drivers/scsi/NCR5380.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * NCR 5380 generic driver routines.  These should make it *trivial*
   4  * to implement 5380 SCSI drivers under Linux with a non-trantor
   5  * architecture.
   6  *
   7  * Note that these routines also work with NR53c400 family chips.
   8  *
   9  * Copyright 1993, Drew Eckhardt
  10  * Visionary Computing
  11  * (Unix and Linux consulting and custom programming)
  12  * drew@colorado.edu
  13  * +1 (303) 666-5836
  14  *
  15  * For more information, please consult
  16  *
  17  * NCR 5380 Family
  18  * SCSI Protocol Controller
  19  * Databook
  20  *
  21  * NCR Microelectronics
  22  * 1635 Aeroplaza Drive
  23  * Colorado Springs, CO 80916
  24  * 1+ (719) 578-3400
  25  * 1+ (800) 334-5454
  26  */
  27
  28 /*
  29  * With contributions from Ray Van Tassle, Ingmar Baumgart,
  30  * Ronald van Cuijlenborg, Alan Cox and others.
  31  */
  32
  33 /* Ported to Atari by Roman Hodek and others. */
  34
  35 /* Adapted for the Sun 3 by Sam Creasey. */
  36
  37 /*
  38  * Design
  39  *
  40  * This is a generic 5380 driver.  To use it on a different platform,
  41  * one simply writes appropriate system specific macros (ie, data
  42  * transfer - some PC's will use the I/O bus, 68K's must use
  43  * memory mapped) and drops this file in their 'C' wrapper.
  44  *
  45  * As far as command queueing, two queues are maintained for
  46  * each 5380 in the system - commands that haven't been issued yet,
  47  * and commands that are currently executing.  This means that an
  48  * unlimited number of commands may be queued, letting
  49  * more commands propagate from the higher driver levels giving higher
  50  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
  51  * allowing multiple commands to propagate all the way to a SCSI-II device
  52  * while a command is already executing.
  53  *
  54  *
  55  * Issues specific to the NCR5380 :
  56  *
  57  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
  58  * piece of hardware that requires you to sit in a loop polling for
  59  * the REQ signal as long as you are connected.  Some devices are
  60  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
  61  * while doing long seek operations. [...] These
  62  * broken devices are the exception rather than the rule and I'd rather
  63  * spend my time optimizing for the normal case.
  64  *
  65  * Architecture :
  66  *
  67  * At the heart of the design is a coroutine, NCR5380_main,
  68  * which is started from a workqueue for each NCR5380 host in the
  69  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
  70  * removing the commands from the issue queue and calling
  71  * NCR5380_select() if a nexus is not established.
  72  *
  73  * Once a nexus is established, the NCR5380_information_transfer()
  74  * phase goes through the various phases as instructed by the target.
  75  * if the target goes into MSG IN and sends a DISCONNECT message,
  76  * the command structure is placed into the per instance disconnected
  77  * queue, and NCR5380_main tries to find more work.  If the target is
  78  * idle for too long, the system will try to sleep.
  79  *
  80  * If a command has disconnected, eventually an interrupt will trigger,
  81  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
  82  * to reestablish a nexus.  This will run main if necessary.
  83  *
  84  * On command termination, the done function will be called as
  85  * appropriate.
  86  *
  87  * SCSI pointers are maintained in the SCp field of SCSI command
  88  * structures, being initialized after the command is connected
  89  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
  90  * Note that in violation of the standard, an implicit SAVE POINTERS operation
  91  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
  92  */
  93
  94 /*
  95  * Using this file :
  96  * This file a skeleton Linux SCSI driver for the NCR 5380 series
  97  * of chips.  To use it, you write an architecture specific functions
  98  * and macros and include this file in your driver.
  99  *
 100  * These macros MUST be defined :
 101  *
 102  * NCR5380_read(register)  - read from the specified register
 103  *
 104  * NCR5380_write(register, value) - write to the specific register
 105  *
 106  * NCR5380_implementation_fields  - additional fields needed for this
 107  * specific implementation of the NCR5380
 108  *
 109  * Either real DMA *or* pseudo DMA may be implemented
 110  *
 111  * NCR5380_dma_xfer_len   - determine size of DMA/PDMA transfer
 112  * NCR5380_dma_send_setup - execute DMA/PDMA from memory to 5380
 113  * NCR5380_dma_recv_setup - execute DMA/PDMA from 5380 to memory
 114  * NCR5380_dma_residual   - residual byte count
 115  *
 116  * The generic driver is initialized by calling NCR5380_init(instance),
 117  * after setting the appropriate host specific fields and ID.
 118  */
 119
 120 #ifndef NCR5380_io_delay
 121 #define NCR5380_io_delay(x)
 122 #endif
 123
 124 #ifndef NCR5380_acquire_dma_irq
 125 #define NCR5380_acquire_dma_irq(x)      (1)
 126 #endif
 127
 128 #ifndef NCR5380_release_dma_irq
 129 #define NCR5380_release_dma_irq(x)
 130 #endif
 131
 132 static int do_abort(struct Scsi_Host *);
 133 static void do_reset(struct Scsi_Host *);
 134
 135 /**
 136  * initialize_SCp - init the scsi pointer field
 137  * @cmd: command block to set up
 138  *
 139  * Set up the internal fields in the SCSI command.
 140  */
 141
 142 static inline void initialize_SCp(struct scsi_cmnd *cmd)
 143 {
 144         /*
 145          * Initialize the Scsi Pointer field so that all of the commands in the
 146          * various queues are valid.
 147          */
 148
 149         if (scsi_bufflen(cmd)) {
 150                 cmd->SCp.buffer = scsi_sglist(cmd);
 151                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 152                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 153                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 154         } else {
 155                 cmd->SCp.buffer = NULL;
 156                 cmd->SCp.buffers_residual = 0;
 157                 cmd->SCp.ptr = NULL;
 158                 cmd->SCp.this_residual = 0;
 159         }
 160
 161         cmd->SCp.Status = 0;
 162         cmd->SCp.Message = 0;
 163 }
 164
 165 /**
 166  * NCR5380_poll_politely2 - wait for two chip register values
 167  * @hostdata: host private data
 168  * @reg1: 5380 register to poll
 169  * @bit1: Bitmask to check
 170  * @val1: Expected value
 171  * @reg2: Second 5380 register to poll
 172  * @bit2: Second bitmask to check
 173  * @val2: Second expected value
 174  * @wait: Time-out in jiffies
 175  *
 176  * Polls the chip in a reasonably efficient manner waiting for an
 177  * event to occur. After a short quick poll we begin to yield the CPU
 178  * (if possible). In irq contexts the time-out is arbitrarily limited.
 179  * Callers may hold locks as long as they are held in irq mode.
 180  *
 181  * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
 182  */
 183
 184 static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
 185                                   unsigned int reg1, u8 bit1, u8 val1,
 186                                   unsigned int reg2, u8 bit2, u8 val2,
 187                                   unsigned long wait)
 188 {
 189         unsigned long n = hostdata->poll_loops;
 190         unsigned long deadline = jiffies + wait;
 191
 192         do {
 193                 if ((NCR5380_read(reg1) & bit1) == val1)
 194                         return 0;
 195                 if ((NCR5380_read(reg2) & bit2) == val2)
 196                         return 0;
 197                 cpu_relax();
 198         } while (n--);
 199
 200         if (irqs_disabled() || in_interrupt())
 201                 return -ETIMEDOUT;
 202
 203         /* Repeatedly sleep for 1 ms until deadline */
 204         while (time_is_after_jiffies(deadline)) {
 205                 schedule_timeout_uninterruptible(1);
 206                 if ((NCR5380_read(reg1) & bit1) == val1)
 207                         return 0;
 208                 if ((NCR5380_read(reg2) & bit2) == val2)
 209                         return 0;
 210         }
 211
 212         return -ETIMEDOUT;
 213 }
 214
 215 #if NDEBUG
 216 static struct {
 217         unsigned char mask;
 218         const char *name;
 219 } signals[] = {
 220         {SR_DBP, "PARITY"},
 221         {SR_RST, "RST"},
 222         {SR_BSY, "BSY"},
 223         {SR_REQ, "REQ"},
 224         {SR_MSG, "MSG"},
 225         {SR_CD, "CD"},
 226         {SR_IO, "IO"},
 227         {SR_SEL, "SEL"},
 228         {0, NULL}
 229 },
 230 basrs[] = {
 231         {BASR_END_DMA_TRANSFER, "END OF DMA"},
 232         {BASR_DRQ, "DRQ"},
 233         {BASR_PARITY_ERROR, "PARITY ERROR"},
 234         {BASR_IRQ, "IRQ"},
 235         {BASR_PHASE_MATCH, "PHASE MATCH"},
 236         {BASR_BUSY_ERROR, "BUSY ERROR"},
 237         {BASR_ATN, "ATN"},
 238         {BASR_ACK, "ACK"},
 239         {0, NULL}
 240 },
 241 icrs[] = {
 242         {ICR_ASSERT_RST, "ASSERT RST"},
 243         {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
 244         {ICR_ARBITRATION_LOST, "LOST ARB."},
 245         {ICR_ASSERT_ACK, "ASSERT ACK"},
 246         {ICR_ASSERT_BSY, "ASSERT BSY"},
 247         {ICR_ASSERT_SEL, "ASSERT SEL"},
 248         {ICR_ASSERT_ATN, "ASSERT ATN"},
 249         {ICR_ASSERT_DATA, "ASSERT DATA"},
 250         {0, NULL}
 251 },
 252 mrs[] = {
 253         {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
 254         {MR_TARGET, "TARGET"},
 255         {MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
 256         {MR_ENABLE_PAR_INTR, "PARITY INTR"},
 257         {MR_ENABLE_EOP_INTR, "EOP INTR"},
 258         {MR_MONITOR_BSY, "MONITOR BSY"},
 259         {MR_DMA_MODE, "DMA MODE"},
 260         {MR_ARBITRATE, "ARBITRATE"},
 261         {0, NULL}
 262 };
 263
 264 /**
 265  * NCR5380_print - print scsi bus signals
 266  * @instance: adapter state to dump
 267  *
 268  * Print the SCSI bus signals for debugging purposes
 269  */
 270
 271 static void NCR5380_print(struct Scsi_Host *instance)
