linux/drivers/scsi/NCR5380.c
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   1/* 
   2 * NCR 5380 generic driver routines.  These should make it *trivial*
   3 *      to implement 5380 SCSI drivers under Linux with a non-trantor
   4 *      architecture.
   5 *
   6 *      Note that these routines also work with NR53c400 family chips.
   7 *
   8 * Copyright 1993, Drew Eckhardt
   9 *      Visionary Computing 
  10 *      (Unix and Linux consulting and custom programming)
  11 *      drew@colorado.edu
  12 *      +1 (303) 666-5836
  13 *
  14 * DISTRIBUTION RELEASE 6. 
  15 *
  16 * For more information, please consult 
  17 *
  18 * NCR 5380 Family
  19 * SCSI Protocol Controller
  20 * Databook
  21 *
  22 * NCR Microelectronics
  23 * 1635 Aeroplaza Drive
  24 * Colorado Springs, CO 80916
  25 * 1+ (719) 578-3400
  26 * 1+ (800) 334-5454
  27 */
  28
  29/*
  30 * $Log: NCR5380.c,v $
  31
  32 * Revision 1.10 1998/9/2       Alan Cox
  33 *                              (alan@lxorguk.ukuu.org.uk)
  34 * Fixed up the timer lockups reported so far. Things still suck. Looking 
  35 * forward to 2.3 and per device request queues. Then it'll be possible to
  36 * SMP thread this beast and improve life no end.
  37 
  38 * Revision 1.9  1997/7/27      Ronald van Cuijlenborg
  39 *                              (ronald.van.cuijlenborg@tip.nl or nutty@dds.nl)
  40 * (hopefully) fixed and enhanced USLEEP
  41 * added support for DTC3181E card (for Mustek scanner)
  42 *
  43
  44 * Revision 1.8                 Ingmar Baumgart
  45 *                              (ingmar@gonzo.schwaben.de)
  46 * added support for NCR53C400a card
  47 *
  48
  49 * Revision 1.7  1996/3/2       Ray Van Tassle (rayvt@comm.mot.com)
  50 * added proc_info
  51 * added support needed for DTC 3180/3280
  52 * fixed a couple of bugs
  53 *
  54
  55 * Revision 1.5  1994/01/19  09:14:57  drew
  56 * Fixed udelay() hack that was being used on DATAOUT phases
  57 * instead of a proper wait for the final handshake.
  58 *
  59 * Revision 1.4  1994/01/19  06:44:25  drew
  60 * *** empty log message ***
  61 *
  62 * Revision 1.3  1994/01/19  05:24:40  drew
  63 * Added support for TCR LAST_BYTE_SENT bit.
  64 *
  65 * Revision 1.2  1994/01/15  06:14:11  drew
  66 * REAL DMA support, bug fixes.
  67 *
  68 * Revision 1.1  1994/01/15  06:00:54  drew
  69 * Initial revision
  70 *
  71 */
  72
  73/*
  74 * Further development / testing that should be done : 
  75 * 1.  Cleanup the NCR5380_transfer_dma function and DMA operation complete
  76 *     code so that everything does the same thing that's done at the 
  77 *     end of a pseudo-DMA read operation.
  78 *
  79 * 2.  Fix REAL_DMA (interrupt driven, polled works fine) -
  80 *     basically, transfer size needs to be reduced by one 
  81 *     and the last byte read as is done with PSEUDO_DMA.
  82 * 
  83 * 4.  Test SCSI-II tagged queueing (I have no devices which support 
  84 *      tagged queueing)
  85 *
  86 * 5.  Test linked command handling code after Eric is ready with 
  87 *      the high level code.
  88 */
  89#include <scsi/scsi_dbg.h>
  90#include <scsi/scsi_transport_spi.h>
  91
  92#ifndef NDEBUG
  93#define NDEBUG 0
  94#endif
  95#ifndef NDEBUG_ABORT
  96#define NDEBUG_ABORT 0
  97#endif
  98
  99#if (NDEBUG & NDEBUG_LISTS)
 100#define LIST(x,y) {printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); }
 101#define REMOVE(w,x,y,z) {printk("LINE:%d   Removing: %p->%p  %p->%p \n", __LINE__, (void*)(w), (void*)(x), (void*)(y), (void*)(z)); if ((x)==(y)) udelay(5); }
 102#else
 103#define LIST(x,y)
 104#define REMOVE(w,x,y,z)
 105#endif
 106
 107#ifndef notyet
 108#undef LINKED
 109#undef REAL_DMA
 110#endif
 111
 112#ifdef REAL_DMA_POLL
 113#undef READ_OVERRUNS
 114#define READ_OVERRUNS
 115#endif
 116
 117#ifdef BOARD_REQUIRES_NO_DELAY
 118#define io_recovery_delay(x)
 119#else
 120#define io_recovery_delay(x)    udelay(x)
 121#endif
 122
 123/*
 124 * Design
 125 *
 126 * This is a generic 5380 driver.  To use it on a different platform, 
 127 * one simply writes appropriate system specific macros (ie, data
 128 * transfer - some PC's will use the I/O bus, 68K's must use 
 129 * memory mapped) and drops this file in their 'C' wrapper.
 130 *
 131 * (Note from hch:  unfortunately it was not enough for the different
 132 * m68k folks and instead of improving this driver they copied it
 133 * and hacked it up for their needs.  As a consequence they lost
 134 * most updates to this driver.  Maybe someone will fix all these
 135 * drivers to use a common core one day..)
 136 *
 137 * As far as command queueing, two queues are maintained for 
 138 * each 5380 in the system - commands that haven't been issued yet,
 139 * and commands that are currently executing.  This means that an 
 140 * unlimited number of commands may be queued, letting 
 141 * more commands propagate from the higher driver levels giving higher 
 142 * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported, 
 143 * allowing multiple commands to propagate all the way to a SCSI-II device 
 144 * while a command is already executing.
 145 *
 146 *
 147 * Issues specific to the NCR5380 : 
 148 *
 149 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead 
 150 * piece of hardware that requires you to sit in a loop polling for 
 151 * the REQ signal as long as you are connected.  Some devices are 
 152 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect 
 153 * while doing long seek operations.
 154 * 
 155 * The workaround for this is to keep track of devices that have
 156 * disconnected.  If the device hasn't disconnected, for commands that
 157 * should disconnect, we do something like 
 158 *
 159 * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
 160 * 
 161 * Some tweaking of N and M needs to be done.  An algorithm based 
 162 * on "time to data" would give the best results as long as short time
 163 * to datas (ie, on the same track) were considered, however these 
 164 * broken devices are the exception rather than the rule and I'd rather
 165 * spend my time optimizing for the normal case.
 166 *
 167 * Architecture :
 168 *
 169 * At the heart of the design is a coroutine, NCR5380_main,
 170 * which is started from a workqueue for each NCR5380 host in the
 171 * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
 172 * removing the commands from the issue queue and calling
 173 * NCR5380_select() if a nexus is not established. 
 174 *
 175 * Once a nexus is established, the NCR5380_information_transfer()
 176 * phase goes through the various phases as instructed by the target.
 177 * if the target goes into MSG IN and sends a DISCONNECT message,
 178 * the command structure is placed into the per instance disconnected
 179 * queue, and NCR5380_main tries to find more work.  If the target is 
 180 * idle for too long, the system will try to sleep.
 181 *
 182 * If a command has disconnected, eventually an interrupt will trigger,
 183 * calling NCR5380_intr()  which will in turn call NCR5380_reselect
 184 * to reestablish a nexus.  This will run main if necessary.
 185 *
 186 * On command termination, the done function will be called as 
 187 * appropriate.
 188 *
 189 * SCSI pointers are maintained in the SCp field of SCSI command 
 190 * structures, being initialized after the command is connected
 191 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
 192 * Note that in violation of the standard, an implicit SAVE POINTERS operation
 193 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
 194 */
 195
 196/*
 197 * Using this file :
 198 * This file a skeleton Linux SCSI driver for the NCR 5380 series
 199 * of chips.  To use it, you write an architecture specific functions 
 200 * and macros and include this file in your driver.
 201 *
 202 * These macros control options : 
 203 * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be 
 204 *      defined.
 205 * 
 206 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
 207 *      for commands that return with a CHECK CONDITION status. 
 208 *
 209 * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
 210 *      transceivers. 
 211 *
 212 * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
 213 *      override-configure an IRQ.
 214 *
 215 * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
 216 *      bytes at a time.  Since interrupts are disabled by default during
 217 *      these transfers, we might need this to give reasonable interrupt
 218 *      service time if the transfer size gets too large.
