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 unsigned int disconnect_mask = ~0;
 133 module_param(disconnect_mask, int, 0444);
 134
 135 static int do_abort(struct Scsi_Host *);
 136 static void do_reset(struct Scsi_Host *);
 137 static void bus_reset_cleanup(struct Scsi_Host *);
 138
 139 /**
 140  * initialize_SCp - init the scsi pointer field
 141  * @cmd: command block to set up
 142  *
 143  * Set up the internal fields in the SCSI command.
 144  */
 145
 146 static inline void initialize_SCp(struct scsi_cmnd *cmd)
 147 {
 148         /*
 149          * Initialize the Scsi Pointer field so that all of the commands in the
 150          * various queues are valid.
 151          */
 152
 153         if (scsi_bufflen(cmd)) {
 154                 cmd->SCp.buffer = scsi_sglist(cmd);
 155                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 156                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 157         } else {
 158                 cmd->SCp.buffer = NULL;
 159                 cmd->SCp.ptr = NULL;
 160                 cmd->SCp.this_residual = 0;
 161         }
 162
 163         cmd->SCp.Status = 0;
 164         cmd->SCp.Message = 0;
 165 }
 166
 167 static inline void advance_sg_buffer(struct scsi_cmnd *cmd)
 168 {
 169         struct scatterlist *s = cmd->SCp.buffer;
 170
 171         if (!cmd->SCp.this_residual && s && !sg_is_last(s)) {
 172                 cmd->SCp.buffer = sg_next(s);
 173                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 174                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 175         }
 176 }
 177
 178 static inline void set_resid_from_SCp(struct scsi_cmnd *cmd)
 179 {
 180         int resid = cmd->SCp.this_residual;
 181         struct scatterlist *s = cmd->SCp.buffer;
 182
 183         if (s)
 184                 while (!sg_is_last(s)) {
 185                         s = sg_next(s);
 186                         resid += s->length;
 187                 }
 188         scsi_set_resid(cmd, resid);
 189 }
 190
 191 /**
 192  * NCR5380_poll_politely2 - wait for two chip register values
 193  * @hostdata: host private data
 194  * @reg1: 5380 register to poll
 195  * @bit1: Bitmask to check
 196  * @val1: Expected value
 197  * @reg2: Second 5380 register to poll
 198  * @bit2: Second bitmask to check
 199  * @val2: Second expected value
 200  * @wait: Time-out in jiffies
 201  *
 202  * Polls the chip in a reasonably efficient manner waiting for an
 203  * event to occur. After a short quick poll we begin to yield the CPU
 204  * (if possible). In irq contexts the time-out is arbitrarily limited.
 205  * Callers may hold locks as long as they are held in irq mode.
 206  *
 207  * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
 208  */
 209
 210 static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
 211                                   unsigned int reg1, u8 bit1, u8 val1,
 212                                   unsigned int reg2, u8 bit2, u8 val2,
 213                                   unsigned long wait)
 214 {
 215         unsigned long n = hostdata->poll_loops;
 216         unsigned long deadline = jiffies + wait;
 217
 218         do {
 219                 if ((NCR5380_read(reg1) & bit1) == val1)
 220                         return 0;
 221                 if ((NCR5380_read(reg2) & bit2) == val2)
 222                         return 0;
 223                 cpu_relax();
 224         } while (n--);
 225
 226         if (irqs_disabled() || in_interrupt())
 227                 return -ETIMEDOUT;
 228
 229         /* Repeatedly sleep for 1 ms until deadline */
 230         while (time_is_after_jiffies(deadline)) {
 231                 schedule_timeout_uninterruptible(1);
 232                 if ((NCR5380_read(reg1) & bit1) == val1)
 233                         return 0;
 234                 if ((NCR5380_read(reg2) & bit2) == val2)
 235                         return 0;
 236         }
 237
 238         return -ETIMEDOUT;
 239 }
 240
 241 #if NDEBUG
 242 static struct {
 243         unsigned char mask;
 244         const char *name;
 245 } signals[] = {
 246         {SR_DBP, "PARITY"},
 247         {SR_RST, "RST"},
 248         {SR_BSY, "BSY"},
 249         {SR_REQ, "REQ"},
 250         {SR_MSG, "MSG"},
 251         {SR_CD, "CD"},
 252         {SR_IO, "IO"},
 253         {SR_SEL, "SEL"},
 254         {0, NULL}
 255 },
 256 basrs[] = {
 257         {BASR_END_DMA_TRANSFER, "END OF DMA"},
 258         {BASR_DRQ, "DRQ"},
 259         {BASR_PARITY_ERROR, "PARITY ERROR"},
 260         {BASR_IRQ, "IRQ"},
 261         {BASR_PHASE_MATCH, "PHASE MATCH"},
 262         {BASR_BUSY_ERROR, "BUSY ERROR"},
 263         {BASR_ATN, "ATN"},
 264         {BASR_ACK, "ACK"},
 265         {0, NULL}
 266 },
 267 icrs[] = {
 268         {ICR_ASSERT_RST, "ASSERT RST"},
 269         {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
 270         {ICR_ARBITRATION_LOST, "LOST ARB."},
 271         {ICR_ASSERT_ACK, "ASSERT ACK"},
 272         {ICR_ASSERT_BSY, "ASSERT BSY"},
 273         {ICR_ASSERT_SEL, "ASSERT SEL"},
 274         {ICR_ASSERT_ATN, "ASSERT ATN"},
 275         {ICR_ASSERT_DATA, "ASSERT DATA"},
 276         {0, NULL}
 277 },
 278 mrs[] = {
 279         {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
 280         {MR_TARGET, "TARGET"},
 281         {MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
 282         {MR_ENABLE_PAR_INTR, "PARITY INTR"},
 283         {MR_ENABLE_EOP_INTR, "EOP INTR"},
 284         {MR_MONITOR_BSY, "MONITOR BSY"},
 285         {MR_DMA_MODE, "DMA MODE"},
 286         {MR_ARBITRATE, "ARBITRATE"},
 287         {0, NULL}
 288 };
 289
 290 /**
 291  * NCR5380_print - print scsi bus signals
 292  * @instance: adapter state to dump
 293  *
 294  * Print the SCSI bus signals for debugging purposes
 295  */
 296
 297 static void NCR5380_print(struct Scsi_Host *instance)
 298 {
 299         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 300         unsigned char status, basr, mr, icr, i;
 301
 302         status = NCR5380_read(STATUS_REG);
 303         mr = NCR5380_read(MODE_REG);
 304         icr = NCR5380_read(INITIATOR_COMMAND_REG);
 305         basr = NCR5380_read(BUS_AND_STATUS_REG);
 306
 307         printk(KERN_DEBUG "SR =   0x%02x : ", status);
 308         for (i = 0; signals[i].mask; ++i)
 309                 if (status & signals[i].mask)
 310                         printk(KERN_CONT "%s, ", signals[i].name);
 311         printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
 312         for (i = 0; basrs[i].mask; ++i)
 313                 if (basr & basrs[i].mask)
 314                         printk(KERN_CONT "%s, ", basrs[i].name);
 315         printk(KERN_CONT "\nICR =  0x%02x : ", icr);
 316         for (i = 0; icrs[i].mask; ++i)
 317                 if (icr & icrs[i].mask)
 318                         printk(KERN_CONT "%s, ", icrs[i].name);
 319         printk(KERN_CONT "\nMR =   0x%02x : ", mr);
 320         for (i = 0; mrs[i].mask; ++i)
 321                 if (mr & mrs[i].mask)
 322                         printk(KERN_CONT "%s, ", mrs[i].name);
 323         printk(KERN_CONT "\n");
 324 }
 325
 326 static struct {
 327         unsigned char value;
 328         const char *name;
 329 } phases[] = {
 330         {PHASE_DATAOUT, "DATAOUT"},
 331         {PHASE_DATAIN, "DATAIN"},
 332         {PHASE_CMDOUT, "CMDOUT"},
 333         {PHASE_STATIN, "STATIN"},
 334         {PHASE_MSGOUT, "MSGOUT"},
 335         {PHASE_MSGIN, "MSGIN"},
 336         {PHASE_UNKNOWN, "UNKNOWN"}
 337 };
 338
 339 /**
 340  * NCR5380_print_phase - show SCSI phase
 341  * @instance: adapter to dump
 342  *
 343  * Print the current SCSI phase for debugging purposes
 344  */
 345
 346 static void NCR5380_print_phase(struct Scsi_Host *instance)
 347 {
 348         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 349         unsigned char status;
 350         int i;
 351
 352         status = NCR5380_read(STATUS_REG);
 353         if (!(status & SR_REQ))
 354                 shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
 355         else {
 356                 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
 357                      (phases[i].value != (status & PHASE_MASK)); ++i)
 358                         ;
 359                 shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
 360         }
 361 }
 362 #endif
 363
 364 /**
 365  * NCR5380_info - report driver and host information
 366  * @instance: relevant scsi host instance
 367  *
 368  * For use as the host template info() handler.
 369  */
 370
 371 static const char *NCR5380_info(struct Scsi_Host *instance)
 372 {
 373         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 374
 375         return hostdata->info;
 376 }
 377
 378 /**
 379  * NCR5380_init - initialise an NCR5380
 380  * @instance: adapter to configure
 381  * @flags: control flags
 382  *
 383  * Initializes *instance and corresponding 5380 chip,
 384  * with flags OR'd into the initial flags value.
