linux/drivers/scsi/NCR5380.c
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   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
 132static unsigned int disconnect_mask = ~0;
 133module_param(disconnect_mask, int, 0444);
 134
 135static int do_abort(struct Scsi_Host *, unsigned int);
 136static void do_reset(struct Scsi_Host *);
 137static void bus_reset_cleanup(struct Scsi_Host *);
 138
 139/**
 140 * initialize_SCp - init the scsi pointer field
 141 * @cmd: command block to set up
 142 *
 143 * Set up the internal fields in the SCSI command.
 144 */
 145
 146static inline void initialize_SCp(struct scsi_cmnd *cmd)
 147{
 148        /*
 149         * Initialize the Scsi Pointer field so that all of the commands in the
 150         * various queues are valid.
 151         */
 152
 153        if (scsi_bufflen(cmd)) {
 154                cmd->SCp.buffer = scsi_sglist(cmd);
 155                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 156                cmd->SCp.this_residual = cmd->SCp.buffer->length;
 157        } else {
 158                cmd->SCp.buffer = NULL;
 159                cmd->SCp.ptr = NULL;
 160                cmd->SCp.this_residual = 0;
 161        }
 162
 163        cmd->SCp.Status = 0;
 164        cmd->SCp.Message = 0;
 165}
 166
 167static inline void advance_sg_buffer(struct scsi_cmnd *cmd)
 168{
 169        struct scatterlist *s = cmd->SCp.buffer;
 170
 171        if (!cmd->SCp.this_residual && s && !sg_is_last(s)) {
 172                cmd->SCp.buffer = sg_next(s);
 173                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 174                cmd->SCp.this_residual = cmd->SCp.buffer->length;
 175        }
 176}
 177
 178static inline void set_resid_from_SCp(struct scsi_cmnd *cmd)
 179{
 180        int resid = cmd->SCp.this_residual;
 181        struct scatterlist *s = cmd->SCp.buffer;
 182
 183        if (s)
 184                while (!sg_is_last(s)) {
 185                        s = sg_next(s);
 186                        resid += s->length;
 187                }
 188        scsi_set_resid(cmd, resid);
 189}
 190
 191/**
 192 * NCR5380_poll_politely2 - wait for two chip register values
 193 * @hostdata: host private data
 194 * @reg1: 5380 register to poll
 195 * @bit1: Bitmask to check
 196 * @val1: Expected value
 197 * @reg2: Second 5380 register to poll
 198 * @bit2: Second bitmask to check
 199 * @val2: Second expected value
 200 * @wait: Time-out in jiffies, 0 if sleeping is not allowed
 201 *
 202 * Polls the chip in a reasonably efficient manner waiting for an
 203 * event to occur. After a short quick poll we begin to yield the CPU
 204 * (if possible). In irq contexts the time-out is arbitrarily limited.
 205 * Callers may hold locks as long as they are held in irq mode.
 206 *
 207 * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
 208 */
 209
 210static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
 211                                  unsigned int reg1, u8 bit1, u8 val1,
 212                                  unsigned int reg2, u8 bit2, u8 val2,
 213                                  unsigned long wait)
 214{
 215        unsigned long n = hostdata->poll_loops;
 216        unsigned long deadline = jiffies + wait;
 217
 218        do {
 219                if ((NCR5380_read(reg1) & bit1) == val1)
 220                        return 0;
 221                if ((NCR5380_read(reg2) & bit2) == val2)
 222                        return 0;
 223                cpu_relax();
 224        } while (n--);
 225
 226        if (!wait)
 227                return -ETIMEDOUT;
 228
 229        /* Repeatedly sleep for 1 ms until deadline */
 230        while (time_is_after_jiffies(deadline)) {
 231                schedule_timeout_uninterruptible(1);
 232                if ((NCR5380_read(reg1) & bit1) == val1)
 233                        return 0;
 234                if ((NCR5380_read(reg2) & bit2) == val2)
 235                        return 0;
 236        }
 237
 238        return -ETIMEDOUT;
 239}
 240
 241#if NDEBUG
 242static struct {
 243        unsigned char mask;
 244        const char *name;
 245} signals[] = {
 246        {SR_DBP, "PARITY"},
 247        {SR_RST, "RST"},
 248        {SR_BSY, "BSY"},
 249        {SR_REQ, "REQ"},
 250        {SR_MSG, "MSG"},
 251        {SR_CD, "CD"},
 252        {SR_IO, "IO"},
 253        {SR_SEL, "SEL"},
 254        {0, NULL}
 255},
 256basrs[] = {
 257        {BASR_END_DMA_TRANSFER, "END OF DMA"},
 258        {BASR_DRQ, "DRQ"},
 259        {BASR_PARITY_ERROR, "PARITY ERROR"},
 260        {BASR_IRQ, "IRQ"},
 261        {BASR_PHASE_MATCH, "PHASE MATCH"},
 262        {BASR_BUSY_ERROR, "BUSY ERROR"},
 263        {BASR_ATN, "ATN"},
 264        {BASR_ACK, "ACK"},
 265        {0, NULL}
 266},
 267icrs[] = {
 268        {ICR_ASSERT_RST, "ASSERT RST"},
 269        {ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
 270        {ICR_ARBITRATION_LOST, "LOST ARB."},
 271        {ICR_ASSERT_ACK, "ASSERT ACK"},
 272        {ICR_ASSERT_BSY, "ASSERT BSY"},
 273        {ICR_ASSERT_SEL, "ASSERT SEL"},
 274        {ICR_ASSERT_ATN, "ASSERT ATN"},
 275        {ICR_ASSERT_DATA, "ASSERT DATA"},
 276        {0, NULL}
 277},
 278mrs[] = {
 279        {MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
 280        {MR_TARGET, "TARGET"},
 281        {MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
 282        {MR_ENABLE_PAR_INTR, "PARITY INTR"},
 283        {MR_ENABLE_EOP_INTR, "EOP INTR"},
 284        {MR_MONITOR_BSY, "MONITOR BSY"},
 285        {MR_DMA_MODE, "DMA MODE"},
 286        {MR_ARBITRATE, "ARBITRATE"},
 287        {0, NULL}
 288};
 289
 290/**
 291 * NCR5380_print - print scsi bus signals
 292 * @instance: adapter state to dump
 293 *
 294 * Print the SCSI bus signals for debugging purposes
 295 */
 296
 297static void NCR5380_print(struct Scsi_Host *instance)
 298{
 299        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 300        unsigned char status, basr, mr, icr, i;
 301
 302        status = NCR5380_read(STATUS_REG);
 303        mr = NCR5380_read(MODE_REG);
 304        icr = NCR5380_read(INITIATOR_COMMAND_REG);
 305        basr = NCR5380_read(BUS_AND_STATUS_REG);
 306
 307        printk(KERN_DEBUG "SR =   0x%02x : ", status);
 308        for (i = 0; signals[i].mask; ++i)
 309                if (status & signals[i].mask)
 310                        printk(KERN_CONT "%s, ", signals[i].name);
 311        printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
 312        for (i = 0; basrs[i].mask; ++i)
 313                if (basr & basrs[i].mask)
 314                        printk(KERN_CONT "%s, ", basrs[i].name);
 315        printk(KERN_CONT "\nICR =  0x%02x : ", icr);
 316        for (i = 0; icrs[i].mask; ++i)
 317                if (icr & icrs[i].mask)
 318                        printk(KERN_CONT "%s, ", icrs[i].name);
 319        printk(KERN_CONT "\nMR =   0x%02x : ", mr);
 320        for (i = 0; mrs[i].mask; ++i)
 321                if (mr & mrs[i].mask)
 322                        printk(KERN_CONT "%s, ", mrs[i].name);
 323        printk(KERN_CONT "\n");
 324}
 325
 326static struct {
 327        unsigned char value;
 328        const char *name;
 329} phases[] = {
 330        {PHASE_DATAOUT, "DATAOUT"},
 331        {PHASE_DATAIN, "DATAIN"},
 332        {PHASE_CMDOUT, "CMDOUT"},
 333        {PHASE_STATIN, "STATIN"},
 334        {PHASE_MSGOUT, "MSGOUT"},
 335        {PHASE_MSGIN, "MSGIN"},
 336        {PHASE_UNKNOWN, "UNKNOWN"}
 337};
 338
 339/**
 340 * NCR5380_print_phase - show SCSI phase
 341 * @instance: adapter to dump
 342 *
 343 * Print the current SCSI phase for debugging purposes
 344 */
 345
 346static void NCR5380_print_phase(struct Scsi_Host *instance)
 347{
 348        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 349        unsigned char status;
 350        int i;
 351
 352        status = NCR5380_read(STATUS_REG);
 353        if (!(status & SR_REQ))
 354                shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
 355        else {
 356                for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
 357                     (phases[i].value != (status & PHASE_MASK)); ++i)
 358                        ;
 359                shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
 360        }
 361}
 362#endif
 363
 364/**
 365 * NCR5380_info - report driver and host information
 366 * @instance: relevant scsi host instance
 367 *
 368 * For use as the host template info() handler.
 369 */
 370
 371static const char *NCR5380_info(struct Scsi_Host *instance)
 372{
 373        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 374
 375        return hostdata->info;
 376}
 377
 378/**
 379 * NCR5380_init - initialise an NCR5380
 380 * @instance: adapter to configure
 381 * @flags: control flags
 382 *
 383 * Initializes *instance and corresponding 5380 chip,
 384 * with flags OR'd into the initial flags value.
 385 *
 386 * Notes : I assume that the host, hostno, and id bits have been
 387 * set correctly. I don't care about the irq and other fields.