 219 *
 220 * LINKED - if defined, linked commands are supported.
 221 *
 222 * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
 223 *
 224 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
 225 *
 226 * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
 227 *      rely on phase mismatch and EOP interrupts to determine end 
 228 *      of phase.
 229 *
 230 * UNSAFE - leave interrupts enabled during pseudo-DMA transfers.  You
 231 *          only really want to use this if you're having a problem with
 232 *          dropped characters during high speed communications, and even
 233 *          then, you're going to be better off twiddling with transfersize
 234 *          in the high level code.
 235 *
 236 * Defaults for these will be provided although the user may want to adjust 
 237 * these to allocate CPU resources to the SCSI driver or "real" code.
 238 * 
 239 * USLEEP_SLEEP - amount of time, in jiffies, to sleep
 240 *
 241 * USLEEP_POLL - amount of time, in jiffies, to poll
 242 *
 243 * These macros MUST be defined :
 244 * NCR5380_local_declare() - declare any local variables needed for your
 245 *      transfer routines.
 246 *
 247 * NCR5380_setup(instance) - initialize any local variables needed from a given
 248 *      instance of the host adapter for NCR5380_{read,write,pread,pwrite}
 249 * 
 250 * NCR5380_read(register)  - read from the specified register
 251 *
 252 * NCR5380_write(register, value) - write to the specific register 
 253 *
 254 * NCR5380_implementation_fields  - additional fields needed for this 
 255 *      specific implementation of the NCR5380
 256 *
 257 * Either real DMA *or* pseudo DMA may be implemented
 258 * REAL functions : 
 259 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
 260 * Note that the DMA setup functions should return the number of bytes 
 261 *      that they were able to program the controller for.
 262 *
 263 * Also note that generic i386/PC versions of these macros are 
 264 *      available as NCR5380_i386_dma_write_setup,
 265 *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
 266 *
 267 * NCR5380_dma_write_setup(instance, src, count) - initialize
 268 * NCR5380_dma_read_setup(instance, dst, count) - initialize
 269 * NCR5380_dma_residual(instance); - residual count
 270 *
 271 * PSEUDO functions :
 272 * NCR5380_pwrite(instance, src, count)
 273 * NCR5380_pread(instance, dst, count);
 274 *
 275 * The generic driver is initialized by calling NCR5380_init(instance),
 276 * after setting the appropriate host specific fields and ID.  If the 
 277 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
 278 * possible) function may be used.
 279 */
 280
 281static int do_abort(struct Scsi_Host *host);
 282static void do_reset(struct Scsi_Host *host);
 283
 284/*
 285 *      initialize_SCp          -       init the scsi pointer field
 286 *      @cmd: command block to set up
 287 *
 288 *      Set up the internal fields in the SCSI command.
 289 */
 290
 291static __inline__ void initialize_SCp(Scsi_Cmnd * cmd)
 292{
 293        /* 
 294         * Initialize the Scsi Pointer field so that all of the commands in the 
 295         * various queues are valid.
 296         */
 297
 298        if (scsi_bufflen(cmd)) {
 299                cmd->SCp.buffer = scsi_sglist(cmd);
 300                cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 301                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 302                cmd->SCp.this_residual = cmd->SCp.buffer->length;
 303        } else {
 304                cmd->SCp.buffer = NULL;
 305                cmd->SCp.buffers_residual = 0;
 306                cmd->SCp.ptr = NULL;
 307                cmd->SCp.this_residual = 0;
 308        }
 309}
 310
 311/**
 312 *      NCR5380_poll_politely   -       wait for NCR5380 status bits
 313 *      @instance: controller to poll
 314 *      @reg: 5380 register to poll
 315 *      @bit: Bitmask to check
 316 *      @val: Value required to exit
 317 *
 318 *      Polls the NCR5380 in a reasonably efficient manner waiting for
 319 *      an event to occur, after a short quick poll we begin giving the
 320 *      CPU back in non IRQ contexts
 321 *
 322 *      Returns the value of the register or a negative error code.
 323 */
 324 
 325static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
 326{
 327        NCR5380_local_declare();
 328        int n = 500;            /* At about 8uS a cycle for the cpu access */
 329        unsigned long end = jiffies + t;
 330        int r;
 331        
 332        NCR5380_setup(instance);
 333
 334        while( n-- > 0)
 335        {
 336                r = NCR5380_read(reg);
 337                if((r & bit) == val)
 338                        return 0;
 339                cpu_relax();
 340        }
 341        
 342        /* t time yet ? */
 343        while(time_before(jiffies, end))
 344        {
 345                r = NCR5380_read(reg);
 346                if((r & bit) == val)
 347                        return 0;
 348                if(!in_interrupt())
 349                        cond_resched();
 350                else
 351                        cpu_relax();
 352        }
 353        return -ETIMEDOUT;
 354}
 355
 356static struct {
 357        unsigned char value;
 358        const char *name;
 359} phases[] __maybe_unused = {
 360        {PHASE_DATAOUT, "DATAOUT"}, 
 361        {PHASE_DATAIN, "DATAIN"}, 
 362        {PHASE_CMDOUT, "CMDOUT"}, 
 363        {PHASE_STATIN, "STATIN"}, 
 364        {PHASE_MSGOUT, "MSGOUT"}, 
 365        {PHASE_MSGIN, "MSGIN"}, 
 366        {PHASE_UNKNOWN, "UNKNOWN"}
 367};
 368
 369#if NDEBUG
 370static struct {
 371        unsigned char mask;
 372        const char *name;
 373} signals[] = { 
 374        {SR_DBP, "PARITY"}, 
 375        {SR_RST, "RST"}, 
 376        {SR_BSY, "BSY"}, 
 377        {SR_REQ, "REQ"}, 
 378        {SR_MSG, "MSG"}, 
 379        {SR_CD, "CD"}, 
 380        {SR_IO, "IO"}, 
 381        {SR_SEL, "SEL"}, 
 382        {0, NULL}
 383}, 
 384basrs[] = {
 385        {BASR_ATN, "ATN"}, 
 386        {BASR_ACK, "ACK"}, 
 387        {0, NULL}
 388}, 
 389icrs[] = { 
 390        {ICR_ASSERT_RST, "ASSERT RST"}, 
 391        {ICR_ASSERT_ACK, "ASSERT ACK"}, 
 392        {ICR_ASSERT_BSY, "ASSERT BSY"}, 
 393        {ICR_ASSERT_SEL, "ASSERT SEL"}, 
 394        {ICR_ASSERT_ATN, "ASSERT ATN"}, 
 395        {ICR_ASSERT_DATA, "ASSERT DATA"}, 
 396        {0, NULL}
 397}, 
 398mrs[] = { 
 399        {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, 
 400        {MR_TARGET, "MODE TARGET"}, 
 401        {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, 
 402        {MR_ENABLE_PAR_INTR, "MODE PARITY INTR"}, 
 403        {MR_MONITOR_BSY, "MODE MONITOR BSY"}, 
 404        {MR_DMA_MODE, "MODE DMA"}, 
 405        {MR_ARBITRATE, "MODE ARBITRATION"}, 
 406        {0, NULL}
 407};
 408
 409/**
 410 *      NCR5380_print   -       print scsi bus signals
 411 *      @instance:      adapter state to dump
 412 *
 413 *      Print the SCSI bus signals for debugging purposes
 414 *
 415 *      Locks: caller holds hostdata lock (not essential)
 416 */
 417
 418static void NCR5380_print(struct Scsi_Host *instance)
 419{
 420        NCR5380_local_declare();
 421        unsigned char status, data, basr, mr, icr, i;
 422        NCR5380_setup(instance);
 423
 424        data = NCR5380_read(CURRENT_SCSI_DATA_REG);
 425        status = NCR5380_read(STATUS_REG);
 426        mr = NCR5380_read(MODE_REG);
 427        icr = NCR5380_read(INITIATOR_COMMAND_REG);
 428        basr = NCR5380_read(BUS_AND_STATUS_REG);
 429
 430        printk("STATUS_REG: %02x ", status);
 431        for (i = 0; signals[i].mask; ++i)
 432                if (status & signals[i].mask)
 433                        printk(",%s", signals[i].name);
 434        printk("\nBASR: %02x ", basr);
 435        for (i = 0; basrs[i].mask; ++i)
 436                if (basr & basrs[i].mask)
 437                        printk(",%s", basrs[i].name);
 438        printk("\nICR: %02x ", icr);
 439        for (i = 0; icrs[i].mask; ++i)
 440                if (icr & icrs[i].mask)
 441                        printk(",%s", icrs[i].name);
 442        printk("\nMODE: %02x ", mr);
 443        for (i = 0; mrs[i].mask; ++i)
 444                if (mr & mrs[i].mask)
 445                        printk(",%s", mrs[i].name);
 446        printk("\n");
 447}
 448
 449
 450/* 
 451 *      NCR5380_print_phase     -       show SCSI phase
 452 *      @instance: adapter to dump
 453 *
 454 *      Print the current SCSI phase for debugging purposes
 455 *
 456 *      Locks: none
 457 */
 458
 459static void NCR5380_print_phase(struct Scsi_Host *instance)
 460{
 461        NCR5380_local_declare();
 462        unsigned char status;
 463        int i;
 464        NCR5380_setup(instance);
 465
 466        status = NCR5380_read(STATUS_REG);
 467        if (!(status & SR_REQ))
 468                printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
 469        else {
 470                for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
 471                printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
 472        }
 473}
 474#endif
 475
 476/*
 477 * These need tweaking, and would probably work best as per-device 
 478 * flags initialized differently for disk, tape, cd, etc devices.
