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 static void bus_reset_cleanup(struct Scsi_Host *);
 135
 136 /**
 137  * initialize_SCp - init the scsi pointer field
 138  * @cmd: command block to set up
 139  *
 140  * Set up the internal fields in the SCSI command.
 141  */
 142
 143 static inline void initialize_SCp(struct scsi_cmnd *cmd)
 144 {
 145         /*
 146          * Initialize the Scsi Pointer field so that all of the commands in the
 147          * various queues are valid.
 148          */
 149
 150         if (scsi_bufflen(cmd)) {
 151                 cmd->SCp.buffer = scsi_sglist(cmd);
 152                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 153                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 154                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 155         } else {
 156                 cmd->SCp.buffer = NULL;
 157                 cmd->SCp.buffers_residual = 0;
 158                 cmd->SCp.ptr = NULL;
 159                 cmd->SCp.this_residual = 0;
 160         }
 161
 162         cmd->SCp.Status = 0;
 163         cmd->SCp.Message = 0;
 164 }
 165
 166 /**
 167  * NCR5380_poll_politely2 - wait for two chip register values
 168  * @hostdata: host private data
 169  * @reg1: 5380 register to poll
 170  * @bit1: Bitmask to check
 171  * @val1: Expected value
 172  * @reg2: Second 5380 register to poll
 173  * @bit2: Second bitmask to check
 174  * @val2: Second expected value
 175  * @wait: Time-out in jiffies
 176  *
 177  * Polls the chip in a reasonably efficient manner waiting for an
 178  * event to occur. After a short quick poll we begin to yield the CPU
 179  * (if possible). In irq contexts the time-out is arbitrarily limited.
 180  * Callers may hold locks as long as they are held in irq mode.
 181  *
 182  * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
 183  */
 184
 185 static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
 186                                   unsigned int reg1, u8 bit1, u8 val1,
 187                                   unsigned int reg2, u8 bit2, u8 val2,
 188                                   unsigned long wait)
 189 {
 190         unsigned long n = hostdata->poll_loops;
 191         unsigned long deadline = jiffies + wait;
 192
 193         do {
 194                 if ((NCR5380_read(reg1) & bit1) == val1)
 195                         return 0;
 196                 if ((NCR5380_read(reg2) & bit2) == val2)
 197                         return 0;
 198                 cpu_relax();
 199         } while (n--);
 200
 201         if (irqs_disabled() || in_interrupt())
 202                 return -ETIMEDOUT;
 203
 204         /* Repeatedly sleep for 1 ms until deadline */
 205         while (time_is_after_jiffies(deadline)) {
 206                 schedule_timeout_uninterruptible(1);
 207                 if ((NCR5380_read(reg1) & bit1) == val1)
 208                         return 0;
 209                 if ((NCR5380_read(reg2) & bit2) == val2)
 210                         return 0;
 211         }
 212
 213         return -ETIMEDOUT;
 214 }
 215
 216 #if NDEBUG
 217 static struct {
 218         unsigned char mask;
 219         const char *name;
 220 } signals[] = {
 221         {SR_DBP, "PARITY"},
 222         {SR_RST, "RST"},
 223         {SR_BSY, "BSY"},
 224         {SR_REQ, "REQ"},
 225         {SR_MSG, "MSG"},
 226         {SR_CD, "CD"},
 227         {SR_IO, "IO"},
 228         {SR_SEL, "SEL"},
 229         {0, NULL}
 230 },
 231 basrs[] = {
 232         {BASR_END_DMA_TRANSFER, "END OF DMA"},
 233         {BASR_DRQ, "DRQ"},
 234         {BASR_PARITY_ERROR, "PARITY ERROR"},
 235         {BASR_IRQ, "IRQ"},
 236         {BASR_PHASE_MATCH, "PHASE MATCH"},
 237         {BASR_BUSY_ERROR, "BUSY ERROR"},
 238         {BASR_ATN, "ATN"},
 239         {BASR_ACK, "ACK"},
 240         {0, NULL}
 241 },
 242 icrs[] = {
 243         {ICR_ASSERT_RST, "ASSERT RST"},
 244         {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
 245         {ICR_ARBITRATION_LOST, "LOST ARB."},
 246         {ICR_ASSERT_ACK, "ASSERT ACK"},
 247         {ICR_ASSERT_BSY, "ASSERT BSY"},
 248         {ICR_ASSERT_SEL, "ASSERT SEL"},
 249         {ICR_ASSERT_ATN, "ASSERT ATN"},
 250         {ICR_ASSERT_DATA, "ASSERT DATA"},
 251         {0, NULL}
 252 },
 253 mrs[] = {
 254         {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
 255         {MR_TARGET, "TARGET"},
 256         {MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
 257         {MR_ENABLE_PAR_INTR, "PARITY INTR"},
 258         {MR_ENABLE_EOP_INTR, "EOP INTR"},
 259         {MR_MONITOR_BSY, "MONITOR BSY"},
 260         {MR_DMA_MODE, "DMA MODE"},
 261         {MR_ARBITRATE, "ARBITRATE"},
 262         {0, NULL}
 263 };
 264
 265 /**
 266  * NCR5380_print - print scsi bus signals
 267  * @instance: adapter state to dump
 268  *
 269  * Print the SCSI bus signals for debugging purposes
 270  */
 271
 272 static void NCR5380_print(struct Scsi_Host *instance)
 273 {
 274         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 275         unsigned char status, basr, mr, icr, i;
 276
 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 (status_byte(cmd->result) != GOOD) {
 517                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 518                 } else {
 519                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 520                         set_driver_byte(cmd, DRIVER_SENSE);
 521                 }
 522                 hostdata->sensing = NULL;
 523         }
 524
 525         cmd->scsi_done(cmd);
 526 }
 527
 528 /**
 529  * NCR5380_queue_command - queue a command
 530  * @instance: the relevant SCSI adapter
 531  * @cmd: SCSI command
 532  *
 533  * cmd is added to the per-instance issue queue, with minor
 534  * twiddling done to the host specific fields of cmd.  If the
 535  * main coroutine is not running, it is restarted.
 536  */
 537
 538 static int NCR5380_queue_command(struct Scsi_Host *instance,
 539                                  struct scsi_cmnd *cmd)
 540 {
 541         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 542         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 543         unsigned long flags;
 544
 545 #if (NDEBUG & NDEBUG_NO_WRITE)
 546         switch (cmd->cmnd[0]) {
 547         case WRITE_6:
 548         case WRITE_10:
 549                 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
 550                 cmd->result = (DID_ERROR << 16);
 551                 cmd->scsi_done(cmd);
 552                 return 0;
 553         }
 554 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 555
 556         cmd->result = 0;
 557
 558         if (!NCR5380_acquire_dma_irq(instance))
 559                 return SCSI_MLQUEUE_HOST_BUSY;
 560
 561         spin_lock_irqsave(&hostdata->lock, flags);
 562
 563         /*
 564          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 565          * commands are added to the head of the queue since any command will
 566          * clear the contingent allegiance condition that exists and the
 567          * sense data is only guaranteed to be valid while the condition exists.
 568          */
 569
 570         if (cmd->cmnd[0] == REQUEST_SENSE)
 571                 list_add(&ncmd->list, &hostdata->unissued);
 572         else
 573                 list_add_tail(&ncmd->list, &hostdata->unissued);
 574
 575         spin_unlock_irqrestore(&hostdata->lock, flags);
 576
 577         dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
 578                  cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 579
 580         /* Kick off command processing */
 581         queue_work(hostdata->work_q, &hostdata->main_task);
 582         return 0;
 583 }
 584
 585 static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
 586 {
 587         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 588
 589         /* Caller does the locking needed to set & test these data atomically */
 590         if (list_empty(&hostdata->disconnected) &&
 591             list_empty(&hostdata->unissued) &&
 592             list_empty(&hostdata->autosense) &&
 593             !hostdata->connected &&
 594             !hostdata->selecting) {
 595                 NCR5380_release_dma_irq(instance);
 596         }
 597 }
 598
 599 /**
 600  * dequeue_next_cmd - dequeue a command for processing
 601  * @instance: the scsi host instance
 602  *
 603  * Priority is given to commands on the autosense queue. These commands
 604  * need autosense because of a CHECK CONDITION result.