 388 *
 389 * Returns 0 for success
 390 */
 391
 392static int NCR5380_init(struct Scsi_Host *instance, int flags)
 393{
 394        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 395        int i;
 396        unsigned long deadline;
 397        unsigned long accesses_per_ms;
 398
 399        instance->max_lun = 7;
 400
 401        hostdata->host = instance;
 402        hostdata->id_mask = 1 << instance->this_id;
 403        hostdata->id_higher_mask = 0;
 404        for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 405                if (i > hostdata->id_mask)
 406                        hostdata->id_higher_mask |= i;
 407        for (i = 0; i < 8; ++i)
 408                hostdata->busy[i] = 0;
 409        hostdata->dma_len = 0;
 410
 411        spin_lock_init(&hostdata->lock);
 412        hostdata->connected = NULL;
 413        hostdata->sensing = NULL;
 414        INIT_LIST_HEAD(&hostdata->autosense);
 415        INIT_LIST_HEAD(&hostdata->unissued);
 416        INIT_LIST_HEAD(&hostdata->disconnected);
 417
 418        hostdata->flags = flags;
 419
 420        INIT_WORK(&hostdata->main_task, NCR5380_main);
 421        hostdata->work_q = alloc_workqueue("ncr5380_%d",
 422                                WQ_UNBOUND | WQ_MEM_RECLAIM,
 423                                1, instance->host_no);
 424        if (!hostdata->work_q)
 425                return -ENOMEM;
 426
 427        snprintf(hostdata->info, sizeof(hostdata->info),
 428                "%s, irq %d, io_port 0x%lx, base 0x%lx, can_queue %d, cmd_per_lun %d, sg_tablesize %d, this_id %d, flags { %s%s%s}",
 429                instance->hostt->name, instance->irq, hostdata->io_port,
 430                hostdata->base, instance->can_queue, instance->cmd_per_lun,
 431                instance->sg_tablesize, instance->this_id,
 432                hostdata->flags & FLAG_DMA_FIXUP     ? "DMA_FIXUP "     : "",
 433                hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
 434                hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
 435
 436        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 437        NCR5380_write(MODE_REG, MR_BASE);
 438        NCR5380_write(TARGET_COMMAND_REG, 0);
 439        NCR5380_write(SELECT_ENABLE_REG, 0);
 440
 441        /* Calibrate register polling loop */
 442        i = 0;
 443        deadline = jiffies + 1;
 444        do {
 445                cpu_relax();
 446        } while (time_is_after_jiffies(deadline));
 447        deadline += msecs_to_jiffies(256);
 448        do {
 449                NCR5380_read(STATUS_REG);
 450                ++i;
 451                cpu_relax();
 452        } while (time_is_after_jiffies(deadline));
 453        accesses_per_ms = i / 256;
 454        hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
 455
 456        return 0;
 457}
 458
 459/**
 460 * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
 461 * @instance: adapter to check
 462 *
 463 * If the system crashed, it may have crashed with a connected target and
 464 * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
 465 * currently established nexus, which we know nothing about. Failing that
 466 * do a bus reset.
 467 *
 468 * Note that a bus reset will cause the chip to assert IRQ.
 469 *
 470 * Returns 0 if successful, otherwise -ENXIO.
 471 */
 472
 473static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
 474{
 475        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 476        int pass;
 477
 478        for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
 479                switch (pass) {
 480                case 1:
 481                case 3:
 482                case 5:
 483                        shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
 484                        NCR5380_poll_politely(hostdata,
 485                                              STATUS_REG, SR_BSY, 0, 5 * HZ);
 486                        break;
 487                case 2:
 488                        shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
 489                        do_abort(instance, 1);
 490                        break;
 491                case 4:
 492                        shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
 493                        do_reset(instance);
 494                        /* Wait after a reset; the SCSI standard calls for
 495                         * 250ms, we wait 500ms to be on the safe side.
 496                         * But some Toshiba CD-ROMs need ten times that.
 497                         */
 498                        if (hostdata->flags & FLAG_TOSHIBA_DELAY)
 499                                msleep(2500);
 500                        else
 501                                msleep(500);
 502                        break;
 503                case 6:
 504                        shost_printk(KERN_ERR, instance, "bus locked solid\n");
 505                        return -ENXIO;
 506                }
 507        }
 508        return 0;
 509}
 510
 511/**
 512 * NCR5380_exit - remove an NCR5380
 513 * @instance: adapter to remove
 514 *
 515 * Assumes that no more work can be queued (e.g. by NCR5380_intr).
 516 */
 517
 518static void NCR5380_exit(struct Scsi_Host *instance)
 519{
 520        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 521
 522        cancel_work_sync(&hostdata->main_task);
 523        destroy_workqueue(hostdata->work_q);
 524}
 525
 526/**
 527 * complete_cmd - finish processing a command and return it to the SCSI ML
 528 * @instance: the host instance
 529 * @cmd: command to complete
 530 */
 531
 532static void complete_cmd(struct Scsi_Host *instance,
 533                         struct scsi_cmnd *cmd)
 534{
 535        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 536
 537        dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
 538
 539        if (hostdata->sensing == cmd) {
 540                /* Autosense processing ends here */
 541                if (get_status_byte(cmd) != SAM_STAT_GOOD) {
 542                        scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 543                } else {
 544                        scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 545                        set_status_byte(cmd, SAM_STAT_CHECK_CONDITION);
 546                }
 547                hostdata->sensing = NULL;
 548        }
 549
 550        cmd->scsi_done(cmd);
 551}
 552
 553/**
 554 * NCR5380_queue_command - queue a command
 555 * @instance: the relevant SCSI adapter
 556 * @cmd: SCSI command
 557 *
 558 * cmd is added to the per-instance issue queue, with minor
 559 * twiddling done to the host specific fields of cmd.  If the
 560 * main coroutine is not running, it is restarted.
 561 */
 562
 563static int NCR5380_queue_command(struct Scsi_Host *instance,
 564                                 struct scsi_cmnd *cmd)
 565{
 566        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 567        struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 568        unsigned long flags;
 569
 570#if (NDEBUG & NDEBUG_NO_WRITE)
 571        switch (cmd->cmnd[0]) {
 572        case WRITE_6:
 573        case WRITE_10:
 574                shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
 575                cmd->result = (DID_ERROR << 16);
 576                cmd->scsi_done(cmd);
 577                return 0;
 578        }
 579#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 580
 581        cmd->result = 0;
 582
 583        spin_lock_irqsave(&hostdata->lock, flags);
 584
 585        if (!NCR5380_acquire_dma_irq(instance)) {
 586                spin_unlock_irqrestore(&hostdata->lock, flags);
 587
 588                return SCSI_MLQUEUE_HOST_BUSY;
 589        }
 590
 591        /*
 592         * Insert the cmd into the issue queue. Note that REQUEST SENSE
 593         * commands are added to the head of the queue since any command will
 594         * clear the contingent allegiance condition that exists and the
 595         * sense data is only guaranteed to be valid while the condition exists.
 596         */
 597
 598        if (cmd->cmnd[0] == REQUEST_SENSE)
 599                list_add(&ncmd->list, &hostdata->unissued);
 600        else
 601                list_add_tail(&ncmd->list, &hostdata->unissued);
 602
 603        spin_unlock_irqrestore(&hostdata->lock, flags);
 604
 605        dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
 606                 cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 607
 608        /* Kick off command processing */
 609        queue_work(hostdata->work_q, &hostdata->main_task);
 610        return 0;
 611}
 612
 613static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
 614{
 615        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 616
 617        /* Caller does the locking needed to set & test these data atomically */
 618        if (list_empty(&hostdata->disconnected) &&
 619            list_empty(&hostdata->unissued) &&
 620            list_empty(&hostdata->autosense) &&
 621            !hostdata->connected &&
 622            !hostdata->selecting) {
 623                NCR5380_release_dma_irq(instance);
 624        }
 625}
 626
 627/**
 628 * dequeue_next_cmd - dequeue a command for processing
 629 * @instance: the scsi host instance
 630 *
 631 * Priority is given to commands on the autosense queue. These commands
 632 * need autosense because of a CHECK CONDITION result.
 633 *
 634 * Returns a command pointer if a command is found for a target that is
 635 * not already busy. Otherwise returns NULL.
 636 */
 637
 638static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
 639{
 640        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 641        struct NCR5380_cmd *ncmd;
 642        struct scsi_cmnd *cmd;
 643
 644        if (hostdata->sensing || list_empty(&hostdata->autosense)) {
 645                list_for_each_entry(ncmd, &hostdata->unissued, list) {
 646                        cmd = NCR5380_to_scmd(ncmd);
 647                        dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
 648                                 cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
 649
 650                        if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
 651                                list_del(&ncmd->list);
 652                                dsprintk(NDEBUG_QUEUES, instance,
 653                                         "dequeue: removed %p from issue queue\n", cmd);
 654                                return cmd;
 655                        }
 656                }
 657        } else {
 658                /* Autosense processing begins here */
 659                ncmd = list_first_entry(&hostdata->autosense,
 660                                        struct NCR5380_cmd, list);
 661                list_del(&ncmd->list);
 662                cmd = NCR5380_to_scmd(ncmd);
 663                dsprintk(NDEBUG_QUEUES, instance,
 664                         "dequeue: removed %p from autosense queue\n", cmd);
 665                scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
 666                hostdata->sensing = cmd;
 667                return cmd;
 668        }
 669        return NULL;
 670}
 671
 672static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 673{
 674        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 675        struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
 676
 677        if (hostdata->sensing == cmd) {
 678                scsi_eh_restore_cmnd(cmd, &hostdata->ses);
 679                list_add(&ncmd->list, &hostdata->autosense);
 680                hostdata->sensing = NULL;
 681        } else
 682                list_add(&ncmd->list, &hostdata->unissued);
 683}
 684
 685/**
 686 * NCR5380_main - NCR state machines
 687 *
 688 * NCR5380_main is a coroutine that runs as long as more work can
 689 * be done on the NCR5380 host adapters in a system.  Both
 690 * NCR5380_queue_command() and NCR5380_intr() will try to start it
 691 * in case it is not running.