 479 * People with broken devices are free to experiment as to what gives
 480 * the best results for them.
 481 *
 482 * USLEEP_SLEEP should be a minimum seek time.
 483 *
 484 * USLEEP_POLL should be a maximum rotational latency.
 485 */
 486#ifndef USLEEP_SLEEP
 487/* 20 ms (reasonable hard disk speed) */
 488#define USLEEP_SLEEP (20*HZ/1000)
 489#endif
 490/* 300 RPM (floppy speed) */
 491#ifndef USLEEP_POLL
 492#define USLEEP_POLL (200*HZ/1000)
 493#endif
 494#ifndef USLEEP_WAITLONG
 495/* RvC: (reasonable time to wait on select error) */
 496#define USLEEP_WAITLONG USLEEP_SLEEP
 497#endif
 498
 499/* 
 500 * Function : int should_disconnect (unsigned char cmd)
 501 *
 502 * Purpose : decide whether a command would normally disconnect or 
 503 *      not, since if it won't disconnect we should go to sleep.
 504 *
 505 * Input : cmd - opcode of SCSI command
 506 *
 507 * Returns : DISCONNECT_LONG if we should disconnect for a really long 
 508 *      time (ie always, sleep, look for REQ active, sleep), 
 509 *      DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
 510 *      time-to-data delay, DISCONNECT_NONE if this command would return
 511 *      immediately.
 512 *
 513 *      Future sleep algorithms based on time to data can exploit 
 514 *      something like this so they can differentiate between "normal" 
 515 *      (ie, read, write, seek) and unusual commands (ie, * format).
 516 *
 517 * Note : We don't deal with commands that handle an immediate disconnect,
 518 *        
 519 */
 520
 521static int should_disconnect(unsigned char cmd)
 522{
 523        switch (cmd) {
 524        case READ_6:
 525        case WRITE_6:
 526        case SEEK_6:
 527        case READ_10:
 528        case WRITE_10:
 529        case SEEK_10:
 530                return DISCONNECT_TIME_TO_DATA;
 531        case FORMAT_UNIT:
 532        case SEARCH_HIGH:
 533        case SEARCH_LOW:
 534        case SEARCH_EQUAL:
 535                return DISCONNECT_LONG;
 536        default:
 537                return DISCONNECT_NONE;
 538        }
 539}
 540
 541static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
 542{
 543        hostdata->time_expires = jiffies + timeout;
 544        schedule_delayed_work(&hostdata->coroutine, timeout);
 545}
 546
 547
 548static int probe_irq __initdata = 0;
 549
 550/**
 551 *      probe_intr      -       helper for IRQ autoprobe
 552 *      @irq: interrupt number
 553 *      @dev_id: unused
 554 *      @regs: unused
 555 *
 556 *      Set a flag to indicate the IRQ in question was received. This is
 557 *      used by the IRQ probe code.
 558 */
 559 
 560static irqreturn_t __init probe_intr(int irq, void *dev_id)
 561{
 562        probe_irq = irq;
 563        return IRQ_HANDLED;
 564}
 565
 566/**
 567 *      NCR5380_probe_irq       -       find the IRQ of an NCR5380
 568 *      @instance: NCR5380 controller
 569 *      @possible: bitmask of ISA IRQ lines
 570 *
 571 *      Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
 572 *      and then looking to see what interrupt actually turned up.
 573 *
 574 *      Locks: none, irqs must be enabled on entry
 575 */
 576
 577static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
 578                                                int possible)
 579{
 580        NCR5380_local_declare();
 581        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
 582        unsigned long timeout;
 583        int trying_irqs, i, mask;
 584        NCR5380_setup(instance);
 585
 586        for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
 587                if ((mask & possible) && (request_irq(i, &probe_intr, IRQF_DISABLED, "NCR-probe", NULL) == 0))
 588                        trying_irqs |= mask;
 589
 590        timeout = jiffies + (250 * HZ / 1000);
 591        probe_irq = SCSI_IRQ_NONE;
 592
 593        /*
 594         * A interrupt is triggered whenever BSY = false, SEL = true
 595         * and a bit set in the SELECT_ENABLE_REG is asserted on the 
 596         * SCSI bus.
 597         *
 598         * Note that the bus is only driven when the phase control signals
 599         * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
 600         * to zero.
 601         */
 602
 603        NCR5380_write(TARGET_COMMAND_REG, 0);
 604        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 605        NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
 606        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
 607
 608        while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
 609                schedule_timeout_uninterruptible(1);
 610        
 611        NCR5380_write(SELECT_ENABLE_REG, 0);
 612        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 613
 614        for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
 615                if (trying_irqs & mask)
 616                        free_irq(i, NULL);
 617
 618        return probe_irq;
 619}
 620
 621/**
 622 *      NCR58380_print_options  -       show options
 623 *      @instance: unused for now
 624 *
 625 *      Called by probe code indicating the NCR5380 driver options that 
 626 *      were selected. At some point this will switch to runtime options
 627 *      read from the adapter in question
 628 *
 629 *      Locks: none
 630 */
 631
 632static void __init __maybe_unused
 633NCR5380_print_options(struct Scsi_Host *instance)
 634{
 635        printk(" generic options"
 636#ifdef AUTOPROBE_IRQ
 637               " AUTOPROBE_IRQ"
 638#endif
 639#ifdef AUTOSENSE
 640               " AUTOSENSE"
 641#endif
 642#ifdef DIFFERENTIAL
 643               " DIFFERENTIAL"
 644#endif
 645#ifdef REAL_DMA
 646               " REAL DMA"
 647#endif
 648#ifdef REAL_DMA_POLL
 649               " REAL DMA POLL"
 650#endif
 651#ifdef PARITY
 652               " PARITY"
 653#endif
 654#ifdef PSEUDO_DMA
 655               " PSEUDO DMA"
 656#endif
 657#ifdef UNSAFE
 658               " UNSAFE "
 659#endif
 660            );
 661        printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
 662        printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
 663        if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
 664                printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
 665        }
 666}
 667
 668/**
 669 *      NCR5380_print_status    -       dump controller info
 670 *      @instance: controller to dump
 671 *
 672 *      Print commands in the various queues, called from NCR5380_abort 
 673 *      and NCR5380_debug to aid debugging.