 272 {
 273         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 274         unsigned char status, data, basr, mr, icr, i;
 275
 276         data = NCR5380_read(CURRENT_SCSI_DATA_REG);
 277         status = NCR5380_read(STATUS_REG);
 278         mr = NCR5380_read(MODE_REG);
 279         icr = NCR5380_read(INITIATOR_COMMAND_REG);
 280         basr = NCR5380_read(BUS_AND_STATUS_REG);
 281
 282         printk(KERN_DEBUG "SR =   0x%02x : ", status);
 283         for (i = 0; signals[i].mask; ++i)
 284                 if (status & signals[i].mask)
 285                         printk(KERN_CONT "%s, ", signals[i].name);
 286         printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
 287         for (i = 0; basrs[i].mask; ++i)
 288                 if (basr & basrs[i].mask)
 289                         printk(KERN_CONT "%s, ", basrs[i].name);
 290         printk(KERN_CONT "\nICR =  0x%02x : ", icr);
 291         for (i = 0; icrs[i].mask; ++i)
 292                 if (icr & icrs[i].mask)
 293                         printk(KERN_CONT "%s, ", icrs[i].name);
 294         printk(KERN_CONT "\nMR =   0x%02x : ", mr);
 295         for (i = 0; mrs[i].mask; ++i)
 296                 if (mr & mrs[i].mask)
 297                         printk(KERN_CONT "%s, ", mrs[i].name);
 298         printk(KERN_CONT "\n");
 299 }
 300
 301 static struct {
 302         unsigned char value;
 303         const char *name;
 304 } phases[] = {
 305         {PHASE_DATAOUT, "DATAOUT"},
 306         {PHASE_DATAIN, "DATAIN"},
 307         {PHASE_CMDOUT, "CMDOUT"},
 308         {PHASE_STATIN, "STATIN"},
 309         {PHASE_MSGOUT, "MSGOUT"},
 310         {PHASE_MSGIN, "MSGIN"},
 311         {PHASE_UNKNOWN, "UNKNOWN"}
 312 };
 313
 314 /**
 315  * NCR5380_print_phase - show SCSI phase
 316  * @instance: adapter to dump
 317  *
 318  * Print the current SCSI phase for debugging purposes
 319  */
 320
 321 static void NCR5380_print_phase(struct Scsi_Host *instance)
 322 {
 323         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 324         unsigned char status;
 325         int i;
 326
 327         status = NCR5380_read(STATUS_REG);
 328         if (!(status & SR_REQ))
 329                 shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
 330         else {
 331                 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
 332                      (phases[i].value != (status & PHASE_MASK)); ++i)
 333                         ;
 334                 shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
 335         }
 336 }
 337 #endif
 338
 339 /**
 340  * NCR5380_info - report driver and host information
 341  * @instance: relevant scsi host instance
 342  *
 343  * For use as the host template info() handler.
 344  */
 345
 346 static const char *NCR5380_info(struct Scsi_Host *instance)
 347 {
 348         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 349
 350         return hostdata->info;
 351 }
 352
 353 /**
 354  * NCR5380_init - initialise an NCR5380
 355  * @instance: adapter to configure
 356  * @flags: control flags
 357  *
 358  * Initializes *instance and corresponding 5380 chip,
 359  * with flags OR'd into the initial flags value.
 360  *
 361  * Notes : I assume that the host, hostno, and id bits have been
 362  * set correctly. I don't care about the irq and other fields.
 363  *
 364  * Returns 0 for success
 365  */
 366
 367 static int NCR5380_init(struct Scsi_Host *instance, int flags)
 368 {
 369         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 370         int i;
 371         unsigned long deadline;
 372         unsigned long accesses_per_ms;
 373
 374         instance->max_lun = 7;
 375
 376         hostdata->host = instance;
 377         hostdata->id_mask = 1 << instance->this_id;
 378         hostdata->id_higher_mask = 0;
 379         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 380                 if (i > hostdata->id_mask)
 381                         hostdata->id_higher_mask |= i;
 382         for (i = 0; i < 8; ++i)
 383                 hostdata->busy[i] = 0;
 384         hostdata->dma_len = 0;
 385
 386         spin_lock_init(&hostdata->lock);
 387         hostdata->connected = NULL;
 388         hostdata->sensing = NULL;
 389         INIT_LIST_HEAD(&hostdata->autosense);
 390         INIT_LIST_HEAD(&hostdata->unissued);
 391         INIT_LIST_HEAD(&hostdata->disconnected);
 392
 393         hostdata->flags = flags;
 394
 395         INIT_WORK(&hostdata->main_task, NCR5380_main);
 396         hostdata->work_q = alloc_workqueue("ncr5380_%d",
 397                                 WQ_UNBOUND | WQ_MEM_RECLAIM,
 398                                 1, instance->host_no);
 399         if (!hostdata->work_q)
 400                 return -ENOMEM;
 401
 402         snprintf(hostdata->info, sizeof(hostdata->info),
 403                 "%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}",
 404                 instance->hostt->name, instance->irq, hostdata->io_port,
 405                 hostdata->base, instance->can_queue, instance->cmd_per_lun,
 406                 instance->sg_tablesize, instance->this_id,
 407                 hostdata->flags & FLAG_DMA_FIXUP     ? "DMA_FIXUP "     : "",
 408                 hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
 409                 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
 410
 411         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 412         NCR5380_write(MODE_REG, MR_BASE);
 413         NCR5380_write(TARGET_COMMAND_REG, 0);
 414         NCR5380_write(SELECT_ENABLE_REG, 0);
 415
 416         /* Calibrate register polling loop */
 417         i = 0;
 418         deadline = jiffies + 1;
 419         do {
 420                 cpu_relax();
 421         } while (time_is_after_jiffies(deadline));
 422         deadline += msecs_to_jiffies(256);
 423         do {
 424                 NCR5380_read(STATUS_REG);
 425                 ++i;
 426                 cpu_relax();
 427         } while (time_is_after_jiffies(deadline));
 428         accesses_per_ms = i / 256;
 429         hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
 430
 431         return 0;
 432 }
 433
 434 /**
 435  * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
 436  * @instance: adapter to check
 437  *
 438  * If the system crashed, it may have crashed with a connected target and
 439  * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
 440  * currently established nexus, which we know nothing about. Failing that
 441  * do a bus reset.
 442  *
 443  * Note that a bus reset will cause the chip to assert IRQ.
 444  *
 445  * Returns 0 if successful, otherwise -ENXIO.
 446  */
 447
 448 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
 449 {
 450         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 451         int pass;
 452
 453         for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
 454                 switch (pass) {
 455                 case 1:
 456                 case 3:
 457                 case 5:
 458                         shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
 459                         NCR5380_poll_politely(hostdata,
 460                                               STATUS_REG, SR_BSY, 0, 5 * HZ);
 461                         break;
 462                 case 2:
 463                         shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
 464                         do_abort(instance);
 465                         break;
 466                 case 4:
 467                         shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
 468                         do_reset(instance);
 469                         /* Wait after a reset; the SCSI standard calls for
 470                          * 250ms, we wait 500ms to be on the safe side.
 471                          * But some Toshiba CD-ROMs need ten times that.
 472                          */
 473                         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
 474                                 msleep(2500);
 475                         else
 476                                 msleep(500);
 477                         break;
 478                 case 6:
 479                         shost_printk(KERN_ERR, instance, "bus locked solid\n");
 480                         return -ENXIO;
 481                 }
 482         }
 483         return 0;
 484 }
 485
 486 /**
 487  * NCR5380_exit - remove an NCR5380
 488  * @instance: adapter to remove
 489  *
 490  * Assumes that no more work can be queued (e.g. by NCR5380_intr).
 491  */
 492
 493 static void NCR5380_exit(struct Scsi_Host *instance)
 494 {
 495         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 496
 497         cancel_work_sync(&hostdata->main_task);
 498         destroy_workqueue(hostdata->work_q);
 499 }
 500
 501 /**
 502  * complete_cmd - finish processing a command and return it to the SCSI ML
 503  * @instance: the host instance
 504  * @cmd: command to complete
 505  */
 506
 507 static void complete_cmd(struct Scsi_Host *instance,
 508                          struct scsi_cmnd *cmd)
 509 {
 510         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 511
 512         dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
 513
 514         if (hostdata->sensing == cmd) {
 515                 /* Autosense processing ends here */
 516                 if ((cmd->result & 0xff) != SAM_STAT_GOOD) {
 517                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 518                         set_host_byte(cmd, DID_ERROR);
 519                 } else
 520                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 521                 hostdata->sensing = NULL;
 522         }
 523
 524         hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
 525
 526         cmd->scsi_done(cmd);
 527 }
 528
 529 /**
 530  * NCR5380_queue_command - queue a command
 531  * @instance: the relevant SCSI adapter
 532  * @cmd: SCSI command
 533  *
 534  * cmd is added to the per-instance issue queue, with minor
 535  * twiddling done to the host specific fields of cmd.  If the
 536  * main coroutine is not running, it is restarted.
