drivers/scsi/NCR5380.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * NCR 5380 generic driver routines.  These should make it *trivial*
   4  * to implement 5380 SCSI drivers under Linux with a non-trantor
   5  * architecture.
   6  *
   7  * Note that these routines also work with NR53c400 family chips.
   8  *
   9  * Copyright 1993, Drew Eckhardt
  10  * Visionary Computing
  11  * (Unix and Linux consulting and custom programming)
  12  * drew@colorado.edu
  13  * +1 (303) 666-5836
  14  *
  15  * For more information, please consult
  16  *
  17  * NCR 5380 Family
  18  * SCSI Protocol Controller
  19  * Databook
  20  *
  21  * NCR Microelectronics
  22  * 1635 Aeroplaza Drive
  23  * Colorado Springs, CO 80916
  24  * 1+ (719) 578-3400
  25  * 1+ (800) 334-5454
  26  */
  27
  28 /*
  29  * With contributions from Ray Van Tassle, Ingmar Baumgart,
  30  * Ronald van Cuijlenborg, Alan Cox and others.
  31  */
  32
  33 /* Ported to Atari by Roman Hodek and others. */
  34
  35 /* Adapted for the Sun 3 by Sam Creasey. */
  36
  37 /*
  38  * Design
  39  *
  40  * This is a generic 5380 driver.  To use it on a different platform,
  41  * one simply writes appropriate system specific macros (ie, data
  42  * transfer - some PC's will use the I/O bus, 68K's must use
  43  * memory mapped) and drops this file in their 'C' wrapper.
  44  *
  45  * As far as command queueing, two queues are maintained for
  46  * each 5380 in the system - commands that haven't been issued yet,
  47  * and commands that are currently executing.  This means that an
  48  * unlimited number of commands may be queued, letting
  49  * more commands propagate from the higher driver levels giving higher
  50  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
  51  * allowing multiple commands to propagate all the way to a SCSI-II device
  52  * while a command is already executing.
  53  *
  54  *
  55  * Issues specific to the NCR5380 :
  56  *
  57  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
  58  * piece of hardware that requires you to sit in a loop polling for
  59  * the REQ signal as long as you are connected.  Some devices are
  60  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
  61  * while doing long seek operations. [...] These
  62  * broken devices are the exception rather than the rule and I'd rather
  63  * spend my time optimizing for the normal case.
  64  *
  65  * Architecture :
  66  *
  67  * At the heart of the design is a coroutine, NCR5380_main,
  68  * which is started from a workqueue for each NCR5380 host in the
  69  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
  70  * removing the commands from the issue queue and calling
  71  * NCR5380_select() if a nexus is not established.
  72  *
  73  * Once a nexus is established, the NCR5380_information_transfer()
  74  * phase goes through the various phases as instructed by the target.
  75  * if the target goes into MSG IN and sends a DISCONNECT message,
  76  * the command structure is placed into the per instance disconnected
  77  * queue, and NCR5380_main tries to find more work.  If the target is
  78  * idle for too long, the system will try to sleep.
  79  *
  80  * If a command has disconnected, eventually an interrupt will trigger,
  81  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
  82  * to reestablish a nexus.  This will run main if necessary.
  83  *
  84  * On command termination, the done function will be called as
  85  * appropriate.
  86  *
  87  * SCSI pointers are maintained in the SCp field of SCSI command
  88  * structures, being initialized after the command is connected
  89  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
  90  * Note that in violation of the standard, an implicit SAVE POINTERS operation
  91  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
  92  */
  93
  94 /*
  95  * Using this file :
  96  * This file a skeleton Linux SCSI driver for the NCR 5380 series
  97  * of chips.  To use it, you write an architecture specific functions
  98  * and macros and include this file in your driver.
  99  *
 100  * These macros MUST be defined :
 101  *
 102  * NCR5380_read(register)  - read from the specified register
 103  *
 104  * NCR5380_write(register, value) - write to the specific register
 105  *
 106  * NCR5380_implementation_fields  - additional fields needed for this
 107  * specific implementation of the NCR5380
 108  *
 109  * Either real DMA *or* pseudo DMA may be implemented
 110  *
 111  * NCR5380_dma_xfer_len   - determine size of DMA/PDMA transfer
 112  * NCR5380_dma_send_setup - execute DMA/PDMA from memory to 5380
 113  * NCR5380_dma_recv_setup - execute DMA/PDMA from 5380 to memory
 114  * NCR5380_dma_residual   - residual byte count
 115  *
 116  * The generic driver is initialized by calling NCR5380_init(instance),
 117  * after setting the appropriate host specific fields and ID.
 118  */
 119
 120 #ifndef NCR5380_io_delay
 121 #define NCR5380_io_delay(x)
 122 #endif
 123
 124 #ifndef NCR5380_acquire_dma_irq
 125 #define NCR5380_acquire_dma_irq(x)      (1)
 126 #endif
 127
 128 #ifndef NCR5380_release_dma_irq
 129 #define NCR5380_release_dma_irq(x)
 130 #endif
 131
 132 static int do_abort(struct Scsi_Host *);
 133 static void do_reset(struct Scsi_Host *);
 134 static void bus_reset_cleanup(struct Scsi_Host *);
 135
 136 /**
 137  * initialize_SCp - init the scsi pointer field
 138  * @cmd: command block to set up
 139  *
 140  * Set up the internal fields in the SCSI command.
 141  */
 142
 143 static inline void initialize_SCp(struct scsi_cmnd *cmd)
 144 {
 145         /*
 146          * Initialize the Scsi Pointer field so that all of the commands in the
 147          * various queues are valid.
 148          */
 149
 150         if (scsi_bufflen(cmd)) {
 151                 cmd->SCp.buffer = scsi_sglist(cmd);
 152                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 153                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 154         } else {
 155                 cmd->SCp.buffer = NULL;
 156                 cmd->SCp.ptr = NULL;
 157                 cmd->SCp.this_residual = 0;
 158         }
 159
 160         cmd->SCp.Status = 0;
 161         cmd->SCp.Message = 0;
 162 }
 163
 164 static inline void advance_sg_buffer(struct scsi_cmnd *cmd)
 165 {
 166         struct scatterlist *s = cmd->SCp.buffer;
 167
 168         if (!cmd->SCp.this_residual && s && !sg_is_last(s)) {
 169                 cmd->SCp.buffer = sg_next(s);
 170                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 171                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 172         }
 173 }
 174
 175 /**
 176  * NCR5380_poll_politely2 - wait for two chip register values
 177  * @hostdata: host private data
 178  * @reg1: 5380 register to poll
 179  * @bit1: Bitmask to check
 180  * @val1: Expected value
 181  * @reg2: Second 5380 register to poll
 182  * @bit2: Second bitmask to check
 183  * @val2: Second expected value
 184  * @wait: Time-out in jiffies
 185  *
 186  * Polls the chip in a reasonably efficient manner waiting for an
 187  * event to occur. After a short quick poll we begin to yield the CPU
 188  * (if possible). In irq contexts the time-out is arbitrarily limited.
 189  * Callers may hold locks as long as they are held in irq mode.