 692 */
 693
 694static void NCR5380_main(struct work_struct *work)
 695{
 696        struct NCR5380_hostdata *hostdata =
 697                container_of(work, struct NCR5380_hostdata, main_task);
 698        struct Scsi_Host *instance = hostdata->host;
 699        int done;
 700
 701        do {
 702                done = 1;
 703
 704                spin_lock_irq(&hostdata->lock);
 705                while (!hostdata->connected && !hostdata->selecting) {
 706                        struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
 707
 708                        if (!cmd)
 709                                break;
 710
 711                        dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
 712
 713                        /*
 714                         * Attempt to establish an I_T_L nexus here.
 715                         * On success, instance->hostdata->connected is set.
 716                         * On failure, we must add the command back to the
 717                         * issue queue so we can keep trying.
 718                         */
 719                        /*
 720                         * REQUEST SENSE commands are issued without tagged
 721                         * queueing, even on SCSI-II devices because the
 722                         * contingent allegiance condition exists for the
 723                         * entire unit.
 724                         */
 725
 726                        if (!NCR5380_select(instance, cmd)) {
 727                                dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
 728                        } else {
 729                                dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
 730                                         "main: select failed, returning %p to queue\n", cmd);
 731                                requeue_cmd(instance, cmd);
 732                        }
 733                }
 734                if (hostdata->connected && !hostdata->dma_len) {
 735                        dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
 736                        NCR5380_information_transfer(instance);
 737                        done = 0;
 738                }
 739                if (!hostdata->connected) {
 740                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 741                        maybe_release_dma_irq(instance);
 742                }
 743                spin_unlock_irq(&hostdata->lock);
 744                if (!done)
 745                        cond_resched();
 746        } while (!done);
 747}
 748
 749/*
 750 * NCR5380_dma_complete - finish DMA transfer
 751 * @instance: the scsi host instance
 752 *
 753 * Called by the interrupt handler when DMA finishes or a phase
 754 * mismatch occurs (which would end the DMA transfer).
 755 */
 756
 757static void NCR5380_dma_complete(struct Scsi_Host *instance)
 758{
 759        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 760        int transferred;
 761        unsigned char **data;
 762        int *count;
 763        int saved_data = 0, overrun = 0;
 764        unsigned char p;
 765
 766        if (hostdata->read_overruns) {
 767                p = hostdata->connected->SCp.phase;
 768                if (p & SR_IO) {
 769                        udelay(10);
 770                        if ((NCR5380_read(BUS_AND_STATUS_REG) &
 771                             (BASR_PHASE_MATCH | BASR_ACK)) ==
 772                            (BASR_PHASE_MATCH | BASR_ACK)) {
 773                                saved_data = NCR5380_read(INPUT_DATA_REG);
 774                                overrun = 1;
 775                                dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
 776                        }
 777                }
 778        }
 779
 780#ifdef CONFIG_SUN3
 781        if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
 782                pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
 783                       instance->host_no);
 784                BUG();
 785        }
 786
 787        if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
 788            (BASR_PHASE_MATCH | BASR_ACK)) {
 789                pr_err("scsi%d: BASR %02x\n", instance->host_no,
 790                       NCR5380_read(BUS_AND_STATUS_REG));
 791                pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
 792                       instance->host_no);
 793                BUG();
 794        }
 795#endif
 796
 797        NCR5380_write(MODE_REG, MR_BASE);
 798        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 799        NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 800
 801        transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
 802        hostdata->dma_len = 0;
 803
 804        data = (unsigned char **)&hostdata->connected->SCp.ptr;
 805        count = &hostdata->connected->SCp.this_residual;
 806        *data += transferred;
 807        *count -= transferred;
 808
 809        if (hostdata->read_overruns) {
 810                int cnt, toPIO;
 811
 812                if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
 813                        cnt = toPIO = hostdata->read_overruns;
 814                        if (overrun) {
 815                                dsprintk(NDEBUG_DMA, instance,
 816                                         "Got an input overrun, using saved byte\n");
 817                                *(*data)++ = saved_data;
 818                                (*count)--;
 819                                cnt--;
 820                                toPIO--;
 821                        }
 822                        if (toPIO > 0) {
 823                                dsprintk(NDEBUG_DMA, instance,
 824                                         "Doing %d byte PIO to 0x%p\n", cnt, *data);
 825                                NCR5380_transfer_pio(instance, &p, &cnt, data, 0);
 826                                *count -= toPIO - cnt;
 827                        }
 828                }
 829        }
 830}
 831
 832/**
 833 * NCR5380_intr - generic NCR5380 irq handler
 834 * @irq: interrupt number
 835 * @dev_id: device info
 836 *
 837 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 838 * from the disconnected queue, and restarting NCR5380_main()
 839 * as required.
 840 *
 841 * The chip can assert IRQ in any of six different conditions. The IRQ flag
 842 * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
 843 * Three of these six conditions are latched in the Bus and Status Register:
 844 * - End of DMA (cleared by ending DMA Mode)
 845 * - Parity error (cleared by reading RPIR)
 846 * - Loss of BSY (cleared by reading RPIR)
 847 * Two conditions have flag bits that are not latched:
 848 * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
 849 * - Bus reset (non-maskable)
 850 * The remaining condition has no flag bit at all:
 851 * - Selection/reselection
 852 *
 853 * Hence, establishing the cause(s) of any interrupt is partly guesswork.
 854 * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
 855 * claimed that "the design of the [DP8490] interrupt logic ensures
 856 * interrupts will not be lost (they can be on the DP5380)."
 857 * The L5380/53C80 datasheet from LOGIC Devices has more details.
 858 *
 859 * Checking for bus reset by reading RST is futile because of interrupt
 860 * latency, but a bus reset will reset chip logic. Checking for parity error
 861 * is unnecessary because that interrupt is never enabled. A Loss of BSY
 862 * condition will clear DMA Mode. We can tell when this occurs because the
 863 * the Busy Monitor interrupt is enabled together with DMA Mode.
 864 */
 865
 866static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
 867{
 868        struct Scsi_Host *instance = dev_id;
 869        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 870        int handled = 0;
 871        unsigned char basr;
 872        unsigned long flags;
 873
 874        spin_lock_irqsave(&hostdata->lock, flags);
 875
 876        basr = NCR5380_read(BUS_AND_STATUS_REG);
 877        if (basr & BASR_IRQ) {
 878                unsigned char mr = NCR5380_read(MODE_REG);
 879                unsigned char sr = NCR5380_read(STATUS_REG);
 880
 881                dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
 882                         irq, basr, sr, mr);
 883
 884                if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
 885                        /* Probably End of DMA, Phase Mismatch or Loss of BSY.
 886                         * We ack IRQ after clearing Mode Register. Workarounds
 887                         * for End of DMA errata need to happen in DMA Mode.
 888                         */
 889
 890                        dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
 891
 892                        if (hostdata->connected) {
 893                                NCR5380_dma_complete(instance);
 894                                queue_work(hostdata->work_q, &hostdata->main_task);
 895                        } else {
 896                                NCR5380_write(MODE_REG, MR_BASE);
 897                                NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 898                        }
 899                } else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
 900                    (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
 901                        /* Probably reselected */
 902                        NCR5380_write(SELECT_ENABLE_REG, 0);
 903                        NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 904
 905                        dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
 906
 907                        if (!hostdata->connected) {
 908                                NCR5380_reselect(instance);
 909                                queue_work(hostdata->work_q, &hostdata->main_task);
 910                        }
 911                        if (!hostdata->connected)
 912                                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 913                } else {
 914                        /* Probably Bus Reset */
 915                        NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 916
 917                        if (sr & SR_RST) {
 918                                /* Certainly Bus Reset */
 919                                shost_printk(KERN_WARNING, instance,
 920                                             "bus reset interrupt\n");
 921                                bus_reset_cleanup(instance);
 922                        } else {
 923                                dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
 924                        }
 925#ifdef SUN3_SCSI_VME
 926                        dregs->csr |= CSR_DMA_ENABLE;
 927#endif
 928                }
 929                handled = 1;
 930        } else {
 931                dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
 932#ifdef SUN3_SCSI_VME
 933                dregs->csr |= CSR_DMA_ENABLE;
 934#endif
 935        }
 936
 937        spin_unlock_irqrestore(&hostdata->lock, flags);
 938
 939        return IRQ_RETVAL(handled);
 940}
 941
 942/**
 943 * NCR5380_select - attempt arbitration and selection for a given command
 944 * @instance: the Scsi_Host instance
 945 * @cmd: the scsi_cmnd to execute
 946 *
 947 * This routine establishes an I_T_L nexus for a SCSI command. This involves
 948 * ARBITRATION, SELECTION and MESSAGE OUT phases and an IDENTIFY message.
 949 *
 950 * Returns true if the operation should be retried.
 951 * Returns false if it should not be retried.
 952 *
 953 * Side effects :
 954 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
 955 * with registers as they should have been on entry - ie
 956 * SELECT_ENABLE will be set appropriately, the NCR5380
 957 * will cease to drive any SCSI bus signals.
 958 *
 959 * If successful : the I_T_L nexus will be established, and
 960 * hostdata->connected will be set to cmd.
 961 * SELECT interrupt will be disabled.