 385  *
 386  * Notes : I assume that the host, hostno, and id bits have been
 387  * set correctly. I don't care about the irq and other fields.
 388  *
 389  * Returns 0 for success
 390  */
 391
 392 static int NCR5380_init(struct Scsi_Host *instance, int flags)
 393 {
 394         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 395         int i;
 396         unsigned long deadline;
 397         unsigned long accesses_per_ms;
 398
 399         instance->max_lun = 7;
 400
 401         hostdata->host = instance;
 402         hostdata->id_mask = 1 << instance->this_id;
 403         hostdata->id_higher_mask = 0;
 404         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 405                 if (i > hostdata->id_mask)
 406                         hostdata->id_higher_mask |= i;
 407         for (i = 0; i < 8; ++i)
 408                 hostdata->busy[i] = 0;
 409         hostdata->dma_len = 0;
 410
 411         spin_lock_init(&hostdata->lock);
 412         hostdata->connected = NULL;
 413         hostdata->sensing = NULL;
 414         INIT_LIST_HEAD(&hostdata->autosense);
 415         INIT_LIST_HEAD(&hostdata->unissued);
 416         INIT_LIST_HEAD(&hostdata->disconnected);
 417
 418         hostdata->flags = flags;
 419
 420         INIT_WORK(&hostdata->main_task, NCR5380_main);
 421         hostdata->work_q = alloc_workqueue("ncr5380_%d",
 422                                 WQ_UNBOUND | WQ_MEM_RECLAIM,
 423                                 1, instance->host_no);
 424         if (!hostdata->work_q)
 425                 return -ENOMEM;
 426
 427         snprintf(hostdata->info, sizeof(hostdata->info),
 428                 "%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}",
 429                 instance->hostt->name, instance->irq, hostdata->io_port,
 430                 hostdata->base, instance->can_queue, instance->cmd_per_lun,
 431                 instance->sg_tablesize, instance->this_id,
 432                 hostdata->flags & FLAG_DMA_FIXUP     ? "DMA_FIXUP "     : "",
 433                 hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
 434                 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
 435
 436         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 437         NCR5380_write(MODE_REG, MR_BASE);
 438         NCR5380_write(TARGET_COMMAND_REG, 0);
 439         NCR5380_write(SELECT_ENABLE_REG, 0);
 440
 441         /* Calibrate register polling loop */
 442         i = 0;
 443         deadline = jiffies + 1;
 444         do {
 445                 cpu_relax();
 446         } while (time_is_after_jiffies(deadline));
 447         deadline += msecs_to_jiffies(256);
 448         do {
 449                 NCR5380_read(STATUS_REG);
 450                 ++i;
 451                 cpu_relax();
 452         } while (time_is_after_jiffies(deadline));
 453         accesses_per_ms = i / 256;
 454         hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
 455
 456         return 0;
 457 }
 458
 459 /**
 460  * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
 461  * @instance: adapter to check
 462  *
 463  * If the system crashed, it may have crashed with a connected target and
 464  * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
 465  * currently established nexus, which we know nothing about. Failing that
 466  * do a bus reset.
 467  *
 468  * Note that a bus reset will cause the chip to assert IRQ.
 469  *
 470  * Returns 0 if successful, otherwise -ENXIO.
 471  */
 472
 473 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
 474 {
 475         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 476         int pass;
 477
 478         for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
 479                 switch (pass) {
 480                 case 1:
 481                 case 3:
 482                 case 5:
 483                         shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
 484                         NCR5380_poll_politely(hostdata,
 485                                               STATUS_REG, SR_BSY, 0, 5 * HZ);
 486                         break;
 487                 case 2:
 488                         shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
 489                         do_abort(instance);
 490                         break;
 491                 case 4:
 492                         shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
 493                         do_reset(instance);
 494                         /* Wait after a reset; the SCSI standard calls for
 495                          * 250ms, we wait 500ms to be on the safe side.
 496                          * But some Toshiba CD-ROMs need ten times that.
 497                          */
 498                         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
 499                                 msleep(2500);
 500                         else
 501                                 msleep(500);
 502                         break;
 503                 case 6:
 504                         shost_printk(KERN_ERR, instance, "bus locked solid\n");
 505                         return -ENXIO;
 506                 }
 507         }
 508         return 0;
 509 }
 510
 511 /**
 512  * NCR5380_exit - remove an NCR5380
 513  * @instance: adapter to remove
 514  *
 515  * Assumes that no more work can be queued (e.g. by NCR5380_intr).
 516  */
 517
 518 static void NCR5380_exit(struct Scsi_Host *instance)
 519 {
 520         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 521
 522         cancel_work_sync(&hostdata->main_task);
 523         destroy_workqueue(hostdata->work_q);
 524 }
 525
 526 /**
 527  * complete_cmd - finish processing a command and return it to the SCSI ML
 528  * @instance: the host instance
 529  * @cmd: command to complete
 530  */
 531
 532 static void complete_cmd(struct Scsi_Host *instance,
 533                          struct scsi_cmnd *cmd)
 534 {
 535         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 536
 537         dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
 538
 539         if (hostdata->sensing == cmd) {
 540                 /* Autosense processing ends here */
 541                 if (status_byte(cmd->result) != GOOD) {
 542                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 543                 } else {
 544                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 545                         set_driver_byte(cmd, DRIVER_SENSE);
 546                 }
 547                 hostdata->sensing = NULL;
 548         }
 549
 550         cmd->scsi_done(cmd);
 551 }
 552
 553 /**
 554  * NCR5380_queue_command - queue a command
 555  * @instance: the relevant SCSI adapter
 556  * @cmd: SCSI command
 557  *
 558  * cmd is added to the per-instance issue queue, with minor
 559  * twiddling done to the host specific fields of cmd.  If the
 560  * main coroutine is not running, it is restarted.
 561  */
 562
 563 static int NCR5380_queue_command(struct Scsi_Host *instance,
 564                                  struct scsi_cmnd *cmd)
 565 {
 566         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 567         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 568         unsigned long flags;
 569
 570 #if (NDEBUG & NDEBUG_NO_WRITE)
 571         switch (cmd->cmnd[0]) {
 572         case WRITE_6:
 573         case WRITE_10:
 574                 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
 575                 cmd->result = (DID_ERROR << 16);
 576                 cmd->scsi_done(cmd);
 577                 return 0;
 578         }
 579 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 580
 581         cmd->result = 0;
 582
 583         if (!NCR5380_acquire_dma_irq(instance))
 584                 return SCSI_MLQUEUE_HOST_BUSY;
 585
 586         spin_lock_irqsave(&hostdata->lock, flags);
 587
 588         /*
 589          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 590          * commands are added to the head of the queue since any command will
 591          * clear the contingent allegiance condition that exists and the
 592          * sense data is only guaranteed to be valid while the condition exists.
 593          */
 594
 595         if (cmd->cmnd[0] == REQUEST_SENSE)
 596                 list_add(&ncmd->list, &hostdata->unissued);
 597         else
 598                 list_add_tail(&ncmd->list, &hostdata->unissued);
 599
 600         spin_unlock_irqrestore(&hostdata->lock, flags);
 601
 602         dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
 603                  cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 604
 605         /* Kick off command processing */
 606         queue_work(hostdata->work_q, &hostdata->main_task);
 607         return 0;
 608 }
 609
 610 static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
 611 {
 612         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 613
 614         /* Caller does the locking needed to set & test these data atomically */
 615         if (list_empty(&hostdata->disconnected) &&
 616             list_empty(&hostdata->unissued) &&
 617             list_empty(&hostdata->autosense) &&
 618             !hostdata->connected &&
 619             !hostdata->selecting) {
 620                 NCR5380_release_dma_irq(instance);
 621         }
 622 }
 623
 624 /**
 625  * dequeue_next_cmd - dequeue a command for processing
 626  * @instance: the scsi host instance
 627  *
 628  * Priority is given to commands on the autosense queue. These commands
 629  * need autosense because of a CHECK CONDITION result.
 630  *
 631  * Returns a command pointer if a command is found for a target that is
 632  * not already busy. Otherwise returns NULL.
 633  */
 634
 635 static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
 636 {
 637         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 638         struct NCR5380_cmd *ncmd;
 639         struct scsi_cmnd *cmd;
 640
 641         if (hostdata->sensing || list_empty(&hostdata->autosense)) {
 642                 list_for_each_entry(ncmd, &hostdata->unissued, list) {
 643                         cmd = NCR5380_to_scmd(ncmd);
 644                         dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
 645                                  cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
 646
 647                         if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
 648                                 list_del(&ncmd->list);
 649                                 dsprintk(NDEBUG_QUEUES, instance,
 650                                          "dequeue: removed %p from issue queue\n", cmd);
 651                                 return cmd;
 652                         }
 653                 }
 654         } else {
 655                 /* Autosense processing begins here */
 656                 ncmd = list_first_entry(&hostdata->autosense,
 657                                         struct NCR5380_cmd, list);
 658                 list_del(&ncmd->list);
 659                 cmd = NCR5380_to_scmd(ncmd);
 660                 dsprintk(NDEBUG_QUEUES, instance,
 661                          "dequeue: removed %p from autosense queue\n", cmd);
 662                 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
 663                 hostdata->sensing = cmd;
 664                 return cmd;
 665         }
 666         return NULL;
 667 }
 668
 669 static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 670 {
 671         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 672         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 673
 674         if (hostdata->sensing == cmd) {
 675                 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 676                 list_add(&ncmd->list, &hostdata->autosense);
 677                 hostdata->sensing = NULL;
 678         } else
 679                 list_add(&ncmd->list, &hostdata->unissued);
 680 }
 681
 682 /**
 683  * NCR5380_main - NCR state machines
 684  *
 685  * NCR5380_main is a coroutine that runs as long as more work can
 686  * be done on the NCR5380 host adapters in a system.  Both
 687  * NCR5380_queue_command() and NCR5380_intr() will try to start it
 688  * in case it is not running.