 190  *
 191  * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
 192  */
 193
 194 static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
 195                                   unsigned int reg1, u8 bit1, u8 val1,
 196                                   unsigned int reg2, u8 bit2, u8 val2,
 197                                   unsigned long wait)
 198 {
 199         unsigned long n = hostdata->poll_loops;
 200         unsigned long deadline = jiffies + wait;
 201
 202         do {
 203                 if ((NCR5380_read(reg1) & bit1) == val1)
 204                         return 0;
 205                 if ((NCR5380_read(reg2) & bit2) == val2)
 206                         return 0;
 207                 cpu_relax();
 208         } while (n--);
 209
 210         if (irqs_disabled() || in_interrupt())
 211                 return -ETIMEDOUT;
 212
 213         /* Repeatedly sleep for 1 ms until deadline */
 214         while (time_is_after_jiffies(deadline)) {
 215                 schedule_timeout_uninterruptible(1);
 216                 if ((NCR5380_read(reg1) & bit1) == val1)
 217                         return 0;
 218                 if ((NCR5380_read(reg2) & bit2) == val2)
 219                         return 0;
 220         }
 221
 222         return -ETIMEDOUT;
 223 }
 224
 225 #if NDEBUG
 226 static struct {
 227         unsigned char mask;
 228         const char *name;
 229 } signals[] = {
 230         {SR_DBP, "PARITY"},
 231         {SR_RST, "RST"},
 232         {SR_BSY, "BSY"},
 233         {SR_REQ, "REQ"},
 234         {SR_MSG, "MSG"},
 235         {SR_CD, "CD"},
 236         {SR_IO, "IO"},
 237         {SR_SEL, "SEL"},
 238         {0, NULL}
 239 },
 240 basrs[] = {
 241         {BASR_END_DMA_TRANSFER, "END OF DMA"},
 242         {BASR_DRQ, "DRQ"},
 243         {BASR_PARITY_ERROR, "PARITY ERROR"},
 244         {BASR_IRQ, "IRQ"},
 245         {BASR_PHASE_MATCH, "PHASE MATCH"},
 246         {BASR_BUSY_ERROR, "BUSY ERROR"},
 247         {BASR_ATN, "ATN"},
 248         {BASR_ACK, "ACK"},
 249         {0, NULL}
 250 },
 251 icrs[] = {
 252         {ICR_ASSERT_RST, "ASSERT RST"},
 253         {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
 254         {ICR_ARBITRATION_LOST, "LOST ARB."},
 255         {ICR_ASSERT_ACK, "ASSERT ACK"},
 256         {ICR_ASSERT_BSY, "ASSERT BSY"},
 257         {ICR_ASSERT_SEL, "ASSERT SEL"},
 258         {ICR_ASSERT_ATN, "ASSERT ATN"},
 259         {ICR_ASSERT_DATA, "ASSERT DATA"},
 260         {0, NULL}
 261 },
 262 mrs[] = {
 263         {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
 264         {MR_TARGET, "TARGET"},
 265         {MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
 266         {MR_ENABLE_PAR_INTR, "PARITY INTR"},
 267         {MR_ENABLE_EOP_INTR, "EOP INTR"},
 268         {MR_MONITOR_BSY, "MONITOR BSY"},
 269         {MR_DMA_MODE, "DMA MODE"},
 270         {MR_ARBITRATE, "ARBITRATE"},
 271         {0, NULL}
 272 };
 273
 274 /**
 275  * NCR5380_print - print scsi bus signals
 276  * @instance: adapter state to dump
 277  *
 278  * Print the SCSI bus signals for debugging purposes
 279  */
 280
 281 static void NCR5380_print(struct Scsi_Host *instance)
 282 {
 283         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 284         unsigned char status, basr, mr, icr, i;
 285
 286         status = NCR5380_read(STATUS_REG);
 287         mr = NCR5380_read(MODE_REG);
 288         icr = NCR5380_read(INITIATOR_COMMAND_REG);
 289         basr = NCR5380_read(BUS_AND_STATUS_REG);
 290
 291         printk(KERN_DEBUG "SR =   0x%02x : ", status);
 292         for (i = 0; signals[i].mask; ++i)
 293                 if (status & signals[i].mask)
 294                         printk(KERN_CONT "%s, ", signals[i].name);
 295         printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
 296         for (i = 0; basrs[i].mask; ++i)
 297                 if (basr & basrs[i].mask)
 298                         printk(KERN_CONT "%s, ", basrs[i].name);
 299         printk(KERN_CONT "\nICR =  0x%02x : ", icr);
 300         for (i = 0; icrs[i].mask; ++i)
 301                 if (icr & icrs[i].mask)
 302                         printk(KERN_CONT "%s, ", icrs[i].name);
 303         printk(KERN_CONT "\nMR =   0x%02x : ", mr);
 304         for (i = 0; mrs[i].mask; ++i)
 305                 if (mr & mrs[i].mask)
 306                         printk(KERN_CONT "%s, ", mrs[i].name);
 307         printk(KERN_CONT "\n");
 308 }
 309
 310 static struct {
 311         unsigned char value;
 312         const char *name;
 313 } phases[] = {
 314         {PHASE_DATAOUT, "DATAOUT"},
 315         {PHASE_DATAIN, "DATAIN"},
 316         {PHASE_CMDOUT, "CMDOUT"},
 317         {PHASE_STATIN, "STATIN"},
 318         {PHASE_MSGOUT, "MSGOUT"},
 319         {PHASE_MSGIN, "MSGIN"},
 320         {PHASE_UNKNOWN, "UNKNOWN"}
 321 };
 322
 323 /**
 324  * NCR5380_print_phase - show SCSI phase
 325  * @instance: adapter to dump
 326  *
 327  * Print the current SCSI phase for debugging purposes
 328  */
 329
 330 static void NCR5380_print_phase(struct Scsi_Host *instance)
 331 {
 332         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 333         unsigned char status;
 334         int i;
 335
 336         status = NCR5380_read(STATUS_REG);
 337         if (!(status & SR_REQ))
 338                 shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
 339         else {
 340                 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
 341                      (phases[i].value != (status & PHASE_MASK)); ++i)
 342                         ;
 343                 shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
 344         }
 345 }
 346 #endif
 347
 348 /**
 349  * NCR5380_info - report driver and host information
 350  * @instance: relevant scsi host instance
 351  *
 352  * For use as the host template info() handler.
 353  */
 354
 355 static const char *NCR5380_info(struct Scsi_Host *instance)
 356 {
 357         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 358
 359         return hostdata->info;
 360 }
 361
 362 /**
 363  * NCR5380_init - initialise an NCR5380
 364  * @instance: adapter to configure
 365  * @flags: control flags
 366  *
 367  * Initializes *instance and corresponding 5380 chip,
 368  * with flags OR'd into the initial flags value.
 369  *
 370  * Notes : I assume that the host, hostno, and id bits have been
 371  * set correctly. I don't care about the irq and other fields.
 372  *
 373  * Returns 0 for success
 374  */
 375
 376 static int NCR5380_init(struct Scsi_Host *instance, int flags)
 377 {
 378         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 379         int i;
 380         unsigned long deadline;
 381         unsigned long accesses_per_ms;
 382
 383         instance->max_lun = 7;
 384
 385         hostdata->host = instance;
 386         hostdata->id_mask = 1 << instance->this_id;
 387         hostdata->id_higher_mask = 0;
 388         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 389                 if (i > hostdata->id_mask)
 390                         hostdata->id_higher_mask |= i;
 391         for (i = 0; i < 8; ++i)
 392                 hostdata->busy[i] = 0;
 393         hostdata->dma_len = 0;
 394
 395         spin_lock_init(&hostdata->lock);
 396         hostdata->connected = NULL;
 397         hostdata->sensing = NULL;
 398         INIT_LIST_HEAD(&hostdata->autosense);
 399         INIT_LIST_HEAD(&hostdata->unissued);
 400         INIT_LIST_HEAD(&hostdata->disconnected);
 401
 402         hostdata->flags = flags;
 403
 404         INIT_WORK(&hostdata->main_task, NCR5380_main);
 405         hostdata->work_q = alloc_workqueue("ncr5380_%d",
 406                                 WQ_UNBOUND | WQ_MEM_RECLAIM,
 407                                 1, instance->host_no);
 408         if (!hostdata->work_q)
 409                 return -ENOMEM;
 410
 411         snprintf(hostdata->info, sizeof(hostdata->info),
 412                 "%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}",
 413                 instance->hostt->name, instance->irq, hostdata->io_port,
 414                 hostdata->base, instance->can_queue, instance->cmd_per_lun,
 415                 instance->sg_tablesize, instance->this_id,
 416                 hostdata->flags & FLAG_DMA_FIXUP     ? "DMA_FIXUP "     : "",
 417                 hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
 418                 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
 419
 420         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 421         NCR5380_write(MODE_REG, MR_BASE);
 422         NCR5380_write(TARGET_COMMAND_REG, 0);
 423         NCR5380_write(SELECT_ENABLE_REG, 0);
 424
 425         /* Calibrate register polling loop */
 426         i = 0;
 427         deadline = jiffies + 1;
 428         do {
 429                 cpu_relax();
 430         } while (time_is_after_jiffies(deadline));
 431         deadline += msecs_to_jiffies(256);
 432         do {
 433                 NCR5380_read(STATUS_REG);
 434                 ++i;
 435                 cpu_relax();
 436         } while (time_is_after_jiffies(deadline));
 437         accesses_per_ms = i / 256;
 438         hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
 439
 440         return 0;
 441 }
 442
 443 /**
 444  * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
 445  * @instance: adapter to check
 446  *
 447  * If the system crashed, it may have crashed with a connected target and
 448  * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
 449  * currently established nexus, which we know nothing about. Failing that
 450  * do a bus reset.
 451  *
 452  * Note that a bus reset will cause the chip to assert IRQ.
 453  *
 454  * Returns 0 if successful, otherwise -ENXIO.
 455  */
 456
 457 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
 458 {
 459         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 460         int pass;
 461
 462         for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
 463                 switch (pass) {
 464                 case 1:
 465                 case 3:
 466                 case 5:
 467                         shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
 468                         NCR5380_poll_politely(hostdata,
 469                                               STATUS_REG, SR_BSY, 0, 5 * HZ);
 470                         break;
 471                 case 2:
 472                         shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
 473                         do_abort(instance);
 474                         break;
 475                 case 4:
 476                         shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
 477                         do_reset(instance);
 478                         /* Wait after a reset; the SCSI standard calls for
 479                          * 250ms, we wait 500ms to be on the safe side.
 480                          * But some Toshiba CD-ROMs need ten times that.
 481                          */
 482                         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
 483                                 msleep(2500);
 484                         else
 485                                 msleep(500);
 486                         break;
 487                 case 6:
 488                         shost_printk(KERN_ERR, instance, "bus locked solid\n");
 489                         return -ENXIO;
 490                 }
 491         }
 492         return 0;
 493 }
 494
 495 /**
 496  * NCR5380_exit - remove an NCR5380
 497  * @instance: adapter to remove
 498  *
 499  * Assumes that no more work can be queued (e.g. by NCR5380_intr).
 500  */
 501
 502 static void NCR5380_exit(struct Scsi_Host *instance)
 503 {
 504         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 505
 506         cancel_work_sync(&hostdata->main_task);
 507         destroy_workqueue(hostdata->work_q);
 508 }
 509
 510 /**
 511  * complete_cmd - finish processing a command and return it to the SCSI ML
 512  * @instance: the host instance
 513  * @cmd: command to complete
 514  */
 515
 516 static void complete_cmd(struct Scsi_Host *instance,
 517                          struct scsi_cmnd *cmd)
 518 {
 519         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 520
 521         dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
 522
 523         if (hostdata->sensing == cmd) {
 524                 /* Autosense processing ends here */
 525                 if (status_byte(cmd->result) != GOOD) {
 526                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 527                 } else {
 528                         scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 529                         set_driver_byte(cmd, DRIVER_SENSE);
 530                 }
 531                 hostdata->sensing = NULL;
 532         }
 533
 534         cmd->scsi_done(cmd);
 535 }
 536
 537 /**
 538  * NCR5380_queue_command - queue a command
 539  * @instance: the relevant SCSI adapter
 540  * @cmd: SCSI command
 541  *
 542  * cmd is added to the per-instance issue queue, with minor
 543  * twiddling done to the host specific fields of cmd.  If the
 544  * main coroutine is not running, it is restarted.