 962 *
 963 * If failed (no target) : cmd->scsi_done() will be called, and the
 964 * cmd->result host byte set to DID_BAD_TARGET.
 965 */
 966
 967static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 968        __releases(&hostdata->lock) __acquires(&hostdata->lock)
 969{
 970        struct NCR5380_hostdata *hostdata = shost_priv(instance);
 971        unsigned char tmp[3], phase;
 972        unsigned char *data;
 973        int len;
 974        int err;
 975        bool ret = true;
 976        bool can_disconnect = instance->irq != NO_IRQ &&
 977                              cmd->cmnd[0] != REQUEST_SENSE &&
 978                              (disconnect_mask & BIT(scmd_id(cmd)));
 979
 980        NCR5380_dprint(NDEBUG_ARBITRATION, instance);
 981        dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
 982                 instance->this_id);
 983
 984        /*
 985         * Arbitration and selection phases are slow and involve dropping the
 986         * lock, so we have to watch out for EH. An exception handler may
 987         * change 'selecting' to NULL. This function will then return false
 988         * so that the caller will forget about 'cmd'. (During information
 989         * transfer phases, EH may change 'connected' to NULL.)
 990         */
 991        hostdata->selecting = cmd;
 992
 993        /*
 994         * Set the phase bits to 0, otherwise the NCR5380 won't drive the
 995         * data bus during SELECTION.
 996         */
 997
 998        NCR5380_write(TARGET_COMMAND_REG, 0);
 999
1000        /*
1001         * Start arbitration.
1002         */
1003
1004        NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1005        NCR5380_write(MODE_REG, MR_ARBITRATE);
1006
1007        /* The chip now waits for BUS FREE phase. Then after the 800 ns
1008         * Bus Free Delay, arbitration will begin.
1009         */
1010
1011        spin_unlock_irq(&hostdata->lock);
1012        err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
1013                        INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
1014                                               ICR_ARBITRATION_PROGRESS, HZ);
1015        spin_lock_irq(&hostdata->lock);
1016        if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
1017                /* Reselection interrupt */
1018                goto out;
1019        }
1020        if (!hostdata->selecting) {
1021                /* Command was aborted */
1022                NCR5380_write(MODE_REG, MR_BASE);
1023                return false;
1024        }
1025        if (err < 0) {
1026                NCR5380_write(MODE_REG, MR_BASE);
1027                shost_printk(KERN_ERR, instance,
1028                             "select: arbitration timeout\n");
1029                goto out;
1030        }
1031        spin_unlock_irq(&hostdata->lock);
1032
1033        /* The SCSI-2 arbitration delay is 2.4 us */
1034        udelay(3);
1035
1036        /* Check for lost arbitration */
1037        if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1038            (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1039            (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1040                NCR5380_write(MODE_REG, MR_BASE);
1041                dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1042                spin_lock_irq(&hostdata->lock);
1043                goto out;
1044        }
1045
1046        /* After/during arbitration, BSY should be asserted.
1047         * IBM DPES-31080 Version S31Q works now
1048         * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1049         */
1050        NCR5380_write(INITIATOR_COMMAND_REG,
1051                      ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1052
1053        /*
1054         * Again, bus clear + bus settle time is 1.2us, however, this is
1055         * a minimum so we'll udelay ceil(1.2)
1056         */
1057
1058        if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1059                udelay(15);
1060        else
1061                udelay(2);
1062
1063        spin_lock_irq(&hostdata->lock);
1064
1065        /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1066        if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1067                goto out;
1068
1069        if (!hostdata->selecting) {
1070                NCR5380_write(MODE_REG, MR_BASE);
1071                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1072                return false;
1073        }
1074
1075        dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1076
1077        /*
1078         * Now that we have won arbitration, start Selection process, asserting
1079         * the host and target ID's on the SCSI bus.
1080         */
1081
1082        NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1083
1084        /*
1085         * Raise ATN while SEL is true before BSY goes false from arbitration,
1086         * since this is the only way to guarantee that we'll get a MESSAGE OUT
1087         * phase immediately after selection.
1088         */
1089
1090        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1091                      ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1092        NCR5380_write(MODE_REG, MR_BASE);
1093
1094        /*
1095         * Reselect interrupts must be turned off prior to the dropping of BSY,
1096         * otherwise we will trigger an interrupt.
1097         */
1098        NCR5380_write(SELECT_ENABLE_REG, 0);
1099
1100        spin_unlock_irq(&hostdata->lock);
1101
1102        /*
1103         * The initiator shall then wait at least two deskew delays and release
1104         * the BSY signal.
1105         */
1106        udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1107
1108        /* Reset BSY */
1109        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1110                      ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1111
1112        /*
1113         * Something weird happens when we cease to drive BSY - looks
1114         * like the board/chip is letting us do another read before the
1115         * appropriate propagation delay has expired, and we're confusing
1116         * a BSY signal from ourselves as the target's response to SELECTION.
1117         *
1118         * A small delay (the 'C++' frontend breaks the pipeline with an
1119         * unnecessary jump, making it work on my 386-33/Trantor T128, the
1120         * tighter 'C' code breaks and requires this) solves the problem -
1121         * the 1 us delay is arbitrary, and only used because this delay will
1122         * be the same on other platforms and since it works here, it should
1123         * work there.
1124         *
1125         * wingel suggests that this could be due to failing to wait
1126         * one deskew delay.
1127         */
1128
1129        udelay(1);
1130
1131        dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1132
1133        /*
1134         * The SCSI specification calls for a 250 ms timeout for the actual
1135         * selection.
1136         */
1137
1138        err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
1139                                    msecs_to_jiffies(250));
1140
1141        if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1142                spin_lock_irq(&hostdata->lock);
1143                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1144                NCR5380_reselect(instance);
1145                shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1146                goto out;
1147        }
1148
1149        if (err < 0) {
1150                spin_lock_irq(&hostdata->lock);
1151                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1152
1153                /* Can't touch cmd if it has been reclaimed by the scsi ML */
1154                if (!hostdata->selecting)
1155                        return false;
1156
1157                cmd->result = DID_BAD_TARGET << 16;
1158                complete_cmd(instance, cmd);
1159                dsprintk(NDEBUG_SELECTION, instance,
1160                        "target did not respond within 250ms\n");
1161                ret = false;
1162                goto out;
1163        }
1164
1165        /*
1166         * No less than two deskew delays after the initiator detects the
1167         * BSY signal is true, it shall release the SEL signal and may
1168         * change the DATA BUS.                                     -wingel
1169         */
1170
1171        udelay(1);
1172
1173        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1174
1175        /*
1176         * Since we followed the SCSI spec, and raised ATN while SEL
1177         * was true but before BSY was false during selection, the information
1178         * transfer phase should be a MESSAGE OUT phase so that we can send the
1179         * IDENTIFY message.
1180         */
1181
1182        /* Wait for start of REQ/ACK handshake */
1183
1184        err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
1185        spin_lock_irq(&hostdata->lock);
1186        if (err < 0) {
1187                shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1188                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1189                goto out;
1190        }
1191        if (!hostdata->selecting) {
1192                do_abort(instance, 0);
1193                return false;
1194        }
1195
1196        dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1197                 scmd_id(cmd));
1198        tmp[0] = IDENTIFY(can_disconnect, cmd->device->lun);
1199
1200        len = 1;
1201        data = tmp;
1202        phase = PHASE_MSGOUT;
1203        NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
1204        if (len) {
1205                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1206                cmd->result = DID_ERROR << 16;
1207                complete_cmd(instance, cmd);
1208                dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
1209                ret = false;
1210                goto out;
1211        }
1212
1213        dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1214
1215        hostdata->connected = cmd;
1216        hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1217
1218#ifdef SUN3_SCSI_VME
1219        dregs->csr |= CSR_INTR;
1220#endif
1221
1222        initialize_SCp(cmd);
1223
1224        ret = false;
1225
1226out:
1227        if (!hostdata->selecting)
1228                return false;
1229        hostdata->selecting = NULL;
1230        return ret;
1231}
1232
1233/*
1234 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1235 * unsigned char *phase, int *count, unsigned char **data)
1236 *
1237 * Purpose : transfers data in given phase using polled I/O
1238 *
1239 * Inputs : instance - instance of driver, *phase - pointer to
1240 * what phase is expected, *count - pointer to number of
1241 * bytes to transfer, **data - pointer to data pointer,
1242 * can_sleep - 1 or 0 when sleeping is permitted or not, respectively.
1243 *
1244 * Returns : -1 when different phase is entered without transferring
1245 * maximum number of bytes, 0 if all bytes are transferred or exit
1246 * is in same phase.
1247 *
1248 * Also, *phase, *count, *data are modified in place.
1249 *
1250 * XXX Note : handling for bus free may be useful.
1251 */
1252
1253/*
1254 * Note : this code is not as quick as it could be, however it
1255 * IS 100% reliable, and for the actual data transfer where speed
1256 * counts, we will always do a pseudo DMA or DMA transfer.