 674 *
 675 *      Locks: called functions disable irqs
 676 */
 677
 678static void NCR5380_print_status(struct Scsi_Host *instance)
 679{
 680        NCR5380_dprint(NDEBUG_ANY, instance);
 681        NCR5380_dprint_phase(NDEBUG_ANY, instance);
 682}
 683
 684/******************************************/
 685/*
 686 * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
 687 *
 688 * *buffer: I/O buffer
 689 * **start: if inout == FALSE pointer into buffer where user read should start
 690 * offset: current offset
 691 * length: length of buffer
 692 * hostno: Scsi_Host host_no
 693 * inout: TRUE - user is writing; FALSE - user is reading
 694 *
 695 * Return the number of bytes read from or written
 696 */
 697
 698static int __maybe_unused NCR5380_write_info(struct Scsi_Host *instance,
 699        char *buffer, int length)
 700{
 701#ifdef DTC_PUBLIC_RELEASE
 702        dtc_wmaxi = dtc_maxi = 0;
 703#endif
 704#ifdef PAS16_PUBLIC_RELEASE
 705        pas_wmaxi = pas_maxi = 0;
 706#endif
 707        return (-ENOSYS);       /* Currently this is a no-op */
 708}
 709
 710#undef SPRINTF
 711#define SPRINTF(args...) seq_printf(m, ## args)
 712static
 713void lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, struct seq_file *m);
 714static
 715void lprint_command(unsigned char *cmd, struct seq_file *m);
 716static
 717void lprint_opcode(int opcode, struct seq_file *m);
 718
 719static int __maybe_unused NCR5380_show_info(struct seq_file *m,
 720        struct Scsi_Host *instance)
 721{
 722        struct NCR5380_hostdata *hostdata;
 723        Scsi_Cmnd *ptr;
 724
 725        hostdata = (struct NCR5380_hostdata *) instance->hostdata;
 726
 727        SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
 728        if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
 729                SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
 730#ifdef DTC_PUBLIC_RELEASE
 731        SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
 732#endif
 733#ifdef T128_PUBLIC_RELEASE
 734        SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
 735#endif
 736#ifdef GENERIC_NCR5380_PUBLIC_RELEASE
 737        SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
 738#endif
 739#ifdef PAS16_PUBLIC_RELEASE
 740        SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
 741#endif
 742
 743        SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
 744        SPRINTF("io_port: %04x      ", (int) instance->io_port);
 745        if (instance->irq == SCSI_IRQ_NONE)
 746                SPRINTF("IRQ: None.\n");
 747        else
 748                SPRINTF("IRQ: %d.\n", instance->irq);
 749
 750#ifdef DTC_PUBLIC_RELEASE
 751        SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
 752#endif
 753#ifdef PAS16_PUBLIC_RELEASE
 754        SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
 755#endif
 756        spin_lock_irq(instance->host_lock);
 757        if (!hostdata->connected)
 758                SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
 759        else
 760                lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, m);
 761        SPRINTF("scsi%d: issue_queue\n", instance->host_no);
 762        for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
 763                lprint_Scsi_Cmnd(ptr, m);
 764
 765        SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
 766        for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
 767                lprint_Scsi_Cmnd(ptr, m);
 768        spin_unlock_irq(instance->host_lock);
 769        return 0;
 770}
 771
 772static void lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, struct seq_file *m)
 773{
 774        SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
 775        SPRINTF("        command = ");
 776        lprint_command(cmd->cmnd, m);
 777}
 778
 779static void lprint_command(unsigned char *command, struct seq_file *m)
 780{
 781        int i, s;
 782        lprint_opcode(command[0], m);
 783        for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 784                SPRINTF("%02x ", command[i]);
 785        SPRINTF("\n");
 786}
 787
 788static void lprint_opcode(int opcode, struct seq_file *m)
 789{
 790        SPRINTF("%2d (0x%02x)", opcode, opcode);
 791}
 792
 793
 794/**
 795 *      NCR5380_init    -       initialise an NCR5380
 796 *      @instance: adapter to configure
 797 *      @flags: control flags
 798 *
 799 *      Initializes *instance and corresponding 5380 chip,
 800 *      with flags OR'd into the initial flags value.
 801 *
 802 *      Notes : I assume that the host, hostno, and id bits have been
 803 *      set correctly.  I don't care about the irq and other fields. 
 804 *
 805 *      Returns 0 for success
 806 *
 807 *      Locks: interrupts must be enabled when we are called 
 808 */
 809
 810static int NCR5380_init(struct Scsi_Host *instance, int flags)
 811{
 812        NCR5380_local_declare();
 813        int i, pass;
 814        unsigned long timeout;
 815        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
 816
 817        if(in_interrupt())
 818                printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
 819        /* 
 820         * On NCR53C400 boards, NCR5380 registers are mapped 8 past 
 821         * the base address.
 822         */
 823
 824#ifdef NCR53C400
 825        if (flags & FLAG_NCR53C400)
 826                instance->NCR5380_instance_name += NCR53C400_address_adjust;
 827#endif
 828
 829        NCR5380_setup(instance);
 830
 831        hostdata->aborted = 0;
 832        hostdata->id_mask = 1 << instance->this_id;
 833        for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 834                if (i > hostdata->id_mask)
 835                        hostdata->id_higher_mask |= i;
 836        for (i = 0; i < 8; ++i)
 837                hostdata->busy[i] = 0;
 838#ifdef REAL_DMA
 839        hostdata->dmalen = 0;
 840#endif
 841        hostdata->targets_present = 0;
 842        hostdata->connected = NULL;
 843        hostdata->issue_queue = NULL;
 844        hostdata->disconnected_queue = NULL;
 845        
 846        INIT_DELAYED_WORK(&hostdata->coroutine, NCR5380_main);
 847        
 848#ifdef NCR5380_STATS
 849        for (i = 0; i < 8; ++i) {
 850                hostdata->time_read[i] = 0;
 851                hostdata->time_write[i] = 0;
 852                hostdata->bytes_read[i] = 0;
 853                hostdata->bytes_write[i] = 0;
 854        }
 855        hostdata->timebase = 0;
 856        hostdata->pendingw = 0;
 857        hostdata->pendingr = 0;
 858#endif
 859
 860        /* The CHECK code seems to break the 53C400. Will check it later maybe */
 861        if (flags & FLAG_NCR53C400)
 862                hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
 863        else
 864                hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
 865
 866        hostdata->host = instance;
 867        hostdata->time_expires = 0;
 868
 869#ifndef AUTOSENSE
 870        if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
 871                    printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
 872                           "         be incorrectly cleared.\n", instance->host_no);
 873#endif                          /* def AUTOSENSE */
 874
 875        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 876        NCR5380_write(MODE_REG, MR_BASE);
 877        NCR5380_write(TARGET_COMMAND_REG, 0);
 878        NCR5380_write(SELECT_ENABLE_REG, 0);
 879
 880#ifdef NCR53C400
 881        if (hostdata->flags & FLAG_NCR53C400) {
 882                NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
 883        }
 884#endif
 885
 886        /* 
 887         * Detect and correct bus wedge problems.
 888         *
 889         * If the system crashed, it may have crashed in a state 
 890         * where a SCSI command was still executing, and the 
 891         * SCSI bus is not in a BUS FREE STATE.
 892         *
 893         * If this is the case, we'll try to abort the currently
 894         * established nexus which we know nothing about, and that
 895         * failing, do a hard reset of the SCSI bus 
 896         */
 897
 898        for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
 899                switch (pass) {
 900                case 1:
 901                case 3:
 902                case 5:
 903                        printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
 904                        timeout = jiffies + 5 * HZ;
 905                        NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
 906                        break;
 907                case 2:
 908                        printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
 909                        do_abort(instance);
 910                        break;
 911                case 4:
 912                        printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
 913                        do_reset(instance);
 914                        break;
 915                case 6:
 916                        printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
 917                        return -ENXIO;
 918                }
 919        }
 920        return 0;
 921}
 922
 923/**
 924 *      NCR5380_exit    -       remove an NCR5380
 925 *      @instance: adapter to remove
 926 */
 927
 928static void NCR5380_exit(struct Scsi_Host *instance)
 929{
 930        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
 931
 932        cancel_delayed_work_sync(&hostdata->coroutine);
 933}
 934
 935/**
 936 *      NCR5380_queue_command           -       queue a command
 937 *      @cmd: SCSI command
 938 *      @done: completion handler
 939 *
 940 *      cmd is added to the per instance issue_queue, with minor 
 941 *      twiddling done to the host specific fields of cmd.  If the 
 942 *      main coroutine is not running, it is restarted.
 943 *
 944 *      Locks: host lock taken by caller
 945 */
 946
 947static int NCR5380_queue_command_lck(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
 948{
 949        struct Scsi_Host *instance = cmd->device->host;
 950        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
 951        Scsi_Cmnd *tmp;
 952
 953#if (NDEBUG & NDEBUG_NO_WRITE)
 954        switch (cmd->cmnd[0]) {
 955        case WRITE_6:
 956        case WRITE_10:
 957                printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
 958                cmd->result = (DID_ERROR << 16);
 959                done(cmd);
 960                return 0;
 961        }
 962#endif                          /* (NDEBUG & NDEBUG_NO_WRITE) */
 963
 964#ifdef NCR5380_STATS
 965        switch (cmd->cmnd[0]) {
 966                case WRITE:
 967                case WRITE_6:
 968                case WRITE_10:
 969                        hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
 970                        hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
 971                        hostdata->pendingw++;
 972                        break;
 973                case READ:
 974                case READ_6:
 975                case READ_10:
 976                        hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
 977                        hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
 978                        hostdata->pendingr++;
 979                        break;
 980        }
 981#endif
 982
 983        /* 
 984         * We use the host_scribble field as a pointer to the next command  
 985         * in a queue 
 986         */
 987
 988        cmd->host_scribble = NULL;
 989        cmd->scsi_done = done;
 990        cmd->result = 0;
 991
 992        /* 
 993         * Insert the cmd into the issue queue. Note that REQUEST SENSE 
 994         * commands are added to the head of the queue since any command will
 995         * clear the contingent allegiance condition that exists and the 
 996         * sense data is only guaranteed to be valid while the condition exists.