 689  */
 690
 691 static void NCR5380_main(struct work_struct *work)
 692 {
 693         struct NCR5380_hostdata *hostdata =
 694                 container_of(work, struct NCR5380_hostdata, main_task);
 695         struct Scsi_Host *instance = hostdata->host;
 696         int done;
 697
 698         do {
 699                 done = 1;
 700
 701                 spin_lock_irq(&hostdata->lock);
 702                 while (!hostdata->connected && !hostdata->selecting) {
 703                         struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
 704
 705                         if (!cmd)
 706                                 break;
 707
 708                         dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
 709
 710                         /*
 711                          * Attempt to establish an I_T_L nexus here.
 712                          * On success, instance->hostdata->connected is set.
 713                          * On failure, we must add the command back to the
 714                          * issue queue so we can keep trying.
 715                          */
 716                         /*
 717                          * REQUEST SENSE commands are issued without tagged
 718                          * queueing, even on SCSI-II devices because the
 719                          * contingent allegiance condition exists for the
 720                          * entire unit.
 721                          */
 722
 723                         if (!NCR5380_select(instance, cmd)) {
 724                                 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
 725                                 maybe_release_dma_irq(instance);
 726                         } else {
 727                                 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
 728                                          "main: select failed, returning %p to queue\n", cmd);
 729                                 requeue_cmd(instance, cmd);
 730                         }
 731                 }
 732                 if (hostdata->connected && !hostdata->dma_len) {
 733                         dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
 734                         NCR5380_information_transfer(instance);
 735                         done = 0;
 736                 }
 737                 if (!hostdata->connected)
 738                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 739                 spin_unlock_irq(&hostdata->lock);
 740                 if (!done)
 741                         cond_resched();
 742         } while (!done);
 743 }
 744
 745 /*
 746  * NCR5380_dma_complete - finish DMA transfer
 747  * @instance: the scsi host instance
 748  *
 749  * Called by the interrupt handler when DMA finishes or a phase
 750  * mismatch occurs (which would end the DMA transfer).
 751  */
 752
 753 static void NCR5380_dma_complete(struct Scsi_Host *instance)
 754 {
 755         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 756         int transferred;
 757         unsigned char **data;
 758         int *count;
 759         int saved_data = 0, overrun = 0;
 760         unsigned char p;
 761
 762         if (hostdata->read_overruns) {
 763                 p = hostdata->connected->SCp.phase;
 764                 if (p & SR_IO) {
 765                         udelay(10);
 766                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
 767                              (BASR_PHASE_MATCH | BASR_ACK)) ==
 768                             (BASR_PHASE_MATCH | BASR_ACK)) {
 769                                 saved_data = NCR5380_read(INPUT_DATA_REG);
 770                                 overrun = 1;
 771                                 dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
 772                         }
 773                 }
 774         }
 775
 776 #ifdef CONFIG_SUN3
 777         if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
 778                 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
 779                        instance->host_no);
 780                 BUG();
 781         }
 782
 783         if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
 784             (BASR_PHASE_MATCH | BASR_ACK)) {
 785                 pr_err("scsi%d: BASR %02x\n", instance->host_no,
 786                        NCR5380_read(BUS_AND_STATUS_REG));
 787                 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
 788                        instance->host_no);
 789                 BUG();
 790         }
 791 #endif
 792
 793         NCR5380_write(MODE_REG, MR_BASE);
 794         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 795         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 796
 797         transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
 798         hostdata->dma_len = 0;
 799
 800         data = (unsigned char **)&hostdata->connected->SCp.ptr;
 801         count = &hostdata->connected->SCp.this_residual;
 802         *data += transferred;
 803         *count -= transferred;
 804
 805         if (hostdata->read_overruns) {
 806                 int cnt, toPIO;
 807
 808                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
 809                         cnt = toPIO = hostdata->read_overruns;
 810                         if (overrun) {
 811                                 dsprintk(NDEBUG_DMA, instance,
 812                                          "Got an input overrun, using saved byte\n");
 813                                 *(*data)++ = saved_data;
 814                                 (*count)--;
 815                                 cnt--;
 816                                 toPIO--;
 817                         }
 818                         if (toPIO > 0) {
 819                                 dsprintk(NDEBUG_DMA, instance,
 820                                          "Doing %d byte PIO to 0x%p\n", cnt, *data);
 821                                 NCR5380_transfer_pio(instance, &p, &cnt, data);
 822                                 *count -= toPIO - cnt;
 823                         }
 824                 }
 825         }
 826 }
 827
 828 /**
 829  * NCR5380_intr - generic NCR5380 irq handler
 830  * @irq: interrupt number
 831  * @dev_id: device info
 832  *
 833  * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 834  * from the disconnected queue, and restarting NCR5380_main()
 835  * as required.
 836  *
 837  * The chip can assert IRQ in any of six different conditions. The IRQ flag
 838  * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
 839  * Three of these six conditions are latched in the Bus and Status Register:
 840  * - End of DMA (cleared by ending DMA Mode)
 841  * - Parity error (cleared by reading RPIR)
 842  * - Loss of BSY (cleared by reading RPIR)
 843  * Two conditions have flag bits that are not latched:
 844  * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
 845  * - Bus reset (non-maskable)
 846  * The remaining condition has no flag bit at all:
 847  * - Selection/reselection
 848  *
 849  * Hence, establishing the cause(s) of any interrupt is partly guesswork.
 850  * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
 851  * claimed that "the design of the [DP8490] interrupt logic ensures
 852  * interrupts will not be lost (they can be on the DP5380)."
 853  * The L5380/53C80 datasheet from LOGIC Devices has more details.
 854  *
 855  * Checking for bus reset by reading RST is futile because of interrupt
 856  * latency, but a bus reset will reset chip logic. Checking for parity error
 857  * is unnecessary because that interrupt is never enabled. A Loss of BSY
 858  * condition will clear DMA Mode. We can tell when this occurs because the
 859  * the Busy Monitor interrupt is enabled together with DMA Mode.
 860  */
 861
 862 static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
 863 {
 864         struct Scsi_Host *instance = dev_id;
 865         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 866         int handled = 0;
 867         unsigned char basr;
 868         unsigned long flags;
 869
 870         spin_lock_irqsave(&hostdata->lock, flags);
 871
 872         basr = NCR5380_read(BUS_AND_STATUS_REG);
 873         if (basr & BASR_IRQ) {
 874                 unsigned char mr = NCR5380_read(MODE_REG);
 875                 unsigned char sr = NCR5380_read(STATUS_REG);
 876
 877                 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
 878                          irq, basr, sr, mr);
 879
 880                 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
 881                         /* Probably End of DMA, Phase Mismatch or Loss of BSY.
 882                          * We ack IRQ after clearing Mode Register. Workarounds
 883                          * for End of DMA errata need to happen in DMA Mode.
 884                          */
 885
 886                         dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
 887
 888                         if (hostdata->connected) {
 889                                 NCR5380_dma_complete(instance);
 890                                 queue_work(hostdata->work_q, &hostdata->main_task);
 891                         } else {
 892                                 NCR5380_write(MODE_REG, MR_BASE);
 893                                 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 894                         }
 895                 } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
 896                     (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
 897                         /* Probably reselected */
 898                         NCR5380_write(SELECT_ENABLE_REG, 0);
 899                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 900
 901                         dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
 902
 903                         if (!hostdata->connected) {
 904                                 NCR5380_reselect(instance);
 905                                 queue_work(hostdata->work_q, &hostdata->main_task);
 906                         }
 907                         if (!hostdata->connected)
 908                                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 909                 } else {
 910                         /* Probably Bus Reset */
 911                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 912
 913                         if (sr & SR_RST) {
 914                                 /* Certainly Bus Reset */
 915                                 shost_printk(KERN_WARNING, instance,
 916                                              "bus reset interrupt\n");
 917                                 bus_reset_cleanup(instance);
 918                         } else {
 919                                 dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
 920                         }
 921 #ifdef SUN3_SCSI_VME
 922                         dregs->csr |= CSR_DMA_ENABLE;
 923 #endif
 924                 }
 925                 handled = 1;
 926         } else {
 927                 dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
 928 #ifdef SUN3_SCSI_VME
 929                 dregs->csr |= CSR_DMA_ENABLE;
 930 #endif
 931         }
 932
 933         spin_unlock_irqrestore(&hostdata->lock, flags);
 934
 935         return IRQ_RETVAL(handled);
 936 }
 937
 938 /**
 939  * NCR5380_select - attempt arbitration and selection for a given command
 940  * @instance: the Scsi_Host instance
 941  * @cmd: the scsi_cmnd to execute
 942  *
 943  * This routine establishes an I_T_L nexus for a SCSI command. This involves
 944  * ARBITRATION, SELECTION and MESSAGE OUT phases and an IDENTIFY message.