 605  *
 606  * Returns a command pointer if a command is found for a target that is
 607  * not already busy. Otherwise returns NULL.
 608  */
 609
 610 static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
 611 {
 612         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 613         struct NCR5380_cmd *ncmd;
 614         struct scsi_cmnd *cmd;
 615
 616         if (hostdata->sensing || list_empty(&hostdata->autosense)) {
 617                 list_for_each_entry(ncmd, &hostdata->unissued, list) {
 618                         cmd = NCR5380_to_scmd(ncmd);
 619                         dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
 620                                  cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
 621
 622                         if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
 623                                 list_del(&ncmd->list);
 624                                 dsprintk(NDEBUG_QUEUES, instance,
 625                                          "dequeue: removed %p from issue queue\n", cmd);
 626                                 return cmd;
 627                         }
 628                 }
 629         } else {
 630                 /* Autosense processing begins here */
 631                 ncmd = list_first_entry(&hostdata->autosense,
 632                                         struct NCR5380_cmd, list);
 633                 list_del(&ncmd->list);
 634                 cmd = NCR5380_to_scmd(ncmd);
 635                 dsprintk(NDEBUG_QUEUES, instance,
 636                          "dequeue: removed %p from autosense queue\n", cmd);
 637                 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
 638                 hostdata->sensing = cmd;
 639                 return cmd;
 640         }
 641         return NULL;
 642 }
 643
 644 static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 645 {
 646         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 647         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 648
 649         if (hostdata->sensing == cmd) {
 650                 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 651                 list_add(&ncmd->list, &hostdata->autosense);
 652                 hostdata->sensing = NULL;
 653         } else
 654                 list_add(&ncmd->list, &hostdata->unissued);
 655 }
 656
 657 /**
 658  * NCR5380_main - NCR state machines
 659  *
 660  * NCR5380_main is a coroutine that runs as long as more work can
 661  * be done on the NCR5380 host adapters in a system.  Both
 662  * NCR5380_queue_command() and NCR5380_intr() will try to start it
 663  * in case it is not running.
 664  */
 665
 666 static void NCR5380_main(struct work_struct *work)
 667 {
 668         struct NCR5380_hostdata *hostdata =
 669                 container_of(work, struct NCR5380_hostdata, main_task);
 670         struct Scsi_Host *instance = hostdata->host;
 671         int done;
 672
 673         do {
 674                 done = 1;
 675
 676                 spin_lock_irq(&hostdata->lock);
 677                 while (!hostdata->connected && !hostdata->selecting) {
 678                         struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
 679
 680                         if (!cmd)
 681                                 break;
 682
 683                         dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
 684
 685                         /*
 686                          * Attempt to establish an I_T_L nexus here.
 687                          * On success, instance->hostdata->connected is set.
 688                          * On failure, we must add the command back to the
 689                          * issue queue so we can keep trying.
 690                          */
 691                         /*
 692                          * REQUEST SENSE commands are issued without tagged
 693                          * queueing, even on SCSI-II devices because the
 694                          * contingent allegiance condition exists for the
 695                          * entire unit.
 696                          */
 697
 698                         if (!NCR5380_select(instance, cmd)) {
 699                                 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
 700                                 maybe_release_dma_irq(instance);
 701                         } else {
 702                                 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
 703                                          "main: select failed, returning %p to queue\n", cmd);
 704                                 requeue_cmd(instance, cmd);
 705                         }
 706                 }
 707                 if (hostdata->connected && !hostdata->dma_len) {
 708                         dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
 709                         NCR5380_information_transfer(instance);
 710                         done = 0;
 711                 }
 712                 if (!hostdata->connected)
 713                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 714                 spin_unlock_irq(&hostdata->lock);
 715                 if (!done)
 716                         cond_resched();
 717         } while (!done);
 718 }
 719
 720 /*
 721  * NCR5380_dma_complete - finish DMA transfer
 722  * @instance: the scsi host instance
 723  *
 724  * Called by the interrupt handler when DMA finishes or a phase
 725  * mismatch occurs (which would end the DMA transfer).
 726  */
 727
 728 static void NCR5380_dma_complete(struct Scsi_Host *instance)
 729 {
 730         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 731         int transferred;
 732         unsigned char **data;
 733         int *count;
 734         int saved_data = 0, overrun = 0;
 735         unsigned char p;
 736
 737         if (hostdata->read_overruns) {
 738                 p = hostdata->connected->SCp.phase;
 739                 if (p & SR_IO) {
 740                         udelay(10);
 741                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
 742                              (BASR_PHASE_MATCH | BASR_ACK)) ==
 743                             (BASR_PHASE_MATCH | BASR_ACK)) {
 744                                 saved_data = NCR5380_read(INPUT_DATA_REG);
 745                                 overrun = 1;
 746                                 dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
 747                         }
 748                 }
 749         }
 750
 751 #ifdef CONFIG_SUN3
 752         if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
 753                 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
 754                        instance->host_no);
 755                 BUG();
 756         }
 757
 758         if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
 759             (BASR_PHASE_MATCH | BASR_ACK)) {
 760                 pr_err("scsi%d: BASR %02x\n", instance->host_no,
 761                        NCR5380_read(BUS_AND_STATUS_REG));
 762                 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
 763                        instance->host_no);
 764                 BUG();
 765         }
 766 #endif
 767
 768         NCR5380_write(MODE_REG, MR_BASE);
 769         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 770         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 771
 772         transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
 773         hostdata->dma_len = 0;
 774
 775         data = (unsigned char **)&hostdata->connected->SCp.ptr;
 776         count = &hostdata->connected->SCp.this_residual;
 777         *data += transferred;
 778         *count -= transferred;
 779
 780         if (hostdata->read_overruns) {
 781                 int cnt, toPIO;
 782
 783                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
 784                         cnt = toPIO = hostdata->read_overruns;
 785                         if (overrun) {
 786                                 dsprintk(NDEBUG_DMA, instance,
 787                                          "Got an input overrun, using saved byte\n");
 788                                 *(*data)++ = saved_data;
 789                                 (*count)--;
 790                                 cnt--;
 791                                 toPIO--;
 792                         }
 793                         if (toPIO > 0) {
 794                                 dsprintk(NDEBUG_DMA, instance,
 795                                          "Doing %d byte PIO to 0x%p\n", cnt, *data);
 796                                 NCR5380_transfer_pio(instance, &p, &cnt, data);
 797                                 *count -= toPIO - cnt;
 798                         }
 799                 }
 800         }
 801 }
 802
 803 /**
 804  * NCR5380_intr - generic NCR5380 irq handler
 805  * @irq: interrupt number
 806  * @dev_id: device info
 807  *
 808  * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 809  * from the disconnected queue, and restarting NCR5380_main()
 810  * as required.
 811  *
 812  * The chip can assert IRQ in any of six different conditions. The IRQ flag
 813  * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
 814  * Three of these six conditions are latched in the Bus and Status Register:
 815  * - End of DMA (cleared by ending DMA Mode)
 816  * - Parity error (cleared by reading RPIR)
 817  * - Loss of BSY (cleared by reading RPIR)
 818  * Two conditions have flag bits that are not latched:
 819  * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
 820  * - Bus reset (non-maskable)
 821  * The remaining condition has no flag bit at all:
 822  * - Selection/reselection
 823  *
 824  * Hence, establishing the cause(s) of any interrupt is partly guesswork.
 825  * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
 826  * claimed that "the design of the [DP8490] interrupt logic ensures
 827  * interrupts will not be lost (they can be on the DP5380)."
 828  * The L5380/53C80 datasheet from LOGIC Devices has more details.
 829  *
 830  * Checking for bus reset by reading RST is futile because of interrupt
 831  * latency, but a bus reset will reset chip logic. Checking for parity error
 832  * is unnecessary because that interrupt is never enabled. A Loss of BSY
 833  * condition will clear DMA Mode. We can tell when this occurs because the
 834  * the Busy Monitor interrupt is enabled together with DMA Mode.