1257 */
1258
1259static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1260                                unsigned char *phase, int *count,
1261                                unsigned char **data, unsigned int can_sleep)
1262{
1263        struct NCR5380_hostdata *hostdata = shost_priv(instance);
1264        unsigned char p = *phase, tmp;
1265        int c = *count;
1266        unsigned char *d = *data;
1267
1268        /*
1269         * The NCR5380 chip will only drive the SCSI bus when the
1270         * phase specified in the appropriate bits of the TARGET COMMAND
1271         * REGISTER match the STATUS REGISTER
1272         */
1273
1274        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1275
1276        do {
1277                /*
1278                 * Wait for assertion of REQ, after which the phase bits will be
1279                 * valid
1280                 */
1281
1282                if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,
1283                                          HZ * can_sleep) < 0)
1284                        break;
1285
1286                dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1287
1288                /* Check for phase mismatch */
1289                if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1290                        dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1291                        NCR5380_dprint_phase(NDEBUG_PIO, instance);
1292                        break;
1293                }
1294
1295                /* Do actual transfer from SCSI bus to / from memory */
1296                if (!(p & SR_IO))
1297                        NCR5380_write(OUTPUT_DATA_REG, *d);
1298                else
1299                        *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1300
1301                ++d;
1302
1303                /*
1304                 * The SCSI standard suggests that in MSGOUT phase, the initiator
1305                 * should drop ATN on the last byte of the message phase
1306                 * after REQ has been asserted for the handshake but before
1307                 * the initiator raises ACK.
1308                 */
1309
1310                if (!(p & SR_IO)) {
1311                        if (!((p & SR_MSG) && c > 1)) {
1312                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1313                                NCR5380_dprint(NDEBUG_PIO, instance);
1314                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1315                                              ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1316                        } else {
1317                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1318                                              ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1319                                NCR5380_dprint(NDEBUG_PIO, instance);
1320                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1321                                              ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1322                        }
1323                } else {
1324                        NCR5380_dprint(NDEBUG_PIO, instance);
1325                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1326                }
1327
1328                if (NCR5380_poll_politely(hostdata,
1329                                          STATUS_REG, SR_REQ, 0, 5 * HZ * can_sleep) < 0)
1330                        break;
1331
1332                dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1333
1334/*
1335 * We have several special cases to consider during REQ/ACK handshaking :
1336 * 1.  We were in MSGOUT phase, and we are on the last byte of the
1337 * message.  ATN must be dropped as ACK is dropped.
1338 *
1339 * 2.  We are in a MSGIN phase, and we are on the last byte of the
1340 * message.  We must exit with ACK asserted, so that the calling
1341 * code may raise ATN before dropping ACK to reject the message.
1342 *
1343 * 3.  ACK and ATN are clear and the target may proceed as normal.
1344 */
1345                if (!(p == PHASE_MSGIN && c == 1)) {
1346                        if (p == PHASE_MSGOUT && c > 1)
1347                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1348                        else
1349                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1350                }
1351        } while (--c);
1352
1353        dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1354
1355        *count = c;
1356        *data = d;
1357        tmp = NCR5380_read(STATUS_REG);
1358        /* The phase read from the bus is valid if either REQ is (already)
1359         * asserted or if ACK hasn't been released yet. The latter applies if
1360         * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1361         */
1362        if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1363                *phase = tmp & PHASE_MASK;
1364        else
1365                *phase = PHASE_UNKNOWN;
1366
1367        if (!c || (*phase == p))
1368                return 0;
1369        else
1370                return -1;
1371}
1372
1373/**
1374 * do_reset - issue a reset command
1375 * @instance: adapter to reset
1376 *
1377 * Issue a reset sequence to the NCR5380 and try and get the bus
1378 * back into sane shape.
1379 *
1380 * This clears the reset interrupt flag because there may be no handler for
1381 * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1382 * been installed. And when in EH we may have released the ST DMA interrupt.
1383 */
1384
1385static void do_reset(struct Scsi_Host *instance)
1386{
1387        struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
1388        unsigned long flags;
1389
1390        local_irq_save(flags);
1391        NCR5380_write(TARGET_COMMAND_REG,
1392                      PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1393        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1394        udelay(50);
1395        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1396        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1397        local_irq_restore(flags);
1398}
1399
1400/**
1401 * do_abort - abort the currently established nexus by going to
1402 * MESSAGE OUT phase and sending an ABORT message.
1403 * @instance: relevant scsi host instance
1404 * @can_sleep: 1 or 0 when sleeping is permitted or not, respectively
1405 *
1406 * Returns 0 on success, negative error code on failure.
1407 */
1408
1409static int do_abort(struct Scsi_Host *instance, unsigned int can_sleep)
1410{
1411        struct NCR5380_hostdata *hostdata = shost_priv(instance);
1412        unsigned char *msgptr, phase, tmp;
1413        int len;
1414        int rc;
1415
1416        /* Request message out phase */
1417        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1418
1419        /*
1420         * Wait for the target to indicate a valid phase by asserting
1421         * REQ.  Once this happens, we'll have either a MSGOUT phase
1422         * and can immediately send the ABORT message, or we'll have some
1423         * other phase and will have to source/sink data.
1424         *
1425         * We really don't care what value was on the bus or what value
1426         * the target sees, so we just handshake.
1427         */
1428
1429        rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,
1430                                   10 * HZ * can_sleep);
1431        if (rc < 0)
1432                goto out;
1433
1434        tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1435
1436        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1437
1438        if (tmp != PHASE_MSGOUT) {
1439                NCR5380_write(INITIATOR_COMMAND_REG,
1440                              ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1441                rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0,
1442                                           3 * HZ * can_sleep);
1443                if (rc < 0)
1444                        goto out;
1445                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1446        }
1447
1448        tmp = ABORT;
1449        msgptr = &tmp;
1450        len = 1;
1451        phase = PHASE_MSGOUT;
1452        NCR5380_transfer_pio(instance, &phase, &len, &msgptr, can_sleep);
1453        if (len)
1454                rc = -ENXIO;
1455
1456        /*
1457         * If we got here, and the command completed successfully,
1458         * we're about to go into bus free state.
1459         */
1460
1461out:
1462        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1463        return rc;
1464}
1465
1466/*
1467 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1468 * unsigned char *phase, int *count, unsigned char **data)
1469 *
1470 * Purpose : transfers data in given phase using either real
1471 * or pseudo DMA.
1472 *
1473 * Inputs : instance - instance of driver, *phase - pointer to
1474 * what phase is expected, *count - pointer to number of
1475 * bytes to transfer, **data - pointer to data pointer.
1476 *
1477 * Returns : -1 when different phase is entered without transferring
1478 * maximum number of bytes, 0 if all bytes or transferred or exit
1479 * is in same phase.
1480 *
1481 * Also, *phase, *count, *data are modified in place.
1482 */
1483
1484
1485static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1486                                unsigned char *phase, int *count,
1487                                unsigned char **data)
1488{
1489        struct NCR5380_hostdata *hostdata = shost_priv(instance);
1490        int c = *count;
1491        unsigned char p = *phase;
1492        unsigned char *d = *data;
1493        unsigned char tmp;
1494        int result = 0;
1495
1496        if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1497                *phase = tmp;
1498                return -1;
1499        }
1500
1501        hostdata->connected->SCp.phase = p;
1502
1503        if (p & SR_IO) {
1504                if (hostdata->read_overruns)
1505                        c -= hostdata->read_overruns;
1506                else if (hostdata->flags & FLAG_DMA_FIXUP)
1507                        --c;
1508        }
1509
1510        dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1511                 (p & SR_IO) ? "receive" : "send", c, d);
1512
1513#ifdef CONFIG_SUN3
1514        /* send start chain */
1515        sun3scsi_dma_start(c, *data);
1516#endif
1517
1518        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1519        NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1520                                MR_ENABLE_EOP_INTR);
1521
1522        if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1523                /* On the Medusa, it is a must to initialize the DMA before
1524                 * starting the NCR. This is also the cleaner way for the TT.
1525                 */
1526                if (p & SR_IO)
1527                        result = NCR5380_dma_recv_setup(hostdata, d, c);
1528                else
1529                        result = NCR5380_dma_send_setup(hostdata, d, c);
1530        }
1531
1532        /*
1533         * On the PAS16 at least I/O recovery delays are not needed here.
1534         * Everyone else seems to want them.
1535         */
1536
1537        if (p & SR_IO) {
1538                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1539                NCR5380_io_delay(1);
1540                NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1541        } else {
1542                NCR5380_io_delay(1);
1543                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1544                NCR5380_io_delay(1);
1545                NCR5380_write(START_DMA_SEND_REG, 0);
1546                NCR5380_io_delay(1);
1547        }
1548
1549#ifdef CONFIG_SUN3
1550#ifdef SUN3_SCSI_VME
1551        dregs->csr |= CSR_DMA_ENABLE;
1552#endif
1553        sun3_dma_active = 1;
1554#endif
1555
1556        if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1557                /* On the Falcon, the DMA setup must be done after the last
1558                 * NCR access, else the DMA setup gets trashed!
1559                 */
1560                if (p & SR_IO)
1561                        result = NCR5380_dma_recv_setup(hostdata, d, c);
1562                else
1563                        result = NCR5380_dma_send_setup(hostdata, d, c);
1564        }
1565
1566        /* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
1567        if (result < 0)
1568                return result;
1569
1570        /* For real DMA, result is the byte count. DMA interrupt is expected. */
1571        if (result > 0) {
1572                hostdata->dma_len = result;
1573                return 0;
1574        }
1575
1576        /* The result is zero iff pseudo DMA send/receive was completed. */
1577        hostdata->dma_len = c;
1578
1579/*
1580 * A note regarding the DMA errata workarounds for early NMOS silicon.