 945  *
 946  * Returns true if the operation should be retried.
 947  * Returns false if it should not be retried.
 948  *
 949  * Side effects :
 950  * If bus busy, arbitration failed, etc, NCR5380_select() will exit
 951  * with registers as they should have been on entry - ie
 952  * SELECT_ENABLE will be set appropriately, the NCR5380
 953  * will cease to drive any SCSI bus signals.
 954  *
 955  * If successful : the I_T_L nexus will be established, and
 956  * hostdata->connected will be set to cmd.
 957  * SELECT interrupt will be disabled.
 958  *
 959  * If failed (no target) : cmd->scsi_done() will be called, and the
 960  * cmd->result host byte set to DID_BAD_TARGET.
 961  */
 962
 963 static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 964         __releases(&hostdata->lock) __acquires(&hostdata->lock)
 965 {
 966         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 967         unsigned char tmp[3], phase;
 968         unsigned char *data;
 969         int len;
 970         int err;
 971         bool ret = true;
 972         bool can_disconnect = instance->irq != NO_IRQ &&
 973                               cmd->cmnd[0] != REQUEST_SENSE &&
 974                               (disconnect_mask & BIT(scmd_id(cmd)));
 975
 976         NCR5380_dprint(NDEBUG_ARBITRATION, instance);
 977         dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
 978                  instance->this_id);
 979
 980         /*
 981          * Arbitration and selection phases are slow and involve dropping the
 982          * lock, so we have to watch out for EH. An exception handler may
 983          * change 'selecting' to NULL. This function will then return false
 984          * so that the caller will forget about 'cmd'. (During information
 985          * transfer phases, EH may change 'connected' to NULL.)
 986          */
 987         hostdata->selecting = cmd;
 988
 989         /*
 990          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
 991          * data bus during SELECTION.
 992          */
 993
 994         NCR5380_write(TARGET_COMMAND_REG, 0);
 995
 996         /*
 997          * Start arbitration.
 998          */
 999
1000         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1001         NCR5380_write(MODE_REG, MR_ARBITRATE);
1002
1003         /* The chip now waits for BUS FREE phase. Then after the 800 ns
1004          * Bus Free Delay, arbitration will begin.
1005          */
1006
1007         spin_unlock_irq(&hostdata->lock);
1008         err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
1009                         INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
1010                                                ICR_ARBITRATION_PROGRESS, HZ);
1011         spin_lock_irq(&hostdata->lock);
1012         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
1013                 /* Reselection interrupt */
1014                 goto out;
1015         }
1016         if (!hostdata->selecting) {
1017                 /* Command was aborted */
1018                 NCR5380_write(MODE_REG, MR_BASE);
1019                 return false;
1020         }
1021         if (err < 0) {
1022                 NCR5380_write(MODE_REG, MR_BASE);
1023                 shost_printk(KERN_ERR, instance,
1024                              "select: arbitration timeout\n");
1025                 goto out;
1026         }
1027         spin_unlock_irq(&hostdata->lock);
1028
1029         /* The SCSI-2 arbitration delay is 2.4 us */
1030         udelay(3);
1031
1032         /* Check for lost arbitration */
1033         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1034             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1035             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1036                 NCR5380_write(MODE_REG, MR_BASE);
1037                 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1038                 spin_lock_irq(&hostdata->lock);
1039                 goto out;
1040         }
1041
1042         /* After/during arbitration, BSY should be asserted.
1043          * IBM DPES-31080 Version S31Q works now
1044          * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1045          */
1046         NCR5380_write(INITIATOR_COMMAND_REG,
1047                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1048
1049         /*
1050          * Again, bus clear + bus settle time is 1.2us, however, this is
1051          * a minimum so we'll udelay ceil(1.2)
1052          */
1053
1054         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1055                 udelay(15);
1056         else
1057                 udelay(2);
1058
1059         spin_lock_irq(&hostdata->lock);
1060
1061         /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1062         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1063                 goto out;
1064
1065         if (!hostdata->selecting) {
1066                 NCR5380_write(MODE_REG, MR_BASE);
1067                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1068                 return false;
1069         }
1070
1071         dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1072
1073         /*
1074          * Now that we have won arbitration, start Selection process, asserting
1075          * the host and target ID's on the SCSI bus.
1076          */
1077
1078         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1079
1080         /*
1081          * Raise ATN while SEL is true before BSY goes false from arbitration,
1082          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1083          * phase immediately after selection.
1084          */
1085
1086         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1087                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1088         NCR5380_write(MODE_REG, MR_BASE);
1089
1090         /*
1091          * Reselect interrupts must be turned off prior to the dropping of BSY,
1092          * otherwise we will trigger an interrupt.
1093          */
1094         NCR5380_write(SELECT_ENABLE_REG, 0);
1095
1096         spin_unlock_irq(&hostdata->lock);
1097
1098         /*
1099          * The initiator shall then wait at least two deskew delays and release
1100          * the BSY signal.
1101          */
1102         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1103
1104         /* Reset BSY */
1105         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1106                       ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1107
1108         /*
1109          * Something weird happens when we cease to drive BSY - looks
1110          * like the board/chip is letting us do another read before the
1111          * appropriate propagation delay has expired, and we're confusing
1112          * a BSY signal from ourselves as the target's response to SELECTION.
1113          *
1114          * A small delay (the 'C++' frontend breaks the pipeline with an
1115          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1116          * tighter 'C' code breaks and requires this) solves the problem -
1117          * the 1 us delay is arbitrary, and only used because this delay will
1118          * be the same on other platforms and since it works here, it should
1119          * work there.
1120          *
1121          * wingel suggests that this could be due to failing to wait
1122          * one deskew delay.
1123          */
1124
1125         udelay(1);
1126
1127         dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1128
1129         /*
1130          * The SCSI specification calls for a 250 ms timeout for the actual
1131          * selection.
1132          */
1133
1134         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
1135                                     msecs_to_jiffies(250));
1136
1137         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1138                 spin_lock_irq(&hostdata->lock);
1139                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1140                 NCR5380_reselect(instance);
1141                 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1142                 goto out;
1143         }
1144
1145         if (err < 0) {
1146                 spin_lock_irq(&hostdata->lock);
1147                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1148
1149                 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1150                 if (!hostdata->selecting)
1151                         return false;
1152
1153                 cmd->result = DID_BAD_TARGET << 16;
1154                 complete_cmd(instance, cmd);
1155                 dsprintk(NDEBUG_SELECTION, instance,
1156                         "target did not respond within 250ms\n");
1157                 ret = false;
1158                 goto out;
1159         }
1160
1161         /*
1162          * No less than two deskew delays after the initiator detects the
1163          * BSY signal is true, it shall release the SEL signal and may
1164          * change the DATA BUS.                                     -wingel
1165          */
1166
1167         udelay(1);
1168
1169         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1170
1171         /*
1172          * Since we followed the SCSI spec, and raised ATN while SEL
1173          * was true but before BSY was false during selection, the information
1174          * transfer phase should be a MESSAGE OUT phase so that we can send the
1175          * IDENTIFY message.
1176          */
1177
1178         /* Wait for start of REQ/ACK handshake */
1179
1180         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1181         spin_lock_irq(&hostdata->lock);
1182         if (err < 0) {
1183                 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1184                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1185                 goto out;
1186         }
1187         if (!hostdata->selecting) {
1188                 do_abort(instance);
1189                 return false;
1190         }
1191
1192         dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1193                  scmd_id(cmd));
1194         tmp[0] = IDENTIFY(can_disconnect, cmd->device->lun);
1195
1196         len = 1;
1197         data = tmp;
1198         phase = PHASE_MSGOUT;
1199         NCR5380_transfer_pio(instance, &phase, &len, &data);
1200         if (len) {
1201                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1202                 cmd->result = DID_ERROR << 16;
1203                 complete_cmd(instance, cmd);
1204                 dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
1205                 ret = false;
1206                 goto out;
1207         }
1208
1209         dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1210
1211         hostdata->connected = cmd;
1212         hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1213
1214 #ifdef SUN3_SCSI_VME
1215         dregs->csr |= CSR_INTR;
1216 #endif
1217
1218         initialize_SCp(cmd);
1219
1220         ret = false;
1221
1222 out:
1223         if (!hostdata->selecting)
1224                 return false;
1225         hostdata->selecting = NULL;
1226         return ret;
1227 }
1228
1229 /*
1230  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1231  * unsigned char *phase, int *count, unsigned char **data)
1232  *
1233  * Purpose : transfers data in given phase using polled I/O
1234  *
1235  * Inputs : instance - instance of driver, *phase - pointer to
1236  * what phase is expected, *count - pointer to number of
1237  * bytes to transfer, **data - pointer to data pointer.
1238  *
1239  * Returns : -1 when different phase is entered without transferring
1240  * maximum number of bytes, 0 if all bytes are transferred or exit
1241  * is in same phase.
1242  *
1243  * Also, *phase, *count, *data are modified in place.
1244  *
1245  * XXX Note : handling for bus free may be useful.
1246  */
1247
1248 /*
1249  * Note : this code is not as quick as it could be, however it
1250  * IS 100% reliable, and for the actual data transfer where speed
1251  * counts, we will always do a pseudo DMA or DMA transfer.