 835  */
 836
 837 static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
 838 {
 839         struct Scsi_Host *instance = dev_id;
 840         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 841         int handled = 0;
 842         unsigned char basr;
 843         unsigned long flags;
 844
 845         spin_lock_irqsave(&hostdata->lock, flags);
 846
 847         basr = NCR5380_read(BUS_AND_STATUS_REG);
 848         if (basr & BASR_IRQ) {
 849                 unsigned char mr = NCR5380_read(MODE_REG);
 850                 unsigned char sr = NCR5380_read(STATUS_REG);
 851
 852                 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
 853                          irq, basr, sr, mr);
 854
 855                 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
 856                         /* Probably End of DMA, Phase Mismatch or Loss of BSY.
 857                          * We ack IRQ after clearing Mode Register. Workarounds
 858                          * for End of DMA errata need to happen in DMA Mode.
 859                          */
 860
 861                         dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
 862
 863                         if (hostdata->connected) {
 864                                 NCR5380_dma_complete(instance);
 865                                 queue_work(hostdata->work_q, &hostdata->main_task);
 866                         } else {
 867                                 NCR5380_write(MODE_REG, MR_BASE);
 868                                 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 869                         }
 870                 } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
 871                     (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
 872                         /* Probably reselected */
 873                         NCR5380_write(SELECT_ENABLE_REG, 0);
 874                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 875
 876                         dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
 877
 878                         if (!hostdata->connected) {
 879                                 NCR5380_reselect(instance);
 880                                 queue_work(hostdata->work_q, &hostdata->main_task);
 881                         }
 882                         if (!hostdata->connected)
 883                                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 884                 } else {
 885                         /* Probably Bus Reset */
 886                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 887
 888                         if (sr & SR_RST) {
 889                                 /* Certainly Bus Reset */
 890                                 shost_printk(KERN_WARNING, instance,
 891                                              "bus reset interrupt\n");
 892                                 bus_reset_cleanup(instance);
 893                         } else {
 894                                 dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
 895                         }
 896 #ifdef SUN3_SCSI_VME
 897                         dregs->csr |= CSR_DMA_ENABLE;
 898 #endif
 899                 }
 900                 handled = 1;
 901         } else {
 902                 dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
 903 #ifdef SUN3_SCSI_VME
 904                 dregs->csr |= CSR_DMA_ENABLE;
 905 #endif
 906         }
 907
 908         spin_unlock_irqrestore(&hostdata->lock, flags);
 909
 910         return IRQ_RETVAL(handled);
 911 }
 912
 913 /**
 914  * NCR5380_select - attempt arbitration and selection for a given command
 915  * @instance: the Scsi_Host instance
 916  * @cmd: the scsi_cmnd to execute
 917  *
 918  * This routine establishes an I_T_L nexus for a SCSI command. This involves
 919  * ARBITRATION, SELECTION and MESSAGE OUT phases and an IDENTIFY message.
 920  *
 921  * Returns true if the operation should be retried.
 922  * Returns false if it should not be retried.
 923  *
 924  * Side effects :
 925  * If bus busy, arbitration failed, etc, NCR5380_select() will exit
 926  * with registers as they should have been on entry - ie
 927  * SELECT_ENABLE will be set appropriately, the NCR5380
 928  * will cease to drive any SCSI bus signals.
 929  *
 930  * If successful : the I_T_L nexus will be established, and
 931  * hostdata->connected will be set to cmd.
 932  * SELECT interrupt will be disabled.
 933  *
 934  * If failed (no target) : cmd->scsi_done() will be called, and the
 935  * cmd->result host byte set to DID_BAD_TARGET.
 936  */
 937
 938 static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 939         __releases(&hostdata->lock) __acquires(&hostdata->lock)
 940 {
 941         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 942         unsigned char tmp[3], phase;
 943         unsigned char *data;
 944         int len;
 945         int err;
 946         bool ret = true;
 947         bool can_disconnect = instance->irq != NO_IRQ &&
 948                               cmd->cmnd[0] != REQUEST_SENSE;
 949
 950         NCR5380_dprint(NDEBUG_ARBITRATION, instance);
 951         dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
 952                  instance->this_id);
 953
 954         /*
 955          * Arbitration and selection phases are slow and involve dropping the
 956          * lock, so we have to watch out for EH. An exception handler may
 957          * change 'selecting' to NULL. This function will then return false
 958          * so that the caller will forget about 'cmd'. (During information
 959          * transfer phases, EH may change 'connected' to NULL.)
 960          */
 961         hostdata->selecting = cmd;
 962
 963         /*
 964          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
 965          * data bus during SELECTION.
 966          */
 967
 968         NCR5380_write(TARGET_COMMAND_REG, 0);
 969
 970         /*
 971          * Start arbitration.
 972          */
 973
 974         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
 975         NCR5380_write(MODE_REG, MR_ARBITRATE);
 976
 977         /* The chip now waits for BUS FREE phase. Then after the 800 ns
 978          * Bus Free Delay, arbitration will begin.
 979          */
 980
 981         spin_unlock_irq(&hostdata->lock);
 982         err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
 983                         INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
 984                                                ICR_ARBITRATION_PROGRESS, HZ);
 985         spin_lock_irq(&hostdata->lock);
 986         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
 987                 /* Reselection interrupt */
 988                 goto out;
 989         }
 990         if (!hostdata->selecting) {
 991                 /* Command was aborted */
 992                 NCR5380_write(MODE_REG, MR_BASE);
 993                 return false;
 994         }
 995         if (err < 0) {
 996                 NCR5380_write(MODE_REG, MR_BASE);
 997                 shost_printk(KERN_ERR, instance,
 998                              "select: arbitration timeout\n");
 999                 goto out;
1000         }
1001         spin_unlock_irq(&hostdata->lock);
1002
1003         /* The SCSI-2 arbitration delay is 2.4 us */
1004         udelay(3);
1005
1006         /* Check for lost arbitration */
1007         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1008             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1009             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1010                 NCR5380_write(MODE_REG, MR_BASE);
1011                 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1012                 spin_lock_irq(&hostdata->lock);
1013                 goto out;
1014         }
1015
1016         /* After/during arbitration, BSY should be asserted.
1017          * IBM DPES-31080 Version S31Q works now
1018          * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1019          */
1020         NCR5380_write(INITIATOR_COMMAND_REG,
1021                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1022
1023         /*
1024          * Again, bus clear + bus settle time is 1.2us, however, this is
1025          * a minimum so we'll udelay ceil(1.2)
1026          */
1027
1028         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1029                 udelay(15);
1030         else
1031                 udelay(2);
1032
1033         spin_lock_irq(&hostdata->lock);
1034
1035         /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1036         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1037                 goto out;
1038
1039         if (!hostdata->selecting) {
1040                 NCR5380_write(MODE_REG, MR_BASE);
1041                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1042                 return false;
1043         }
1044
1045         dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1046
1047         /*
1048          * Now that we have won arbitration, start Selection process, asserting
1049          * the host and target ID's on the SCSI bus.
1050          */
1051
1052         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1053
1054         /*
1055          * Raise ATN while SEL is true before BSY goes false from arbitration,
1056          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1057          * phase immediately after selection.
1058          */
1059
1060         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1061                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1062         NCR5380_write(MODE_REG, MR_BASE);
1063
1064         /*
1065          * Reselect interrupts must be turned off prior to the dropping of BSY,
1066          * otherwise we will trigger an interrupt.
1067          */
1068         NCR5380_write(SELECT_ENABLE_REG, 0);
1069
1070         spin_unlock_irq(&hostdata->lock);
1071
1072         /*
1073          * The initiator shall then wait at least two deskew delays and release
1074          * the BSY signal.
1075          */
1076         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1077
1078         /* Reset BSY */
1079         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1080                       ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1081
1082         /*
1083          * Something weird happens when we cease to drive BSY - looks
1084          * like the board/chip is letting us do another read before the
1085          * appropriate propagation delay has expired, and we're confusing
1086          * a BSY signal from ourselves as the target's response to SELECTION.