 997         */
 998
 999        if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1000                LIST(cmd, hostdata->issue_queue);
1001                cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
1002                hostdata->issue_queue = cmd;
1003        } else {
1004                for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
1005                LIST(cmd, tmp);
1006                tmp->host_scribble = (unsigned char *) cmd;
1007        }
1008        dprintk(NDEBUG_QUEUES, ("scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"));
1009
1010        /* Run the coroutine if it isn't already running. */
1011        /* Kick off command processing */
1012        schedule_delayed_work(&hostdata->coroutine, 0);
1013        return 0;
1014}
1015
1016static DEF_SCSI_QCMD(NCR5380_queue_command)
1017
1018/**
1019 *      NCR5380_main    -       NCR state machines
1020 *
1021 *      NCR5380_main is a coroutine that runs as long as more work can 
1022 *      be done on the NCR5380 host adapters in a system.  Both 
1023 *      NCR5380_queue_command() and NCR5380_intr() will try to start it 
1024 *      in case it is not running.
1025 * 
1026 *      Locks: called as its own thread with no locks held. Takes the
1027 *      host lock and called routines may take the isa dma lock.
1028 */
1029
1030static void NCR5380_main(struct work_struct *work)
1031{
1032        struct NCR5380_hostdata *hostdata =
1033                container_of(work, struct NCR5380_hostdata, coroutine.work);
1034        struct Scsi_Host *instance = hostdata->host;
1035        Scsi_Cmnd *tmp, *prev;
1036        int done;
1037        
1038        spin_lock_irq(instance->host_lock);
1039        do {
1040                /* Lock held here */
1041                done = 1;
1042                if (!hostdata->connected && !hostdata->selecting) {
1043                        dprintk(NDEBUG_MAIN, ("scsi%d : not connected\n", instance->host_no));
1044                        /*
1045                         * Search through the issue_queue for a command destined
1046                         * for a target that's not busy.
1047                         */
1048                        for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble) 
1049                        {
1050                                if (prev != tmp)
1051                                        dprintk(NDEBUG_LISTS, ("MAIN tmp=%p   target=%d   busy=%d lun=%d\n", tmp, tmp->target, hostdata->busy[tmp->target], tmp->lun));
1052                                /*  When we find one, remove it from the issue queue. */
1053                                if (!(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))) {
1054                                        if (prev) {
1055                                                REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1056                                                prev->host_scribble = tmp->host_scribble;
1057                                        } else {
1058                                                REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1059                                                hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1060                                        }
1061                                        tmp->host_scribble = NULL;
1062
1063                                        /* 
1064                                         * Attempt to establish an I_T_L nexus here. 
1065                                         * On success, instance->hostdata->connected is set.
1066                                         * On failure, we must add the command back to the
1067                                         *   issue queue so we can keep trying. 
1068                                         */
1069                                        dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main() : command for target %d lun %d removed from issue_queue\n", instance->host_no, tmp->target, tmp->lun));
1070        
1071                                        /*
1072                                         * A successful selection is defined as one that 
1073                                         * leaves us with the command connected and 
1074                                         * in hostdata->connected, OR has terminated the
1075                                         * command.
1076                                         *
1077                                         * With successful commands, we fall through
1078                                         * and see if we can do an information transfer,
1079                                         * with failures we will restart.
1080                                         */
1081                                        hostdata->selecting = NULL;
1082                                        /* RvC: have to preset this to indicate a new command is being performed */
1083
1084                                        if (!NCR5380_select(instance, tmp,
1085                                                            /* 
1086                                                             * REQUEST SENSE commands are issued without tagged
1087                                                             * queueing, even on SCSI-II devices because the 
1088                                                             * contingent allegiance condition exists for the 
1089                                                             * entire unit.
1090                                                             */
1091                                                            (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1092                                                break;
1093                                        } else {
1094                                                LIST(tmp, hostdata->issue_queue);
1095                                                tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1096                                                hostdata->issue_queue = tmp;
1097                                                done = 0;
1098                                                dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no));
1099                                        }
1100                                        /* lock held here still */
1101                                }       /* if target/lun is not busy */
1102                        }       /* for */
1103                        /* exited locked */
1104                }       /* if (!hostdata->connected) */
1105                if (hostdata->selecting) {
1106                        tmp = (Scsi_Cmnd *) hostdata->selecting;
1107                        /* Selection will drop and retake the lock */
1108                        if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1109                                /* Ok ?? */
1110                        } else {
1111                                /* RvC: device failed, so we wait a long time
1112                                   this is needed for Mustek scanners, that
1113                                   do not respond to commands immediately
1114                                   after a scan */
1115                                printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1116                                LIST(tmp, hostdata->issue_queue);
1117                                tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1118                                hostdata->issue_queue = tmp;
1119                                NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1120                        }
1121                }       /* if hostdata->selecting */
1122                if (hostdata->connected
1123#ifdef REAL_DMA
1124                    && !hostdata->dmalen
1125#endif
1126                    && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1127                    ) {
1128                        dprintk(NDEBUG_MAIN, ("scsi%d : main() : performing information transfer\n", instance->host_no));
1129                        NCR5380_information_transfer(instance);
1130                        dprintk(NDEBUG_MAIN, ("scsi%d : main() : done set false\n", instance->host_no));
1131                        done = 0;
1132                } else
1133                        break;
1134        } while (!done);
1135        
1136        spin_unlock_irq(instance->host_lock);
1137}
1138
1139#ifndef DONT_USE_INTR
1140
1141/**
1142 *      NCR5380_intr    -       generic NCR5380 irq handler
1143 *      @irq: interrupt number
1144 *      @dev_id: device info
1145 *
1146 *      Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1147 *      from the disconnected queue, and restarting NCR5380_main() 
1148 *      as required.
1149 *
1150 *      Locks: takes the needed instance locks
1151 */
1152
1153static irqreturn_t NCR5380_intr(int dummy, void *dev_id)
1154{
1155        NCR5380_local_declare();
1156        struct Scsi_Host *instance = dev_id;
1157        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1158        int done;
1159        unsigned char basr;
1160        unsigned long flags;
1161
1162        dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n",
1163                instance->irq));
1164
1165        do {
1166                done = 1;
1167                spin_lock_irqsave(instance->host_lock, flags);
1168                /* Look for pending interrupts */
1169                NCR5380_setup(instance);
1170                basr = NCR5380_read(BUS_AND_STATUS_REG);
1171                /* XXX dispatch to appropriate routine if found and done=0 */
1172                if (basr & BASR_IRQ) {
1173                        NCR5380_dprint(NDEBUG_INTR, instance);
1174                        if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1175                                done = 0;
1176                                dprintk(NDEBUG_INTR, ("scsi%d : SEL interrupt\n", instance->host_no));
1177                                NCR5380_reselect(instance);
1178                                (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1179                        } else if (basr & BASR_PARITY_ERROR) {
1180                                dprintk(NDEBUG_INTR, ("scsi%d : PARITY interrupt\n", instance->host_no));
1181                                (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1182                        } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1183                                dprintk(NDEBUG_INTR, ("scsi%d : RESET interrupt\n", instance->host_no));
1184                                (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1185                        } else {
1186#if defined(REAL_DMA)
1187                                /*
1188                                 * We should only get PHASE MISMATCH and EOP interrupts
1189                                 * if we have DMA enabled, so do a sanity check based on
1190                                 * the current setting of the MODE register.