 537  */
 538
 539 static int NCR5380_queue_command(struct Scsi_Host *instance,
 540                                  struct scsi_cmnd *cmd)
 541 {
 542         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 543         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 544         unsigned long flags;
 545
 546 #if (NDEBUG & NDEBUG_NO_WRITE)
 547         switch (cmd->cmnd[0]) {
 548         case WRITE_6:
 549         case WRITE_10:
 550                 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
 551                 cmd->result = (DID_ERROR << 16);
 552                 cmd->scsi_done(cmd);
 553                 return 0;
 554         }
 555 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 556
 557         cmd->result = 0;
 558
 559         if (!NCR5380_acquire_dma_irq(instance))
 560                 return SCSI_MLQUEUE_HOST_BUSY;
 561
 562         spin_lock_irqsave(&hostdata->lock, flags);
 563
 564         /*
 565          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 566          * commands are added to the head of the queue since any command will
 567          * clear the contingent allegiance condition that exists and the
 568          * sense data is only guaranteed to be valid while the condition exists.
 569          */
 570
 571         if (cmd->cmnd[0] == REQUEST_SENSE)
 572                 list_add(&ncmd->list, &hostdata->unissued);
 573         else
 574                 list_add_tail(&ncmd->list, &hostdata->unissued);
 575
 576         spin_unlock_irqrestore(&hostdata->lock, flags);
 577
 578         dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
 579                  cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 580
 581         /* Kick off command processing */
 582         queue_work(hostdata->work_q, &hostdata->main_task);
 583         return 0;
 584 }
 585
 586 static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
 587 {
 588         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 589
 590         /* Caller does the locking needed to set & test these data atomically */
 591         if (list_empty(&hostdata->disconnected) &&
 592             list_empty(&hostdata->unissued) &&
 593             list_empty(&hostdata->autosense) &&
 594             !hostdata->connected &&
 595             !hostdata->selecting) {
 596                 NCR5380_release_dma_irq(instance);
 597         }
 598 }
 599
 600 /**
 601  * dequeue_next_cmd - dequeue a command for processing
 602  * @instance: the scsi host instance
 603  *
 604  * Priority is given to commands on the autosense queue. These commands
 605  * need autosense because of a CHECK CONDITION result.
 606  *
 607  * Returns a command pointer if a command is found for a target that is
 608  * not already busy. Otherwise returns NULL.
 609  */
 610
 611 static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
 612 {
 613         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 614         struct NCR5380_cmd *ncmd;
 615         struct scsi_cmnd *cmd;
 616
 617         if (hostdata->sensing || list_empty(&hostdata->autosense)) {
 618                 list_for_each_entry(ncmd, &hostdata->unissued, list) {
 619                         cmd = NCR5380_to_scmd(ncmd);
 620                         dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
 621                                  cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
 622
 623                         if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
 624                                 list_del(&ncmd->list);
 625                                 dsprintk(NDEBUG_QUEUES, instance,
 626                                          "dequeue: removed %p from issue queue\n", cmd);
 627                                 return cmd;
 628                         }
 629                 }
 630         } else {
 631                 /* Autosense processing begins here */
 632                 ncmd = list_first_entry(&hostdata->autosense,
 633                                         struct NCR5380_cmd, list);
 634                 list_del(&ncmd->list);
 635                 cmd = NCR5380_to_scmd(ncmd);
 636                 dsprintk(NDEBUG_QUEUES, instance,
 637                          "dequeue: removed %p from autosense queue\n", cmd);
 638                 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
 639                 hostdata->sensing = cmd;
 640                 return cmd;
 641         }
 642         return NULL;
 643 }
 644
 645 static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 646 {
 647         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 648         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 649
 650         if (hostdata->sensing == cmd) {
 651                 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 652                 list_add(&ncmd->list, &hostdata->autosense);
 653                 hostdata->sensing = NULL;
 654         } else
 655                 list_add(&ncmd->list, &hostdata->unissued);
 656 }
 657
 658 /**
 659  * NCR5380_main - NCR state machines
 660  *
 661  * NCR5380_main is a coroutine that runs as long as more work can
 662  * be done on the NCR5380 host adapters in a system.  Both
 663  * NCR5380_queue_command() and NCR5380_intr() will try to start it
 664  * in case it is not running.
 665  */
 666
 667 static void NCR5380_main(struct work_struct *work)
 668 {
 669         struct NCR5380_hostdata *hostdata =
 670                 container_of(work, struct NCR5380_hostdata, main_task);
 671         struct Scsi_Host *instance = hostdata->host;
 672         int done;
 673
 674         do {
 675                 done = 1;
 676
 677                 spin_lock_irq(&hostdata->lock);
 678                 while (!hostdata->connected && !hostdata->selecting) {
 679                         struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
 680
 681                         if (!cmd)
 682                                 break;
 683
 684                         dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
 685
 686                         /*
 687                          * Attempt to establish an I_T_L nexus here.
 688                          * On success, instance->hostdata->connected is set.
 689                          * On failure, we must add the command back to the
 690                          * issue queue so we can keep trying.
 691                          */
 692                         /*
 693                          * REQUEST SENSE commands are issued without tagged
 694                          * queueing, even on SCSI-II devices because the
 695                          * contingent allegiance condition exists for the
 696                          * entire unit.
 697                          */
 698
 699                         if (!NCR5380_select(instance, cmd)) {
 700                                 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
 701                                 maybe_release_dma_irq(instance);
 702                         } else {
 703                                 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
 704                                          "main: select failed, returning %p to queue\n", cmd);
 705                                 requeue_cmd(instance, cmd);
 706                         }
 707                 }
 708                 if (hostdata->connected && !hostdata->dma_len) {
 709                         dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
 710                         NCR5380_information_transfer(instance);
 711                         done = 0;
 712                 }
 713                 spin_unlock_irq(&hostdata->lock);
 714                 if (!done)
 715                         cond_resched();
 716         } while (!done);
 717 }
 718
 719 /*
 720  * NCR5380_dma_complete - finish DMA transfer
 721  * @instance: the scsi host instance
 722  *
 723  * Called by the interrupt handler when DMA finishes or a phase
 724  * mismatch occurs (which would end the DMA transfer).
 725  */
 726
 727 static void NCR5380_dma_complete(struct Scsi_Host *instance)
 728 {
 729         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 730         int transferred;
 731         unsigned char **data;
 732         int *count;
 733         int saved_data = 0, overrun = 0;
 734         unsigned char p;
 735
 736         if (hostdata->read_overruns) {
 737                 p = hostdata->connected->SCp.phase;
 738                 if (p & SR_IO) {
 739                         udelay(10);
 740                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
 741                              (BASR_PHASE_MATCH | BASR_ACK)) ==
 742                             (BASR_PHASE_MATCH | BASR_ACK)) {
 743                                 saved_data = NCR5380_read(INPUT_DATA_REG);
 744                                 overrun = 1;
 745                                 dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
 746                         }
 747                 }
 748         }
 749
 750 #ifdef CONFIG_SUN3
 751         if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
 752                 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
 753                        instance->host_no);
 754                 BUG();
 755         }
 756
 757         if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
 758             (BASR_PHASE_MATCH | BASR_ACK)) {
 759                 pr_err("scsi%d: BASR %02x\n", instance->host_no,
 760                        NCR5380_read(BUS_AND_STATUS_REG));
 761                 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
 762                        instance->host_no);
 763                 BUG();
 764         }
 765 #endif
 766
 767         NCR5380_write(MODE_REG, MR_BASE);
 768         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 769         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 770
 771         transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
 772         hostdata->dma_len = 0;
 773
 774         data = (unsigned char **)&hostdata->connected->SCp.ptr;
 775         count = &hostdata->connected->SCp.this_residual;
 776         *data += transferred;
 777         *count -= transferred;
 778
 779         if (hostdata->read_overruns) {
 780                 int cnt, toPIO;
 781
 782                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
 783                         cnt = toPIO = hostdata->read_overruns;
 784                         if (overrun) {
 785                                 dsprintk(NDEBUG_DMA, instance,
 786                                          "Got an input overrun, using saved byte\n");
 787                                 *(*data)++ = saved_data;
 788                                 (*count)--;
 789                                 cnt--;
 790                                 toPIO--;
 791                         }
 792                         if (toPIO > 0) {
 793                                 dsprintk(NDEBUG_DMA, instance,
 794                                          "Doing %d byte PIO to 0x%p\n", cnt, *data);
 795                                 NCR5380_transfer_pio(instance, &p, &cnt, data);
 796                                 *count -= toPIO - cnt;
 797                         }
 798                 }
 799         }
 800 }
 801
 802 /**
 803  * NCR5380_intr - generic NCR5380 irq handler
 804  * @irq: interrupt number
 805  * @dev_id: device info
 806  *
 807  * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 808  * from the disconnected queue, and restarting NCR5380_main()
 809  * as required.
 810  *
 811  * The chip can assert IRQ in any of six different conditions. The IRQ flag
 812  * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
 813  * Three of these six conditions are latched in the Bus and Status Register:
 814  * - End of DMA (cleared by ending DMA Mode)
 815  * - Parity error (cleared by reading RPIR)
 816  * - Loss of BSY (cleared by reading RPIR)
 817  * Two conditions have flag bits that are not latched:
 818  * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
 819  * - Bus reset (non-maskable)
 820  * The remaining condition has no flag bit at all:
 821  * - Selection/reselection
 822  *
 823  * Hence, establishing the cause(s) of any interrupt is partly guesswork.
 824  * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
 825  * claimed that "the design of the [DP8490] interrupt logic ensures
 826  * interrupts will not be lost (they can be on the DP5380)."
 827  * The L5380/53C80 datasheet from LOGIC Devices has more details.
 828  *
 829  * Checking for bus reset by reading RST is futile because of interrupt
 830  * latency, but a bus reset will reset chip logic. Checking for parity error
 831  * is unnecessary because that interrupt is never enabled. A Loss of BSY
 832  * condition will clear DMA Mode. We can tell when this occurs because the
 833  * the Busy Monitor interrupt is enabled together with DMA Mode.