1252  */
1253
1254 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1255                                 unsigned char *phase, int *count,
1256                                 unsigned char **data)
1257 {
1258         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1259         unsigned char p = *phase, tmp;
1260         int c = *count;
1261         unsigned char *d = *data;
1262
1263         /*
1264          * The NCR5380 chip will only drive the SCSI bus when the
1265          * phase specified in the appropriate bits of the TARGET COMMAND
1266          * REGISTER match the STATUS REGISTER
1267          */
1268
1269         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1270
1271         do {
1272                 /*
1273                  * Wait for assertion of REQ, after which the phase bits will be
1274                  * valid
1275                  */
1276
1277                 if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1278                         break;
1279
1280                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1281
1282                 /* Check for phase mismatch */
1283                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1284                         dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1285                         NCR5380_dprint_phase(NDEBUG_PIO, instance);
1286                         break;
1287                 }
1288
1289                 /* Do actual transfer from SCSI bus to / from memory */
1290                 if (!(p & SR_IO))
1291                         NCR5380_write(OUTPUT_DATA_REG, *d);
1292                 else
1293                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1294
1295                 ++d;
1296
1297                 /*
1298                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1299                  * should drop ATN on the last byte of the message phase
1300                  * after REQ has been asserted for the handshake but before
1301                  * the initiator raises ACK.
1302                  */
1303
1304                 if (!(p & SR_IO)) {
1305                         if (!((p & SR_MSG) && c > 1)) {
1306                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1307                                 NCR5380_dprint(NDEBUG_PIO, instance);
1308                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1309                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1310                         } else {
1311                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1312                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1313                                 NCR5380_dprint(NDEBUG_PIO, instance);
1314                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1315                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1316                         }
1317                 } else {
1318                         NCR5380_dprint(NDEBUG_PIO, instance);
1319                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1320                 }
1321
1322                 if (NCR5380_poll_politely(hostdata,
1323                                           STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1324                         break;
1325
1326                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1327
1328 /*
1329  * We have several special cases to consider during REQ/ACK handshaking :
1330  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1331  * message.  ATN must be dropped as ACK is dropped.
1332  *
1333  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1334  * message.  We must exit with ACK asserted, so that the calling
1335  * code may raise ATN before dropping ACK to reject the message.
1336  *
1337  * 3.  ACK and ATN are clear and the target may proceed as normal.
1338  */
1339                 if (!(p == PHASE_MSGIN && c == 1)) {
1340                         if (p == PHASE_MSGOUT && c > 1)
1341                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1342                         else
1343                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1344                 }
1345         } while (--c);
1346
1347         dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1348
1349         *count = c;
1350         *data = d;
1351         tmp = NCR5380_read(STATUS_REG);
1352         /* The phase read from the bus is valid if either REQ is (already)
1353          * asserted or if ACK hasn't been released yet. The latter applies if
1354          * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1355          */
1356         if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1357                 *phase = tmp & PHASE_MASK;
1358         else
1359                 *phase = PHASE_UNKNOWN;
1360
1361         if (!c || (*phase == p))
1362                 return 0;
1363         else
1364                 return -1;
1365 }
1366
1367 /**
1368  * do_reset - issue a reset command
1369  * @instance: adapter to reset
1370  *
1371  * Issue a reset sequence to the NCR5380 and try and get the bus
1372  * back into sane shape.
1373  *
1374  * This clears the reset interrupt flag because there may be no handler for
1375  * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1376  * been installed. And when in EH we may have released the ST DMA interrupt.
1377  */
1378
1379 static void do_reset(struct Scsi_Host *instance)
1380 {
1381         struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
1382         unsigned long flags;
1383
1384         local_irq_save(flags);
1385         NCR5380_write(TARGET_COMMAND_REG,
1386                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1387         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1388         udelay(50);
1389         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1390         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1391         local_irq_restore(flags);
1392 }
1393
1394 /**
1395  * do_abort - abort the currently established nexus by going to
1396  * MESSAGE OUT phase and sending an ABORT message.
1397  * @instance: relevant scsi host instance
1398  *
1399  * Returns 0 on success, negative error code on failure.
1400  */
1401
1402 static int do_abort(struct Scsi_Host *instance)
1403 {
1404         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1405         unsigned char *msgptr, phase, tmp;
1406         int len;
1407         int rc;
1408
1409         /* Request message out phase */
1410         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1411
1412         /*
1413          * Wait for the target to indicate a valid phase by asserting
1414          * REQ.  Once this happens, we'll have either a MSGOUT phase
1415          * and can immediately send the ABORT message, or we'll have some
1416          * other phase and will have to source/sink data.
1417          *
1418          * We really don't care what value was on the bus or what value
1419          * the target sees, so we just handshake.
1420          */
1421
1422         rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1423         if (rc < 0)
1424                 goto out;
1425
1426         tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1427
1428         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1429
1430         if (tmp != PHASE_MSGOUT) {
1431                 NCR5380_write(INITIATOR_COMMAND_REG,
1432                               ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1433                 rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
1434                 if (rc < 0)
1435                         goto out;
1436                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1437         }
1438
1439         tmp = ABORT;
1440         msgptr = &tmp;
1441         len = 1;
1442         phase = PHASE_MSGOUT;
1443         NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1444         if (len)
1445                 rc = -ENXIO;
1446
1447         /*
1448          * If we got here, and the command completed successfully,
1449          * we're about to go into bus free state.
1450          */
1451
1452 out:
1453         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1454         return rc;
1455 }
1456
1457 /*
1458  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1459  * unsigned char *phase, int *count, unsigned char **data)
1460  *
1461  * Purpose : transfers data in given phase using either real
1462  * or pseudo DMA.
1463  *
1464  * Inputs : instance - instance of driver, *phase - pointer to
1465  * what phase is expected, *count - pointer to number of
1466  * bytes to transfer, **data - pointer to data pointer.
1467  *
1468  * Returns : -1 when different phase is entered without transferring
1469  * maximum number of bytes, 0 if all bytes or transferred or exit
1470  * is in same phase.
1471  *
1472  * Also, *phase, *count, *data are modified in place.
1473  */
1474
1475
1476 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1477                                 unsigned char *phase, int *count,
1478                                 unsigned char **data)
1479 {
1480         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1481         int c = *count;
1482         unsigned char p = *phase;
1483         unsigned char *d = *data;
1484         unsigned char tmp;
1485         int result = 0;
1486
1487         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1488                 *phase = tmp;
1489                 return -1;
1490         }
1491
1492         hostdata->connected->SCp.phase = p;
1493
1494         if (p & SR_IO) {
1495                 if (hostdata->read_overruns)
1496                         c -= hostdata->read_overruns;
1497                 else if (hostdata->flags & FLAG_DMA_FIXUP)
1498                         --c;
1499         }
1500
1501         dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1502                  (p & SR_IO) ? "receive" : "send", c, d);
1503
1504 #ifdef CONFIG_SUN3
1505         /* send start chain */
1506         sun3scsi_dma_start(c, *data);
1507 #endif
1508
1509         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1510         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1511                                 MR_ENABLE_EOP_INTR);
1512
1513         if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1514                 /* On the Medusa, it is a must to initialize the DMA before
1515                  * starting the NCR. This is also the cleaner way for the TT.
1516                  */
1517                 if (p & SR_IO)
1518                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1519                 else
1520                         result = NCR5380_dma_send_setup(hostdata, d, c);
1521         }
1522
1523         /*
1524          * On the PAS16 at least I/O recovery delays are not needed here.
1525          * Everyone else seems to want them.
1526          */
1527
1528         if (p & SR_IO) {
1529                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1530                 NCR5380_io_delay(1);
1531                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1532         } else {
1533                 NCR5380_io_delay(1);
1534                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1535                 NCR5380_io_delay(1);
1536                 NCR5380_write(START_DMA_SEND_REG, 0);
1537                 NCR5380_io_delay(1);
1538         }
1539
1540 #ifdef CONFIG_SUN3
1541 #ifdef SUN3_SCSI_VME
1542         dregs->csr |= CSR_DMA_ENABLE;
1543 #endif
1544         sun3_dma_active = 1;
1545 #endif
1546
1547         if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1548                 /* On the Falcon, the DMA setup must be done after the last
1549                  * NCR access, else the DMA setup gets trashed!
1550                  */
1551                 if (p & SR_IO)
1552                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1553                 else
1554                         result = NCR5380_dma_send_setup(hostdata, d, c);
1555         }
1556
1557         /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
1558         if (result < 0)
1559                 return result;
1560
1561         /* For real DMA, result is the byte count. DMA interrupt is expected. */
1562         if (result > 0) {
1563                 hostdata->dma_len = result;
1564                 return 0;
1565         }
1566
1567         /* The result is zero iff pseudo DMA send/receive was completed. */
1568         hostdata->dma_len = c;
1569
1570 /*
1571  * A note regarding the DMA errata workarounds for early NMOS silicon.