 545  */
 546
 547 static int NCR5380_queue_command(struct Scsi_Host *instance,
 548                                  struct scsi_cmnd *cmd)
 549 {
 550         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 551         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 552         unsigned long flags;
 553
 554 #if (NDEBUG & NDEBUG_NO_WRITE)
 555         switch (cmd->cmnd[0]) {
 556         case WRITE_6:
 557         case WRITE_10:
 558                 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
 559                 cmd->result = (DID_ERROR << 16);
 560                 cmd->scsi_done(cmd);
 561                 return 0;
 562         }
 563 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 564
 565         cmd->result = 0;
 566
 567         if (!NCR5380_acquire_dma_irq(instance))
 568                 return SCSI_MLQUEUE_HOST_BUSY;
 569
 570         spin_lock_irqsave(&hostdata->lock, flags);
 571
 572         /*
 573          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 574          * commands are added to the head of the queue since any command will
 575          * clear the contingent allegiance condition that exists and the
 576          * sense data is only guaranteed to be valid while the condition exists.
 577          */
 578
 579         if (cmd->cmnd[0] == REQUEST_SENSE)
 580                 list_add(&ncmd->list, &hostdata->unissued);
 581         else
 582                 list_add_tail(&ncmd->list, &hostdata->unissued);
 583
 584         spin_unlock_irqrestore(&hostdata->lock, flags);
 585
 586         dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
 587                  cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 588
 589         /* Kick off command processing */
 590         queue_work(hostdata->work_q, &hostdata->main_task);
 591         return 0;
 592 }
 593
 594 static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
 595 {
 596         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 597
 598         /* Caller does the locking needed to set & test these data atomically */
 599         if (list_empty(&hostdata->disconnected) &&
 600             list_empty(&hostdata->unissued) &&
 601             list_empty(&hostdata->autosense) &&
 602             !hostdata->connected &&
 603             !hostdata->selecting) {
 604                 NCR5380_release_dma_irq(instance);
 605         }
 606 }
 607
 608 /**
 609  * dequeue_next_cmd - dequeue a command for processing
 610  * @instance: the scsi host instance
 611  *
 612  * Priority is given to commands on the autosense queue. These commands
 613  * need autosense because of a CHECK CONDITION result.
 614  *
 615  * Returns a command pointer if a command is found for a target that is
 616  * not already busy. Otherwise returns NULL.
 617  */
 618
 619 static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
 620 {
 621         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 622         struct NCR5380_cmd *ncmd;
 623         struct scsi_cmnd *cmd;
 624
 625         if (hostdata->sensing || list_empty(&hostdata->autosense)) {
 626                 list_for_each_entry(ncmd, &hostdata->unissued, list) {
 627                         cmd = NCR5380_to_scmd(ncmd);
 628                         dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
 629                                  cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
 630
 631                         if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
 632                                 list_del(&ncmd->list);
 633                                 dsprintk(NDEBUG_QUEUES, instance,
 634                                          "dequeue: removed %p from issue queue\n", cmd);
 635                                 return cmd;
 636                         }
 637                 }
 638         } else {
 639                 /* Autosense processing begins here */
 640                 ncmd = list_first_entry(&hostdata->autosense,
 641                                         struct NCR5380_cmd, list);
 642                 list_del(&ncmd->list);
 643                 cmd = NCR5380_to_scmd(ncmd);
 644                 dsprintk(NDEBUG_QUEUES, instance,
 645                          "dequeue: removed %p from autosense queue\n", cmd);
 646                 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
 647                 hostdata->sensing = cmd;
 648                 return cmd;
 649         }
 650         return NULL;
 651 }
 652
 653 static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 654 {
 655         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 656         struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 657
 658         if (hostdata->sensing == cmd) {
 659                 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 660                 list_add(&ncmd->list, &hostdata->autosense);
 661                 hostdata->sensing = NULL;
 662         } else
 663                 list_add(&ncmd->list, &hostdata->unissued);
 664 }
 665
 666 /**
 667  * NCR5380_main - NCR state machines
 668  *
 669  * NCR5380_main is a coroutine that runs as long as more work can
 670  * be done on the NCR5380 host adapters in a system.  Both
 671  * NCR5380_queue_command() and NCR5380_intr() will try to start it
 672  * in case it is not running.
 673  */
 674
 675 static void NCR5380_main(struct work_struct *work)
 676 {
 677         struct NCR5380_hostdata *hostdata =
 678                 container_of(work, struct NCR5380_hostdata, main_task);
 679         struct Scsi_Host *instance = hostdata->host;
 680         int done;
 681
 682         do {
 683                 done = 1;
 684
 685                 spin_lock_irq(&hostdata->lock);
 686                 while (!hostdata->connected && !hostdata->selecting) {
 687                         struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
 688
 689                         if (!cmd)
 690                                 break;
 691
 692                         dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
 693
 694                         /*
 695                          * Attempt to establish an I_T_L nexus here.
 696                          * On success, instance->hostdata->connected is set.
 697                          * On failure, we must add the command back to the
 698                          * issue queue so we can keep trying.
 699                          */
 700                         /*
 701                          * REQUEST SENSE commands are issued without tagged
 702                          * queueing, even on SCSI-II devices because the
 703                          * contingent allegiance condition exists for the
 704                          * entire unit.
 705                          */
 706
 707                         if (!NCR5380_select(instance, cmd)) {
 708                                 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
 709                                 maybe_release_dma_irq(instance);
 710                         } else {
 711                                 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
 712                                          "main: select failed, returning %p to queue\n", cmd);
 713                                 requeue_cmd(instance, cmd);
 714                         }
 715                 }
 716                 if (hostdata->connected && !hostdata->dma_len) {
 717                         dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
 718                         NCR5380_information_transfer(instance);
 719                         done = 0;
 720                 }
 721                 if (!hostdata->connected)
 722                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 723                 spin_unlock_irq(&hostdata->lock);
 724                 if (!done)
 725                         cond_resched();
 726         } while (!done);
 727 }
 728
 729 /*
 730  * NCR5380_dma_complete - finish DMA transfer
 731  * @instance: the scsi host instance
 732  *
 733  * Called by the interrupt handler when DMA finishes or a phase
 734  * mismatch occurs (which would end the DMA transfer).
 735  */
 736
 737 static void NCR5380_dma_complete(struct Scsi_Host *instance)
 738 {
 739         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 740         int transferred;
 741         unsigned char **data;
 742         int *count;
 743         int saved_data = 0, overrun = 0;
 744         unsigned char p;
 745
 746         if (hostdata->read_overruns) {
 747                 p = hostdata->connected->SCp.phase;
 748                 if (p & SR_IO) {
 749                         udelay(10);
 750                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
 751                              (BASR_PHASE_MATCH | BASR_ACK)) ==
 752                             (BASR_PHASE_MATCH | BASR_ACK)) {
 753                                 saved_data = NCR5380_read(INPUT_DATA_REG);
 754                                 overrun = 1;
 755                                 dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
 756                         }
 757                 }
 758         }
 759
 760 #ifdef CONFIG_SUN3
 761         if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
 762                 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
 763                        instance->host_no);
 764                 BUG();
 765         }
 766
 767         if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
 768             (BASR_PHASE_MATCH | BASR_ACK)) {
 769                 pr_err("scsi%d: BASR %02x\n", instance->host_no,
 770                        NCR5380_read(BUS_AND_STATUS_REG));
 771                 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
 772                        instance->host_no);
 773                 BUG();
 774         }
 775 #endif
 776
 777         NCR5380_write(MODE_REG, MR_BASE);
 778         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 779         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 780
 781         transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
 782         hostdata->dma_len = 0;
 783
 784         data = (unsigned char **)&hostdata->connected->SCp.ptr;
 785         count = &hostdata->connected->SCp.this_residual;
 786         *data += transferred;
 787         *count -= transferred;
 788
 789         if (hostdata->read_overruns) {
 790                 int cnt, toPIO;
 791
 792                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
 793                         cnt = toPIO = hostdata->read_overruns;
 794                         if (overrun) {
 795                                 dsprintk(NDEBUG_DMA, instance,
 796                                          "Got an input overrun, using saved byte\n");
 797                                 *(*data)++ = saved_data;
 798                                 (*count)--;
 799                                 cnt--;
 800                                 toPIO--;
 801                         }
 802                         if (toPIO > 0) {
 803                                 dsprintk(NDEBUG_DMA, instance,
 804                                          "Doing %d byte PIO to 0x%p\n", cnt, *data);
 805                                 NCR5380_transfer_pio(instance, &p, &cnt, data);
 806                                 *count -= toPIO - cnt;
 807                         }
 808                 }
 809         }
 810 }
 811
 812 /**
 813  * NCR5380_intr - generic NCR5380 irq handler
 814  * @irq: interrupt number
 815  * @dev_id: device info
 816  *
 817  * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 818  * from the disconnected queue, and restarting NCR5380_main()
 819  * as required.
 820  *
 821  * The chip can assert IRQ in any of six different conditions. The IRQ flag
 822  * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
 823  * Three of these six conditions are latched in the Bus and Status Register:
 824  * - End of DMA (cleared by ending DMA Mode)
 825  * - Parity error (cleared by reading RPIR)
 826  * - Loss of BSY (cleared by reading RPIR)
 827  * Two conditions have flag bits that are not latched:
 828  * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
 829  * - Bus reset (non-maskable)
 830  * The remaining condition has no flag bit at all:
 831  * - Selection/reselection
 832  *
 833  * Hence, establishing the cause(s) of any interrupt is partly guesswork.
 834  * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
 835  * claimed that "the design of the [DP8490] interrupt logic ensures
 836  * interrupts will not be lost (they can be on the DP5380)."
 837  * The L5380/53C80 datasheet from LOGIC Devices has more details.
 838  *
 839  * Checking for bus reset by reading RST is futile because of interrupt
 840  * latency, but a bus reset will reset chip logic. Checking for parity error
 841  * is unnecessary because that interrupt is never enabled. A Loss of BSY
 842  * condition will clear DMA Mode. We can tell when this occurs because the
 843  * the Busy Monitor interrupt is enabled together with DMA Mode.