 834  */
 835
 836 static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
 837 {
 838         struct Scsi_Host *instance = dev_id;
 839         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 840         int handled = 0;
 841         unsigned char basr;
 842         unsigned long flags;
 843
 844         spin_lock_irqsave(&hostdata->lock, flags);
 845
 846         basr = NCR5380_read(BUS_AND_STATUS_REG);
 847         if (basr & BASR_IRQ) {
 848                 unsigned char mr = NCR5380_read(MODE_REG);
 849                 unsigned char sr = NCR5380_read(STATUS_REG);
 850
 851                 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
 852                          irq, basr, sr, mr);
 853
 854                 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
 855                         /* Probably End of DMA, Phase Mismatch or Loss of BSY.
 856                          * We ack IRQ after clearing Mode Register. Workarounds
 857                          * for End of DMA errata need to happen in DMA Mode.
 858                          */
 859
 860                         dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
 861
 862                         if (hostdata->connected) {
 863                                 NCR5380_dma_complete(instance);
 864                                 queue_work(hostdata->work_q, &hostdata->main_task);
 865                         } else {
 866                                 NCR5380_write(MODE_REG, MR_BASE);
 867                                 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 868                         }
 869                 } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
 870                     (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
 871                         /* Probably reselected */
 872                         NCR5380_write(SELECT_ENABLE_REG, 0);
 873                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 874
 875                         dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
 876
 877                         if (!hostdata->connected) {
 878                                 NCR5380_reselect(instance);
 879                                 queue_work(hostdata->work_q, &hostdata->main_task);
 880                         }
 881                         if (!hostdata->connected)
 882                                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 883                 } else {
 884                         /* Probably Bus Reset */
 885                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 886
 887                         dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
 888 #ifdef SUN3_SCSI_VME
 889                         dregs->csr |= CSR_DMA_ENABLE;
 890 #endif
 891                 }
 892                 handled = 1;
 893         } else {
 894                 dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
 895 #ifdef SUN3_SCSI_VME
 896                 dregs->csr |= CSR_DMA_ENABLE;
 897 #endif
 898         }
 899
 900         spin_unlock_irqrestore(&hostdata->lock, flags);
 901
 902         return IRQ_RETVAL(handled);
 903 }
 904
 905 /*
 906  * Function : int NCR5380_select(struct Scsi_Host *instance,
 907  * struct scsi_cmnd *cmd)
 908  *
 909  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
 910  * including ARBITRATION, SELECTION, and initial message out for
 911  * IDENTIFY and queue messages.
 912  *
 913  * Inputs : instance - instantiation of the 5380 driver on which this
 914  * target lives, cmd - SCSI command to execute.
 915  *
 916  * Returns cmd if selection failed but should be retried,
 917  * NULL if selection failed and should not be retried, or
 918  * NULL if selection succeeded (hostdata->connected == cmd).
 919  *
 920  * Side effects :
 921  * If bus busy, arbitration failed, etc, NCR5380_select() will exit
 922  * with registers as they should have been on entry - ie
 923  * SELECT_ENABLE will be set appropriately, the NCR5380
 924  * will cease to drive any SCSI bus signals.
 925  *
 926  * If successful : I_T_L or I_T_L_Q nexus will be established,
 927  * instance->connected will be set to cmd.
 928  * SELECT interrupt will be disabled.
 929  *
 930  * If failed (no target) : cmd->scsi_done() will be called, and the
 931  * cmd->result host byte set to DID_BAD_TARGET.
 932  */
 933
 934 static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
 935                                         struct scsi_cmnd *cmd)
 936         __releases(&hostdata->lock) __acquires(&hostdata->lock)
 937 {
 938         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 939         unsigned char tmp[3], phase;
 940         unsigned char *data;
 941         int len;
 942         int err;
 943
 944         NCR5380_dprint(NDEBUG_ARBITRATION, instance);
 945         dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
 946                  instance->this_id);
 947
 948         /*
 949          * Arbitration and selection phases are slow and involve dropping the
 950          * lock, so we have to watch out for EH. An exception handler may
 951          * change 'selecting' to NULL. This function will then return NULL
 952          * so that the caller will forget about 'cmd'. (During information
 953          * transfer phases, EH may change 'connected' to NULL.)
 954          */
 955         hostdata->selecting = cmd;
 956
 957         /*
 958          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
 959          * data bus during SELECTION.
 960          */
 961
 962         NCR5380_write(TARGET_COMMAND_REG, 0);
 963
 964         /*
 965          * Start arbitration.
 966          */
 967
 968         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
 969         NCR5380_write(MODE_REG, MR_ARBITRATE);
 970
 971         /* The chip now waits for BUS FREE phase. Then after the 800 ns
 972          * Bus Free Delay, arbitration will begin.
 973          */
 974
 975         spin_unlock_irq(&hostdata->lock);
 976         err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
 977                         INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
 978                                                ICR_ARBITRATION_PROGRESS, HZ);
 979         spin_lock_irq(&hostdata->lock);
 980         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
 981                 /* Reselection interrupt */
 982                 goto out;
 983         }
 984         if (!hostdata->selecting) {
 985                 /* Command was aborted */
 986                 NCR5380_write(MODE_REG, MR_BASE);
 987                 goto out;
 988         }
 989         if (err < 0) {
 990                 NCR5380_write(MODE_REG, MR_BASE);
 991                 shost_printk(KERN_ERR, instance,
 992                              "select: arbitration timeout\n");
 993                 goto out;
 994         }
 995         spin_unlock_irq(&hostdata->lock);
 996
 997         /* The SCSI-2 arbitration delay is 2.4 us */
 998         udelay(3);
 999
1000         /* Check for lost arbitration */
1001         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1002             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1003             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1004                 NCR5380_write(MODE_REG, MR_BASE);
1005                 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1006                 spin_lock_irq(&hostdata->lock);
1007                 goto out;
1008         }
1009
1010         /* After/during arbitration, BSY should be asserted.
1011          * IBM DPES-31080 Version S31Q works now
1012          * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1013          */
1014         NCR5380_write(INITIATOR_COMMAND_REG,
1015                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1016
1017         /*
1018          * Again, bus clear + bus settle time is 1.2us, however, this is
1019          * a minimum so we'll udelay ceil(1.2)
1020          */
1021
1022         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1023                 udelay(15);
1024         else
1025                 udelay(2);
1026
1027         spin_lock_irq(&hostdata->lock);
1028
1029         /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1030         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1031                 goto out;
1032
1033         if (!hostdata->selecting) {
1034                 NCR5380_write(MODE_REG, MR_BASE);
1035                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1036                 goto out;
1037         }
1038
1039         dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1040
1041         /*
1042          * Now that we have won arbitration, start Selection process, asserting
1043          * the host and target ID's on the SCSI bus.
1044          */
1045
1046         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1047
1048         /*
1049          * Raise ATN while SEL is true before BSY goes false from arbitration,
1050          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1051          * phase immediately after selection.
1052          */
1053
1054         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1055                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1056         NCR5380_write(MODE_REG, MR_BASE);
1057
1058         /*
1059          * Reselect interrupts must be turned off prior to the dropping of BSY,
1060          * otherwise we will trigger an interrupt.
1061          */
1062         NCR5380_write(SELECT_ENABLE_REG, 0);
1063
1064         spin_unlock_irq(&hostdata->lock);
1065
1066         /*
1067          * The initiator shall then wait at least two deskew delays and release
1068          * the BSY signal.
1069          */
1070         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1071
1072         /* Reset BSY */
1073         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1074                       ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1075
1076         /*
1077          * Something weird happens when we cease to drive BSY - looks
1078          * like the board/chip is letting us do another read before the
1079          * appropriate propagation delay has expired, and we're confusing
1080          * a BSY signal from ourselves as the target's response to SELECTION.
1081          *
1082          * A small delay (the 'C++' frontend breaks the pipeline with an
1083          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1084          * tighter 'C' code breaks and requires this) solves the problem -
1085          * the 1 us delay is arbitrary, and only used because this delay will
1086          * be the same on other platforms and since it works here, it should
1087          * work there.
1088          *
1089          * wingel suggests that this could be due to failing to wait
1090          * one deskew delay.
1091          */
1092
1093         udelay(1);
1094
1095         dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1096
1097         /*
1098          * The SCSI specification calls for a 250 ms timeout for the actual
1099          * selection.
1100          */
1101
1102         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
1103                                     msecs_to_jiffies(250));
1104
1105         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1106                 spin_lock_irq(&hostdata->lock);
1107                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1108                 NCR5380_reselect(instance);
1109                 if (!hostdata->connected)
1110                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1111                 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1112                 goto out;
1113         }
1114
1115         if (err < 0) {
1116                 spin_lock_irq(&hostdata->lock);
1117                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1118                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1119                 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1120                 if (hostdata->selecting) {
1121                         cmd->result = DID_BAD_TARGET << 16;
1122                         complete_cmd(instance, cmd);
1123                         dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n");
1124                         cmd = NULL;
1125                 }
1126                 goto out;
1127         }
1128
1129         /*
1130          * No less than two deskew delays after the initiator detects the
1131          * BSY signal is true, it shall release the SEL signal and may
1132          * change the DATA BUS.                                     -wingel
1133          */
1134
1135         udelay(1);
1136
1137         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1138
1139         /*
1140          * Since we followed the SCSI spec, and raised ATN while SEL
1141          * was true but before BSY was false during selection, the information
1142          * transfer phase should be a MESSAGE OUT phase so that we can send the
1143          * IDENTIFY message.