1581 *
1582 * For DMA sends, we want to wait until the last byte has been
1583 * transferred out over the bus before we turn off DMA mode.  Alas, there
1584 * seems to be no terribly good way of doing this on a 5380 under all
1585 * conditions.  For non-scatter-gather operations, we can wait until REQ
1586 * and ACK both go false, or until a phase mismatch occurs.  Gather-sends
1587 * are nastier, since the device will be expecting more data than we
1588 * are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1589 * could test Last Byte Sent to assure transfer (I imagine this is precisely
1590 * why this signal was added to the newer chips) but on the older 538[01]
1591 * this signal does not exist.  The workaround for this lack is a watchdog;
1592 * we bail out of the wait-loop after a modest amount of wait-time if
1593 * the usual exit conditions are not met.  Not a terribly clean or
1594 * correct solution :-%
1595 *
1596 * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1597 * If the chip is in DMA receive mode, it will respond to a target's
1598 * REQ by latching the SCSI data into the INPUT DATA register and asserting
1599 * ACK, even if it has _already_ been notified by the DMA controller that
1600 * the current DMA transfer has completed!  If the NCR5380 is then taken
1601 * out of DMA mode, this already-acknowledged byte is lost. This is
1602 * not a problem for "one DMA transfer per READ command", because
1603 * the situation will never arise... either all of the data is DMA'ed
1604 * properly, or the target switches to MESSAGE IN phase to signal a
1605 * disconnection (either operation bringing the DMA to a clean halt).
1606 * However, in order to handle scatter-receive, we must work around the
1607 * problem.  The chosen fix is to DMA fewer bytes, then check for the
1608 * condition before taking the NCR5380 out of DMA mode.  One or two extra
1609 * bytes are transferred via PIO as necessary to fill out the original
1610 * request.
1611 */
1612
1613        if (hostdata->flags & FLAG_DMA_FIXUP) {
1614                if (p & SR_IO) {
1615                        /*
1616                         * The workaround was to transfer fewer bytes than we
1617                         * intended to with the pseudo-DMA read function, wait for
1618                         * the chip to latch the last byte, read it, and then disable
1619                         * pseudo-DMA mode.
1620                         *
1621                         * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1622                         * REQ is deasserted when ACK is asserted, and not reasserted
1623                         * until ACK goes false.  Since the NCR5380 won't lower ACK
1624                         * until DACK is asserted, which won't happen unless we twiddle
1625                         * the DMA port or we take the NCR5380 out of DMA mode, we
1626                         * can guarantee that we won't handshake another extra
1627                         * byte.
1628                         */
1629
1630                        if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
1631                                                  BASR_DRQ, BASR_DRQ, 0) < 0) {
1632                                result = -1;
1633                                shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1634                        }
1635                        if (NCR5380_poll_politely(hostdata, STATUS_REG,
1636                                                  SR_REQ, 0, 0) < 0) {
1637                                result = -1;
1638                                shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1639                        }
1640                        d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
1641                } else {
1642                        /*
1643                         * Wait for the last byte to be sent.  If REQ is being asserted for
1644                         * the byte we're interested, we'll ACK it and it will go false.
1645                         */
1646                        if (NCR5380_poll_politely2(hostdata,
1647                             BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1648                             BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, 0) < 0) {
1649                                result = -1;
1650                                shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1651                        }
1652                }
1653        }
1654
1655        NCR5380_dma_complete(instance);
1656        return result;
1657}
1658
1659/*
1660 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1661 *
1662 * Purpose : run through the various SCSI phases and do as the target
1663 * directs us to.  Operates on the currently connected command,
1664 * instance->connected.
1665 *
1666 * Inputs : instance, instance for which we are doing commands
1667 *
1668 * Side effects : SCSI things happen, the disconnected queue will be
1669 * modified if a command disconnects, *instance->connected will
1670 * change.
1671 *
1672 * XXX Note : we need to watch for bus free or a reset condition here
1673 * to recover from an unexpected bus free condition.
1674 */
1675
1676static void NCR5380_information_transfer(struct Scsi_Host *instance)
1677        __releases(&hostdata->lock) __acquires(&hostdata->lock)
1678{
1679        struct NCR5380_hostdata *hostdata = shost_priv(instance);
1680        unsigned char msgout = NOP;
1681        int sink = 0;
1682        int len;
1683        int transfersize;
1684        unsigned char *data;
1685        unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1686        struct scsi_cmnd *cmd;
1687
1688#ifdef SUN3_SCSI_VME
1689        dregs->csr |= CSR_INTR;
1690#endif
1691
1692        while ((cmd = hostdata->connected)) {
1693                struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1694
1695                tmp = NCR5380_read(STATUS_REG);
1696                /* We only have a valid SCSI phase when REQ is asserted */
1697                if (tmp & SR_REQ) {
1698                        phase = (tmp & PHASE_MASK);
1699                        if (phase != old_phase) {
1700                                old_phase = phase;
1701                                NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1702                        }
1703#ifdef CONFIG_SUN3
1704                        if (phase == PHASE_CMDOUT &&
1705                            sun3_dma_setup_done != cmd) {
1706                                int count;
1707
1708                                advance_sg_buffer(cmd);
1709
1710                                count = sun3scsi_dma_xfer_len(hostdata, cmd);
1711
1712                                if (count > 0) {
1713                                        if (rq_data_dir(cmd->request))
1714                                                sun3scsi_dma_send_setup(hostdata,
1715                                                                        cmd->SCp.ptr, count);
1716                                        else
1717                                                sun3scsi_dma_recv_setup(hostdata,
1718                                                                        cmd->SCp.ptr, count);
1719                                        sun3_dma_setup_done = cmd;
1720                                }
1721#ifdef SUN3_SCSI_VME
1722                                dregs->csr |= CSR_INTR;
1723#endif
1724                        }
1725#endif /* CONFIG_SUN3 */
1726
1727                        if (sink && (phase != PHASE_MSGOUT)) {
1728                                NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1729
1730                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1731                                              ICR_ASSERT_ACK);
1732                                while (NCR5380_read(STATUS_REG) & SR_REQ)
1733                                        ;
1734                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1735                                              ICR_ASSERT_ATN);
1736                                sink = 0;
1737                                continue;
1738                        }
1739
1740                        switch (phase) {
1741                        case PHASE_DATAOUT:
1742#if (NDEBUG & NDEBUG_NO_DATAOUT)
1743                                shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1744                                sink = 1;
1745                                do_abort(instance, 0);
1746                                cmd->result = DID_ERROR << 16;
1747                                complete_cmd(instance, cmd);
1748                                hostdata->connected = NULL;
1749                                hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1750                                return;
1751#endif
1752                        case PHASE_DATAIN:
1753                                /*
1754                                 * If there is no room left in the current buffer in the
1755                                 * scatter-gather list, move onto the next one.
1756                                 */
1757
1758                                advance_sg_buffer(cmd);
1759                                dsprintk(NDEBUG_INFORMATION, instance,
1760                                        "this residual %d, sg ents %d\n",
1761                                        cmd->SCp.this_residual,
1762                                        sg_nents(cmd->SCp.buffer));
1763
1764                                /*
1765                                 * The preferred transfer method is going to be
1766                                 * PSEUDO-DMA for systems that are strictly PIO,
1767                                 * since we can let the hardware do the handshaking.
1768                                 *
1769                                 * For this to work, we need to know the transfersize
1770                                 * ahead of time, since the pseudo-DMA code will sit
1771                                 * in an unconditional loop.
1772                                 */
1773
1774                                transfersize = 0;
1775                                if (!cmd->device->borken)
1776                                        transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
1777
1778                                if (transfersize > 0) {
1779                                        len = transfersize;
1780                                        if (NCR5380_transfer_dma(instance, &phase,
1781                                            &len, (unsigned char **)&cmd->SCp.ptr)) {
1782                                                /*
1783                                                 * If the watchdog timer fires, all future
1784                                                 * accesses to this device will use the
1785                                                 * polled-IO.
1786                                                 */
1787                                                scmd_printk(KERN_INFO, cmd,
1788                                                        "switching to slow handshake\n");
1789                                                cmd->device->borken = 1;
1790                                                do_reset(instance);
1791                                                bus_reset_cleanup(instance);
1792                                        }
1793                                } else {
1794                                        /* Transfer a small chunk so that the
1795                                         * irq mode lock is not held too long.
1796                                         */
1797                                        transfersize = min(cmd->SCp.this_residual,
1798                                                           NCR5380_PIO_CHUNK_SIZE);
1799                                        len = transfersize;
1800                                        NCR5380_transfer_pio(instance, &phase, &len,
1801                                                             (unsigned char **)&cmd->SCp.ptr,
1802                                                             0);
1803                                        cmd->SCp.this_residual -= transfersize - len;
1804                                }
1805#ifdef CONFIG_SUN3
1806                                if (sun3_dma_setup_done == cmd)
1807                                        sun3_dma_setup_done = NULL;
1808#endif
1809                                return;
1810                        case PHASE_MSGIN:
1811                                len = 1;
1812                                data = &tmp;
1813                                NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
1814                                cmd->SCp.Message = tmp;
1815
1816                                switch (tmp) {
1817                                case ABORT:
1818                                        set_host_byte(cmd, DID_ABORT);
1819                                        fallthrough;
1820                                case COMMAND_COMPLETE:
1821                                        /* Accept message by clearing ACK */
1822                                        sink = 1;
1823                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1824                                        dsprintk(NDEBUG_QUEUES, instance,
1825                                                 "COMMAND COMPLETE %p target %d lun %llu\n",
1826                                                 cmd, scmd_id(cmd), cmd->device->lun);
1827
1828                                        hostdata->connected = NULL;
1829                                        hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1830
1831                                        set_status_byte(cmd, cmd->SCp.Status);
1832
1833                                        set_resid_from_SCp(cmd);
1834
1835                                        if (cmd->cmnd[0] == REQUEST_SENSE)
1836                                                complete_cmd(instance, cmd);
1837                                        else {
1838                                                if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1839                                                    cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1840                                                        dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1841                                                                 cmd);
1842                                                        list_add_tail(&ncmd->list,
1843                                                                      &hostdata->autosense);
1844                                                } else
1845                                                        complete_cmd(instance, cmd);
1846                                        }
1847
1848                                        /*
1849                                         * Restore phase bits to 0 so an interrupted selection,
1850                                         * arbitration can resume.