1087          *
1088          * A small delay (the 'C++' frontend breaks the pipeline with an
1089          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1090          * tighter 'C' code breaks and requires this) solves the problem -
1091          * the 1 us delay is arbitrary, and only used because this delay will
1092          * be the same on other platforms and since it works here, it should
1093          * work there.
1094          *
1095          * wingel suggests that this could be due to failing to wait
1096          * one deskew delay.
1097          */
1098
1099         udelay(1);
1100
1101         dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1102
1103         /*
1104          * The SCSI specification calls for a 250 ms timeout for the actual
1105          * selection.
1106          */
1107
1108         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
1109                                     msecs_to_jiffies(250));
1110
1111         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1112                 spin_lock_irq(&hostdata->lock);
1113                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1114                 NCR5380_reselect(instance);
1115                 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1116                 goto out;
1117         }
1118
1119         if (err < 0) {
1120                 spin_lock_irq(&hostdata->lock);
1121                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1122
1123                 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1124                 if (!hostdata->selecting)
1125                         return false;
1126
1127                 cmd->result = DID_BAD_TARGET << 16;
1128                 complete_cmd(instance, cmd);
1129                 dsprintk(NDEBUG_SELECTION, instance,
1130                         "target did not respond within 250ms\n");
1131                 ret = false;
1132                 goto out;
1133         }
1134
1135         /*
1136          * No less than two deskew delays after the initiator detects the
1137          * BSY signal is true, it shall release the SEL signal and may
1138          * change the DATA BUS.                                     -wingel
1139          */
1140
1141         udelay(1);
1142
1143         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1144
1145         /*
1146          * Since we followed the SCSI spec, and raised ATN while SEL
1147          * was true but before BSY was false during selection, the information
1148          * transfer phase should be a MESSAGE OUT phase so that we can send the
1149          * IDENTIFY message.
1150          */
1151
1152         /* Wait for start of REQ/ACK handshake */
1153
1154         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1155         spin_lock_irq(&hostdata->lock);
1156         if (err < 0) {
1157                 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1158                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1159                 goto out;
1160         }
1161         if (!hostdata->selecting) {
1162                 do_abort(instance);
1163                 return false;
1164         }
1165
1166         dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1167                  scmd_id(cmd));
1168         tmp[0] = IDENTIFY(can_disconnect, cmd->device->lun);
1169
1170         len = 1;
1171         data = tmp;
1172         phase = PHASE_MSGOUT;
1173         NCR5380_transfer_pio(instance, &phase, &len, &data);
1174         if (len) {
1175                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1176                 cmd->result = DID_ERROR << 16;
1177                 complete_cmd(instance, cmd);
1178                 dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
1179                 ret = false;
1180                 goto out;
1181         }
1182
1183         dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1184
1185         hostdata->connected = cmd;
1186         hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1187
1188 #ifdef SUN3_SCSI_VME
1189         dregs->csr |= CSR_INTR;
1190 #endif
1191
1192         initialize_SCp(cmd);
1193
1194         ret = false;
1195
1196 out:
1197         if (!hostdata->selecting)
1198                 return false;
1199         hostdata->selecting = NULL;
1200         return ret;
1201 }
1202
1203 /*
1204  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1205  * unsigned char *phase, int *count, unsigned char **data)
1206  *
1207  * Purpose : transfers data in given phase using polled I/O
1208  *
1209  * Inputs : instance - instance of driver, *phase - pointer to
1210  * what phase is expected, *count - pointer to number of
1211  * bytes to transfer, **data - pointer to data pointer.
1212  *
1213  * Returns : -1 when different phase is entered without transferring
1214  * maximum number of bytes, 0 if all bytes are transferred or exit
1215  * is in same phase.
1216  *
1217  * Also, *phase, *count, *data are modified in place.
1218  *
1219  * XXX Note : handling for bus free may be useful.
1220  */
1221
1222 /*
1223  * Note : this code is not as quick as it could be, however it
1224  * IS 100% reliable, and for the actual data transfer where speed
1225  * counts, we will always do a pseudo DMA or DMA transfer.
1226  */
1227
1228 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1229                                 unsigned char *phase, int *count,
1230                                 unsigned char **data)
1231 {
1232         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1233         unsigned char p = *phase, tmp;
1234         int c = *count;
1235         unsigned char *d = *data;
1236
1237         /*
1238          * The NCR5380 chip will only drive the SCSI bus when the
1239          * phase specified in the appropriate bits of the TARGET COMMAND
1240          * REGISTER match the STATUS REGISTER
1241          */
1242
1243         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1244
1245         do {
1246                 /*
1247                  * Wait for assertion of REQ, after which the phase bits will be
1248                  * valid
1249                  */
1250
1251                 if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1252                         break;
1253
1254                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1255
1256                 /* Check for phase mismatch */
1257                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1258                         dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1259                         NCR5380_dprint_phase(NDEBUG_PIO, instance);
1260                         break;
1261                 }
1262
1263                 /* Do actual transfer from SCSI bus to / from memory */
1264                 if (!(p & SR_IO))
1265                         NCR5380_write(OUTPUT_DATA_REG, *d);
1266                 else
1267                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1268
1269                 ++d;
1270
1271                 /*
1272                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1273                  * should drop ATN on the last byte of the message phase
1274                  * after REQ has been asserted for the handshake but before
1275                  * the initiator raises ACK.
1276                  */
1277
1278                 if (!(p & SR_IO)) {
1279                         if (!((p & SR_MSG) && c > 1)) {
1280                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1281                                 NCR5380_dprint(NDEBUG_PIO, instance);
1282                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1283                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1284                         } else {
1285                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1286                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1287                                 NCR5380_dprint(NDEBUG_PIO, instance);
1288                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1289                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1290                         }
1291                 } else {
1292                         NCR5380_dprint(NDEBUG_PIO, instance);
1293                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1294                 }
1295
1296                 if (NCR5380_poll_politely(hostdata,
1297                                           STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1298                         break;
1299
1300                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1301
1302 /*
1303  * We have several special cases to consider during REQ/ACK handshaking :
1304  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1305  * message.  ATN must be dropped as ACK is dropped.
1306  *
1307  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1308  * message.  We must exit with ACK asserted, so that the calling
1309  * code may raise ATN before dropping ACK to reject the message.
1310  *
1311  * 3.  ACK and ATN are clear and the target may proceed as normal.
1312  */
1313                 if (!(p == PHASE_MSGIN && c == 1)) {
1314                         if (p == PHASE_MSGOUT && c > 1)
1315                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1316                         else
1317                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1318                 }
1319         } while (--c);
1320
1321         dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1322
1323         *count = c;
1324         *data = d;
1325         tmp = NCR5380_read(STATUS_REG);
1326         /* The phase read from the bus is valid if either REQ is (already)
1327          * asserted or if ACK hasn't been released yet. The latter applies if
1328          * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1329          */
1330         if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1331                 *phase = tmp & PHASE_MASK;
1332         else
1333                 *phase = PHASE_UNKNOWN;
1334
1335         if (!c || (*phase == p))
1336                 return 0;
1337         else
1338                 return -1;
1339 }
1340
1341 /**
1342  * do_reset - issue a reset command
1343  * @instance: adapter to reset
1344  *
1345  * Issue a reset sequence to the NCR5380 and try and get the bus
1346  * back into sane shape.
1347  *
1348  * This clears the reset interrupt flag because there may be no handler for
1349  * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1350  * been installed. And when in EH we may have released the ST DMA interrupt.
1351  */
1352
1353 static void do_reset(struct Scsi_Host *instance)
1354 {
1355         struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
1356         unsigned long flags;
1357
1358         local_irq_save(flags);
1359         NCR5380_write(TARGET_COMMAND_REG,
1360                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1361         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1362         udelay(50);
1363         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1364         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1365         local_irq_restore(flags);
1366 }
1367
1368 /**
1369  * do_abort - abort the currently established nexus by going to
1370  * MESSAGE OUT phase and sending an ABORT message.