1144          */
1145
1146         /* Wait for start of REQ/ACK handshake */
1147
1148         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1149         spin_lock_irq(&hostdata->lock);
1150         if (err < 0) {
1151                 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1152                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1153                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1154                 goto out;
1155         }
1156         if (!hostdata->selecting) {
1157                 do_abort(instance);
1158                 goto out;
1159         }
1160
1161         dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1162                  scmd_id(cmd));
1163         tmp[0] = IDENTIFY(((instance->irq == NO_IRQ) ? 0 : 1), cmd->device->lun);
1164
1165         len = 1;
1166         data = tmp;
1167         phase = PHASE_MSGOUT;
1168         NCR5380_transfer_pio(instance, &phase, &len, &data);
1169         if (len) {
1170                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1171                 cmd->result = DID_ERROR << 16;
1172                 complete_cmd(instance, cmd);
1173                 dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
1174                 cmd = NULL;
1175                 goto out;
1176         }
1177
1178         dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1179
1180         hostdata->connected = cmd;
1181         hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1182
1183 #ifdef SUN3_SCSI_VME
1184         dregs->csr |= CSR_INTR;
1185 #endif
1186
1187         initialize_SCp(cmd);
1188
1189         cmd = NULL;
1190
1191 out:
1192         if (!hostdata->selecting)
1193                 return NULL;
1194         hostdata->selecting = NULL;
1195         return cmd;
1196 }
1197
1198 /*
1199  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1200  * unsigned char *phase, int *count, unsigned char **data)
1201  *
1202  * Purpose : transfers data in given phase using polled I/O
1203  *
1204  * Inputs : instance - instance of driver, *phase - pointer to
1205  * what phase is expected, *count - pointer to number of
1206  * bytes to transfer, **data - pointer to data pointer.
1207  *
1208  * Returns : -1 when different phase is entered without transferring
1209  * maximum number of bytes, 0 if all bytes are transferred or exit
1210  * is in same phase.
1211  *
1212  * Also, *phase, *count, *data are modified in place.
1213  *
1214  * XXX Note : handling for bus free may be useful.
1215  */
1216
1217 /*
1218  * Note : this code is not as quick as it could be, however it
1219  * IS 100% reliable, and for the actual data transfer where speed
1220  * counts, we will always do a pseudo DMA or DMA transfer.
1221  */
1222
1223 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1224                                 unsigned char *phase, int *count,
1225                                 unsigned char **data)
1226 {
1227         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1228         unsigned char p = *phase, tmp;
1229         int c = *count;
1230         unsigned char *d = *data;
1231
1232         /*
1233          * The NCR5380 chip will only drive the SCSI bus when the
1234          * phase specified in the appropriate bits of the TARGET COMMAND
1235          * REGISTER match the STATUS REGISTER
1236          */
1237
1238         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1239
1240         do {
1241                 /*
1242                  * Wait for assertion of REQ, after which the phase bits will be
1243                  * valid
1244                  */
1245
1246                 if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1247                         break;
1248
1249                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1250
1251                 /* Check for phase mismatch */
1252                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1253                         dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1254                         NCR5380_dprint_phase(NDEBUG_PIO, instance);
1255                         break;
1256                 }
1257
1258                 /* Do actual transfer from SCSI bus to / from memory */
1259                 if (!(p & SR_IO))
1260                         NCR5380_write(OUTPUT_DATA_REG, *d);
1261                 else
1262                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1263
1264                 ++d;
1265
1266                 /*
1267                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1268                  * should drop ATN on the last byte of the message phase
1269                  * after REQ has been asserted for the handshake but before
1270                  * the initiator raises ACK.
1271                  */
1272
1273                 if (!(p & SR_IO)) {
1274                         if (!((p & SR_MSG) && c > 1)) {
1275                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1276                                 NCR5380_dprint(NDEBUG_PIO, instance);
1277                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1278                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1279                         } else {
1280                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1281                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1282                                 NCR5380_dprint(NDEBUG_PIO, instance);
1283                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1284                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1285                         }
1286                 } else {
1287                         NCR5380_dprint(NDEBUG_PIO, instance);
1288                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1289                 }
1290
1291                 if (NCR5380_poll_politely(hostdata,
1292                                           STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1293                         break;
1294
1295                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1296
1297 /*
1298  * We have several special cases to consider during REQ/ACK handshaking :
1299  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1300  * message.  ATN must be dropped as ACK is dropped.
1301  *
1302  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1303  * message.  We must exit with ACK asserted, so that the calling
1304  * code may raise ATN before dropping ACK to reject the message.
1305  *
1306  * 3.  ACK and ATN are clear and the target may proceed as normal.
1307  */
1308                 if (!(p == PHASE_MSGIN && c == 1)) {
1309                         if (p == PHASE_MSGOUT && c > 1)
1310                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1311                         else
1312                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1313                 }
1314         } while (--c);
1315
1316         dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1317
1318         *count = c;
1319         *data = d;
1320         tmp = NCR5380_read(STATUS_REG);
1321         /* The phase read from the bus is valid if either REQ is (already)
1322          * asserted or if ACK hasn't been released yet. The latter applies if
1323          * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1324          */
1325         if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1326                 *phase = tmp & PHASE_MASK;
1327         else
1328                 *phase = PHASE_UNKNOWN;
1329
1330         if (!c || (*phase == p))
1331                 return 0;
1332         else
1333                 return -1;
1334 }
1335
1336 /**
1337  * do_reset - issue a reset command
1338  * @instance: adapter to reset
1339  *
1340  * Issue a reset sequence to the NCR5380 and try and get the bus
1341  * back into sane shape.
1342  *
1343  * This clears the reset interrupt flag because there may be no handler for
1344  * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1345  * been installed. And when in EH we may have released the ST DMA interrupt.
1346  */
1347
1348 static void do_reset(struct Scsi_Host *instance)
1349 {
1350         struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
1351         unsigned long flags;
1352
1353         local_irq_save(flags);
1354         NCR5380_write(TARGET_COMMAND_REG,
1355                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1356         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1357         udelay(50);
1358         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1359         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1360         local_irq_restore(flags);
1361 }
1362
1363 /**
1364  * do_abort - abort the currently established nexus by going to
1365  * MESSAGE OUT phase and sending an ABORT message.
1366  * @instance: relevant scsi host instance
1367  *
1368  * Returns 0 on success, -1 on failure.
1369  */
1370
1371 static int do_abort(struct Scsi_Host *instance)
1372 {
1373         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1374         unsigned char *msgptr, phase, tmp;
1375         int len;
1376         int rc;
1377
1378         /* Request message out phase */
1379         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1380
1381         /*
1382          * Wait for the target to indicate a valid phase by asserting
1383          * REQ.  Once this happens, we'll have either a MSGOUT phase
1384          * and can immediately send the ABORT message, or we'll have some
1385          * other phase and will have to source/sink data.
1386          *
1387          * We really don't care what value was on the bus or what value
1388          * the target sees, so we just handshake.
1389          */
1390
1391         rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1392         if (rc < 0)
1393                 goto timeout;
1394
1395         tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1396
1397         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1398
1399         if (tmp != PHASE_MSGOUT) {
1400                 NCR5380_write(INITIATOR_COMMAND_REG,
1401                               ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1402                 rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
1403                 if (rc < 0)
1404                         goto timeout;
1405                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1406         }
1407
1408         tmp = ABORT;
1409         msgptr = &tmp;
1410         len = 1;
1411         phase = PHASE_MSGOUT;
1412         NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1413
1414         /*
1415          * If we got here, and the command completed successfully,
1416          * we're about to go into bus free state.
1417          */
1418
1419         return len ? -1 : 0;
1420
1421 timeout:
1422         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1423         return -1;
1424 }
1425
1426 /*
1427  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1428  * unsigned char *phase, int *count, unsigned char **data)
1429  *
1430  * Purpose : transfers data in given phase using either real
1431  * or pseudo DMA.
1432  *
1433  * Inputs : instance - instance of driver, *phase - pointer to
1434  * what phase is expected, *count - pointer to number of
1435  * bytes to transfer, **data - pointer to data pointer.
1436  *
1437  * Returns : -1 when different phase is entered without transferring
1438  * maximum number of bytes, 0 if all bytes or transferred or exit
1439  * is in same phase.
1440  *
1441  * Also, *phase, *count, *data are modified in place.
1442  */
1443
1444
1445 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1446                                 unsigned char *phase, int *count,
1447                                 unsigned char **data)
1448 {
1449         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1450         int c = *count;
1451         unsigned char p = *phase;
1452         unsigned char *d = *data;
1453         unsigned char tmp;
1454         int result = 0;
1455
1456         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1457                 *phase = tmp;
1458                 return -1;
1459         }
1460
1461         hostdata->connected->SCp.phase = p;
1462
1463         if (p & SR_IO) {
1464                 if (hostdata->read_overruns)
1465                         c -= hostdata->read_overruns;
1466                 else if (hostdata->flags & FLAG_DMA_FIXUP)
1467                         --c;
1468         }
1469
1470         dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1471                  (p & SR_IO) ? "receive" : "send", c, d);
1472
1473 #ifdef CONFIG_SUN3
1474         /* send start chain */
1475         sun3scsi_dma_start(c, *data);
1476 #endif
1477
1478         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1479         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1480                                 MR_ENABLE_EOP_INTR);
1481
1482         if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1483                 /* On the Medusa, it is a must to initialize the DMA before
1484                  * starting the NCR. This is also the cleaner way for the TT.
1485                  */
1486                 if (p & SR_IO)
1487                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1488                 else
1489                         result = NCR5380_dma_send_setup(hostdata, d, c);
1490         }
1491
1492         /*
1493          * On the PAS16 at least I/O recovery delays are not needed here.
1494          * Everyone else seems to want them.
1495          */
1496
1497         if (p & SR_IO) {
1498                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1499                 NCR5380_io_delay(1);
1500                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1501         } else {
1502                 NCR5380_io_delay(1);
1503                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1504                 NCR5380_io_delay(1);
1505                 NCR5380_write(START_DMA_SEND_REG, 0);
1506                 NCR5380_io_delay(1);
1507         }
1508
1509 #ifdef CONFIG_SUN3
1510 #ifdef SUN3_SCSI_VME
1511         dregs->csr |= CSR_DMA_ENABLE;
1512 #endif
1513         sun3_dma_active = 1;
1514 #endif
1515
1516         if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1517                 /* On the Falcon, the DMA setup must be done after the last
1518                  * NCR access, else the DMA setup gets trashed!