1851                                         */
1852                                        NCR5380_write(TARGET_COMMAND_REG, 0);
1853
1854                                        return;
1855                                case MESSAGE_REJECT:
1856                                        /* Accept message by clearing ACK */
1857                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1858                                        switch (hostdata->last_message) {
1859                                        case HEAD_OF_QUEUE_TAG:
1860                                        case ORDERED_QUEUE_TAG:
1861                                        case SIMPLE_QUEUE_TAG:
1862                                                cmd->device->simple_tags = 0;
1863                                                hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1864                                                break;
1865                                        default:
1866                                                break;
1867                                        }
1868                                        break;
1869                                case DISCONNECT:
1870                                        /* Accept message by clearing ACK */
1871                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1872                                        hostdata->connected = NULL;
1873                                        list_add(&ncmd->list, &hostdata->disconnected);
1874                                        dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1875                                                 instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1876                                                 cmd, scmd_id(cmd), cmd->device->lun);
1877
1878                                        /*
1879                                         * Restore phase bits to 0 so an interrupted selection,
1880                                         * arbitration can resume.
1881                                         */
1882                                        NCR5380_write(TARGET_COMMAND_REG, 0);
1883
1884#ifdef SUN3_SCSI_VME
1885                                        dregs->csr |= CSR_DMA_ENABLE;
1886#endif
1887                                        return;
1888                                        /*
1889                                         * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1890                                         * operation, in violation of the SCSI spec so we can safely
1891                                         * ignore SAVE/RESTORE pointers calls.
1892                                         *
1893                                         * Unfortunately, some disks violate the SCSI spec and
1894                                         * don't issue the required SAVE_POINTERS message before
1895                                         * disconnecting, and we have to break spec to remain
1896                                         * compatible.
1897                                         */
1898                                case SAVE_POINTERS:
1899                                case RESTORE_POINTERS:
1900                                        /* Accept message by clearing ACK */
1901                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1902                                        break;
1903                                case EXTENDED_MESSAGE:
1904                                        /*
1905                                         * Start the message buffer with the EXTENDED_MESSAGE
1906                                         * byte, since spi_print_msg() wants the whole thing.
1907                                         */
1908                                        extended_msg[0] = EXTENDED_MESSAGE;
1909                                        /* Accept first byte by clearing ACK */
1910                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1911
1912                                        spin_unlock_irq(&hostdata->lock);
1913
1914                                        dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1915
1916                                        len = 2;
1917                                        data = extended_msg + 1;
1918                                        phase = PHASE_MSGIN;
1919                                        NCR5380_transfer_pio(instance, &phase, &len, &data, 1);
1920                                        dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1921                                                 (int)extended_msg[1],
1922                                                 (int)extended_msg[2]);
1923
1924                                        if (!len && extended_msg[1] > 0 &&
1925                                            extended_msg[1] <= sizeof(extended_msg) - 2) {
1926                                                /* Accept third byte by clearing ACK */
1927                                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1928                                                len = extended_msg[1] - 1;
1929                                                data = extended_msg + 3;
1930                                                phase = PHASE_MSGIN;
1931
1932                                                NCR5380_transfer_pio(instance, &phase, &len, &data, 1);
1933                                                dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
1934                                                         len);
1935
1936                                                switch (extended_msg[2]) {
1937                                                case EXTENDED_SDTR:
1938                                                case EXTENDED_WDTR:
1939                                                        tmp = 0;
1940                                                }
1941                                        } else if (len) {
1942                                                shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1943                                                tmp = 0;
1944                                        } else {
1945                                                shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
1946                                                             extended_msg[2], extended_msg[1]);
1947                                                tmp = 0;
1948                                        }
1949
1950                                        spin_lock_irq(&hostdata->lock);
1951                                        if (!hostdata->connected)
1952                                                return;
1953
1954                                        /* Reject message */
1955                                        fallthrough;
1956                                default:
1957                                        /*
1958                                         * If we get something weird that we aren't expecting,
1959                                         * log it.
1960                                         */
1961                                        if (tmp == EXTENDED_MESSAGE)
1962                                                scmd_printk(KERN_INFO, cmd,
1963                                                            "rejecting unknown extended message code %02x, length %d\n",
1964                                                            extended_msg[2], extended_msg[1]);
1965                                        else if (tmp)
1966                                                scmd_printk(KERN_INFO, cmd,
1967                                                            "rejecting unknown message code %02x\n",
1968                                                            tmp);
1969
1970                                        msgout = MESSAGE_REJECT;
1971                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1972                                        break;
1973                                } /* switch (tmp) */
1974                                break;
1975                        case PHASE_MSGOUT:
1976                                len = 1;
1977                                data = &msgout;
1978                                hostdata->last_message = msgout;
1979                                NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
1980                                if (msgout == ABORT) {
1981                                        hostdata->connected = NULL;
1982                                        hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
1983                                        cmd->result = DID_ERROR << 16;
1984                                        complete_cmd(instance, cmd);
1985                                        return;
1986                                }
1987                                msgout = NOP;
1988                                break;
1989                        case PHASE_CMDOUT:
1990                                len = cmd->cmd_len;
1991                                data = cmd->cmnd;
1992                                /*
1993                                 * XXX for performance reasons, on machines with a
1994                                 * PSEUDO-DMA architecture we should probably
1995                                 * use the dma transfer function.
1996                                 */
1997                                NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
1998                                break;
1999                        case PHASE_STATIN:
2000                                len = 1;
2001                                data = &tmp;
2002                                NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
2003                                cmd->SCp.Status = tmp;
2004                                break;
2005                        default:
2006                                shost_printk(KERN_ERR, instance, "unknown phase\n");
2007                                NCR5380_dprint(NDEBUG_ANY, instance);
2008                        } /* switch(phase) */
2009                } else {
2010                        spin_unlock_irq(&hostdata->lock);
2011                        NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
2012                        spin_lock_irq(&hostdata->lock);
2013                }
2014        }
2015}
2016
2017/*
2018 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2019 *
2020 * Purpose : does reselection, initializing the instance->connected
2021 * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2022 * nexus has been reestablished,
2023 *
2024 * Inputs : instance - this instance of the NCR5380.
2025 */
2026
2027static void NCR5380_reselect(struct Scsi_Host *instance)
2028{
2029        struct NCR5380_hostdata *hostdata = shost_priv(instance);
2030        unsigned char target_mask;
2031        unsigned char lun;
2032        unsigned char msg[3];
2033        struct NCR5380_cmd *ncmd;
2034        struct scsi_cmnd *tmp;
2035
2036        /*
2037         * Disable arbitration, etc. since the host adapter obviously
2038         * lost, and tell an interrupted NCR5380_select() to restart.
2039         */
2040
2041        NCR5380_write(MODE_REG, MR_BASE);
2042
2043        target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2044        if (!target_mask || target_mask & (target_mask - 1)) {
2045                shost_printk(KERN_WARNING, instance,
2046                             "reselect: bad target_mask 0x%02x\n", target_mask);
2047                return;
2048        }
2049
2050        /*
2051         * At this point, we have detected that our SCSI ID is on the bus,
2052         * SEL is true and BSY was false for at least one bus settle delay
2053         * (400 ns).
2054         *
2055         * We must assert BSY ourselves, until the target drops the SEL
2056         * signal.
2057         */
2058
2059        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2060        if (NCR5380_poll_politely(hostdata,
2061                                  STATUS_REG, SR_SEL, 0, 0) < 0) {
2062                shost_printk(KERN_ERR, instance, "reselect: !SEL timeout\n");
2063                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2064                return;
2065        }
2066        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2067
2068        /*
2069         * Wait for target to go into MSGIN.
2070         */
2071
2072        if (NCR5380_poll_politely(hostdata,
2073                                  STATUS_REG, SR_REQ, SR_REQ, 0) < 0) {
2074                if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
2075                        /* BUS FREE phase */
2076                        return;
2077                shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
2078                do_abort(instance, 0);
2079                return;
2080        }
2081
2082#ifdef CONFIG_SUN3
2083        /* acknowledge toggle to MSGIN */
2084        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2085
2086        /* peek at the byte without really hitting the bus */
2087        msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2088#else
2089        {
2090                int len = 1;
2091                unsigned char *data = msg;
2092                unsigned char phase = PHASE_MSGIN;
2093
2094                NCR5380_transfer_pio(instance, &phase, &len, &data, 0);
2095
2096                if (len) {
2097                        do_abort(instance, 0);
2098                        return;
2099                }
2100        }
2101#endif /* CONFIG_SUN3 */
2102
2103        if (!(msg[0] & 0x80)) {
2104                shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2105                spi_print_msg(msg);
2106                printk("\n");
2107                do_abort(instance, 0);
2108                return;
2109        }
2110        lun = msg[0] & 0x07;
2111
2112        /*
2113         * We need to add code for SCSI-II to track which devices have
2114         * I_T_L_Q nexuses established, and which have simple I_T_L
2115         * nexuses so we can chose to do additional data transfer.
2116         */
2117
2118        /*
2119         * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2120         * just reestablished, and remove it from the disconnected queue.
2121         */
2122
2123        tmp = NULL;
2124        list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2125                struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2126
2127                if (target_mask == (1 << scmd_id(cmd)) &&
2128                    lun == (u8)cmd->device->lun) {
2129                        list_del(&ncmd->list);
2130                        tmp = cmd;
2131                        break;
2132                }
2133        }
2134
2135        if (tmp) {
2136                dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2137                         "reselect: removed %p from disconnected queue\n", tmp);
2138        } else {
2139                int target = ffs(target_mask) - 1;
2140
2141                shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2142                             target_mask, lun);
2143                /*
2144                 * Since we have an established nexus that we can't do anything
2145                 * with, we must abort it.