1572  *
1573  * For DMA sends, we want to wait until the last byte has been
1574  * transferred out over the bus before we turn off DMA mode.  Alas, there
1575  * seems to be no terribly good way of doing this on a 5380 under all
1576  * conditions.  For non-scatter-gather operations, we can wait until REQ
1577  * and ACK both go false, or until a phase mismatch occurs.  Gather-sends
1578  * are nastier, since the device will be expecting more data than we
1579  * are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1580  * could test Last Byte Sent to assure transfer (I imagine this is precisely
1581  * why this signal was added to the newer chips) but on the older 538[01]
1582  * this signal does not exist.  The workaround for this lack is a watchdog;
1583  * we bail out of the wait-loop after a modest amount of wait-time if
1584  * the usual exit conditions are not met.  Not a terribly clean or
1585  * correct solution :-%
1586  *
1587  * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1588  * If the chip is in DMA receive mode, it will respond to a target's
1589  * REQ by latching the SCSI data into the INPUT DATA register and asserting
1590  * ACK, even if it has _already_ been notified by the DMA controller that
1591  * the current DMA transfer has completed!  If the NCR5380 is then taken
1592  * out of DMA mode, this already-acknowledged byte is lost. This is
1593  * not a problem for "one DMA transfer per READ command", because
1594  * the situation will never arise... either all of the data is DMA'ed
1595  * properly, or the target switches to MESSAGE IN phase to signal a
1596  * disconnection (either operation bringing the DMA to a clean halt).
1597  * However, in order to handle scatter-receive, we must work around the
1598  * problem.  The chosen fix is to DMA fewer bytes, then check for the
1599  * condition before taking the NCR5380 out of DMA mode.  One or two extra
1600  * bytes are transferred via PIO as necessary to fill out the original
1601  * request.
1602  */
1603
1604         if (hostdata->flags & FLAG_DMA_FIXUP) {
1605                 if (p & SR_IO) {
1606                         /*
1607                          * The workaround was to transfer fewer bytes than we
1608                          * intended to with the pseudo-DMA read function, wait for
1609                          * the chip to latch the last byte, read it, and then disable
1610                          * pseudo-DMA mode.
1611                          *
1612                          * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1613                          * REQ is deasserted when ACK is asserted, and not reasserted
1614                          * until ACK goes false.  Since the NCR5380 won't lower ACK
1615                          * until DACK is asserted, which won't happen unless we twiddle
1616                          * the DMA port or we take the NCR5380 out of DMA mode, we
1617                          * can guarantee that we won't handshake another extra
1618                          * byte.
1619                          */
1620
1621                         if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
1622                                                   BASR_DRQ, BASR_DRQ, HZ) < 0) {
1623                                 result = -1;
1624                                 shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1625                         }
1626                         if (NCR5380_poll_politely(hostdata, STATUS_REG,
1627                                                   SR_REQ, 0, HZ) < 0) {
1628                                 result = -1;
1629                                 shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1630                         }
1631                         d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
1632                 } else {
1633                         /*
1634                          * Wait for the last byte to be sent.  If REQ is being asserted for
1635                          * the byte we're interested, we'll ACK it and it will go false.
1636                          */
1637                         if (NCR5380_poll_politely2(hostdata,
1638                              BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1639                              BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
1640                                 result = -1;
1641                                 shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1642                         }
1643                 }
1644         }
1645
1646         NCR5380_dma_complete(instance);
1647         return result;
1648 }
1649
1650 /*
1651  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1652  *
1653  * Purpose : run through the various SCSI phases and do as the target
1654  * directs us to.  Operates on the currently connected command,
1655  * instance->connected.
1656  *
1657  * Inputs : instance, instance for which we are doing commands
1658  *
1659  * Side effects : SCSI things happen, the disconnected queue will be
1660  * modified if a command disconnects, *instance->connected will
1661  * change.
1662  *
1663  * XXX Note : we need to watch for bus free or a reset condition here
1664  * to recover from an unexpected bus free condition.
1665  */
1666
1667 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1668         __releases(&hostdata->lock) __acquires(&hostdata->lock)
1669 {
1670         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1671         unsigned char msgout = NOP;
1672         int sink = 0;
1673         int len;
1674         int transfersize;
1675         unsigned char *data;
1676         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1677         struct scsi_cmnd *cmd;
1678
1679 #ifdef SUN3_SCSI_VME
1680         dregs->csr |= CSR_INTR;
1681 #endif
1682
1683         while ((cmd = hostdata->connected)) {
1684                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1685
1686                 tmp = NCR5380_read(STATUS_REG);
1687                 /* We only have a valid SCSI phase when REQ is asserted */
1688                 if (tmp & SR_REQ) {
1689                         phase = (tmp & PHASE_MASK);
1690                         if (phase != old_phase) {
1691                                 old_phase = phase;
1692                                 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1693                         }
1694 #ifdef CONFIG_SUN3
1695                         if (phase == PHASE_CMDOUT &&
1696                             sun3_dma_setup_done != cmd) {
1697                                 int count;
1698
1699                                 advance_sg_buffer(cmd);
1700
1701                                 count = sun3scsi_dma_xfer_len(hostdata, cmd);
1702
1703                                 if (count > 0) {
1704                                         if (rq_data_dir(cmd->request))
1705                                                 sun3scsi_dma_send_setup(hostdata,
1706                                                                         cmd->SCp.ptr, count);
1707                                         else
1708                                                 sun3scsi_dma_recv_setup(hostdata,
1709                                                                         cmd->SCp.ptr, count);
1710                                         sun3_dma_setup_done = cmd;
1711                                 }
1712 #ifdef SUN3_SCSI_VME
1713                                 dregs->csr |= CSR_INTR;
1714 #endif
1715                         }
1716 #endif /* CONFIG_SUN3 */
1717
1718                         if (sink && (phase != PHASE_MSGOUT)) {
1719                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1720
1721                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1722                                               ICR_ASSERT_ACK);
1723                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1724                                         ;
1725                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1726                                               ICR_ASSERT_ATN);
1727                                 sink = 0;
1728                                 continue;
1729                         }
1730
1731                         switch (phase) {
1732                         case PHASE_DATAOUT:
1733 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1734                                 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1735                                 sink = 1;
1736                                 do_abort(instance);
1737                                 cmd->result = DID_ERROR << 16;
1738                                 complete_cmd(instance, cmd);
1739                                 hostdata->connected = NULL;
1740                                 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1741                                 return;
1742 #endif
1743                         case PHASE_DATAIN:
1744                                 /*
1745                                  * If there is no room left in the current buffer in the
1746                                  * scatter-gather list, move onto the next one.
1747                                  */
1748
1749                                 advance_sg_buffer(cmd);
1750                                 dsprintk(NDEBUG_INFORMATION, instance,
1751                                         "this residual %d, sg ents %d\n",
1752                                         cmd->SCp.this_residual,
1753                                         sg_nents(cmd->SCp.buffer));
1754
1755                                 /*
1756                                  * The preferred transfer method is going to be
1757                                  * PSEUDO-DMA for systems that are strictly PIO,
1758                                  * since we can let the hardware do the handshaking.
1759                                  *
1760                                  * For this to work, we need to know the transfersize
1761                                  * ahead of time, since the pseudo-DMA code will sit
1762                                  * in an unconditional loop.
1763                                  */
1764
1765                                 transfersize = 0;
1766                                 if (!cmd->device->borken)
1767                                         transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
1768
1769                                 if (transfersize > 0) {
1770                                         len = transfersize;
1771                                         if (NCR5380_transfer_dma(instance, &phase,
1772                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
1773                                                 /*
1774                                                  * If the watchdog timer fires, all future
1775                                                  * accesses to this device will use the
1776                                                  * polled-IO.
1777                                                  */
1778                                                 scmd_printk(KERN_INFO, cmd,
1779                                                         "switching to slow handshake\n");
1780                                                 cmd->device->borken = 1;
1781                                                 do_reset(instance);
1782                                                 bus_reset_cleanup(instance);
1783                                         }
1784                                 } else {
1785                                         /* Transfer a small chunk so that the
1786                                          * irq mode lock is not held too long.
1787                                          */
1788                                         transfersize = min(cmd->SCp.this_residual,
1789                                                            NCR5380_PIO_CHUNK_SIZE);
1790                                         len = transfersize;
1791                                         NCR5380_transfer_pio(instance, &phase, &len,
1792                                                              (unsigned char **)&cmd->SCp.ptr);
1793                                         cmd->SCp.this_residual -= transfersize - len;
1794                                 }
1795 #ifdef CONFIG_SUN3
1796                                 if (sun3_dma_setup_done == cmd)
1797                                         sun3_dma_setup_done = NULL;
1798 #endif
1799                                 return;
1800                         case PHASE_MSGIN:
1801                                 len = 1;
1802                                 data = &tmp;
1803                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1804                                 cmd->SCp.Message = tmp;
1805
1806                                 switch (tmp) {
1807                                 case ABORT:
1808                                 case COMMAND_COMPLETE:
1809                                         /* Accept message by clearing ACK */
1810                                         sink = 1;
1811                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1812                                         dsprintk(NDEBUG_QUEUES, instance,
1813                                                  "COMMAND COMPLETE %p target %d lun %llu\n",
1814                                                  cmd, scmd_id(cmd), cmd->device->lun);
1815
1816                                         hostdata->connected = NULL;
1817                                         hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1818
1819                                         cmd->result &= ~0xffff;
1820                                         cmd->result |= cmd->SCp.Status;
1821                                         cmd->result |= cmd->SCp.Message << 8;
1822
1823                                         set_resid_from_SCp(cmd);
1824
1825                                         if (cmd->cmnd[0] == REQUEST_SENSE)
1826                                                 complete_cmd(instance, cmd);
1827                                         else {
1828                                                 if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1829                                                     cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1830                                                         dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1831                                                                  cmd);
1832                                                         list_add_tail(&ncmd->list,
1833                                                                       &hostdata->autosense);
1834                                                 } else
1835                                                         complete_cmd(instance, cmd);
1836                                         }
1837
1838                                         /*
1839                                          * Restore phase bits to 0 so an interrupted selection,
1840                                          * arbitration can resume.