1371  * @instance: relevant scsi host instance
1372  *
1373  * Returns 0 on success, -1 on failure.
1374  */
1375
1376 static int do_abort(struct Scsi_Host *instance)
1377 {
1378         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1379         unsigned char *msgptr, phase, tmp;
1380         int len;
1381         int rc;
1382
1383         /* Request message out phase */
1384         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1385
1386         /*
1387          * Wait for the target to indicate a valid phase by asserting
1388          * REQ.  Once this happens, we'll have either a MSGOUT phase
1389          * and can immediately send the ABORT message, or we'll have some
1390          * other phase and will have to source/sink data.
1391          *
1392          * We really don't care what value was on the bus or what value
1393          * the target sees, so we just handshake.
1394          */
1395
1396         rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1397         if (rc < 0)
1398                 goto timeout;
1399
1400         tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1401
1402         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1403
1404         if (tmp != PHASE_MSGOUT) {
1405                 NCR5380_write(INITIATOR_COMMAND_REG,
1406                               ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1407                 rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
1408                 if (rc < 0)
1409                         goto timeout;
1410                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1411         }
1412
1413         tmp = ABORT;
1414         msgptr = &tmp;
1415         len = 1;
1416         phase = PHASE_MSGOUT;
1417         NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1418
1419         /*
1420          * If we got here, and the command completed successfully,
1421          * we're about to go into bus free state.
1422          */
1423
1424         return len ? -1 : 0;
1425
1426 timeout:
1427         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1428         return -1;
1429 }
1430
1431 /*
1432  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1433  * unsigned char *phase, int *count, unsigned char **data)
1434  *
1435  * Purpose : transfers data in given phase using either real
1436  * or pseudo DMA.
1437  *
1438  * Inputs : instance - instance of driver, *phase - pointer to
1439  * what phase is expected, *count - pointer to number of
1440  * bytes to transfer, **data - pointer to data pointer.
1441  *
1442  * Returns : -1 when different phase is entered without transferring
1443  * maximum number of bytes, 0 if all bytes or transferred or exit
1444  * is in same phase.
1445  *
1446  * Also, *phase, *count, *data are modified in place.
1447  */
1448
1449
1450 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1451                                 unsigned char *phase, int *count,
1452                                 unsigned char **data)
1453 {
1454         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1455         int c = *count;
1456         unsigned char p = *phase;
1457         unsigned char *d = *data;
1458         unsigned char tmp;
1459         int result = 0;
1460
1461         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1462                 *phase = tmp;
1463                 return -1;
1464         }
1465
1466         hostdata->connected->SCp.phase = p;
1467
1468         if (p & SR_IO) {
1469                 if (hostdata->read_overruns)
1470                         c -= hostdata->read_overruns;
1471                 else if (hostdata->flags & FLAG_DMA_FIXUP)
1472                         --c;
1473         }
1474
1475         dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1476                  (p & SR_IO) ? "receive" : "send", c, d);
1477
1478 #ifdef CONFIG_SUN3
1479         /* send start chain */
1480         sun3scsi_dma_start(c, *data);
1481 #endif
1482
1483         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1484         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1485                                 MR_ENABLE_EOP_INTR);
1486
1487         if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1488                 /* On the Medusa, it is a must to initialize the DMA before
1489                  * starting the NCR. This is also the cleaner way for the TT.
1490                  */
1491                 if (p & SR_IO)
1492                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1493                 else
1494                         result = NCR5380_dma_send_setup(hostdata, d, c);
1495         }
1496
1497         /*
1498          * On the PAS16 at least I/O recovery delays are not needed here.
1499          * Everyone else seems to want them.
1500          */
1501
1502         if (p & SR_IO) {
1503                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1504                 NCR5380_io_delay(1);
1505                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1506         } else {
1507                 NCR5380_io_delay(1);
1508                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1509                 NCR5380_io_delay(1);
1510                 NCR5380_write(START_DMA_SEND_REG, 0);
1511                 NCR5380_io_delay(1);
1512         }
1513
1514 #ifdef CONFIG_SUN3
1515 #ifdef SUN3_SCSI_VME
1516         dregs->csr |= CSR_DMA_ENABLE;
1517 #endif
1518         sun3_dma_active = 1;
1519 #endif
1520
1521         if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1522                 /* On the Falcon, the DMA setup must be done after the last
1523                  * NCR access, else the DMA setup gets trashed!
1524                  */
1525                 if (p & SR_IO)
1526                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1527                 else
1528                         result = NCR5380_dma_send_setup(hostdata, d, c);
1529         }
1530
1531         /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
1532         if (result < 0)
1533                 return result;
1534
1535         /* For real DMA, result is the byte count. DMA interrupt is expected. */
1536         if (result > 0) {
1537                 hostdata->dma_len = result;
1538                 return 0;
1539         }
1540
1541         /* The result is zero iff pseudo DMA send/receive was completed. */
1542         hostdata->dma_len = c;
1543
1544 /*
1545  * A note regarding the DMA errata workarounds for early NMOS silicon.
1546  *
1547  * For DMA sends, we want to wait until the last byte has been
1548  * transferred out over the bus before we turn off DMA mode.  Alas, there
1549  * seems to be no terribly good way of doing this on a 5380 under all
1550  * conditions.  For non-scatter-gather operations, we can wait until REQ
1551  * and ACK both go false, or until a phase mismatch occurs.  Gather-sends
1552  * are nastier, since the device will be expecting more data than we
1553  * are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1554  * could test Last Byte Sent to assure transfer (I imagine this is precisely
1555  * why this signal was added to the newer chips) but on the older 538[01]
1556  * this signal does not exist.  The workaround for this lack is a watchdog;
1557  * we bail out of the wait-loop after a modest amount of wait-time if
1558  * the usual exit conditions are not met.  Not a terribly clean or
1559  * correct solution :-%
1560  *
1561  * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1562  * If the chip is in DMA receive mode, it will respond to a target's
1563  * REQ by latching the SCSI data into the INPUT DATA register and asserting
1564  * ACK, even if it has _already_ been notified by the DMA controller that
1565  * the current DMA transfer has completed!  If the NCR5380 is then taken
1566  * out of DMA mode, this already-acknowledged byte is lost. This is
1567  * not a problem for "one DMA transfer per READ command", because
1568  * the situation will never arise... either all of the data is DMA'ed
1569  * properly, or the target switches to MESSAGE IN phase to signal a
1570  * disconnection (either operation bringing the DMA to a clean halt).
1571  * However, in order to handle scatter-receive, we must work around the
1572  * problem.  The chosen fix is to DMA fewer bytes, then check for the
1573  * condition before taking the NCR5380 out of DMA mode.  One or two extra
1574  * bytes are transferred via PIO as necessary to fill out the original
1575  * request.
1576  */
1577
1578         if (hostdata->flags & FLAG_DMA_FIXUP) {
1579                 if (p & SR_IO) {
1580                         /*
1581                          * The workaround was to transfer fewer bytes than we
1582                          * intended to with the pseudo-DMA read function, wait for
1583                          * the chip to latch the last byte, read it, and then disable
1584                          * pseudo-DMA mode.
1585                          *
1586                          * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1587                          * REQ is deasserted when ACK is asserted, and not reasserted
1588                          * until ACK goes false.  Since the NCR5380 won't lower ACK
1589                          * until DACK is asserted, which won't happen unless we twiddle
1590                          * the DMA port or we take the NCR5380 out of DMA mode, we
1591                          * can guarantee that we won't handshake another extra
1592                          * byte.
1593                          */
1594
1595                         if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
1596                                                   BASR_DRQ, BASR_DRQ, HZ) < 0) {
1597                                 result = -1;
1598                                 shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1599                         }
1600                         if (NCR5380_poll_politely(hostdata, STATUS_REG,
1601                                                   SR_REQ, 0, HZ) < 0) {
1602                                 result = -1;
1603                                 shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1604                         }
1605                         d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
1606                 } else {
1607                         /*
1608                          * Wait for the last byte to be sent.  If REQ is being asserted for
1609                          * the byte we're interested, we'll ACK it and it will go false.