1191                                 */
1192
1193                                if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1194                                        int transferred;
1195
1196                                        if (!hostdata->connected)
1197                                                panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1198
1199                                        transferred = (hostdata->dmalen - NCR5380_dma_residual(instance));
1200                                        hostdata->connected->SCp.this_residual -= transferred;
1201                                        hostdata->connected->SCp.ptr += transferred;
1202                                        hostdata->dmalen = 0;
1203
1204                                        (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1205                                                        
1206                                        /* FIXME: we need to poll briefly then defer a workqueue task ! */
1207                                        NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1208
1209                                        NCR5380_write(MODE_REG, MR_BASE);
1210                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1211                                }
1212#else
1213                                dprintk(NDEBUG_INTR, ("scsi : unknown interrupt, BASR 0x%X, MR 0x%X, SR 0x%x\n", basr, NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG)));
1214                                (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1215#endif
1216                        }
1217                }       /* if BASR_IRQ */
1218                spin_unlock_irqrestore(instance->host_lock, flags);
1219                if(!done)
1220                        schedule_delayed_work(&hostdata->coroutine, 0);
1221        } while (!done);
1222        return IRQ_HANDLED;
1223}
1224
1225#endif 
1226
1227/**
1228 *      collect_stats           -       collect stats on a scsi command
1229 *      @hostdata: adapter 
1230 *      @cmd: command being issued
1231 *
1232 *      Update the statistical data by parsing the command in question
1233 */
1234 
1235static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd) 
1236{
1237#ifdef NCR5380_STATS
1238        switch (cmd->cmnd[0]) {
1239        case WRITE:
1240        case WRITE_6:
1241        case WRITE_10:
1242                hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1243                hostdata->pendingw--;
1244                break;
1245        case READ:
1246        case READ_6:
1247        case READ_10:
1248                hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1249                hostdata->pendingr--;
1250                break;
1251        }
1252#endif
1253}
1254
1255
1256/* 
1257 * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, 
1258 *      int tag);
1259 *
1260 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1261 *      including ARBITRATION, SELECTION, and initial message out for 
1262 *      IDENTIFY and queue messages. 
1263 *
1264 * Inputs : instance - instantiation of the 5380 driver on which this 
1265 *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for 
1266 *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for 
1267 *      the command that is presently connected.
1268 * 
1269 * Returns : -1 if selection could not execute for some reason,
1270 *      0 if selection succeeded or failed because the target 
1271 *      did not respond.
1272 *
1273 * Side effects : 
1274 *      If bus busy, arbitration failed, etc, NCR5380_select() will exit 
1275 *              with registers as they should have been on entry - ie
1276 *              SELECT_ENABLE will be set appropriately, the NCR5380
1277 *              will cease to drive any SCSI bus signals.
1278 *
1279 *      If successful : I_T_L or I_T_L_Q nexus will be established, 
1280 *              instance->connected will be set to cmd.  
1281 *              SELECT interrupt will be disabled.
1282 *
1283 *      If failed (no target) : cmd->scsi_done() will be called, and the 
1284 *              cmd->result host byte set to DID_BAD_TARGET.
1285 *
1286 *      Locks: caller holds hostdata lock in IRQ mode
1287 */
1288 
1289static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag) 
1290{
1291        NCR5380_local_declare();
1292        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1293        unsigned char tmp[3], phase;
1294        unsigned char *data;
1295        int len;
1296        unsigned long timeout;
1297        unsigned char value;
1298        int err;
1299        NCR5380_setup(instance);
1300
1301        if (hostdata->selecting)
1302                goto part2;
1303
1304        hostdata->restart_select = 0;
1305
1306        NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1307        dprintk(NDEBUG_ARBITRATION, ("scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id));
1308
1309        /* 
1310         * Set the phase bits to 0, otherwise the NCR5380 won't drive the 
1311         * data bus during SELECTION.
1312         */
1313
1314        NCR5380_write(TARGET_COMMAND_REG, 0);
1315
1316        /* 
1317         * Start arbitration.
1318         */
1319
1320        NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1321        NCR5380_write(MODE_REG, MR_ARBITRATE);
1322
1323
1324        /* We can be relaxed here, interrupts are on, we are
1325           in workqueue context, the birds are singing in the trees */
1326        spin_unlock_irq(instance->host_lock);
1327        err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1328        spin_lock_irq(instance->host_lock);
1329        if (err < 0) {
1330                printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1331                NCR5380_write(MODE_REG, MR_BASE);
1332                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1333                goto failed;
1334        }
1335
1336        dprintk(NDEBUG_ARBITRATION, ("scsi%d : arbitration complete\n", instance->host_no));
1337
1338        /* 
1339         * The arbitration delay is 2.2us, but this is a minimum and there is 
1340         * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1341         * the integral nature of udelay().
1342         *
1343         */
1344
1345        udelay(3);
1346
1347        /* Check for lost arbitration */
1348        if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1349                NCR5380_write(MODE_REG, MR_BASE);
1350                dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no));
1351                goto failed;
1352        }
1353        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1354
1355        if (!(hostdata->flags & FLAG_DTC3181E) &&
1356            /* RvC: DTC3181E has some trouble with this
1357             *      so we simply removed it. Seems to work with
1358             *      only Mustek scanner attached
1359             */
1360            (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1361                NCR5380_write(MODE_REG, MR_BASE);
1362                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1363                dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no));
1364                goto failed;
1365        }
1366        /* 
1367         * Again, bus clear + bus settle time is 1.2us, however, this is 
1368         * a minimum so we'll udelay ceil(1.2)
1369         */
1370
1371        udelay(2);
1372
1373        dprintk(NDEBUG_ARBITRATION, ("scsi%d : won arbitration\n", instance->host_no));
1374
1375        /* 
1376         * Now that we have won arbitration, start Selection process, asserting 
1377         * the host and target ID's on the SCSI bus.
1378         */
1379
1380        NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1381
1382        /* 
1383         * Raise ATN while SEL is true before BSY goes false from arbitration,
1384         * since this is the only way to guarantee that we'll get a MESSAGE OUT
1385         * phase immediately after selection.
1386         */
1387
1388        NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1389        NCR5380_write(MODE_REG, MR_BASE);
1390
1391        /* 
1392         * Reselect interrupts must be turned off prior to the dropping of BSY,
1393         * otherwise we will trigger an interrupt.
1394         */
1395        NCR5380_write(SELECT_ENABLE_REG, 0);
1396
1397        /*
1398         * The initiator shall then wait at least two deskew delays and release 
1399         * the BSY signal.
1400         */
1401        udelay(1);              /* wingel -- wait two bus deskew delay >2*45ns */
1402
1403        /* Reset BSY */
1404        NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1405
1406        /* 
1407         * Something weird happens when we cease to drive BSY - looks
1408         * like the board/chip is letting us do another read before the 
1409         * appropriate propagation delay has expired, and we're confusing
1410         * a BSY signal from ourselves as the target's response to SELECTION.
1411         *
1412         * A small delay (the 'C++' frontend breaks the pipeline with an
1413         * unnecessary jump, making it work on my 386-33/Trantor T128, the
1414         * tighter 'C' code breaks and requires this) solves the problem - 
1415         * the 1 us delay is arbitrary, and only used because this delay will 
1416         * be the same on other platforms and since it works here, it should 
1417         * work there.
1418         *
1419         * wingel suggests that this could be due to failing to wait
1420         * one deskew delay.
1421         */
1422
1423        udelay(1);
1424
1425        dprintk(NDEBUG_SELECTION, ("scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd)));
1426
1427        /* 
1428         * The SCSI specification calls for a 250 ms timeout for the actual 
1429         * selection.
1430         */
1431
1432        timeout = jiffies + (250 * HZ / 1000);
1433
1434        /* 
1435         * XXX very interesting - we're seeing a bounce where the BSY we 
1436         * asserted is being reflected / still asserted (propagation delay?)
1437         * and it's detecting as true.  Sigh.
1438         */
1439
1440        hostdata->select_time = 0;      /* we count the clock ticks at which we polled */
1441        hostdata->selecting = cmd;
1442
1443part2:
1444        /* RvC: here we enter after a sleeping period, or immediately after
1445           execution of part 1
1446           we poll only once ech clock tick */
1447        value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1448
1449        if (!value && (hostdata->select_time < HZ/4)) {
1450                /* RvC: we still must wait for a device response */
1451                hostdata->select_time++;        /* after 25 ticks the device has failed */
1452                NCR5380_set_timer(hostdata, 1);
1453                return 0;       /* RvC: we return here with hostdata->selecting set,
1454                                   to go to sleep */
1455        }
1456
1457        hostdata->selecting = NULL;/* clear this pointer, because we passed the
1458                                           waiting period */
1459        if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1460                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1461                NCR5380_reselect(instance);
1462                printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1463                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1464                return -1;
1465        }
1466        /* 
1467         * No less than two deskew delays after the initiator detects the 
1468         * BSY signal is true, it shall release the SEL signal and may 
1469         * change the DATA BUS.                                     -wingel
1470         */
1471
1472        udelay(1);
1473
1474        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1475
1476        if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1477                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1478                if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1479                        printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1480                        if (hostdata->restart_select)
1481                                printk(KERN_DEBUG "\trestart select\n");
1482                        NCR5380_dprint(NDEBUG_SELECTION, instance);
1483                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1484                        return -1;
1485                }
1486                cmd->result = DID_BAD_TARGET << 16;
1487                collect_stats(hostdata, cmd);
1488                cmd->scsi_done(cmd);
1489                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1490                dprintk(NDEBUG_SELECTION, ("scsi%d : target did not respond within 250ms\n", instance->host_no));
1491                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1492                return 0;
1493        }
1494        hostdata->targets_present |= (1 << scmd_id(cmd));
1495
1496        /*
1497         * Since we followed the SCSI spec, and raised ATN while SEL 
1498         * was true but before BSY was false during selection, the information
1499         * transfer phase should be a MESSAGE OUT phase so that we can send the
1500         * IDENTIFY message.