 844  */
 845
 846 static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
 847 {
 848         struct Scsi_Host *instance = dev_id;
 849         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 850         int handled = 0;
 851         unsigned char basr;
 852         unsigned long flags;
 853
 854         spin_lock_irqsave(&hostdata->lock, flags);
 855
 856         basr = NCR5380_read(BUS_AND_STATUS_REG);
 857         if (basr & BASR_IRQ) {
 858                 unsigned char mr = NCR5380_read(MODE_REG);
 859                 unsigned char sr = NCR5380_read(STATUS_REG);
 860
 861                 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
 862                          irq, basr, sr, mr);
 863
 864                 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
 865                         /* Probably End of DMA, Phase Mismatch or Loss of BSY.
 866                          * We ack IRQ after clearing Mode Register. Workarounds
 867                          * for End of DMA errata need to happen in DMA Mode.
 868                          */
 869
 870                         dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
 871
 872                         if (hostdata->connected) {
 873                                 NCR5380_dma_complete(instance);
 874                                 queue_work(hostdata->work_q, &hostdata->main_task);
 875                         } else {
 876                                 NCR5380_write(MODE_REG, MR_BASE);
 877                                 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 878                         }
 879                 } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
 880                     (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
 881                         /* Probably reselected */
 882                         NCR5380_write(SELECT_ENABLE_REG, 0);
 883                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 884
 885                         dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
 886
 887                         if (!hostdata->connected) {
 888                                 NCR5380_reselect(instance);
 889                                 queue_work(hostdata->work_q, &hostdata->main_task);
 890                         }
 891                         if (!hostdata->connected)
 892                                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 893                 } else {
 894                         /* Probably Bus Reset */
 895                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 896
 897                         if (sr & SR_RST) {
 898                                 /* Certainly Bus Reset */
 899                                 shost_printk(KERN_WARNING, instance,
 900                                              "bus reset interrupt\n");
 901                                 bus_reset_cleanup(instance);
 902                         } else {
 903                                 dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
 904                         }
 905 #ifdef SUN3_SCSI_VME
 906                         dregs->csr |= CSR_DMA_ENABLE;
 907 #endif
 908                 }
 909                 handled = 1;
 910         } else {
 911                 dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
 912 #ifdef SUN3_SCSI_VME
 913                 dregs->csr |= CSR_DMA_ENABLE;
 914 #endif
 915         }
 916
 917         spin_unlock_irqrestore(&hostdata->lock, flags);
 918
 919         return IRQ_RETVAL(handled);
 920 }
 921
 922 /**
 923  * NCR5380_select - attempt arbitration and selection for a given command
 924  * @instance: the Scsi_Host instance
 925  * @cmd: the scsi_cmnd to execute
 926  *
 927  * This routine establishes an I_T_L nexus for a SCSI command. This involves
 928  * ARBITRATION, SELECTION and MESSAGE OUT phases and an IDENTIFY message.
 929  *
 930  * Returns true if the operation should be retried.
 931  * Returns false if it should not be retried.
 932  *
 933  * Side effects :
 934  * If bus busy, arbitration failed, etc, NCR5380_select() will exit
 935  * with registers as they should have been on entry - ie
 936  * SELECT_ENABLE will be set appropriately, the NCR5380
 937  * will cease to drive any SCSI bus signals.
 938  *
 939  * If successful : the I_T_L nexus will be established, and
 940  * hostdata->connected will be set to cmd.
 941  * SELECT interrupt will be disabled.
 942  *
 943  * If failed (no target) : cmd->scsi_done() will be called, and the
 944  * cmd->result host byte set to DID_BAD_TARGET.
 945  */
 946
 947 static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 948         __releases(&hostdata->lock) __acquires(&hostdata->lock)
 949 {
 950         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 951         unsigned char tmp[3], phase;
 952         unsigned char *data;
 953         int len;
 954         int err;
 955         bool ret = true;
 956         bool can_disconnect = instance->irq != NO_IRQ &&
 957                               cmd->cmnd[0] != REQUEST_SENSE;
 958
 959         NCR5380_dprint(NDEBUG_ARBITRATION, instance);
 960         dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
 961                  instance->this_id);
 962
 963         /*
 964          * Arbitration and selection phases are slow and involve dropping the
 965          * lock, so we have to watch out for EH. An exception handler may
 966          * change 'selecting' to NULL. This function will then return false
 967          * so that the caller will forget about 'cmd'. (During information
 968          * transfer phases, EH may change 'connected' to NULL.)
 969          */
 970         hostdata->selecting = cmd;
 971
 972         /*
 973          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
 974          * data bus during SELECTION.
 975          */
 976
 977         NCR5380_write(TARGET_COMMAND_REG, 0);
 978
 979         /*
 980          * Start arbitration.
 981          */
 982
 983         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
 984         NCR5380_write(MODE_REG, MR_ARBITRATE);
 985
 986         /* The chip now waits for BUS FREE phase. Then after the 800 ns
 987          * Bus Free Delay, arbitration will begin.
 988          */
 989
 990         spin_unlock_irq(&hostdata->lock);
 991         err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
 992                         INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
 993                                                ICR_ARBITRATION_PROGRESS, HZ);
 994         spin_lock_irq(&hostdata->lock);
 995         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
 996                 /* Reselection interrupt */
 997                 goto out;
 998         }
 999         if (!hostdata->selecting) {
1000                 /* Command was aborted */
1001                 NCR5380_write(MODE_REG, MR_BASE);
1002                 return false;
1003         }
1004         if (err < 0) {
1005                 NCR5380_write(MODE_REG, MR_BASE);
1006                 shost_printk(KERN_ERR, instance,
1007                              "select: arbitration timeout\n");
1008                 goto out;
1009         }
1010         spin_unlock_irq(&hostdata->lock);
1011
1012         /* The SCSI-2 arbitration delay is 2.4 us */
1013         udelay(3);
1014
1015         /* Check for lost arbitration */
1016         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1017             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1018             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1019                 NCR5380_write(MODE_REG, MR_BASE);
1020                 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1021                 spin_lock_irq(&hostdata->lock);
1022                 goto out;
1023         }
1024
1025         /* After/during arbitration, BSY should be asserted.
1026          * IBM DPES-31080 Version S31Q works now
1027          * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1028          */
1029         NCR5380_write(INITIATOR_COMMAND_REG,
1030                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1031
1032         /*
1033          * Again, bus clear + bus settle time is 1.2us, however, this is
1034          * a minimum so we'll udelay ceil(1.2)
1035          */
1036
1037         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1038                 udelay(15);
1039         else
1040                 udelay(2);
1041
1042         spin_lock_irq(&hostdata->lock);
1043
1044         /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1045         if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1046                 goto out;
1047
1048         if (!hostdata->selecting) {
1049                 NCR5380_write(MODE_REG, MR_BASE);
1050                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1051                 return false;
1052         }
1053
1054         dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1055
1056         /*
1057          * Now that we have won arbitration, start Selection process, asserting
1058          * the host and target ID's on the SCSI bus.
1059          */
1060
1061         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1062
1063         /*
1064          * Raise ATN while SEL is true before BSY goes false from arbitration,
1065          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1066          * phase immediately after selection.
1067          */
1068
1069         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1070                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1071         NCR5380_write(MODE_REG, MR_BASE);
1072
1073         /*
1074          * Reselect interrupts must be turned off prior to the dropping of BSY,
1075          * otherwise we will trigger an interrupt.
1076          */
1077         NCR5380_write(SELECT_ENABLE_REG, 0);
1078
1079         spin_unlock_irq(&hostdata->lock);
1080
1081         /*
1082          * The initiator shall then wait at least two deskew delays and release
1083          * the BSY signal.
1084          */
1085         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1086
1087         /* Reset BSY */
1088         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1089                       ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1090
1091         /*
1092          * Something weird happens when we cease to drive BSY - looks
1093          * like the board/chip is letting us do another read before the
1094          * appropriate propagation delay has expired, and we're confusing
1095          * a BSY signal from ourselves as the target's response to SELECTION.
1096          *
1097          * A small delay (the 'C++' frontend breaks the pipeline with an
1098          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1099          * tighter 'C' code breaks and requires this) solves the problem -
1100          * the 1 us delay is arbitrary, and only used because this delay will
1101          * be the same on other platforms and since it works here, it should
1102          * work there.
1103          *
1104          * wingel suggests that this could be due to failing to wait
1105          * one deskew delay.
1106          */
1107
1108         udelay(1);
1109
1110         dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1111
1112         /*
1113          * The SCSI specification calls for a 250 ms timeout for the actual
1114          * selection.
1115          */
1116
1117         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
1118                                     msecs_to_jiffies(250));
1119
1120         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1121                 spin_lock_irq(&hostdata->lock);
1122                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1123                 NCR5380_reselect(instance);
1124                 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1125                 goto out;
1126         }
1127
1128         if (err < 0) {
1129                 spin_lock_irq(&hostdata->lock);
1130                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1131
1132                 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1133                 if (!hostdata->selecting)
1134                         return false;
1135
1136                 cmd->result = DID_BAD_TARGET << 16;
1137                 complete_cmd(instance, cmd);
1138                 dsprintk(NDEBUG_SELECTION, instance,
1139                         "target did not respond within 250ms\n");
1140                 ret = false;
1141                 goto out;
1142         }
1143
1144         /*
1145          * No less than two deskew delays after the initiator detects the
1146          * BSY signal is true, it shall release the SEL signal and may
1147          * change the DATA BUS.                                     -wingel
1148          */
1149
1150         udelay(1);
1151
1152         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1153
1154         /*
1155          * Since we followed the SCSI spec, and raised ATN while SEL
1156          * was true but before BSY was false during selection, the information
1157          * transfer phase should be a MESSAGE OUT phase so that we can send the
1158          * IDENTIFY message.