1610                          */
1611                         if (NCR5380_poll_politely2(hostdata,
1612                              BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1613                              BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
1614                                 result = -1;
1615                                 shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1616                         }
1617                 }
1618         }
1619
1620         NCR5380_dma_complete(instance);
1621         return result;
1622 }
1623
1624 /*
1625  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1626  *
1627  * Purpose : run through the various SCSI phases and do as the target
1628  * directs us to.  Operates on the currently connected command,
1629  * instance->connected.
1630  *
1631  * Inputs : instance, instance for which we are doing commands
1632  *
1633  * Side effects : SCSI things happen, the disconnected queue will be
1634  * modified if a command disconnects, *instance->connected will
1635  * change.
1636  *
1637  * XXX Note : we need to watch for bus free or a reset condition here
1638  * to recover from an unexpected bus free condition.
1639  */
1640
1641 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1642         __releases(&hostdata->lock) __acquires(&hostdata->lock)
1643 {
1644         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1645         unsigned char msgout = NOP;
1646         int sink = 0;
1647         int len;
1648         int transfersize;
1649         unsigned char *data;
1650         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1651         struct scsi_cmnd *cmd;
1652
1653 #ifdef SUN3_SCSI_VME
1654         dregs->csr |= CSR_INTR;
1655 #endif
1656
1657         while ((cmd = hostdata->connected)) {
1658                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1659
1660                 tmp = NCR5380_read(STATUS_REG);
1661                 /* We only have a valid SCSI phase when REQ is asserted */
1662                 if (tmp & SR_REQ) {
1663                         phase = (tmp & PHASE_MASK);
1664                         if (phase != old_phase) {
1665                                 old_phase = phase;
1666                                 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1667                         }
1668 #ifdef CONFIG_SUN3
1669                         if (phase == PHASE_CMDOUT &&
1670                             sun3_dma_setup_done != cmd) {
1671                                 int count;
1672
1673                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1674                                         ++cmd->SCp.buffer;
1675                                         --cmd->SCp.buffers_residual;
1676                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
1677                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1678                                 }
1679
1680                                 count = sun3scsi_dma_xfer_len(hostdata, cmd);
1681
1682                                 if (count > 0) {
1683                                         if (rq_data_dir(cmd->request))
1684                                                 sun3scsi_dma_send_setup(hostdata,
1685                                                                         cmd->SCp.ptr, count);
1686                                         else
1687                                                 sun3scsi_dma_recv_setup(hostdata,
1688                                                                         cmd->SCp.ptr, count);
1689                                         sun3_dma_setup_done = cmd;
1690                                 }
1691 #ifdef SUN3_SCSI_VME
1692                                 dregs->csr |= CSR_INTR;
1693 #endif
1694                         }
1695 #endif /* CONFIG_SUN3 */
1696
1697                         if (sink && (phase != PHASE_MSGOUT)) {
1698                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1699
1700                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1701                                               ICR_ASSERT_ACK);
1702                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1703                                         ;
1704                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1705                                               ICR_ASSERT_ATN);
1706                                 sink = 0;
1707                                 continue;
1708                         }
1709
1710                         switch (phase) {
1711                         case PHASE_DATAOUT:
1712 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1713                                 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1714                                 sink = 1;
1715                                 do_abort(instance);
1716                                 cmd->result = DID_ERROR << 16;
1717                                 complete_cmd(instance, cmd);
1718                                 hostdata->connected = NULL;
1719                                 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1720                                 return;
1721 #endif
1722                         case PHASE_DATAIN:
1723                                 /*
1724                                  * If there is no room left in the current buffer in the
1725                                  * scatter-gather list, move onto the next one.
1726                                  */
1727
1728                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1729                                         ++cmd->SCp.buffer;
1730                                         --cmd->SCp.buffers_residual;
1731                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
1732                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1733                                         dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
1734                                                  cmd->SCp.this_residual,
1735                                                  cmd->SCp.buffers_residual);
1736                                 }
1737
1738                                 /*
1739                                  * The preferred transfer method is going to be
1740                                  * PSEUDO-DMA for systems that are strictly PIO,
1741                                  * since we can let the hardware do the handshaking.
1742                                  *
1743                                  * For this to work, we need to know the transfersize
1744                                  * ahead of time, since the pseudo-DMA code will sit
1745                                  * in an unconditional loop.
1746                                  */
1747
1748                                 transfersize = 0;
1749                                 if (!cmd->device->borken)
1750                                         transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
1751
1752                                 if (transfersize > 0) {
1753                                         len = transfersize;
1754                                         if (NCR5380_transfer_dma(instance, &phase,
1755                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
1756                                                 /*
1757                                                  * If the watchdog timer fires, all future
1758                                                  * accesses to this device will use the
1759                                                  * polled-IO.
1760                                                  */
1761                                                 scmd_printk(KERN_INFO, cmd,
1762                                                         "switching to slow handshake\n");
1763                                                 cmd->device->borken = 1;
1764                                                 do_reset(instance);
1765                                                 bus_reset_cleanup(instance);
1766                                         }
1767                                 } else {
1768                                         /* Transfer a small chunk so that the
1769                                          * irq mode lock is not held too long.
1770                                          */
1771                                         transfersize = min(cmd->SCp.this_residual,
1772                                                            NCR5380_PIO_CHUNK_SIZE);
1773                                         len = transfersize;
1774                                         NCR5380_transfer_pio(instance, &phase, &len,
1775                                                              (unsigned char **)&cmd->SCp.ptr);
1776                                         cmd->SCp.this_residual -= transfersize - len;
1777                                 }
1778 #ifdef CONFIG_SUN3
1779                                 if (sun3_dma_setup_done == cmd)
1780                                         sun3_dma_setup_done = NULL;
1781 #endif
1782                                 return;
1783                         case PHASE_MSGIN:
1784                                 len = 1;
1785                                 data = &tmp;
1786                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1787                                 cmd->SCp.Message = tmp;
1788
1789                                 switch (tmp) {
1790                                 case ABORT:
1791                                 case COMMAND_COMPLETE:
1792                                         /* Accept message by clearing ACK */
1793                                         sink = 1;
1794                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1795                                         dsprintk(NDEBUG_QUEUES, instance,
1796                                                  "COMMAND COMPLETE %p target %d lun %llu\n",
1797                                                  cmd, scmd_id(cmd), cmd->device->lun);
1798
1799                                         hostdata->connected = NULL;
1800                                         hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1801
1802                                         cmd->result &= ~0xffff;
1803                                         cmd->result |= cmd->SCp.Status;
1804                                         cmd->result |= cmd->SCp.Message << 8;
1805
1806                                         if (cmd->cmnd[0] == REQUEST_SENSE)
1807                                                 complete_cmd(instance, cmd);
1808                                         else {
1809                                                 if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1810                                                     cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1811                                                         dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1812                                                                  cmd);
1813                                                         list_add_tail(&ncmd->list,
1814                                                                       &hostdata->autosense);
1815                                                 } else
1816                                                         complete_cmd(instance, cmd);
1817                                         }
1818
1819                                         /*
1820                                          * Restore phase bits to 0 so an interrupted selection,
1821                                          * arbitration can resume.
1822                                          */
1823                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1824
1825                                         maybe_release_dma_irq(instance);
1826                                         return;
1827                                 case MESSAGE_REJECT:
1828                                         /* Accept message by clearing ACK */
1829                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1830                                         switch (hostdata->last_message) {
1831                                         case HEAD_OF_QUEUE_TAG:
1832                                         case ORDERED_QUEUE_TAG:
1833                                         case SIMPLE_QUEUE_TAG:
1834                                                 cmd->device->simple_tags = 0;
1835                                                 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1836                                                 break;
1837                                         default:
1838                                                 break;
1839                                         }
1840                                         break;
1841                                 case DISCONNECT:
1842                                         /* Accept message by clearing ACK */
1843                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1844                                         hostdata->connected = NULL;
1845                                         list_add(&ncmd->list, &hostdata->disconnected);
1846                                         dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1847                                                  instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1848                                                  cmd, scmd_id(cmd), cmd->device->lun);
1849
1850                                         /*
1851                                          * Restore phase bits to 0 so an interrupted selection,
1852                                          * arbitration can resume.
