmd->result = DID_RESET << 16;
2336                 cmd->scsi_done(cmd);
2337         }
2338
2339         if (hostdata->selecting) {
2340                 hostdata->selecting->result = DID_RESET << 16;
2341                 complete_cmd(instance, hostdata->selecting);
2342                 hostdata->selecting = NULL;
2343         }
2344
2345         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2346                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2347
2348                 set_host_byte(cmd, DID_RESET);
2349                 complete_cmd(instance, cmd);
2350         }
2351         INIT_LIST_HEAD(&hostdata->disconnected);
2352
2353         list_for_each_entry(ncmd, &hostdata->autosense, list) {
2354                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2355
2356                 set_host_byte(cmd, DID_RESET);
2357                 cmd->scsi_done(cmd);
2358         }
2359         INIT_LIST_HEAD(&hostdata->autosense);
2360
2361         if (hostdata->connected) {
2362                 set_host_byte(hostdata->connected, DID_RESET);
2363                 complete_cmd(instance, hostdata->connected);
2364                 hostdata->connected = NULL;
2365         }
2366
2367         for (i = 0; i < 8; ++i)
2368                 hostdata->busy[i] = 0;
2369         hostdata->dma_len = 0;
2370
2371         queue_work(hostdata->work_q, &hostdata->main_task);
2372         maybe_release_dma_irq(instance);
2373         spin_unlock_irqrestore(&hostdata->lock, flags);
2374
2375         return SUCCESS;
2376 }