1159          */
1160
1161         /* Wait for start of REQ/ACK handshake */
1162
1163         err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1164         spin_lock_irq(&hostdata->lock);
1165         if (err < 0) {
1166                 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1167                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1168                 goto out;
1169         }
1170         if (!hostdata->selecting) {
1171                 do_abort(instance);
1172                 return false;
1173         }
1174
1175         dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1176                  scmd_id(cmd));
1177         tmp[0] = IDENTIFY(can_disconnect, cmd->device->lun);
1178
1179         len = 1;
1180         data = tmp;
1181         phase = PHASE_MSGOUT;
1182         NCR5380_transfer_pio(instance, &phase, &len, &data);
1183         if (len) {
1184                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1185                 cmd->result = DID_ERROR << 16;
1186                 complete_cmd(instance, cmd);
1187                 dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
1188                 ret = false;
1189                 goto out;
1190         }
1191
1192         dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1193
1194         hostdata->connected = cmd;
1195         hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1196
1197 #ifdef SUN3_SCSI_VME
1198         dregs->csr |= CSR_INTR;
1199 #endif
1200
1201         initialize_SCp(cmd);
1202
1203         ret = false;
1204
1205 out:
1206         if (!hostdata->selecting)
1207                 return false;
1208         hostdata->selecting = NULL;
1209         return ret;
1210 }
1211
1212 /*
1213  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1214  * unsigned char *phase, int *count, unsigned char **data)
1215  *
1216  * Purpose : transfers data in given phase using polled I/O
1217  *
1218  * Inputs : instance - instance of driver, *phase - pointer to
1219  * what phase is expected, *count - pointer to number of
1220  * bytes to transfer, **data - pointer to data pointer.
1221  *
1222  * Returns : -1 when different phase is entered without transferring
1223  * maximum number of bytes, 0 if all bytes are transferred or exit
1224  * is in same phase.
1225  *
1226  * Also, *phase, *count, *data are modified in place.
1227  *
1228  * XXX Note : handling for bus free may be useful.
1229  */
1230
1231 /*
1232  * Note : this code is not as quick as it could be, however it
1233  * IS 100% reliable, and for the actual data transfer where speed
1234  * counts, we will always do a pseudo DMA or DMA transfer.
1235  */
1236
1237 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1238                                 unsigned char *phase, int *count,
1239                                 unsigned char **data)
1240 {
1241         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1242         unsigned char p = *phase, tmp;
1243         int c = *count;
1244         unsigned char *d = *data;
1245
1246         /*
1247          * The NCR5380 chip will only drive the SCSI bus when the
1248          * phase specified in the appropriate bits of the TARGET COMMAND
1249          * REGISTER match the STATUS REGISTER
1250          */
1251
1252         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1253
1254         do {
1255                 /*
1256                  * Wait for assertion of REQ, after which the phase bits will be
1257                  * valid
1258                  */
1259
1260                 if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1261                         break;
1262
1263                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1264
1265                 /* Check for phase mismatch */
1266                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1267                         dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1268                         NCR5380_dprint_phase(NDEBUG_PIO, instance);
1269                         break;
1270                 }
1271
1272                 /* Do actual transfer from SCSI bus to / from memory */
1273                 if (!(p & SR_IO))
1274                         NCR5380_write(OUTPUT_DATA_REG, *d);
1275                 else
1276                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1277
1278                 ++d;
1279
1280                 /*
1281                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1282                  * should drop ATN on the last byte of the message phase
1283                  * after REQ has been asserted for the handshake but before
1284                  * the initiator raises ACK.
1285                  */
1286
1287                 if (!(p & SR_IO)) {
1288                         if (!((p & SR_MSG) && c > 1)) {
1289                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1290                                 NCR5380_dprint(NDEBUG_PIO, instance);
1291                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1292                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1293                         } else {
1294                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1295                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1296                                 NCR5380_dprint(NDEBUG_PIO, instance);
1297                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1298                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1299                         }
1300                 } else {
1301                         NCR5380_dprint(NDEBUG_PIO, instance);
1302                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1303                 }
1304
1305                 if (NCR5380_poll_politely(hostdata,
1306                                           STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1307                         break;
1308
1309                 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1310
1311 /*
1312  * We have several special cases to consider during REQ/ACK handshaking :
1313  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1314  * message.  ATN must be dropped as ACK is dropped.
1315  *
1316  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1317  * message.  We must exit with ACK asserted, so that the calling
1318  * code may raise ATN before dropping ACK to reject the message.
1319  *
1320  * 3.  ACK and ATN are clear and the target may proceed as normal.
1321  */
1322                 if (!(p == PHASE_MSGIN && c == 1)) {
1323                         if (p == PHASE_MSGOUT && c > 1)
1324                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1325                         else
1326                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1327                 }
1328         } while (--c);
1329
1330         dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1331
1332         *count = c;
1333         *data = d;
1334         tmp = NCR5380_read(STATUS_REG);
1335         /* The phase read from the bus is valid if either REQ is (already)
1336          * asserted or if ACK hasn't been released yet. The latter applies if
1337          * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1338          */
1339         if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1340                 *phase = tmp & PHASE_MASK;
1341         else
1342                 *phase = PHASE_UNKNOWN;
1343
1344         if (!c || (*phase == p))
1345                 return 0;
1346         else
1347                 return -1;
1348 }
1349
1350 /**
1351  * do_reset - issue a reset command
1352  * @instance: adapter to reset
1353  *
1354  * Issue a reset sequence to the NCR5380 and try and get the bus
1355  * back into sane shape.
1356  *
1357  * This clears the reset interrupt flag because there may be no handler for
1358  * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1359  * been installed. And when in EH we may have released the ST DMA interrupt.
1360  */
1361
1362 static void do_reset(struct Scsi_Host *instance)
1363 {
1364         struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
1365         unsigned long flags;
1366
1367         local_irq_save(flags);
1368         NCR5380_write(TARGET_COMMAND_REG,
1369                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1370         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1371         udelay(50);
1372         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1373         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1374         local_irq_restore(flags);
1375 }
1376
1377 /**
1378  * do_abort - abort the currently established nexus by going to
1379  * MESSAGE OUT phase and sending an ABORT message.
1380  * @instance: relevant scsi host instance
1381  *
1382  * Returns 0 on success, -1 on failure.
1383  */
1384
1385 static int do_abort(struct Scsi_Host *instance)
1386 {
1387         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1388         unsigned char *msgptr, phase, tmp;
1389         int len;
1390         int rc;
1391
1392         /* Request message out phase */
1393         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1394
1395         /*
1396          * Wait for the target to indicate a valid phase by asserting
1397          * REQ.  Once this happens, we'll have either a MSGOUT phase
1398          * and can immediately send the ABORT message, or we'll have some
1399          * other phase and will have to source/sink data.
1400          *
1401          * We really don't care what value was on the bus or what value
1402          * the target sees, so we just handshake.
1403          */
1404
1405         rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1406         if (rc < 0)
1407                 goto timeout;
1408
1409         tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1410
1411         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1412
1413         if (tmp != PHASE_MSGOUT) {
1414                 NCR5380_write(INITIATOR_COMMAND_REG,
1415                               ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1416                 rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
1417                 if (rc < 0)
1418                         goto timeout;
1419                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1420         }
1421
1422         tmp = ABORT;
1423         msgptr = &tmp;
1424         len = 1;
1425         phase = PHASE_MSGOUT;
1426         NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1427
1428         /*
1429          * If we got here, and the command completed successfully,
1430          * we're about to go into bus free state.
1431          */
1432
1433         return len ? -1 : 0;
1434
1435 timeout:
1436         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1437         return -1;
1438 }
1439
1440 /*
1441  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1442  * unsigned char *phase, int *count, unsigned char **data)
1443  *
1444  * Purpose : transfers data in given phase using either real
1445  * or pseudo DMA.
1446  *
1447  * Inputs : instance - instance of driver, *phase - pointer to
1448  * what phase is expected, *count - pointer to number of
1449  * bytes to transfer, **data - pointer to data pointer.
1450  *
1451  * Returns : -1 when different phase is entered without transferring
1452  * maximum number of bytes, 0 if all bytes or transferred or exit
1453  * is in same phase.
1454  *
1455  * Also, *phase, *count, *data are modified in place.
1456  */
1457
1458
1459 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1460                                 unsigned char *phase, int *count,
1461                                 unsigned char **data)
1462 {
1463         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1464         int c = *count;
1465         unsigned char p = *phase;
1466         unsigned char *d = *data;
1467         unsigned char tmp;
1468         int result = 0;
1469
1470         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1471                 *phase = tmp;
1472                 return -1;
1473         }
1474
1475         hostdata->connected->SCp.phase = p;
1476
1477         if (p & SR_IO) {
1478                 if (hostdata->read_overruns)
1479                         c -= hostdata->read_overruns;
1480                 else if (hostdata->flags & FLAG_DMA_FIXUP)
1481                         --c;
1482         }
1483
1484         dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1485                  (p & SR_IO) ? "receive" : "send", c, d);
1486
1487 #ifdef CONFIG_SUN3
1488         /* send start chain */
1489         sun3scsi_dma_start(c, *data);
1490 #endif
1491
1492         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1493         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1494                                 MR_ENABLE_EOP_INTR);
1495
1496         if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1497                 /* On the Medusa, it is a must to initialize the DMA before
1498                  * starting the NCR. This is also the cleaner way for the TT.
1499                  */
1500                 if (p & SR_IO)
1501                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1502                 else
1503                         result = NCR5380_dma_send_setup(hostdata, d, c);
1504         }
1505
1506         /*
1507          * On the PAS16 at least I/O recovery delays are not needed here.
1508          * Everyone else seems to want them.
1509          */
1510
1511         if (p & SR_IO) {
1512                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1513                 NCR5380_io_delay(1);
1514                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1515         } else {
1516                 NCR5380_io_delay(1);
1517                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1518                 NCR5380_io_delay(1);
1519                 NCR5380_write(START_DMA_SEND_REG, 0);
1520                 NCR5380_io_delay(1);
1521         }
1522
1523 #ifdef CONFIG_SUN3
1524 #ifdef SUN3_SCSI_VME
1525         dregs->csr |= CSR_DMA_ENABLE;
1526 #endif
1527         sun3_dma_active = 1;
1528 #endif
1529
1530         if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1531                 /* On the Falcon, the DMA setup must be done after the last
1532                  * NCR access, else the DMA setup gets trashed!