1853                                          */
1854                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1855
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                                                         tmp = 0;
1912                                                 }
1913                                         } else if (len) {
1914                                                 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1915                                                 tmp = 0;
1916                                         } else {
1917                                                 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
1918                                                              extended_msg[2], extended_msg[1]);
1919                                                 tmp = 0;
1920                                         }
1921
1922                                         spin_lock_irq(&hostdata->lock);
1923                                         if (!hostdata->connected)
1924                                                 return;
1925
1926                                         /* Reject message */
1927                                         /* Fall through */
1928                                 default:
1929                                         /*
1930                                          * If we get something weird that we aren't expecting,
1931                                          * log it.
1932                                          */
1933                                         if (tmp == EXTENDED_MESSAGE)
1934                                                 scmd_printk(KERN_INFO, cmd,
1935                                                             "rejecting unknown extended message code %02x, length %d\n",
1936                                                             extended_msg[2], extended_msg[1]);
1937                                         else if (tmp)
1938                                                 scmd_printk(KERN_INFO, cmd,
1939                                                             "rejecting unknown message code %02x\n",
1940                                                             tmp);
1941
1942                                         msgout = MESSAGE_REJECT;
1943                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1944                                         break;
1945                                 } /* switch (tmp) */
1946                                 break;
1947                         case PHASE_MSGOUT:
1948                                 len = 1;
1949                                 data = &msgout;
1950                                 hostdata->last_message = msgout;
1951                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1952                                 if (msgout == ABORT) {
1953                                         hostdata->connected = NULL;
1954                                         hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1955                                         cmd->result = DID_ERROR << 16;
1956                                         complete_cmd(instance, cmd);
1957                                         maybe_release_dma_irq(instance);
1958                                         return;
1959                                 }
1960                                 msgout = NOP;
1961                                 break;
1962                         case PHASE_CMDOUT:
1963                                 len = cmd->cmd_len;
1964                                 data = cmd->cmnd;
1965                                 /*
1966                                  * XXX for performance reasons, on machines with a
1967                                  * PSEUDO-DMA architecture we should probably
1968                                  * use the dma transfer function.
1969                                  */
1970                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1971                                 break;
1972                         case PHASE_STATIN:
1973                                 len = 1;
1974                                 data = &tmp;
1975                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1976                                 cmd->SCp.Status = tmp;
1977                                 break;
1978                         default:
1979                                 shost_printk(KERN_ERR, instance, "unknown phase\n");
1980                                 NCR5380_dprint(NDEBUG_ANY, instance);
1981                         } /* switch(phase) */
1982                 } else {
1983                         spin_unlock_irq(&hostdata->lock);
1984                         NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1985                         spin_lock_irq(&hostdata->lock);
1986                 }
1987         }
1988 }
1989
1990 /*
1991  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
1992  *
1993  * Purpose : does reselection, initializing the instance->connected
1994  * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
1995  * nexus has been reestablished,
1996  *
1997  * Inputs : instance - this instance of the NCR5380.
1998  */
1999
2000 static void NCR5380_reselect(struct Scsi_Host *instance)
2001 {
2002         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2003         unsigned char target_mask;
2004         unsigned char lun;
2005         unsigned char msg[3];
2006         struct NCR5380_cmd *ncmd;
2007         struct scsi_cmnd *tmp;
2008
2009         /*
2010          * Disable arbitration, etc. since the host adapter obviously
2011          * lost, and tell an interrupted NCR5380_select() to restart.
2012          */
2013
2014         NCR5380_write(MODE_REG, MR_BASE);
2015
2016         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2017         if (!target_mask || target_mask & (target_mask - 1)) {
2018                 shost_printk(KERN_WARNING, instance,
2019                              "reselect: bad target_mask 0x%02x\n", target_mask);
2020                 return;
2021         }
2022
2023         /*
2024          * At this point, we have detected that our SCSI ID is on the bus,
2025          * SEL is true and BSY was false for at least one bus settle delay
2026          * (400 ns).
2027          *
2028          * We must assert BSY ourselves, until the target drops the SEL
2029          * signal.
2030          */
2031
2032         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2033         if (NCR5380_poll_politely(hostdata,
2034                                   STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2035                 shost_printk(KERN_ERR, instance, "reselect: !SEL timeout\n");
2036                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2037                 return;
2038         }
2039         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2040
2041         /*
2042          * Wait for target to go into MSGIN.
2043          */
2044
2045         if (NCR5380_poll_politely(hostdata,
2046                                   STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2047                 if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
2048                         /* BUS FREE phase */
2049                         return;
2050                 shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
2051                 do_abort(instance);
2052                 return;
2053         }
2054
2055 #ifdef CONFIG_SUN3
2056         /* acknowledge toggle to MSGIN */
2057         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2058
2059         /* peek at the byte without really hitting the bus */
2060         msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2061 #else
2062         {
2063                 int len = 1;
2064                 unsigned char *data = msg;
2065                 unsigned char phase = PHASE_MSGIN;
2066
2067                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2068
2069                 if (len) {
2070                         do_abort(instance);
2071                         return;
2072                 }
2073         }
2074 #endif /* CONFIG_SUN3 */
2075
2076         if (!(msg[0] & 0x80)) {
2077                 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2078                 spi_print_msg(msg);
2079                 printk("\n");
2080                 do_abort(instance);
2081                 return;
2082         }
2083         lun = msg[0] & 0x07;
2084
2085         /*
2086          * We need to add code for SCSI-II to track which devices have
2087          * I_T_L_Q nexuses established, and which have simple I_T_L
2088          * nexuses so we can chose to do additional data transfer.
2089          */
2090
2091         /*
2092          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2093          * just reestablished, and remove it from the disconnected queue.
2094          */
2095
2096         tmp = NULL;
2097         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2098                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2099
2100                 if (target_mask == (1 << scmd_id(cmd)) &&
2101                     lun == (u8)cmd->device->lun) {
2102                         list_del(&ncmd->list);
2103                         tmp = cmd;
2104                         break;
2105                 }
2106         }
2107
2108         if (tmp) {
2109                 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2110                          "reselect: removed %p from disconnected queue\n", tmp);
2111         } else {
2112                 int target = ffs(target_mask) - 1;
2113
2114                 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2115                              target_mask, lun);
2116                 /*
2117                  * Since we have an established nexus that we can't do anything
2118                  * with, we must abort it.
2119                  */
2120                 if (do_abort(instance) == 0)
2121                         hostdata->busy[target] &= ~(1 << lun);
2122                 return;
2123         }
2124
2125 #ifdef CONFIG_SUN3
2126         if (sun3_dma_setup_done != tmp) {
2127                 int count;
2128
2129                 if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
2130                         ++tmp->SCp.buffer;
2131                         --tmp->SCp.buffers_residual;
2132                         tmp->SCp.this_residual = tmp->SCp.buffer->length;
2133                         tmp->SCp.ptr = sg_virt(tmp->SCp.buffer);
2134                 }
2135
2136                 count = sun3scsi_dma_xfer_len(hostdata, tmp);
2137
2138                 if (count > 0) {
2139                         if (rq_data_dir(tmp->request))
2140                                 sun3scsi_dma_send_setup(hostdata,
2141                                                         tmp->SCp.ptr, count);
2142                         else
2143                                 sun3scsi_dma_recv_setup(hostdata,
2144                                                         tmp->SCp.ptr, count);
2145                         sun3_dma_setup_done = tmp;
2146                 }
2147         }
2148
2149         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2150 #endif /* CONFIG_SUN3 */
2151
2152         /* Accept message by clearing ACK */
2153         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2154
2155         hostdata->connected = tmp;
2156         dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
2157                  scmd_id(tmp), tmp->device->lun);
2158 }
2159
2160 /**
2161  * list_find_cmd - test for presence of a command in a linked list
2162  * @haystack: list of commands
2163  * @needle: command to search for
2164  */
2165
2166 static bool list_find_cmd(struct list_head *haystack,
2167                           struct scsi_cmnd *needle)
2168 {
2169         struct NCR5380_cmd *ncmd;
2170
2171         list_for_each_entry(ncmd, haystack, list)
2172                 if (NCR5380_to_scmd(ncmd) == needle)
2173                         return true;
2174         return false;
2175 }
2176
2177 /**
2178  * list_remove_cmd - remove a command from linked list
2179  * @haystack: list of commands
2180  * @needle: command to remove
2181  */
2182
2183 static bool list_del_cmd(struct list_head *haystack,
2184                          struct scsi_cmnd *needle)
2185 {
2186         if (list_find_cmd(haystack, needle)) {
2187                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2188
2189                 list_del(&ncmd->list);
2190                 return true;
2191         }
2192         return false;
2193 }
2194
2195 /**
2196  * NCR5380_abort - scsi host eh_abort_handler() method
2197  * @cmd: the command to be aborted
2198  *
2199  * Try to abort a given command by removing it from queues and/or sending
2200  * the target an abort message. This may not succeed in causing a target
2201  * to abort the command. Nonetheless, the low-level driver must forget about
2202  * the command because the mid-layer reclaims it and it may be re-issued.