1519                  */
1520                 if (p & SR_IO)
1521                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1522                 else
1523                         result = NCR5380_dma_send_setup(hostdata, d, c);
1524         }
1525
1526         /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
1527         if (result < 0)
1528                 return result;
1529
1530         /* For real DMA, result is the byte count. DMA interrupt is expected. */
1531         if (result > 0) {
1532                 hostdata->dma_len = result;
1533                 return 0;
1534         }
1535
1536         /* The result is zero iff pseudo DMA send/receive was completed. */
1537         hostdata->dma_len = c;
1538
1539 /*
1540  * A note regarding the DMA errata workarounds for early NMOS silicon.
1541  *
1542  * For DMA sends, we want to wait until the last byte has been
1543  * transferred out over the bus before we turn off DMA mode.  Alas, there
1544  * seems to be no terribly good way of doing this on a 5380 under all
1545  * conditions.  For non-scatter-gather operations, we can wait until REQ
1546  * and ACK both go false, or until a phase mismatch occurs.  Gather-sends
1547  * are nastier, since the device will be expecting more data than we
1548  * are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1549  * could test Last Byte Sent to assure transfer (I imagine this is precisely
1550  * why this signal was added to the newer chips) but on the older 538[01]
1551  * this signal does not exist.  The workaround for this lack is a watchdog;
1552  * we bail out of the wait-loop after a modest amount of wait-time if
1553  * the usual exit conditions are not met.  Not a terribly clean or
1554  * correct solution :-%
1555  *
1556  * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1557  * If the chip is in DMA receive mode, it will respond to a target's
1558  * REQ by latching the SCSI data into the INPUT DATA register and asserting
1559  * ACK, even if it has _already_ been notified by the DMA controller that
1560  * the current DMA transfer has completed!  If the NCR5380 is then taken
1561  * out of DMA mode, this already-acknowledged byte is lost. This is
1562  * not a problem for "one DMA transfer per READ command", because
1563  * the situation will never arise... either all of the data is DMA'ed
1564  * properly, or the target switches to MESSAGE IN phase to signal a
1565  * disconnection (either operation bringing the DMA to a clean halt).
1566  * However, in order to handle scatter-receive, we must work around the
1567  * problem.  The chosen fix is to DMA fewer bytes, then check for the
1568  * condition before taking the NCR5380 out of DMA mode.  One or two extra
1569  * bytes are transferred via PIO as necessary to fill out the original
1570  * request.
1571  */
1572
1573         if (hostdata->flags & FLAG_DMA_FIXUP) {
1574                 if (p & SR_IO) {
1575                         /*
1576                          * The workaround was to transfer fewer bytes than we
1577                          * intended to with the pseudo-DMA read function, wait for
1578                          * the chip to latch the last byte, read it, and then disable
1579                          * pseudo-DMA mode.
1580                          *
1581                          * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1582                          * REQ is deasserted when ACK is asserted, and not reasserted
1583                          * until ACK goes false.  Since the NCR5380 won't lower ACK
1584                          * until DACK is asserted, which won't happen unless we twiddle
1585                          * the DMA port or we take the NCR5380 out of DMA mode, we
1586                          * can guarantee that we won't handshake another extra
1587                          * byte.
1588                          */
1589
1590                         if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
1591                                                   BASR_DRQ, BASR_DRQ, HZ) < 0) {
1592                                 result = -1;
1593                                 shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1594                         }
1595                         if (NCR5380_poll_politely(hostdata, STATUS_REG,
1596                                                   SR_REQ, 0, HZ) < 0) {
1597                                 result = -1;
1598                                 shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1599                         }
1600                         d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
1601                 } else {
1602                         /*
1603                          * Wait for the last byte to be sent.  If REQ is being asserted for
1604                          * the byte we're interested, we'll ACK it and it will go false.
1605                          */
1606                         if (NCR5380_poll_politely2(hostdata,
1607                              BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1608                              BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
1609                                 result = -1;
1610                                 shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1611                         }
1612                 }
1613         }
1614
1615         NCR5380_dma_complete(instance);
1616         return result;
1617 }
1618
1619 /*
1620  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1621  *
1622  * Purpose : run through the various SCSI phases and do as the target
1623  * directs us to.  Operates on the currently connected command,
1624  * instance->connected.
1625  *
1626  * Inputs : instance, instance for which we are doing commands
1627  *
1628  * Side effects : SCSI things happen, the disconnected queue will be
1629  * modified if a command disconnects, *instance->connected will
1630  * change.
1631  *
1632  * XXX Note : we need to watch for bus free or a reset condition here
1633  * to recover from an unexpected bus free condition.
1634  */
1635
1636 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1637         __releases(&hostdata->lock) __acquires(&hostdata->lock)
1638 {
1639         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1640         unsigned char msgout = NOP;
1641         int sink = 0;
1642         int len;
1643         int transfersize;
1644         unsigned char *data;
1645         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1646         struct scsi_cmnd *cmd;
1647
1648 #ifdef SUN3_SCSI_VME
1649         dregs->csr |= CSR_INTR;
1650 #endif
1651
1652         while ((cmd = hostdata->connected)) {
1653                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1654
1655                 tmp = NCR5380_read(STATUS_REG);
1656                 /* We only have a valid SCSI phase when REQ is asserted */
1657                 if (tmp & SR_REQ) {
1658                         phase = (tmp & PHASE_MASK);
1659                         if (phase != old_phase) {
1660                                 old_phase = phase;
1661                                 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1662                         }
1663 #ifdef CONFIG_SUN3
1664                         if (phase == PHASE_CMDOUT &&
1665                             sun3_dma_setup_done != cmd) {
1666                                 int count;
1667
1668                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1669                                         ++cmd->SCp.buffer;
1670                                         --cmd->SCp.buffers_residual;
1671                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
1672                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1673                                 }
1674
1675                                 count = sun3scsi_dma_xfer_len(hostdata, cmd);
1676
1677                                 if (count > 0) {
1678                                         if (rq_data_dir(cmd->request))
1679                                                 sun3scsi_dma_send_setup(hostdata,
1680                                                                         cmd->SCp.ptr, count);
1681                                         else
1682                                                 sun3scsi_dma_recv_setup(hostdata,
1683                                                                         cmd->SCp.ptr, count);
1684                                         sun3_dma_setup_done = cmd;
1685                                 }
1686 #ifdef SUN3_SCSI_VME
1687                                 dregs->csr |= CSR_INTR;
1688 #endif
1689                         }
1690 #endif /* CONFIG_SUN3 */
1691
1692                         if (sink && (phase != PHASE_MSGOUT)) {
1693                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1694
1695                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1696                                               ICR_ASSERT_ACK);
1697                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1698                                         ;
1699                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1700                                               ICR_ASSERT_ATN);
1701                                 sink = 0;
1702                                 continue;
1703                         }
1704
1705                         switch (phase) {
1706                         case PHASE_DATAOUT:
1707 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1708                                 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1709                                 sink = 1;
1710                                 do_abort(instance);
1711                                 cmd->result = DID_ERROR << 16;
1712                                 complete_cmd(instance, cmd);
1713                                 hostdata->connected = NULL;
1714                                 return;
1715 #endif
1716                         case PHASE_DATAIN:
1717                                 /*
1718                                  * If there is no room left in the current buffer in the
1719                                  * scatter-gather list, move onto the next one.
1720                                  */
1721
1722                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1723                                         ++cmd->SCp.buffer;
1724                                         --cmd->SCp.buffers_residual;
1725                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
1726                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1727                                         dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
1728                                                  cmd->SCp.this_residual,
1729                                                  cmd->SCp.buffers_residual);
1730                                 }
1731
1732                                 /*
1733                                  * The preferred transfer method is going to be
1734                                  * PSEUDO-DMA for systems that are strictly PIO,
1735                                  * since we can let the hardware do the handshaking.
1736                                  *
1737                                  * For this to work, we need to know the transfersize
1738                                  * ahead of time, since the pseudo-DMA code will sit
1739                                  * in an unconditional loop.
1740                                  */
1741
1742                                 transfersize = 0;
1743                                 if (!cmd->device->borken)
1744                                         transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
1745
1746                                 if (transfersize > 0) {
1747                                         len = transfersize;
1748                                         if (NCR5380_transfer_dma(instance, &phase,
1749                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
1750                                                 /*
1751                                                  * If the watchdog timer fires, all future
1752                                                  * accesses to this device will use the
1753                                                  * polled-IO.
1754                                                  */
1755                                                 scmd_printk(KERN_INFO, cmd,
1756                                                         "switching to slow handshake\n");
1757                                                 cmd->device->borken = 1;
1758                                                 sink = 1;
1759                                                 do_abort(instance);
1760                                                 cmd->result = DID_ERROR << 16;
1761                                                 /* XXX - need to source or sink data here, as appropriate */
1762                                         }
1763                                 } else {
1764                                         /* Transfer a small chunk so that the
1765                                          * irq mode lock is not held too long.