1533                  */
1534                 if (p & SR_IO)
1535                         result = NCR5380_dma_recv_setup(hostdata, d, c);
1536                 else
1537                         result = NCR5380_dma_send_setup(hostdata, d, c);
1538         }
1539
1540         /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
1541         if (result < 0)
1542                 return result;
1543
1544         /* For real DMA, result is the byte count. DMA interrupt is expected. */
1545         if (result > 0) {
1546                 hostdata->dma_len = result;
1547                 return 0;
1548         }
1549
1550         /* The result is zero iff pseudo DMA send/receive was completed. */
1551         hostdata->dma_len = c;
1552
1553 /*
1554  * A note regarding the DMA errata workarounds for early NMOS silicon.
1555  *
1556  * For DMA sends, we want to wait until the last byte has been
1557  * transferred out over the bus before we turn off DMA mode.  Alas, there
1558  * seems to be no terribly good way of doing this on a 5380 under all
1559  * conditions.  For non-scatter-gather operations, we can wait until REQ
1560  * and ACK both go false, or until a phase mismatch occurs.  Gather-sends
1561  * are nastier, since the device will be expecting more data than we
1562  * are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1563  * could test Last Byte Sent to assure transfer (I imagine this is precisely
1564  * why this signal was added to the newer chips) but on the older 538[01]
1565  * this signal does not exist.  The workaround for this lack is a watchdog;
1566  * we bail out of the wait-loop after a modest amount of wait-time if
1567  * the usual exit conditions are not met.  Not a terribly clean or
1568  * correct solution :-%
1569  *
1570  * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1571  * If the chip is in DMA receive mode, it will respond to a target's
1572  * REQ by latching the SCSI data into the INPUT DATA register and asserting
1573  * ACK, even if it has _already_ been notified by the DMA controller that
1574  * the current DMA transfer has completed!  If the NCR5380 is then taken
1575  * out of DMA mode, this already-acknowledged byte is lost. This is
1576  * not a problem for "one DMA transfer per READ command", because
1577  * the situation will never arise... either all of the data is DMA'ed
1578  * properly, or the target switches to MESSAGE IN phase to signal a
1579  * disconnection (either operation bringing the DMA to a clean halt).
1580  * However, in order to handle scatter-receive, we must work around the
1581  * problem.  The chosen fix is to DMA fewer bytes, then check for the
1582  * condition before taking the NCR5380 out of DMA mode.  One or two extra
1583  * bytes are transferred via PIO as necessary to fill out the original
1584  * request.
1585  */
1586
1587         if (hostdata->flags & FLAG_DMA_FIXUP) {
1588                 if (p & SR_IO) {
1589                         /*
1590                          * The workaround was to transfer fewer bytes than we
1591                          * intended to with the pseudo-DMA read function, wait for
1592                          * the chip to latch the last byte, read it, and then disable
1593                          * pseudo-DMA mode.
1594                          *
1595                          * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1596                          * REQ is deasserted when ACK is asserted, and not reasserted
1597                          * until ACK goes false.  Since the NCR5380 won't lower ACK
1598                          * until DACK is asserted, which won't happen unless we twiddle
1599                          * the DMA port or we take the NCR5380 out of DMA mode, we
1600                          * can guarantee that we won't handshake another extra
1601                          * byte.
1602                          */
1603
1604                         if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
1605                                                   BASR_DRQ, BASR_DRQ, HZ) < 0) {
1606                                 result = -1;
1607                                 shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1608                         }
1609                         if (NCR5380_poll_politely(hostdata, STATUS_REG,
1610                                                   SR_REQ, 0, HZ) < 0) {
1611                                 result = -1;
1612                                 shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1613                         }
1614                         d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
1615                 } else {
1616                         /*
1617                          * Wait for the last byte to be sent.  If REQ is being asserted for
1618                          * the byte we're interested, we'll ACK it and it will go false.
1619                          */
1620                         if (NCR5380_poll_politely2(hostdata,
1621                              BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1622                              BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
1623                                 result = -1;
1624                                 shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1625                         }
1626                 }
1627         }
1628
1629         NCR5380_dma_complete(instance);
1630         return result;
1631 }
1632
1633 /*
1634  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1635  *
1636  * Purpose : run through the various SCSI phases and do as the target
1637  * directs us to.  Operates on the currently connected command,
1638  * instance->connected.
1639  *
1640  * Inputs : instance, instance for which we are doing commands
1641  *
1642  * Side effects : SCSI things happen, the disconnected queue will be
1643  * modified if a command disconnects, *instance->connected will
1644  * change.
1645  *
1646  * XXX Note : we need to watch for bus free or a reset condition here
1647  * to recover from an unexpected bus free condition.
1648  */
1649
1650 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1651         __releases(&hostdata->lock) __acquires(&hostdata->lock)
1652 {
1653         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1654         unsigned char msgout = NOP;
1655         int sink = 0;
1656         int len;
1657         int transfersize;
1658         unsigned char *data;
1659         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1660         struct scsi_cmnd *cmd;
1661
1662 #ifdef SUN3_SCSI_VME
1663         dregs->csr |= CSR_INTR;
1664 #endif
1665
1666         while ((cmd = hostdata->connected)) {
1667                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1668
1669                 tmp = NCR5380_read(STATUS_REG);
1670                 /* We only have a valid SCSI phase when REQ is asserted */
1671                 if (tmp & SR_REQ) {
1672                         phase = (tmp & PHASE_MASK);
1673                         if (phase != old_phase) {
1674                                 old_phase = phase;
1675                                 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1676                         }
1677 #ifdef CONFIG_SUN3
1678                         if (phase == PHASE_CMDOUT &&
1679                             sun3_dma_setup_done != cmd) {
1680                                 int count;
1681
1682                                 advance_sg_buffer(cmd);
1683
1684                                 count = sun3scsi_dma_xfer_len(hostdata, cmd);
1685
1686                                 if (count > 0) {
1687                                         if (rq_data_dir(cmd->request))
1688                                                 sun3scsi_dma_send_setup(hostdata,
1689                                                                         cmd->SCp.ptr, count);
1690                                         else
1691                                                 sun3scsi_dma_recv_setup(hostdata,
1692                                                                         cmd->SCp.ptr, count);
1693                                         sun3_dma_setup_done = cmd;
1694                                 }
1695 #ifdef SUN3_SCSI_VME
1696                                 dregs->csr |= CSR_INTR;
1697 #endif
1698                         }
1699 #endif /* CONFIG_SUN3 */
1700
1701                         if (sink && (phase != PHASE_MSGOUT)) {
1702                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1703
1704                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1705                                               ICR_ASSERT_ACK);
1706                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1707                                         ;
1708                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1709                                               ICR_ASSERT_ATN);
1710                                 sink = 0;
1711                                 continue;
1712                         }
1713
1714                         switch (phase) {
1715                         case PHASE_DATAOUT:
1716 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1717                                 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1718                                 sink = 1;
1719                                 do_abort(instance);
1720                                 cmd->result = DID_ERROR << 16;
1721                                 complete_cmd(instance, cmd);
1722                                 hostdata->connected = NULL;
1723                                 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1724                                 return;
1725 #endif
1726                         case PHASE_DATAIN:
1727                                 /*
1728                                  * If there is no room left in the current buffer in the
1729                                  * scatter-gather list, move onto the next one.
1730                                  */
1731
1732                                 advance_sg_buffer(cmd);
1733                                 dsprintk(NDEBUG_INFORMATION, instance,
1734                                         "this residual %d, sg ents %d\n",
1735                                         cmd->SCp.this_residual,
1736                                         sg_nents(cmd->SCp.buffer));
1737
1738                                 /*
1739                                  * The preferred transfer method is going to be
1740                                  * PSEUDO-DMA for systems that are strictly PIO,
1741                                  * since we can let the hardware do the handshaking.
1742                                  *
1743                                  * For this to work, we need to know the transfersize
1744                                  * ahead of time, since the pseudo-DMA code will sit
1745                                  * in an unconditional loop.
1746                                  */
1747
1748                                 transfersize = 0;
1749                                 if (!cmd->device->borken)
1750                                         transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
1751
1752                                 if (transfersize > 0) {
1753                                         len = transfersize;
1754                                         if (NCR5380_transfer_dma(instance, &phase,
1755                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
1756                                                 /*
1757                                                  * If the watchdog timer fires, all future
1758                                                  * accesses to this device will use the
1759                                                  * polled-IO.
1760                                                  */
1761                                                 scmd_printk(KERN_INFO, cmd,
1762                                                         "switching to slow handshake\n");
1763                                                 cmd->device->borken = 1;
1764                                                 do_reset(instance);
1765                                                 bus_reset_cleanup(instance);
1766                                         }
1767                                 } else {
1768                                         /* Transfer a small chunk so that the
1769                                          * irq mode lock is not held too long.