1501         * 
1502         * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1503         * message (2 bytes) with a tag ID that we increment with every command
1504         * until it wraps back to 0.
1505         *
1506         * XXX - it turns out that there are some broken SCSI-II devices,
1507         *       which claim to support tagged queuing but fail when more than
1508         *       some number of commands are issued at once.
1509         */
1510
1511        /* Wait for start of REQ/ACK handshake */
1512
1513        spin_unlock_irq(instance->host_lock);
1514        err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1515        spin_lock_irq(instance->host_lock);
1516        
1517        if(err) {
1518                printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1519                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1520                goto failed;
1521        }
1522
1523        dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
1524        tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1525
1526        len = 1;
1527        cmd->tag = 0;
1528
1529        /* Send message(s) */
1530        data = tmp;
1531        phase = PHASE_MSGOUT;
1532        NCR5380_transfer_pio(instance, &phase, &len, &data);
1533        dprintk(NDEBUG_SELECTION, ("scsi%d : nexus established.\n", instance->host_no));
1534        /* XXX need to handle errors here */
1535        hostdata->connected = cmd;
1536        hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1537
1538        initialize_SCp(cmd);
1539
1540        return 0;
1541
1542        /* Selection failed */
1543failed:
1544        return -1;
1545
1546}
1547
1548/* 
1549 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance, 
1550 *      unsigned char *phase, int *count, unsigned char **data)
1551 *
1552 * Purpose : transfers data in given phase using polled I/O
1553 *
1554 * Inputs : instance - instance of driver, *phase - pointer to 
1555 *      what phase is expected, *count - pointer to number of 
1556 *      bytes to transfer, **data - pointer to data pointer.
1557 * 
1558 * Returns : -1 when different phase is entered without transferring
1559 *      maximum number of bytes, 0 if all bytes or transferred or exit
1560 *      is in same phase.
1561 *
1562 *      Also, *phase, *count, *data are modified in place.
1563 *
1564 * XXX Note : handling for bus free may be useful.
1565 */
1566
1567/*
1568 * Note : this code is not as quick as it could be, however it 
1569 * IS 100% reliable, and for the actual data transfer where speed
1570 * counts, we will always do a pseudo DMA or DMA transfer.
1571 */
1572
1573static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1574        NCR5380_local_declare();
1575        unsigned char p = *phase, tmp;
1576        int c = *count;
1577        unsigned char *d = *data;
1578        /*
1579         *      RvC: some administrative data to process polling time
1580         */
1581        int break_allowed = 0;
1582        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1583        NCR5380_setup(instance);
1584
1585        if (!(p & SR_IO))
1586                dprintk(NDEBUG_PIO, ("scsi%d : pio write %d bytes\n", instance->host_no, c));
1587        else
1588                dprintk(NDEBUG_PIO, ("scsi%d : pio read %d bytes\n", instance->host_no, c));
1589
1590        /* 
1591         * The NCR5380 chip will only drive the SCSI bus when the 
1592         * phase specified in the appropriate bits of the TARGET COMMAND
1593         * REGISTER match the STATUS REGISTER
1594         */
1595
1596         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1597
1598        /* RvC: don't know if this is necessary, but other SCSI I/O is short
1599         *      so breaks are not necessary there
1600         */
1601        if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1602                break_allowed = 1;
1603        }
1604        do {
1605                /* 
1606                 * Wait for assertion of REQ, after which the phase bits will be 
1607                 * valid 
1608                 */
1609
1610                /* RvC: we simply poll once, after that we stop temporarily
1611                 *      and let the device buffer fill up
1612                 *      if breaking is not allowed, we keep polling as long as needed
1613                 */
1614
1615                /* FIXME */
1616                while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1617                if (!(tmp & SR_REQ)) {
1618                        /* timeout condition */
1619                        NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1620                        break;
1621                }
1622
1623                dprintk(NDEBUG_HANDSHAKE, ("scsi%d : REQ detected\n", instance->host_no));
1624
1625                /* Check for phase mismatch */
1626                if ((tmp & PHASE_MASK) != p) {
1627                        dprintk(NDEBUG_HANDSHAKE, ("scsi%d : phase mismatch\n", instance->host_no));
1628                        NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1629                        break;
1630                }
1631                /* Do actual transfer from SCSI bus to / from memory */
1632                if (!(p & SR_IO))
1633                        NCR5380_write(OUTPUT_DATA_REG, *d);
1634                else
1635                        *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1636
1637                ++d;
1638
1639                /* 
1640                 * The SCSI standard suggests that in MSGOUT phase, the initiator
1641                 * should drop ATN on the last byte of the message phase
1642                 * after REQ has been asserted for the handshake but before
1643                 * the initiator raises ACK.
1644                 */
1645
1646                if (!(p & SR_IO)) {
1647                        if (!((p & SR_MSG) && c > 1)) {
1648                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1649                                NCR5380_dprint(NDEBUG_PIO, instance);
1650                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1651                        } else {
1652                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1653                                NCR5380_dprint(NDEBUG_PIO, instance);
1654                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1655                        }
1656                } else {
1657                        NCR5380_dprint(NDEBUG_PIO, instance);
1658                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1659                }
1660
1661                /* FIXME - if this fails bus reset ?? */
1662                NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1663                dprintk(NDEBUG_HANDSHAKE, ("scsi%d : req false, handshake complete\n", instance->host_no));
1664
1665/*
1666 * We have several special cases to consider during REQ/ACK handshaking : 
1667 * 1.  We were in MSGOUT phase, and we are on the last byte of the 
1668 *      message.  ATN must be dropped as ACK is dropped.
1669 *
1670 * 2.  We are in a MSGIN phase, and we are on the last byte of the  
1671 *      message.  We must exit with ACK asserted, so that the calling
1672 *      code may raise ATN before dropping ACK to reject the message.
1673 *
1674 * 3.  ACK and ATN are clear and the target may proceed as normal.
1675 */
1676                if (!(p == PHASE_MSGIN && c == 1)) {
1677                        if (p == PHASE_MSGOUT && c > 1)
1678                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1679                        else
1680                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1681                }
1682        } while (--c);
1683
1684        dprintk(NDEBUG_PIO, ("scsi%d : residual %d\n", instance->host_no, c));
1685
1686        *count = c;
1687        *data = d;
1688        tmp = NCR5380_read(STATUS_REG);
1689        if (tmp & SR_REQ)
1690                *phase = tmp & PHASE_MASK;
1691        else
1692                *phase = PHASE_UNKNOWN;
1693
1694        if (!c || (*phase == p))
1695                return 0;
1696        else
1697                return -1;
1698}
1699
1700/**
1701 *      do_reset        -       issue a reset command
1702 *      @host: adapter to reset
1703 *
1704 *      Issue a reset sequence to the NCR5380 and try and get the bus
1705 *      back into sane shape.
1706 *
1707 *      Locks: caller holds queue lock
1708 */
1709 
1710static void do_reset(struct Scsi_Host *host) {
1711        NCR5380_local_declare();
1712        NCR5380_setup(host);
1713
1714        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1715        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1716        udelay(25);
1717        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1718}
1719
1720/*
1721 * Function : do_abort (Scsi_Host *host)
1722 * 
1723 * Purpose : abort the currently established nexus.  Should only be 
1724 *      called from a routine which can drop into a 
1725 * 
1726 * Returns : 0 on success, -1 on failure.
1727 *
1728 * Locks: queue lock held by caller
1729 *      FIXME: sort this out and get new_eh running
1730 */
1731
1732static int do_abort(struct Scsi_Host *host) {
1733        NCR5380_local_declare();
1734        unsigned char *msgptr, phase, tmp;
1735        int len;
1736        int rc;
1737        NCR5380_setup(host);
1738
1739
1740        /* Request message out phase */
1741        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1742
1743        /* 
1744         * Wait for the target to indicate a valid phase by asserting 
1745         * REQ.  Once this happens, we'll have either a MSGOUT phase 
1746         * and can immediately send the ABORT message, or we'll have some 
1747         * other phase and will have to source/sink data.