2203  *
2204  * The normal path taken by a command is as follows. For EH we trace this
2205  * same path to locate and abort the command.
2206  *
2207  * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2208  * [disconnected -> connected ->]...
2209  * [autosense -> connected ->] done
2210  *
2211  * If cmd was not found at all then presumably it has already been completed,
2212  * in which case return SUCCESS to try to avoid further EH measures.
2213  *
2214  * If the command has not completed yet, we must not fail to find it.
2215  * We have no option but to forget the aborted command (even if it still
2216  * lacks sense data). The mid-layer may re-issue a command that is in error
2217  * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2218  * this driver are such that a command can appear on one queue only.
2219  *
2220  * The lock protects driver data structures, but EH handlers also use it
2221  * to serialize their own execution and prevent their own re-entry.
2222  */
2223
2224 static int NCR5380_abort(struct scsi_cmnd *cmd)
2225 {
2226         struct Scsi_Host *instance = cmd->device->host;
2227         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2228         unsigned long flags;
2229         int result = SUCCESS;
2230
2231         spin_lock_irqsave(&hostdata->lock, flags);
2232
2233 #if (NDEBUG & NDEBUG_ANY)
2234         scmd_printk(KERN_INFO, cmd, __func__);
2235 #endif
2236         NCR5380_dprint(NDEBUG_ANY, instance);
2237         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2238
2239         if (list_del_cmd(&hostdata->unissued, cmd)) {
2240                 dsprintk(NDEBUG_ABORT, instance,
2241                          "abort: removed %p from issue queue\n", cmd);
2242                 cmd->result = DID_ABORT << 16;
2243                 cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2244                 goto out;
2245         }
2246
2247         if (hostdata->selecting == cmd) {
2248                 dsprintk(NDEBUG_ABORT, instance,
2249                          "abort: cmd %p == selecting\n", cmd);
2250                 hostdata->selecting = NULL;
2251                 cmd->result = DID_ABORT << 16;
2252                 complete_cmd(instance, cmd);
2253                 goto out;
2254         }
2255
2256         if (list_del_cmd(&hostdata->disconnected, cmd)) {
2257                 dsprintk(NDEBUG_ABORT, instance,
2258                          "abort: removed %p from disconnected list\n", cmd);
2259                 /* Can't call NCR5380_select() and send ABORT because that
2260                  * means releasing the lock. Need a bus reset.
2261                  */
2262                 set_host_byte(cmd, DID_ERROR);
2263                 complete_cmd(instance, cmd);
2264                 result = FAILED;
2265                 goto out;
2266         }
2267
2268         if (hostdata->connected == cmd) {
2269                 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2270                 hostdata->connected = NULL;
2271                 hostdata->dma_len = 0;
2272                 if (do_abort(instance)) {
2273                         set_host_byte(cmd, DID_ERROR);
2274                         complete_cmd(instance, cmd);
2275                         result = FAILED;
2276                         goto out;
2277                 }
2278                 set_host_byte(cmd, DID_ABORT);
2279                 complete_cmd(instance, cmd);
2280                 goto out;
2281         }
2282
2283         if (list_del_cmd(&hostdata->autosense, cmd)) {
2284                 dsprintk(NDEBUG_ABORT, instance,
2285                          "abort: removed %p from sense queue\n", cmd);
2286                 complete_cmd(instance, cmd);
2287         }
2288
2289 out:
2290         if (result == FAILED)
2291                 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2292         else {
2293                 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
2294                 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2295         }
2296
2297         queue_work(hostdata->work_q, &hostdata->main_task);
2298         maybe_release_dma_irq(instance);
2299         spin_unlock_irqrestore(&hostdata->lock, flags);
2300
2301         return result;
2302 }
2303
2304
2305 static void bus_reset_cleanup(struct Scsi_Host *instance)
2306 {
2307         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2308         int i;
2309         struct NCR5380_cmd *ncmd;
2310
2311         /* reset NCR registers */
2312         NCR5380_write(MODE_REG, MR_BASE);
2313         NCR5380_write(TARGET_COMMAND_REG, 0);
2314         NCR5380_write(SELECT_ENABLE_REG, 0);
2315
2316         /* After the reset, there are no more connected or disconnected commands
2317          * and no busy units; so clear the low-level status here to avoid
2318          * conflicts when the mid-level code tries to wake up the affected
2319          * commands!
2320          */
2321
2322         if (hostdata->selecting) {
2323                 hostdata->selecting->result = DID_RESET << 16;
2324                 complete_cmd(instance, hostdata->selecting);
2325                 hostdata->selecting = NULL;
2326         }
2327
2328         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2329                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2330
2331                 set_host_byte(cmd, DID_RESET);
2332                 complete_cmd(instance, cmd);
2333         }
2334         INIT_LIST_HEAD(&hostdata->disconnected);
2335
2336         list_for_each_entry(ncmd, &hostdata->autosense, list) {
2337                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2338
2339                 cmd->scsi_done(cmd);
2340         }
2341         INIT_LIST_HEAD(&hostdata->autosense);
2342
2343         if (hostdata->connected) {
2344                 set_host_byte(hostdata->connected, DID_RESET);
2345                 complete_cmd(instance, hostdata->connected);
2346                 hostdata->connected = NULL;
2347         }
2348
2349         for (i = 0; i < 8; ++i)
2350                 hostdata->busy[i] = 0;
2351         hostdata->dma_len = 0;
2352
2353         queue_work(hostdata->work_q, &hostdata->main_task);
2354         maybe_release_dma_irq(instance);
2355 }
2356
2357 /**
2358  * NCR5380_host_reset - reset the SCSI host
2359  * @cmd: SCSI command undergoing EH
2360  *
2361  * Returns SUCCESS
2362  */
2363
2364 static int NCR5380_host_reset(struct scsi_cmnd *cmd)
2365 {
2366         struct Scsi_Host *instance = cmd->device->host;
2367         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2368         unsigned long flags;
2369         struct NCR5380_cmd *ncmd;
2370
2371         spin_lock_irqsave(&hostdata->lock, flags);
2372
2373 #if (NDEBUG & NDEBUG_ANY)
2374         shost_printk(KERN_INFO, instance, __func__);
2375 #endif
2376         NCR5380_dprint(NDEBUG_ANY, instance);
2377         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2378
2379         list_for_each_entry(ncmd, &hostdata->unissued, list) {
2380                 struct scsi_cmnd *scmd = NCR5380_to_scmd(ncmd);
2381
2382                 scmd->result = DID_RESET << 16;
2383                 scmd->scsi_done(scmd);
2384         }
2385         INIT_LIST_HEAD(&hostdata->unissued);
2386
2387         do_reset(instance);
2388         bus_reset_cleanup(instance);
2389
2390         spin_unlock_irqrestore(&hostdata->lock, flags);
2391
2392         return SUCCESS;
2393 }