1770                                          */
1771                                         transfersize = min(cmd->SCp.this_residual,
1772                                                            NCR5380_PIO_CHUNK_SIZE);
1773                                         len = transfersize;
1774                                         NCR5380_transfer_pio(instance, &phase, &len,
1775                                                              (unsigned char **)&cmd->SCp.ptr);
1776                                         cmd->SCp.this_residual -= transfersize - len;
1777                                 }
1778 #ifdef CONFIG_SUN3
1779                                 if (sun3_dma_setup_done == cmd)
1780                                         sun3_dma_setup_done = NULL;
1781 #endif
1782                                 return;
1783                         case PHASE_MSGIN:
1784                                 len = 1;
1785                                 data = &tmp;
1786                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1787                                 cmd->SCp.Message = tmp;
1788
1789                                 switch (tmp) {
1790                                 case ABORT:
1791                                 case COMMAND_COMPLETE:
1792                                         /* Accept message by clearing ACK */
1793                                         sink = 1;
1794                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1795                                         dsprintk(NDEBUG_QUEUES, instance,
1796                                                  "COMMAND COMPLETE %p target %d lun %llu\n",
1797                                                  cmd, scmd_id(cmd), cmd->device->lun);
1798
1799                                         hostdata->connected = NULL;
1800                                         hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1801
1802                                         cmd->result &= ~0xffff;
1803                                         cmd->result |= cmd->SCp.Status;
1804                                         cmd->result |= cmd->SCp.Message << 8;
1805
1806                                         if (cmd->cmnd[0] == REQUEST_SENSE)
1807                                                 complete_cmd(instance, cmd);
1808                                         else {
1809                                                 if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1810                                                     cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1811                                                         dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1812                                                                  cmd);
1813                                                         list_add_tail(&ncmd->list,
1814                                                                       &hostdata->autosense);
1815                                                 } else
1816                                                         complete_cmd(instance, cmd);
1817                                         }
1818
1819                                         /*
1820                                          * Restore phase bits to 0 so an interrupted selection,
1821                                          * arbitration can resume.
1822                                          */
1823                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1824
1825                                         maybe_release_dma_irq(instance);
1826                                         return;
1827                                 case MESSAGE_REJECT:
1828                                         /* Accept message by clearing ACK */
1829                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1830                                         switch (hostdata->last_message) {
1831                                         case HEAD_OF_QUEUE_TAG:
1832                                         case ORDERED_QUEUE_TAG:
1833                                         case SIMPLE_QUEUE_TAG:
1834                                                 cmd->device->simple_tags = 0;
1835                                                 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1836                                                 break;
1837                                         default:
1838                                                 break;
1839                                         }
1840                                         break;
1841                                 case DISCONNECT:
1842                                         /* Accept message by clearing ACK */
1843                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1844                                         hostdata->connected = NULL;
1845                                         list_add(&ncmd->list, &hostdata->disconnected);
1846                                         dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1847                                                  instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1848                                                  cmd, scmd_id(cmd), cmd->device->lun);
1849
1850                                         /*
1851                                          * Restore phase bits to 0 so an interrupted selection,
1852                                          * arbitration can resume.
1853                                          */
1854                                         NCR5380_write(TARGET_COMMAND_REG, 0);
1855
1856 #ifdef SUN3_SCSI_VME
1857                                         dregs->csr |= CSR_DMA_ENABLE;
1858 #endif
1859                                         return;
1860                                         /*
1861                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1862                                          * operation, in violation of the SCSI spec so we can safely
1863                                          * ignore SAVE/RESTORE pointers calls.
1864                                          *
1865                                          * Unfortunately, some disks violate the SCSI spec and
1866                                          * don't issue the required SAVE_POINTERS message before
1867                                          * disconnecting, and we have to break spec to remain
1868                                          * compatible.
1869                                          */
1870                                 case SAVE_POINTERS:
1871                                 case RESTORE_POINTERS:
1872                                         /* Accept message by clearing ACK */
1873                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1874                                         break;
1875                                 case EXTENDED_MESSAGE:
1876                                         /*
1877                                          * Start the message buffer with the EXTENDED_MESSAGE
1878                                          * byte, since spi_print_msg() wants the whole thing.
1879                                          */
1880                                         extended_msg[0] = EXTENDED_MESSAGE;
1881                                         /* Accept first byte by clearing ACK */
1882                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1883
1884                                         spin_unlock_irq(&hostdata->lock);
1885
1886                                         dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1887
1888                                         len = 2;
1889                                         data = extended_msg + 1;
1890                                         phase = PHASE_MSGIN;
1891                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
1892                                         dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1893                                                  (int)extended_msg[1],
1894                                                  (int)extended_msg[2]);
1895
1896                                         if (!len && extended_msg[1] > 0 &&
1897                                             extended_msg[1] <= sizeof(extended_msg) - 2) {
1898                                                 /* Accept third byte by clearing ACK */
1899                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1900                                                 len = extended_msg[1] - 1;
1901                                                 data = extended_msg + 3;
1902                                                 phase = PHASE_MSGIN;
1903
1904                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1905                                                 dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
1906                                                          len);
1907
1908                                                 switch (extended_msg[2]) {
1909                                                 case EXTENDED_SDTR:
1910                                                 case EXTENDED_WDTR:
1911                                                         tmp = 0;
1912                                                 }
1913                                         } else if (len) {
1914                                                 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1915                                                 tmp = 0;
1916                                         } else {
1917                                                 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
1918                                                              extended_msg[2], extended_msg[1]);
1919                                                 tmp = 0;
1920                                         }
1921
1922                                         spin_lock_irq(&hostdata->lock);
1923                                         if (!hostdata->connected)
1924                                                 return;
1925
1926                                         /* Reject message */
1927                                         /* Fall through */
1928                                 default:
1929                                         /*
1930                                          * If we get something weird that we aren't expecting,
1931                                          * log it.
1932                                          */
1933                                         if (tmp == EXTENDED_MESSAGE)
1934                                                 scmd_printk(KERN_INFO, cmd,
1935                                                             "rejecting unknown extended message code %02x, length %d\n",
1936                                                             extended_msg[2], extended_msg[1]);
1937                                         else if (tmp)
1938                                                 scmd_printk(KERN_INFO, cmd,
1939                                                             "rejecting unknown message code %02x\n",
1940                                                             tmp);
1941
1942                                         msgout = MESSAGE_REJECT;
1943                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1944                                         break;
1945                                 } /* switch (tmp) */
1946                                 break;
1947                         case PHASE_MSGOUT:
1948                                 len = 1;
1949                                 data = &msgout;
1950                                 hostdata->last_message = msgout;
1951                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1952                                 if (msgout == ABORT) {
1953                                         hostdata->connected = NULL;
1954                                         hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1955                                         cmd->result = DID_ERROR << 16;
1956                                         complete_cmd(instance, cmd);
1957                                         maybe_release_dma_irq(instance);
1958                                         return;
1959                                 }
1960                                 msgout = NOP;
1961                                 break;
1962                         case PHASE_CMDOUT:
1963                                 len = cmd->cmd_len;
1964                                 data = cmd->cmnd;
1965                                 /*
1966                                  * XXX for performance reasons, on machines with a
1967                                  * PSEUDO-DMA architecture we should probably
1968                                  * use the dma transfer function.
1969                                  */
1970                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1971                                 break;
1972                         case PHASE_STATIN:
1973                                 len = 1;
1974                                 data = &tmp;
1975                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
1976                                 cmd->SCp.Status = tmp;
1977                                 break;
1978                         default:
1979                                 shost_printk(KERN_ERR, instance, "unknown phase\n");
1980                                 NCR5380_dprint(NDEBUG_ANY, instance);
1981                         } /* switch(phase) */
1982                 } else {
1983                         spin_unlock_irq(&hostdata->lock);
1984                         NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1985                         spin_lock_irq(&hostdata->lock);
1986                 }
1987         }
1988 }
1989
1990 /*
1991  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
1992  *
1993  * Purpose : does reselection, initializing the instance->connected
1994  * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
1995  * nexus has been reestablished,
1996  *
1997  * Inputs : instance - this instance of the NCR5380.
1998  */
1999
2000 static void NCR5380_reselect(struct Scsi_Host *instance)
2001 {
2002         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2003         unsigned char target_mask;
2004         unsigned char lun;
2005         unsigned char msg[3];
2006         struct NCR5380_cmd *ncmd;
2007         struct scsi_cmnd *tmp;
2008
2009         /*
2010          * Disable arbitration, etc. since the host adapter obviously
2011          * lost, and tell an interrupted NCR5380_select() to restart.
2012          */
2013
2014         NCR5380_write(MODE_REG, MR_BASE);
2015
2016         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2017         if (!target_mask || target_mask & (target_mask - 1)) {
2018                 shost_printk(KERN_WARNING, instance,
2019                              "reselect: bad target_mask 0x%02x\n", target_mask);
2020                 return;
2021         }
2022
2023         /*
2024          * At this point, we have detected that our SCSI ID is on the bus,
2025          * SEL is true and BSY was false for at least one bus settle delay
2026          * (400 ns).
2027          *
2028          * We must assert BSY ourselves, until the target drops the SEL
2029          * signal.
2030          */
2031
2032         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2033         if (NCR5380_poll_politely(hostdata,
2034                                   STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2035                 shost_printk(KERN_ERR, instance, "reselect: !SEL timeout\n");
2036                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2037                 return;
2038         }
2039         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2040
2041         /*
2042          * Wait for target to go into MSGIN.
2043          */
2044
2045         if (NCR5380_poll_politely(hostdata,
2046                                   STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2047                 if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
2048                         /* BUS FREE phase */
2049                         return;
2050                 shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
2051                 do_abort(instance);
2052                 return;
2053         }
2054
2055 #ifdef CONFIG_SUN3
2056         /* acknowledge toggle to MSGIN */
2057         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2058
2059         /* peek at the byte without really hitting the bus */
2060         msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2061 #else
2062         {
2063                 int len = 1;
2064                 unsigned char *data = msg;
2065                 unsigned char phase = PHASE_MSGIN;
2066
2067                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2068
2069                 if (len) {
2070                         do_abort(instance);
2071                         return;
2072                 }
2073         }
2074 #endif /* CONFIG_SUN3 */
2075
2076         if (!(msg[0] & 0x80)) {
2077                 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2078                 spi_print_msg(msg);
2079                 printk("\n");
2080                 do_abort(instance);
2081                 return;
2082         }
2083         lun = msg[0] & 0x07;
2084
2085         /*
2086          * We need to add code for SCSI-II to track which devices have
2087          * I_T_L_Q nexuses established, and which have simple I_T_L
2088          * nexuses so we can chose to do additional data transfer.
2089          */
2090
2091         /*
2092          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2093          * just reestablished, and remove it from the disconnected queue.