1766                                          */
1767                                         transfersize = min(cmd->SCp.this_residual,
1768                                                            NCR5380_PIO_CHUNK_SIZE);
1769                                         len = transfersize;
1770                                         NCR5380_transfer_pio(instance, &phase, &len,
1771                                                              (unsigned char **)&cmd->SCp.ptr);
1772                                         cmd->SCp.this_residual -= transfersize - len;
1773                                 }
1774 #ifdef CONFIG_SUN3
1775                                 if (sun3_dma_setup_done == cmd)
1776                                         sun3_dma_setup_done = NULL;
1777 #endif
1778                                 return;
1779                         case PHASE_MSGIN:
1780                                 len = 1;
1781                                 data = &tmp;
1782                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1783                                 cmd->SCp.Message = tmp;
1784
1785                                 switch (tmp) {
1786                                 case ABORT:
1787                                 case COMMAND_COMPLETE:
1788                                         /* Accept message by clearing ACK */
1789                                         sink = 1;
1790                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1791                                         dsprintk(NDEBUG_QUEUES, instance,
1792                                                  "COMMAND COMPLETE %p target %d lun %llu\n",
1793                                                  cmd, scmd_id(cmd), cmd->device->lun);
1794
1795                                         hostdata->connected = NULL;
1796
1797                                         cmd->result &= ~0xffff;
1798                                         cmd->result |= cmd->SCp.Status;
1799                                         cmd->result |= cmd->SCp.Message << 8;
1800
1801                                         if (cmd->cmnd[0] == REQUEST_SENSE)
1802                                                 complete_cmd(instance, cmd);
1803                                         else {
1804                                                 if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1805                                                     cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1806                                                         dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1807                                                                  cmd);
1808                                                         list_add_tail(&ncmd->list,
1809                                                                       &hostdata->autosense);
1810                                                 } else
1811                                                         complete_cmd(instance, cmd);
1812                                         }
1813
1814                                         /*
1815                                          * Restore phase bits to 0 so an interrupted selection,
1816                                          * arbitration can resume.
1817                                          */
1818                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1819
1820                                         /* Enable reselect interrupts */
1821                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1822
1823                                         maybe_release_dma_irq(instance);
1824                                         return;
1825                                 case MESSAGE_REJECT:
1826                                         /* Accept message by clearing ACK */
1827                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1828                                         switch (hostdata->last_message) {
1829                                         case HEAD_OF_QUEUE_TAG:
1830                                         case ORDERED_QUEUE_TAG:
1831                                         case SIMPLE_QUEUE_TAG:
1832                                                 cmd->device->simple_tags = 0;
1833                                                 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1834                                                 break;
1835                                         default:
1836                                                 break;
1837                                         }
1838                                         break;
1839                                 case DISCONNECT:
1840                                         /* Accept message by clearing ACK */
1841                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1842                                         hostdata->connected = NULL;
1843                                         list_add(&ncmd->list, &hostdata->disconnected);
1844                                         dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1845                                                  instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1846                                                  cmd, scmd_id(cmd), cmd->device->lun);
1847
1848                                         /*
1849                                          * Restore phase bits to 0 so an interrupted selection,
1850                                          * arbitration can resume.
1851                                          */
1852                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1853
1854                                         /* Enable reselect interrupts */
1855                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1856 #ifdef SUN3_SCSI_VME
1857                                         dregs->csr |= CSR_DMA_ENABLE;
1858 #endif
1859                                         return;
1860                                         /*
1861                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1862                                          * operation, in violation of the SCSI spec so we can safely
1863                                          * ignore SAVE/RESTORE pointers calls.
1864                                          *
1865                                          * Unfortunately, some disks violate the SCSI spec and
1866                                          * don't issue the required SAVE_POINTERS message before
1867                                          * disconnecting, and we have to break spec to remain
1868                                          * compatible.
1869                                          */
1870                                 case SAVE_POINTERS:
1871                                 case RESTORE_POINTERS:
1872                                         /* Accept message by clearing ACK */
1873                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1874                                         break;
1875                                 case EXTENDED_MESSAGE:
1876                                         /*
1877                                          * Start the message buffer with the EXTENDED_MESSAGE
1878                                          * byte, since spi_print_msg() wants the whole thing.
1879                                          */
1880                                         extended_msg[0] = EXTENDED_MESSAGE;
1881                                         /* Accept first byte by clearing ACK */
1882                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1883
1884                                         spin_unlock_irq(&hostdata->lock);
1885
1886                                         dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1887
1888                                         len = 2;
1889                                         data = extended_msg + 1;
1890                                         phase = PHASE_MSGIN;
1891                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
1892                                         dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1893                                                  (int)extended_msg[1],
1894                                                  (int)extended_msg[2]);
1895
1896                                         if (!len && extended_msg[1] > 0 &&
1897                                             extended_msg[1] <= sizeof(extended_msg) - 2) {
1898                                                 /* Accept third byte by clearing ACK */
1899                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1900                                                 len = extended_msg[1] - 1;
1901                                                 data = extended_msg + 3;
1902                                                 phase = PHASE_MSGIN;
1903
1904                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1905                                                 dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
1906                                                          len);
1907
1908                                                 switch (extended_msg[2]) {
1909                                                 case EXTENDED_SDTR:
1910                                                 case EXTENDED_WDTR:
1911                                                 case EXTENDED_MODIFY_DATA_POINTER:
1912                                                 case EXTENDED_EXTENDED_IDENTIFY:
1913                                                         tmp = 0;
1914                                                 }
1915                                         } else if (len) {
1916                                                 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1917                                                 tmp = 0;
1918                                         } else {
1919                                                 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
1920                                                              extended_msg[2], extended_msg[1]);
1921                                                 tmp = 0;
1922                                         }
1923
1924                                         spin_lock_irq(&hostdata->lock);
1925                                         if (!hostdata->connected)
1926                                                 return;
1927
1928                                         /* Fall through to reject message */
1929
1930                                         /*
1931                                          * If we get something weird that we aren't expecting,
1932                                          * reject it.
1933                                          */
1934                                 default:
1935                                         if (!tmp) {
1936                                                 shost_printk(KERN_ERR, instance, "rejecting message ");
1937                                                 spi_print_msg(extended_msg);
1938                                                 printk("\n");
1939                                         } else if (tmp != EXTENDED_MESSAGE)
1940                                                 scmd_printk(KERN_INFO, cmd,
1941                                                             "rejecting unknown message %02x\n",
1942                                                             tmp);
1943                                         else
1944                                                 scmd_printk(KERN_INFO, cmd,
1945                                                             "rejecting unknown extended message code %02x, length %d\n",
1946                                                             extended_msg[1], extended_msg[0]);
1947
1948                                         msgout = MESSAGE_REJECT;
1949                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1950                                         break;
1951                                 } /* switch (tmp) */
1952                                 break;
1953                         case PHASE_MSGOUT:
1954                                 len = 1;
1955                                 data = &msgout;
1956                                 hostdata->last_message = msgout;
1957                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1958                                 if (msgout == ABORT) {
1959                                         hostdata->connected = NULL;
1960                                         cmd->result = DID_ERROR << 16;
1961                                         complete_cmd(instance, cmd);
1962                                         maybe_release_dma_irq(instance);
1963                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1964                                         return;
1965                                 }
1966                                 msgout = NOP;
1967                                 break;
1968                         case PHASE_CMDOUT:
1969                                 len = cmd->cmd_len;
1970                                 data = cmd->cmnd;
1971                                 /*
1972                                  * XXX for performance reasons, on machines with a
1973                                  * PSEUDO-DMA architecture we should probably
1974                                  * use the dma transfer function.
1975                                  */
1976                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1977                                 break;
1978                         case PHASE_STATIN:
1979                                 len = 1;
1980                                 data = &tmp;
1981                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1982                                 cmd->SCp.Status = tmp;
1983                                 break;
1984                         default:
1985                                 shost_printk(KERN_ERR, instance, "unknown phase\n");
1986                                 NCR5380_dprint(NDEBUG_ANY, instance);
1987                         } /* switch(phase) */
1988                 } else {
1989                         spin_unlock_irq(&hostdata->lock);
1990                         NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1991                         spin_lock_irq(&hostdata->lock);
1992                 }
1993         }
1994 }
1995
1996 /*
1997  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
1998  *
1999  * Purpose : does reselection, initializing the instance->connected
2000  * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2001  * nexus has been reestablished,
2002  *
2003  * Inputs : instance - this instance of the NCR5380.
2004  */
2005
2006 static void NCR5380_reselect(struct Scsi_Host *instance)
2007 {
2008         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2009         unsigned char target_mask;
2010         unsigned char lun;
2011         unsigned char msg[3];
2012         struct NCR5380_cmd *ncmd;
2013         struct scsi_cmnd *tmp;
2014
2015         /*
2016          * Disable arbitration, etc. since the host adapter obviously
2017          * lost, and tell an interrupted NCR5380_select() to restart.
2018          */
2019
2020         NCR5380_write(MODE_REG, MR_BASE);
2021
2022         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2023
2024         dsprintk(NDEBUG_RESELECTION, instance, "reselect\n");
2025
2026         /*
2027          * At this point, we have detected that our SCSI ID is on the bus,
2028          * SEL is true and BSY was false for at least one bus settle delay
2029          * (400 ns).
2030          *
2031          * We must assert BSY ourselves, until the target drops the SEL
2032          * signal.
2033          */
2034
2035         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2036         if (NCR5380_poll_politely(hostdata,
2037                                   STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2038                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2039                 return;
2040         }
2041         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2042
2043         /*
2044          * Wait for target to go into MSGIN.
2045          */
2046
2047         if (NCR5380_poll_politely(hostdata,
2048                                   STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2049                 do_abort(instance);
2050                 return;
2051         }
2052
2053 #ifdef CONFIG_SUN3
2054         /* acknowledge toggle to MSGIN */
2055         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2056
2057         /* peek at the byte without really hitting the bus */
2058         msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2059 #else
2060         {
2061                 int len = 1;
2062                 unsigned char *data = msg;
2063                 unsigned char phase = PHASE_MSGIN;
2064
2065                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2066
2067                 if (len) {
2068                         do_abort(instance);
2069                         return;
2070                 }
2071         }
2072 #endif /* CONFIG_SUN3 */
2073
2074         if (!(msg[0] & 0x80)) {
2075                 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2076                 spi_print_msg(msg);
2077                 printk("\n");
2078                 do_abort(instance);
2079                 return;
2080         }
2081         lun = msg[0] & 0x07;
2082
2083         /*
2084          * We need to add code for SCSI-II to track which devices have
2085          * I_T_L_Q nexuses established, and which have simple I_T_L
2086          * nexuses so we can chose to do additional data transfer.