2146                 */
2147                if (do_abort(instance, 0) == 0)
2148                        hostdata->busy[target] &= ~(1 << lun);
2149                return;
2150        }
2151
2152#ifdef CONFIG_SUN3
2153        if (sun3_dma_setup_done != tmp) {
2154                int count;
2155
2156                advance_sg_buffer(tmp);
2157
2158                count = sun3scsi_dma_xfer_len(hostdata, tmp);
2159
2160                if (count > 0) {
2161                        if (rq_data_dir(tmp->request))
2162                                sun3scsi_dma_send_setup(hostdata,
2163                                                        tmp->SCp.ptr, count);
2164                        else
2165                                sun3scsi_dma_recv_setup(hostdata,
2166                                                        tmp->SCp.ptr, count);
2167                        sun3_dma_setup_done = tmp;
2168                }
2169        }
2170
2171        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2172#endif /* CONFIG_SUN3 */
2173
2174        /* Accept message by clearing ACK */
2175        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2176
2177        hostdata->connected = tmp;
2178        dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
2179                 scmd_id(tmp), tmp->device->lun);
2180}
2181
2182/**
2183 * list_find_cmd - test for presence of a command in a linked list
2184 * @haystack: list of commands
2185 * @needle: command to search for
2186 */
2187
2188static bool list_find_cmd(struct list_head *haystack,
2189                          struct scsi_cmnd *needle)
2190{
2191        struct NCR5380_cmd *ncmd;
2192
2193        list_for_each_entry(ncmd, haystack, list)
2194                if (NCR5380_to_scmd(ncmd) == needle)
2195                        return true;
2196        return false;
2197}
2198
2199/**
2200 * list_remove_cmd - remove a command from linked list
2201 * @haystack: list of commands
2202 * @needle: command to remove
2203 */
2204
2205static bool list_del_cmd(struct list_head *haystack,
2206                         struct scsi_cmnd *needle)
2207{
2208        if (list_find_cmd(haystack, needle)) {
2209                struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2210
2211                list_del(&ncmd->list);
2212                return true;
2213        }
2214        return false;
2215}
2216
2217/**
2218 * NCR5380_abort - scsi host eh_abort_handler() method
2219 * @cmd: the command to be aborted
2220 *
2221 * Try to abort a given command by removing it from queues and/or sending
2222 * the target an abort message. This may not succeed in causing a target
2223 * to abort the command. Nonetheless, the low-level driver must forget about
2224 * the command because the mid-layer reclaims it and it may be re-issued.
2225 *
2226 * The normal path taken by a command is as follows. For EH we trace this
2227 * same path to locate and abort the command.
2228 *
2229 * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2230 * [disconnected -> connected ->]...
2231 * [autosense -> connected ->] done
2232 *
2233 * If cmd was not found at all then presumably it has already been completed,
2234 * in which case return SUCCESS to try to avoid further EH measures.
2235 *
2236 * If the command has not completed yet, we must not fail to find it.
2237 * We have no option but to forget the aborted command (even if it still
2238 * lacks sense data). The mid-layer may re-issue a command that is in error
2239 * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2240 * this driver are such that a command can appear on one queue only.
2241 *
2242 * The lock protects driver data structures, but EH handlers also use it
2243 * to serialize their own execution and prevent their own re-entry.
2244 */
2245
2246static int NCR5380_abort(struct scsi_cmnd *cmd)
2247{
2248        struct Scsi_Host *instance = cmd->device->host;
2249        struct NCR5380_hostdata *hostdata = shost_priv(instance);
2250        unsigned long flags;
2251        int result = SUCCESS;
2252
2253        spin_lock_irqsave(&hostdata->lock, flags);
2254
2255#if (NDEBUG & NDEBUG_ANY)
2256        scmd_printk(KERN_INFO, cmd, __func__);
2257#endif
2258        NCR5380_dprint(NDEBUG_ANY, instance);
2259        NCR5380_dprint_phase(NDEBUG_ANY, instance);
2260
2261        if (list_del_cmd(&hostdata->unissued, cmd)) {
2262                dsprintk(NDEBUG_ABORT, instance,
2263                         "abort: removed %p from issue queue\n", cmd);
2264                cmd->result = DID_ABORT << 16;
2265                cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2266                goto out;
2267        }
2268
2269        if (hostdata->selecting == cmd) {
2270                dsprintk(NDEBUG_ABORT, instance,
2271                         "abort: cmd %p == selecting\n", cmd);
2272                hostdata->selecting = NULL;
2273                cmd->result = DID_ABORT << 16;
2274                complete_cmd(instance, cmd);
2275                goto out;
2276        }
2277
2278        if (list_del_cmd(&hostdata->disconnected, cmd)) {
2279                dsprintk(NDEBUG_ABORT, instance,
2280                         "abort: removed %p from disconnected list\n", cmd);
2281                /* Can't call NCR5380_select() and send ABORT because that
2282                 * means releasing the lock. Need a bus reset.
2283                 */
2284                set_host_byte(cmd, DID_ERROR);
2285                complete_cmd(instance, cmd);
2286                result = FAILED;
2287                goto out;
2288        }
2289
2290        if (hostdata->connected == cmd) {
2291                dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2292                hostdata->connected = NULL;
2293                hostdata->dma_len = 0;
2294                if (do_abort(instance, 0) < 0) {
2295                        set_host_byte(cmd, DID_ERROR);
2296                        complete_cmd(instance, cmd);
2297                        result = FAILED;
2298                        goto out;
2299                }
2300                set_host_byte(cmd, DID_ABORT);
2301                complete_cmd(instance, cmd);
2302                goto out;
2303        }
2304
2305        if (list_del_cmd(&hostdata->autosense, cmd)) {
2306                dsprintk(NDEBUG_ABORT, instance,
2307                         "abort: removed %p from sense queue\n", cmd);
2308                complete_cmd(instance, cmd);
2309        }
2310
2311out:
2312        if (result == FAILED)
2313                dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2314        else {
2315                hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
2316                dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2317        }
2318
2319        queue_work(hostdata->work_q, &hostdata->main_task);
2320        spin_unlock_irqrestore(&hostdata->lock, flags);
2321
2322        return result;
2323}
2324
2325
2326static void bus_reset_cleanup(struct Scsi_Host *instance)
2327{
2328        struct NCR5380_hostdata *hostdata = shost_priv(instance);
2329        int i;
2330        struct NCR5380_cmd *ncmd;
2331
2332        /* reset NCR registers */
2333        NCR5380_write(MODE_REG, MR_BASE);
2334        NCR5380_write(TARGET_COMMAND_REG, 0);
2335        NCR5380_write(SELECT_ENABLE_REG, 0);
2336
2337        /* After the reset, there are no more connected or disconnected commands
2338         * and no busy units; so clear the low-level status here to avoid
2339         * conflicts when the mid-level code tries to wake up the affected
2340         * commands!
2341         */
2342
2343        if (hostdata->selecting) {
2344                hostdata->selecting->result = DID_RESET << 16;
2345                complete_cmd(instance, hostdata->selecting);
2346                hostdata->selecting = NULL;
2347        }
2348
2349        list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2350                struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2351
2352                set_host_byte(cmd, DID_RESET);
2353                complete_cmd(instance, cmd);
2354        }
2355        INIT_LIST_HEAD(&hostdata->disconnected);
2356
2357        list_for_each_entry(ncmd, &hostdata->autosense, list) {
2358                struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2359
2360                cmd->scsi_done(cmd);
2361        }
2362        INIT_LIST_HEAD(&hostdata->autosense);
2363
2364        if (hostdata->connected) {
2365                set_host_byte(hostdata->connected, DID_RESET);
2366                complete_cmd(instance, hostdata->connected);
2367                hostdata->connected = NULL;
2368        }
2369
2370        for (i = 0; i < 8; ++i)
2371                hostdata->busy[i] = 0;
2372        hostdata->dma_len = 0;
2373
2374        queue_work(hostdata->work_q, &hostdata->main_task);
2375}
2376
2377/**
2378 * NCR5380_host_reset - reset the SCSI host
2379 * @cmd: SCSI command undergoing EH
2380 *
2381 * Returns SUCCESS
2382 */
2383
2384static int NCR5380_host_reset(struct scsi_cmnd *cmd)
2385{
2386        struct Scsi_Host *instance = cmd->device->host;
2387        struct NCR5380_hostdata *hostdata = shost_priv(instance);
2388        unsigned long flags;
2389        struct NCR5380_cmd *ncmd;
2390
2391        spin_lock_irqsave(&hostdata->lock, flags);
2392
2393#if (NDEBUG & NDEBUG_ANY)
2394        shost_printk(KERN_INFO, instance, __func__);
2395#endif
2396        NCR5380_dprint(NDEBUG_ANY, instance);
2397        NCR5380_dprint_phase(NDEBUG_ANY, instance);
2398
2399        list_for_each_entry(ncmd, &hostdata->unissued, list) {
2400                struct scsi_cmnd *scmd = NCR5380_to_scmd(ncmd);
2401
2402                scmd->result = DID_RESET << 16;
2403                scmd->scsi_done(scmd);
2404        }
2405        INIT_LIST_HEAD(&hostdata->unissued);
2406
2407        do_reset(instance);
2408        bus_reset_cleanup(instance);
2409
2410        spin_unlock_irqrestore(&hostdata->lock, flags);
2411
2412        return SUCCESS;
2413}
2414