2094          */
2095
2096         tmp = NULL;
2097         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2098                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2099
2100                 if (target_mask == (1 << scmd_id(cmd)) &&
2101                     lun == (u8)cmd->device->lun) {
2102                         list_del(&ncmd->list);
2103                         tmp = cmd;
2104                         break;
2105                 }
2106         }
2107
2108         if (tmp) {
2109                 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2110                          "reselect: removed %p from disconnected queue\n", tmp);
2111         } else {
2112                 int target = ffs(target_mask) - 1;
2113
2114                 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2115                              target_mask, lun);
2116                 /*
2117                  * Since we have an established nexus that we can't do anything
2118                  * with, we must abort it.
2119                  */
2120                 if (do_abort(instance) == 0)
2121                         hostdata->busy[target] &= ~(1 << lun);
2122                 return;
2123         }
2124
2125 #ifdef CONFIG_SUN3
2126         if (sun3_dma_setup_done != tmp) {
2127                 int count;
2128
2129                 advance_sg_buffer(tmp);
2130
2131                 count = sun3scsi_dma_xfer_len(hostdata, tmp);
2132
2133                 if (count > 0) {
2134                         if (rq_data_dir(tmp->request))
2135                                 sun3scsi_dma_send_setup(hostdata,
2136                                                         tmp->SCp.ptr, count);
2137                         else
2138                                 sun3scsi_dma_recv_setup(hostdata,
2139                                                         tmp->SCp.ptr, count);
2140                         sun3_dma_setup_done = tmp;
2141                 }
2142         }
2143
2144         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2145 #endif /* CONFIG_SUN3 */
2146
2147         /* Accept message by clearing ACK */
2148         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2149
2150         hostdata->connected = tmp;
2151         dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
2152                  scmd_id(tmp), tmp->device->lun);
2153 }
2154
2155 /**
2156  * list_find_cmd - test for presence of a command in a linked list
2157  * @haystack: list of commands
2158  * @needle: command to search for
2159  */
2160
2161 static bool list_find_cmd(struct list_head *haystack,
2162                           struct scsi_cmnd *needle)
2163 {
2164         struct NCR5380_cmd *ncmd;
2165
2166         list_for_each_entry(ncmd, haystack, list)
2167                 if (NCR5380_to_scmd(ncmd) == needle)
2168                         return true;
2169         return false;
2170 }
2171
2172 /**
2173  * list_remove_cmd - remove a command from linked list
2174  * @haystack: list of commands
2175  * @needle: command to remove
2176  */
2177
2178 static bool list_del_cmd(struct list_head *haystack,
2179                          struct scsi_cmnd *needle)
2180 {
2181         if (list_find_cmd(haystack, needle)) {
2182                 struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2183
2184                 list_del(&ncmd->list);
2185                 return true;
2186         }
2187         return false;
2188 }
2189
2190 /**
2191  * NCR5380_abort - scsi host eh_abort_handler() method
2192  * @cmd: the command to be aborted
2193  *
2194  * Try to abort a given command by removing it from queues and/or sending
2195  * the target an abort message. This may not succeed in causing a target
2196  * to abort the command. Nonetheless, the low-level driver must forget about
2197  * the command because the mid-layer reclaims it and it may be re-issued.
2198  *
2199  * The normal path taken by a command is as follows. For EH we trace this
2200  * same path to locate and abort the command.
2201  *
2202  * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2203  * [disconnected -> connected ->]...
2204  * [autosense -> connected ->] done
2205  *
2206  * If cmd was not found at all then presumably it has already been completed,
2207  * in which case return SUCCESS to try to avoid further EH measures.
2208  *
2209  * If the command has not completed yet, we must not fail to find it.
2210  * We have no option but to forget the aborted command (even if it still
2211  * lacks sense data). The mid-layer may re-issue a command that is in error
2212  * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2213  * this driver are such that a command can appear on one queue only.
2214  *
2215  * The lock protects driver data structures, but EH handlers also use it
2216  * to serialize their own execution and prevent their own re-entry.
2217  */
2218
2219 static int NCR5380_abort(struct scsi_cmnd *cmd)
2220 {
2221         struct Scsi_Host *instance = cmd->device->host;
2222         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2223         unsigned long flags;
2224         int result = SUCCESS;
2225
2226         spin_lock_irqsave(&hostdata->lock, flags);
2227
2228 #if (NDEBUG & NDEBUG_ANY)
2229         scmd_printk(KERN_INFO, cmd, __func__);
2230 #endif
2231         NCR5380_dprint(NDEBUG_ANY, instance);
2232         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2233
2234         if (list_del_cmd(&hostdata->unissued, cmd)) {
2235                 dsprintk(NDEBUG_ABORT, instance,
2236                          "abort: removed %p from issue queue\n", cmd);
2237                 cmd->result = DID_ABORT << 16;
2238                 cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2239                 goto out;
2240         }
2241
2242         if (hostdata->selecting == cmd) {
2243                 dsprintk(NDEBUG_ABORT, instance,
2244                          "abort: cmd %p == selecting\n", cmd);
2245                 hostdata->selecting = NULL;
2246                 cmd->result = DID_ABORT << 16;
2247                 complete_cmd(instance, cmd);
2248                 goto out;
2249         }
2250
2251         if (list_del_cmd(&hostdata->disconnected, cmd)) {
2252                 dsprintk(NDEBUG_ABORT, instance,
2253                          "abort: removed %p from disconnected list\n", cmd);
2254                 /* Can't call NCR5380_select() and send ABORT because that
2255                  * means releasing the lock. Need a bus reset.
2256                  */
2257                 set_host_byte(cmd, DID_ERROR);
2258                 complete_cmd(instance, cmd);
2259                 result = FAILED;
2260                 goto out;
2261         }
2262
2263         if (hostdata->connected == cmd) {
2264                 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2265                 hostdata->connected = NULL;
2266                 hostdata->dma_len = 0;
2267                 if (do_abort(instance)) {
2268                         set_host_byte(cmd, DID_ERROR);
2269                         complete_cmd(instance, cmd);
2270                         result = FAILED;
2271                         goto out;
2272                 }
2273                 set_host_byte(cmd, DID_ABORT);
2274                 complete_cmd(instance, cmd);
2275                 goto out;
2276         }
2277
2278         if (list_del_cmd(&hostdata->autosense, cmd)) {
2279                 dsprintk(NDEBUG_ABORT, instance,
2280                          "abort: removed %p from sense queue\n", cmd);
2281                 complete_cmd(instance, cmd);
2282         }
2283
2284 out:
2285         if (result == FAILED)
2286                 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2287         else {
2288                 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
2289                 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2290         }
2291
2292         queue_work(hostdata->work_q, &hostdata->main_task);
2293         maybe_release_dma_irq(instance);
2294         spin_unlock_irqrestore(&hostdata->lock, flags);
2295
2296         return result;
2297 }
2298
2299
2300 static void bus_reset_cleanup(struct Scsi_Host *instance)
2301 {
2302         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2303         int i;
2304         struct NCR5380_cmd *ncmd;
2305
2306         /* reset NCR registers */
2307         NCR5380_write(MODE_REG, MR_BASE);
2308         NCR5380_write(TARGET_COMMAND_REG, 0);
2309         NCR5380_write(SELECT_ENABLE_REG, 0);
2310
2311         /* After the reset, there are no more connected or disconnected commands
2312          * and no busy units; so clear the low-level status here to avoid
2313          * conflicts when the mid-level code tries to wake up the affected
2314          * commands!
2315          */
2316
2317         if (hostdata->selecting) {
2318                 hostdata->selecting->result = DID_RESET << 16;
2319                 complete_cmd(instance, hostdata->selecting);
2320                 hostdata->selecting = NULL;
2321         }
2322
2323         list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2324                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2325
2326                 set_host_byte(cmd, DID_RESET);
2327                 complete_cmd(instance, cmd);
2328         }
2329         INIT_LIST_HEAD(&hostdata->disconnected);
2330
2331         list_for_each_entry(ncmd, &hostdata->autosense, list) {
2332                 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2333
2334                 cmd->scsi_done(cmd);
2335         }
2336         INIT_LIST_HEAD(&hostdata->autosense);
2337
2338         if (hostdata->connected) {
2339                 set_host_byte(hostdata->connected, DID_RESET);
2340                 complete_cmd(instance, hostdata->connected);
2341                 hostdata->connected = NULL;
2342         }
2343
2344         for (i = 0; i < 8; ++i)
2345                 hostdata->busy[i] = 0;
2346         hostdata->dma_len = 0;
2347
2348         queue_work(hostdata->work_q, &hostdata->main_task);
2349         maybe_release_dma_irq(instance);
2350 }
2351
2352 /**
2353  * NCR5380_host_reset - reset the SCSI host
2354  * @cmd: SCSI command undergoing EH
2355  *
2356  * Returns SUCCESS
2357  */
2358
2359 static int NCR5380_host_reset(struct scsi_cmnd *cmd)
2360 {
2361         struct Scsi_Host *instance = cmd->device->host;
2362         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2363         unsigned long flags;
2364         struct NCR5380_cmd *ncmd;
2365
2366         spin_lock_irqsave(&hostdata->lock, flags);
2367
2368 #if (NDEBUG & NDEBUG_ANY)
2369         shost_printk(KERN_INFO, instance, __func__);
2370 #endif
2371         NCR5380_dprint(NDEBUG_ANY, instance);
2372         NCR5380_dprint_phase(NDEBUG_ANY, instance);
2373
2374         list_for_each_entry(ncmd, &hostdata->unissued, list) {
2375                 struct scsi_cmnd *scmd = NCR5380_to_scmd(ncmd);
2376
2377                 scmd->result = DID_RESET << 16;
2378                 scmd->scsi_done(scmd);
2379         }
2380         INIT_LIST_HEAD(&hostdata->unissued);
2381
2382         do_reset(instance);
2383         bus_reset_cleanup(instance);
2384
2385         spin_unlock_irqrestore(&hostdata->lock, flags);
2386
2387         return SUCCESS;
2388 }