2087          */
2088
2089         /*
2090          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2091          * just reestablished, and remove it from the disconnected queue.
2092          */
2093
2094         tmp = NULL;
2095         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2096                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2097
2098                 if (target_mask == (1 << scmd_id(cmd)) &&
2099                     lun == (u8)cmd->device->lun) {
2100                         list_del(&ncmd->list);
2101                         tmp = cmd;
2102                         break;
2103                 }
2104         }
2105
2106         if (tmp) {
2107                 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2108                          "reselect: removed %p from disconnected queue\n", tmp);
2109         } else {
2110                 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2111                              target_mask, lun);
2112                 /*
2113                  * Since we have an established nexus that we can't do anything
2114                  * with, we must abort it.
2115                  */
2116                 do_abort(instance);
2117                 return;
2118         }
2119
2120 #ifdef CONFIG_SUN3
2121         if (sun3_dma_setup_done != tmp) {
2122                 int count;
2123
2124                 if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
2125                         ++tmp->SCp.buffer;
2126                         --tmp->SCp.buffers_residual;
2127                         tmp->SCp.this_residual = tmp->SCp.buffer->length;
2128                         tmp->SCp.ptr = sg_virt(tmp->SCp.buffer);
2129                 }
2130
2131                 count = sun3scsi_dma_xfer_len(hostdata, tmp);
2132
2133                 if (count > 0) {
2134                         if (rq_data_dir(tmp->request))
2135                                 sun3scsi_dma_send_setup(hostdata,
2136                                                         tmp->SCp.ptr, count);
2137                         else
2138                                 sun3scsi_dma_recv_setup(hostdata,
2139                                                         tmp->SCp.ptr, count);
2140                         sun3_dma_setup_done = tmp;
2141                 }
2142         }
2143
2144         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2145 #endif /* CONFIG_SUN3 */
2146
2147         /* Accept message by clearing ACK */
2148         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2149
2150         hostdata->connected = tmp;
2151         dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
2152                  scmd_id(tmp), tmp->device->lun);
2153 }
2154
2155 /**
2156  * list_find_cmd - test for presence of a command in a linked list
2157  * @haystack: list of commands
2158  * @needle: command to search for
2159  */
2160
2161 static bool list_find_cmd(struct list_head *haystack,
2162                           struct scsi_cmnd *needle)
2163 {
2164         struct NCR5380_cmd *ncmd;
2165
2166         list_for_each_entry(ncmd, haystack, list)
2167                 if (NCR5380_to_scmd(ncmd) == needle)
2168                         return true;
2169         return false;
2170 }
2171
2172 /**
2173  * list_remove_cmd - remove a command from linked list
2174  * @haystack: list of commands
2175  * @needle: command to remove
2176  */
2177
2178 static bool list_del_cmd(struct list_head *haystack,
2179                          struct scsi_cmnd *needle)
2180 {
2181         if (list_find_cmd(haystack, needle)) {
2182                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2183
2184                 list_del(&ncmd->list);
2185                 return true;
2186         }
2187         return false;
2188 }
2189
2190 /**
2191  * NCR5380_abort - scsi host eh_abort_handler() method
2192  * @cmd: the command to be aborted
2193  *
2194  * Try to abort a given command by removing it from queues and/or sending
2195  * the target an abort message. This may not succeed in causing a target
2196  * to abort the command. Nonetheless, the low-level driver must forget about
2197  * the command because the mid-layer reclaims it and it may be re-issued.
2198  *
2199  * The normal path taken by a command is as follows. For EH we trace this
2200  * same path to locate and abort the command.
2201  *
2202  * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2203  * [disconnected -> connected ->]...
2204  * [autosense -> connected ->] done
2205  *
2206  * If cmd was not found at all then presumably it has already been completed,
2207  * in which case return SUCCESS to try to avoid further EH measures.
2208  *
2209  * If the command has not completed yet, we must not fail to find it.
2210  * We have no option but to forget the aborted command (even if it still
2211  * lacks sense data). The mid-layer may re-issue a command that is in error
2212  * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2213  * this driver are such that a command can appear on one queue only.
2214  *
2215  * The lock protects driver data structures, but EH handlers also use it
2216  * to serialize their own execution and prevent their own re-entry.
2217  */
2218
2219 static int NCR5380_abort(struct scsi_cmnd *cmd)
2220 {
2221         struct Scsi_Host *instance = cmd->device->host;
2222         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2223         unsigned long flags;
2224         int result = SUCCESS;
2225
2226         spin_lock_irqsave(&hostdata->lock, flags);
2227
2228 #if (NDEBUG & NDEBUG_ANY)
2229         scmd_printk(KERN_INFO, cmd, __func__);
2230 #endif
2231         NCR5380_dprint(NDEBUG_ANY, instance);
2232         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2233
2234         if (list_del_cmd(&hostdata->unissued, cmd)) {
2235                 dsprintk(NDEBUG_ABORT, instance,
2236                          "abort: removed %p from issue queue\n", cmd);
2237                 cmd->result = DID_ABORT << 16;
2238                 cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2239                 goto out;
2240         }
2241
2242         if (hostdata->selecting == cmd) {
2243                 dsprintk(NDEBUG_ABORT, instance,
2244                          "abort: cmd %p == selecting\n", cmd);
2245                 hostdata->selecting = NULL;
2246                 cmd->result = DID_ABORT << 16;
2247                 complete_cmd(instance, cmd);
2248                 goto out;
2249         }
2250
2251         if (list_del_cmd(&hostdata->disconnected, cmd)) {
2252                 dsprintk(NDEBUG_ABORT, instance,
2253                          "abort: removed %p from disconnected list\n", cmd);
2254                 /* Can't call NCR5380_select() and send ABORT because that
2255                  * means releasing the lock. Need a bus reset.
2256                  */
2257                 set_host_byte(cmd, DID_ERROR);
2258                 complete_cmd(instance, cmd);
2259                 result = FAILED;
2260                 goto out;
2261         }
2262
2263         if (hostdata->connected == cmd) {
2264                 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2265                 hostdata->connected = NULL;
2266                 hostdata->dma_len = 0;
2267                 if (do_abort(instance)) {
2268                         set_host_byte(cmd, DID_ERROR);
2269                         complete_cmd(instance, cmd);
2270                         result = FAILED;
2271                         goto out;
2272                 }
2273                 set_host_byte(cmd, DID_ABORT);
2274                 complete_cmd(instance, cmd);
2275                 goto out;
2276         }
2277
2278         if (list_del_cmd(&hostdata->autosense, cmd)) {
2279                 dsprintk(NDEBUG_ABORT, instance,
2280                          "abort: removed %p from sense queue\n", cmd);
2281                 set_host_byte(cmd, DID_ERROR);
2282                 complete_cmd(instance, cmd);
2283         }
2284
2285 out:
2286         if (result == FAILED)
2287                 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2288         else
2289                 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2290
2291         queue_work(hostdata->work_q, &hostdata->main_task);
2292         maybe_release_dma_irq(instance);
2293         spin_unlock_irqrestore(&hostdata->lock, flags);
2294
2295         return result;
2296 }
2297
2298
2299 /**
2300  * NCR5380_host_reset - reset the SCSI host
2301  * @cmd: SCSI command undergoing EH
2302  *
2303  * Returns SUCCESS
2304  */
2305
2306 static int NCR5380_host_reset(struct scsi_cmnd *cmd)
2307 {
2308         struct Scsi_Host *instance = cmd->device->host;
2309         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2310         int i;
2311         unsigned long flags;
2312         struct NCR5380_cmd *ncmd;
2313
2314         spin_lock_irqsave(&hostdata->lock, flags);
2315
2316 #if (NDEBUG & NDEBUG_ANY)
2317         scmd_printk(KERN_INFO, cmd, __func__);
2318 #endif
2319         NCR5380_dprint(NDEBUG_ANY, instance);
2320         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2321
2322         do_reset(instance);
2323
2324         /* reset NCR registers */
2325         NCR5380_write(MODE_REG, MR_BASE);
2326         NCR5380_write(TARGET_COMMAND_REG, 0);
2327         NCR5380_write(SELECT_ENABLE_REG, 0);
2328
2329         /* After the reset, there are no more connected or disconnected commands
2330          * and no busy units; so clear the low-level status here to avoid
2331          * conflicts when the mid-level code tries to wake up the affected
2332          * commands!
2333          */
2334
2335         if (list_del_cmd(&hostdata->unissued, cmd)) {
2336                 cmd->result = DID_RESET << 16;
2337                 cmd->scsi_done(cmd);
2338         }
2339
2340         if (hostdata->selecting) {
2341                 hostdata->selecting->result = DID_RESET << 16;
2342                 complete_cmd(instance, hostdata->selecting);
2343                 hostdata->selecting = NULL;
2344         }
2345
2346         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2347                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2348
2349                 set_host_byte(cmd, DID_RESET);
2350                 complete_cmd(instance, cmd);
2351         }
2352         INIT_LIST_HEAD(&hostdata->disconnected);
2353
2354         list_for_each_entry(ncmd, &hostdata->autosense, list) {
2355                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2356
2357                 set_host_byte(cmd, DID_RESET);
2358                 cmd->scsi_done(cmd);
2359         }
2360         INIT_LIST_HEAD(&hostdata->autosense);
2361
2362         if (hostdata->connected) {
2363                 set_host_byte(hostdata->connected, DID_RESET);
2364                 complete_cmd(instance, hostdata->connected);
2365                 hostdata->connected = NULL;
2366         }
2367
2368         for (i = 0; i < 8; ++i)
2369                 hostdata->busy[i] = 0;
2370         hostdata->dma_len = 0;
2371
2372         queue_work(hostdata->work_q, &hostdata->main_task);
2373         maybe_release_dma_irq(instance);
2374         spin_unlock_irqrestore(&hostdata->lock, flags);
2375
2376         return SUCCESS;
2377 }