1841                                          */
1842                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1843
1844                                         maybe_release_dma_irq(instance);
1845                                         return;
1846                                 case MESSAGE_REJECT:
1847                                         /* Accept message by clearing ACK */
1848                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1849                                         switch (hostdata->last_message) {
1850                                         case HEAD_OF_QUEUE_TAG:
1851                                         case ORDERED_QUEUE_TAG:
1852                                         case SIMPLE_QUEUE_TAG:
1853                                                 cmd->device->simple_tags = 0;
1854                                                 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1855                                                 break;
1856                                         default:
1857                                                 break;
1858                                         }
1859                                         break;
1860                                 case DISCONNECT:
1861                                         /* Accept message by clearing ACK */
1862                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1863                                         hostdata->connected = NULL;
1864                                         list_add(&ncmd->list, &hostdata->disconnected);
1865                                         dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1866                                                  instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1867                                                  cmd, scmd_id(cmd), cmd->device->lun);
1868
1869                                         /*
1870                                          * Restore phase bits to 0 so an interrupted selection,
1871                                          * arbitration can resume.
1872                                          */
1873                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1874
1875 #ifdef SUN3_SCSI_VME
1876                                         dregs->csr |= CSR_DMA_ENABLE;
1877 #endif
1878                                         return;
1879                                         /*
1880                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1881                                          * operation, in violation of the SCSI spec so we can safely
1882                                          * ignore SAVE/RESTORE pointers calls.
1883                                          *
1884                                          * Unfortunately, some disks violate the SCSI spec and
1885                                          * don't issue the required SAVE_POINTERS message before
1886                                          * disconnecting, and we have to break spec to remain
1887                                          * compatible.
1888                                          */
1889                                 case SAVE_POINTERS:
1890                                 case RESTORE_POINTERS:
1891                                         /* Accept message by clearing ACK */
1892                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1893                                         break;
1894                                 case EXTENDED_MESSAGE:
1895                                         /*
1896                                          * Start the message buffer with the EXTENDED_MESSAGE
1897                                          * byte, since spi_print_msg() wants the whole thing.
1898                                          */
1899                                         extended_msg[0] = EXTENDED_MESSAGE;
1900                                         /* Accept first byte by clearing ACK */
1901                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1902
1903                                         spin_unlock_irq(&hostdata->lock);
1904
1905                                         dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1906
1907                                         len = 2;
1908                                         data = extended_msg + 1;
1909                                         phase = PHASE_MSGIN;
1910                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
1911                                         dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1912                                                  (int)extended_msg[1],
1913                                                  (int)extended_msg[2]);
1914
1915                                         if (!len && extended_msg[1] > 0 &&
1916                                             extended_msg[1] <= sizeof(extended_msg) - 2) {
1917                                                 /* Accept third byte by clearing ACK */
1918                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1919                                                 len = extended_msg[1] - 1;
1920                                                 data = extended_msg + 3;
1921                                                 phase = PHASE_MSGIN;
1922
1923                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1924                                                 dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
1925                                                          len);
1926
1927                                                 switch (extended_msg[2]) {
1928                                                 case EXTENDED_SDTR:
1929                                                 case EXTENDED_WDTR:
1930                                                         tmp = 0;
1931                                                 }
1932                                         } else if (len) {
1933                                                 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1934                                                 tmp = 0;
1935                                         } else {
1936                                                 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
1937                                                              extended_msg[2], extended_msg[1]);
1938                                                 tmp = 0;
1939                                         }
1940
1941                                         spin_lock_irq(&hostdata->lock);
1942                                         if (!hostdata->connected)
1943                                                 return;
1944
1945                                         /* Reject message */
1946                                         fallthrough;
1947                                 default:
1948                                         /*
1949                                          * If we get something weird that we aren't expecting,
1950                                          * log it.
1951                                          */
1952                                         if (tmp == EXTENDED_MESSAGE)
1953                                                 scmd_printk(KERN_INFO, cmd,
1954                                                             "rejecting unknown extended message code %02x, length %d\n",
1955                                                             extended_msg[2], extended_msg[1]);
1956                                         else if (tmp)
1957                                                 scmd_printk(KERN_INFO, cmd,
1958                                                             "rejecting unknown message code %02x\n",
1959                                                             tmp);
1960
1961                                         msgout = MESSAGE_REJECT;
1962                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1963                                         break;
1964                                 } /* switch (tmp) */
1965                                 break;
1966                         case PHASE_MSGOUT:
1967                                 len = 1;
1968                                 data = &msgout;
1969                                 hostdata->last_message = msgout;
1970                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1971                                 if (msgout == ABORT) {
1972                                         hostdata->connected = NULL;
1973                                         hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1974                                         cmd->result = DID_ERROR << 16;
1975                                         complete_cmd(instance, cmd);
1976                                         maybe_release_dma_irq(instance);
1977                                         return;
1978                                 }
1979                                 msgout = NOP;
1980                                 break;
1981                         case PHASE_CMDOUT:
1982                                 len = cmd->cmd_len;
1983                                 data = cmd->cmnd;
1984                                 /*
1985                                  * XXX for performance reasons, on machines with a
1986                                  * PSEUDO-DMA architecture we should probably
1987                                  * use the dma transfer function.
1988                                  */
1989                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1990                                 break;
1991                         case PHASE_STATIN:
1992                                 len = 1;
1993                                 data = &tmp;
1994                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1995                                 cmd->SCp.Status = tmp;
1996                                 break;
1997                         default:
1998                                 shost_printk(KERN_ERR, instance, "unknown phase\n");
1999                                 NCR5380_dprint(NDEBUG_ANY, instance);
2000                         } /* switch(phase) */
2001                 } else {
2002                         spin_unlock_irq(&hostdata->lock);
2003                         NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
2004                         spin_lock_irq(&hostdata->lock);
2005                 }
2006         }
2007 }
2008
2009 /*
2010  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2011  *
2012  * Purpose : does reselection, initializing the instance->connected
2013  * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2014  * nexus has been reestablished,
2015  *
2016  * Inputs : instance - this instance of the NCR5380.
2017  */
2018
2019 static void NCR5380_reselect(struct Scsi_Host *instance)
2020 {
2021         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2022         unsigned char target_mask;
2023         unsigned char lun;
2024         unsigned char msg[3];
2025         struct NCR5380_cmd *ncmd;
2026         struct scsi_cmnd *tmp;
2027
2028         /*
2029          * Disable arbitration, etc. since the host adapter obviously
2030          * lost, and tell an interrupted NCR5380_select() to restart.
2031          */
2032
2033         NCR5380_write(MODE_REG, MR_BASE);
2034
2035         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2036         if (!target_mask || target_mask & (target_mask - 1)) {
2037                 shost_printk(KERN_WARNING, instance,
2038                              "reselect: bad target_mask 0x%02x\n", target_mask);
2039                 return;
2040         }
2041
2042         /*
2043          * At this point, we have detected that our SCSI ID is on the bus,
2044          * SEL is true and BSY was false for at least one bus settle delay
2045          * (400 ns).
2046          *
2047          * We must assert BSY ourselves, until the target drops the SEL
2048          * signal.
2049          */
2050
2051         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2052         if (NCR5380_poll_politely(hostdata,
2053                                   STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2054                 shost_printk(KERN_ERR, instance, "reselect: !SEL timeout\n");
2055                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2056                 return;
2057         }
2058         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2059
2060         /*
2061          * Wait for target to go into MSGIN.
2062          */
2063
2064         if (NCR5380_poll_politely(hostdata,
2065                                   STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2066                 if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
2067                         /* BUS FREE phase */
2068                         return;
2069                 shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
2070                 do_abort(instance);
2071                 return;
2072         }
2073
2074 #ifdef CONFIG_SUN3
2075         /* acknowledge toggle to MSGIN */
2076         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2077
2078         /* peek at the byte without really hitting the bus */
2079         msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2080 #else
2081         {
2082                 int len = 1;
2083                 unsigned char *data = msg;
2084                 unsigned char phase = PHASE_MSGIN;
2085
2086                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2087
2088                 if (len) {
2089                         do_abort(instance);
2090                         return;
2091                 }
2092         }
2093 #endif /* CONFIG_SUN3 */
2094
2095         if (!(msg[0] & 0x80)) {
2096                 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2097                 spi_print_msg(msg);
2098                 printk("\n");
2099                 do_abort(instance);
2100                 return;
2101         }
2102         lun = msg[0] & 0x07;
2103
2104         /*
2105          * We need to add code for SCSI-II to track which devices have
2106          * I_T_L_Q nexuses established, and which have simple I_T_L
2107          * nexuses so we can chose to do additional data transfer.
2108          */
2109
2110         /*
2111          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2112          * just reestablished, and remove it from the disconnected queue.
2113          */
2114
2115         tmp = NULL;
2116         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2117                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2118
2119                 if (target_mask == (1 << scmd_id(cmd)) &&
2120                     lun == (u8)cmd->device->lun) {
2121                         list_del(&ncmd->list);
2122                         tmp = cmd;
2123                         break;
2124                 }
2125         }
2126
2127         if (tmp) {
2128                 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2129                          "reselect: removed %p from disconnected queue\n", tmp);
2130         } else {
2131                 int target = ffs(target_mask) - 1;
2132
2133                 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2134                              target_mask, lun);
2135                 /*
2136                  * Since we have an established nexus that we can't do anything
2137                  * with, we must abort it.
2138                  */
2139                 if (do_abort(instance) == 0)
2140                         hostdata->busy[target] &= ~(1 << lun);
2141                 return;
2142         }
2143
2144 #ifdef CONFIG_SUN3
2145         if (sun3_dma_setup_done != tmp) {
2146                 int count;
2147
2148                 advance_sg_buffer(tmp);
2149
2150                 count = sun3scsi_dma_xfer_len(hostdata, tmp);
2151
2152                 if (count > 0) {
2153                         if (rq_data_dir(tmp->request))
2154                                 sun3scsi_dma_send_setup(hostdata,
2155                                                         tmp->SCp.ptr, count);
2156                         else
2157                                 sun3scsi_dma_recv_setup(hostdata,
2158                                                         tmp->SCp.ptr, count);
2159                         sun3_dma_setup_done = tmp;
2160                 }
2161         }
2162
2163         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2164 #endif /* CONFIG_SUN3 */
2165
2166         /* Accept message by clearing ACK */
2167         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2168
2169         hostdata->connected = tmp;
2170         dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
2171                  scmd_id(tmp), tmp->device->lun);
2172 }
2173
2174 /**
2175  * list_find_cmd - test for presence of a command in a linked list
2176  * @haystack: list of commands
2177  * @needle: command to search for
2178  */
2179
2180 static bool list_find_cmd(struct list_head *haystack,
2181                           struct scsi_cmnd *needle)
2182 {
2183         struct NCR5380_cmd *ncmd;
2184
2185         list_for_each_entry(ncmd, haystack, list)
2186                 if (NCR5380_to_scmd(ncmd) == needle)
2187                         return true;
2188         return false;
2189 }
2190
2191 /**
2192  * list_remove_cmd - remove a command from linked list
2193  * @haystack: list of commands
2194  * @needle: command to remove
2195  */
2196
2197 static bool list_del_cmd(struct list_head *haystack,
2198                          struct scsi_cmnd *needle)
2199 {
2200         if (list_find_cmd(haystack, needle)) {
2201                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2202
2203                 list_del(&ncmd->list);
2204                 return true;
2205         }
2206         return false;
2207 }
2208
2209 /**
2210  * NCR5380_abort - scsi host eh_abort_handler() method
2211  * @cmd: the command to be aborted
2212  *
2213  * Try to abort a given command by removing it from queues and/or sending
2214  * the target an abort message. This may not succeed in causing a target
2215  * to abort the command. Nonetheless, the low-level driver must forget about
2216  * the command because the mid-layer reclaims it and it may be re-issued.
2217  *
2218  * The normal path taken by a command is as follows. For EH we trace this
2219  * same path to locate and abort the command.
2220  *
2221  * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2222  * [disconnected -> connected ->]...
2223  * [autosense -> connected ->] done
2224  *
2225  * If cmd was not found at all then presumably it has already been completed,
2226  * in which case return SUCCESS to try to avoid further EH measures.
2227  *
2228  * If the command has not completed yet, we must not fail to find it.
2229  * We have no option but to forget the aborted command (even if it still
2230  * lacks sense data). The mid-layer may re-issue a command that is in error
2231  * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2232  * this driver are such that a command can appear on one queue only.
2233  *
2234  * The lock protects driver data structures, but EH handlers also use it
2235  * to serialize their own execution and prevent their own re-entry.
2236  */
2237
2238 static int NCR5380_abort(struct scsi_cmnd *cmd)
2239 {
2240         struct Scsi_Host *instance = cmd->device->host;
2241         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2242         unsigned long flags;
2243         int result = SUCCESS;
2244
2245         spin_lock_irqsave(&hostdata->lock, flags);
2246
2247 #if (NDEBUG & NDEBUG_ANY)
2248         scmd_printk(KERN_INFO, cmd, __func__);
2249 #endif
2250         NCR5380_dprint(NDEBUG_ANY, instance);
2251         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2252
2253         if (list_del_cmd(&hostdata->unissued, cmd)) {
2254                 dsprintk(NDEBUG_ABORT, instance,
2255                          "abort: removed %p from issue queue\n", cmd);
2256                 cmd->result = DID_ABORT << 16;
2257                 cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2258                 goto out;
2259         }
2260
2261         if (hostdata->selecting == cmd) {
2262                 dsprintk(NDEBUG_ABORT, instance,
2263                          "abort: cmd %p == selecting\n", cmd);
2264                 hostdata->selecting = NULL;
2265                 cmd->result = DID_ABORT << 16;
2266                 complete_cmd(instance, cmd);
2267                 goto out;
2268         }
2269
2270         if (list_del_cmd(&hostdata->disconnected, cmd)) {
2271                 dsprintk(NDEBUG_ABORT, instance,
2272                          "abort: removed %p from disconnected list\n", cmd);
2273                 /* Can't call NCR5380_select() and send ABORT because that
2274                  * means releasing the lock. Need a bus reset.
2275                  */
2276                 set_host_byte(cmd, DID_ERROR);
2277                 complete_cmd(instance, cmd);
2278                 result = FAILED;
2279                 goto out;
2280         }
2281
2282         if (hostdata->connected == cmd) {
2283                 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2284                 hostdata->connected = NULL;
2285                 hostdata->dma_len = 0;
2286                 if (do_abort(instance) < 0) {
2287                         set_host_byte(cmd, DID_ERROR);
2288                         complete_cmd(instance, cmd);
2289                         result = FAILED;
2290                         goto out;
2291                 }
2292                 set_host_byte(cmd, DID_ABORT);
2293                 complete_cmd(instance, cmd);
2294                 goto out;
2295         }
2296
2297         if (list_del_cmd(&hostdata->autosense, cmd)) {
2298                 dsprintk(NDEBUG_ABORT, instance,
2299                          "abort: removed %p from sense queue\n", cmd);
2300                 complete_cmd(instance, cmd);
2301         }
2302
2303 out:
2304         if (result == FAILED)
2305                 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2306         else {
2307                 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
2308                 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2309         }
2310
2311         queue_work(hostdata->work_q, &hostdata->main_task);
2312         maybe_release_dma_irq(instance);
2313         spin_unlock_irqrestore(&hostdata->lock, flags);
2314
2315         return result;
2316 }
2317
2318
2319 static void bus_reset_cleanup(struct Scsi_Host *instance)
2320 {
2321         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2322         int i;
2323         struct NCR5380_cmd *ncmd;
2324
2325         /* reset NCR registers */
2326         NCR5380_write(MODE_REG, MR_BASE);
2327         NCR5380_write(TARGET_COMMAND_REG, 0);
2328         NCR5380_write(SELECT_ENABLE_REG, 0);
2329
2330         /* After the reset, there are no more connected or disconnected commands
2331          * and no busy units; so clear the low-level status here to avoid
2332          * conflicts when the mid-level code tries to wake up the affected
2333          * commands!
2334          */
2335
2336         if (hostdata->selecting) {
2337                 hostdata->selecting->result = DID_RESET << 16;
2338                 complete_cmd(instance, hostdata->selecting);
2339                 hostdata->selecting = NULL;
2340         }
2341
2342         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2343                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2344
2345                 set_host_byte(cmd, DID_RESET);
2346                 complete_cmd(instance, cmd);
2347         }
2348         INIT_LIST_HEAD(&hostdata->disconnected);
2349
2350         list_for_each_entry(ncmd, &hostdata->autosense, list) {
2351                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2352
2353                 cmd->scsi_done(cmd);
2354         }
2355         INIT_LIST_HEAD(&hostdata->autosense);
2356
2357         if (hostdata->connected) {
2358                 set_host_byte(hostdata->connected, DID_RESET);
2359                 complete_cmd(instance, hostdata->connected);
2360                 hostdata->connected = NULL;
2361         }
2362
2363         for (i = 0; i < 8; ++i)
2364                 hostdata->busy[i] = 0;
2365         hostdata->dma_len = 0;
2366
2367         queue_work(hostdata->work_q, &hostdata->main_task);
2368         maybe_release_dma_irq(instance);
2369 }
2370
2371 /**
2372  * NCR5380_host_reset - reset the SCSI host
2373  * @cmd: SCSI command undergoing EH
2374  *
2375  * Returns SUCCESS
2376  */
2377
2378 static int NCR5380_host_reset(struct scsi_cmnd *cmd)
2379 {
2380         struct Scsi_Host *instance = cmd->device->host;
2381         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2382         unsigned long flags;
2383         struct NCR5380_cmd *ncmd;
2384
2385         spin_lock_irqsave(&hostdata->lock, flags);
2386
2387 #if (NDEBUG & NDEBUG_ANY)
2388         shost_printk(KERN_INFO, instance, __func__);
2389 #endif
2390         NCR5380_dprint(NDEBUG_ANY, instance);
2391         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2392
2393         list_for_each_entry(ncmd, &hostdata->unissued, list) {
2394                 struct scsi_cmnd *scmd = NCR5380_to_scmd(ncmd);
2395
2396                 scmd->result = DID_RESET << 16;
2397                 scmd->scsi_done(scmd);
2398         }
2399         INIT_LIST_HEAD(&hostdata->unissued);
2400
2401         do_reset(instance);
2402         bus_reset_cleanup(instance);
2403
2404         spin_unlock_irqrestore(&hostdata->lock, flags);
2405
2406         return SUCCESS;
2407 }