1748         * 
1749         * We really don't care what value was on the bus or what value
1750         * the target sees, so we just handshake.
1751         */
1752
1753        rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1754        
1755        if(rc < 0)
1756                return -1;
1757
1758        tmp = (unsigned char)rc;
1759        
1760        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1761
1762        if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1763                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1764                rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1765                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1766                if(rc == -1)
1767                        return -1;
1768        }
1769        tmp = ABORT;
1770        msgptr = &tmp;
1771        len = 1;
1772        phase = PHASE_MSGOUT;
1773        NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1774
1775        /*
1776         * If we got here, and the command completed successfully,
1777         * we're about to go into bus free state.
1778         */
1779
1780        return len ? -1 : 0;
1781}
1782
1783#if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1784/* 
1785 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance, 
1786 *      unsigned char *phase, int *count, unsigned char **data)
1787 *
1788 * Purpose : transfers data in given phase using either real
1789 *      or pseudo DMA.
1790 *
1791 * Inputs : instance - instance of driver, *phase - pointer to 
1792 *      what phase is expected, *count - pointer to number of 
1793 *      bytes to transfer, **data - pointer to data pointer.
1794 * 
1795 * Returns : -1 when different phase is entered without transferring
1796 *      maximum number of bytes, 0 if all bytes or transferred or exit
1797 *      is in same phase.
1798 *
1799 *      Also, *phase, *count, *data are modified in place.
1800 *
1801 *      Locks: io_request lock held by caller
1802 */
1803
1804
1805static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1806        NCR5380_local_declare();
1807        register int c = *count;
1808        register unsigned char p = *phase;
1809        register unsigned char *d = *data;
1810        unsigned char tmp;
1811        int foo;
1812#if defined(REAL_DMA_POLL)
1813        int cnt, toPIO;
1814        unsigned char saved_data = 0, overrun = 0, residue;
1815#endif
1816
1817        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1818
1819        NCR5380_setup(instance);
1820
1821        if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1822                *phase = tmp;
1823                return -1;
1824        }
1825#if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1826#ifdef READ_OVERRUNS
1827        if (p & SR_IO) {
1828                c -= 2;
1829        }
1830#endif
1831        dprintk(NDEBUG_DMA, ("scsi%d : initializing DMA channel %d for %s, %d bytes %s %0x\n", instance->host_no, instance->dma_channel, (p & SR_IO) ? "reading" : "writing", c, (p & SR_IO) ? "to" : "from", (unsigned) d));
1832        hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1833#endif
1834
1835        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1836
1837#ifdef REAL_DMA
1838        NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1839#elif defined(REAL_DMA_POLL)
1840        NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1841#else
1842        /*
1843         * Note : on my sample board, watch-dog timeouts occurred when interrupts
1844         * were not disabled for the duration of a single DMA transfer, from 
1845         * before the setting of DMA mode to after transfer of the last byte.
1846         */
1847
1848#if defined(PSEUDO_DMA) && defined(UNSAFE)
1849        spin_unlock_irq(instance->host_lock);
1850#endif
1851        /* KLL May need eop and parity in 53c400 */
1852        if (hostdata->flags & FLAG_NCR53C400)
1853                NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE |
1854                                MR_ENABLE_PAR_CHECK | MR_ENABLE_PAR_INTR |
1855                                MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1856        else
1857                NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1858#endif                          /* def REAL_DMA */
1859
1860        dprintk(NDEBUG_DMA, ("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)));
1861
1862        /* 
1863         *      On the PAS16 at least I/O recovery delays are not needed here.
1864         *      Everyone else seems to want them.
1865         */
1866
1867        if (p & SR_IO) {
1868                io_recovery_delay(1);
1869                NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1870        } else {
1871                io_recovery_delay(1);
1872                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1873                io_recovery_delay(1);
1874                NCR5380_write(START_DMA_SEND_REG, 0);
1875                io_recovery_delay(1);
1876        }
1877
1878#if defined(REAL_DMA_POLL)
1879        do {
1880                tmp = NCR5380_read(BUS_AND_STATUS_REG);
1881        } while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1882
1883/*
1884   At this point, either we've completed DMA, or we have a phase mismatch,
1885   or we've unexpectedly lost BUSY (which is a real error).
1886
1887   For write DMAs, we want to wait until the last byte has been
1888   transferred out over the bus before we turn off DMA mode.  Alas, there
1889   seems to be no terribly good way of doing this on a 5380 under all
1890   conditions.  For non-scatter-gather operations, we can wait until REQ
1891   and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1892   are nastier, since the device will be expecting more data than we
1893   are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1894   could test LAST BIT SENT to assure transfer (I imagine this is precisely
1895   why this signal was added to the newer chips) but on the older 538[01]
1896   this signal does not exist.  The workaround for this lack is a watchdog;
1897   we bail out of the wait-loop after a modest amount of wait-time if
1898   the usual exit conditions are not met.  Not a terribly clean or
1899   correct solution :-%
1900
1901   Reads are equally tricky due to a nasty characteristic of the NCR5380.
1902   If the chip is in DMA mode for an READ, it will respond to a target's
1903   REQ by latching the SCSI data into the INPUT DATA register and asserting
1904   ACK, even if it has _already_ been notified by the DMA controller that
1905   the current DMA transfer has completed!  If the NCR5380 is then taken
1906   out of DMA mode, this already-acknowledged byte is lost.
1907
1908   This is not a problem for "one DMA transfer per command" reads, because
1909   the situation will never arise... either all of the data is DMA'ed
1910   properly, or the target switches to MESSAGE IN phase to signal a
1911   disconnection (either operation bringing the DMA to a clean halt).
1912   However, in order to handle scatter-reads, we must work around the
1913   problem.  The chosen fix is to DMA N-2 bytes, then check for the
1914   condition before taking the NCR5380 out of DMA mode.  One or two extra
1915   bytes are transferred via PIO as necessary to fill out the original
1916   request.
1917 */
1918
1919        if (p & SR_IO) {
1920#ifdef READ_OVERRUNS
1921                udelay(10);
1922                if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1923                        saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1924                        overrun = 1;
1925                }
1926#endif
1927        } else {
1928                int limit = 100;
1929                while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1930                        if (!(tmp & BASR_PHASE_MATCH))
1931                                break;
1932                        if (--limit < 0)
1933                                break;
1934                }
1935        }
1936
1937        dprintk(NDEBUG_DMA, ("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG)));
1938
1939        NCR5380_write(MODE_REG, MR_BASE);
1940        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1941
1942        residue = NCR5380_dma_residual(instance);
1943        c -= residue;
1944        *count -= c;
1945        *data += c;
1946        *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1947
1948#ifdef READ_OVERRUNS
1949        if (*phase == p && (p & SR_IO) && residue == 0) {
1950                if (overrun) {
1951                        dprintk(NDEBUG_DMA, ("Got an input overrun, using saved byte\n"));
1952                        **data = saved_data;
1953                        *data += 1;
1954                        *count -= 1;
1955                        cnt = toPIO = 1;
1956                } else {
1957                        printk("No overrun??\n");
1958                        cnt = toPIO = 2;
1959                }
1960                dprintk(NDEBUG_DMA, ("Doing %d-byte PIO to 0x%X\n", cnt, *data));
1961                NCR5380_transfer_pio(instance, phase, &cnt, data);
1962                *count -= toPIO - cnt;
1963        }
1964#endif
1965
1966        dprintk(NDEBUG_DMA, ("Return with data ptr = 0x%X, count %d, last 0x%X, next 0x%X\n", *data, *count, *(*data + *count - 1), *(*data + *count)));
1967        return 0;
1968
1969#elif defined(REAL_DMA)
1970        return 0;
1971#else                           /* defined(REAL_DMA_POLL) */
1972        if (p & SR_IO) {
1973#ifdef DMA_WORKS_RIGHT
1974                foo = NCR5380_pread(instance, d, c);
1975#else
1976                int diff = 1;
1977                if (hostdata->flags & FLAG_NCR53C400) {
1978                        diff = 0;
1979                }
1980                if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1981                        /*
1982                         * We can't disable DMA mode after successfully transferring 
1983                         * what we plan to be the last byte, since that would open up
1984                         * a race condition where if the target asserted REQ before 
1985                         * we got the DMA mode reset, the NCR5380 would have latched
1986                         * an additional byte into the INPUT DATA register and we'd
1987                         * have dropped it.
1988                         * 
1989                         * The workaround was to transfer one fewer bytes than we 
1990                         * intended to with the pseudo-DMA read function, wait for 
1991                         * the chip to latch the last byte, read it, and then disable
1992                         * pseudo-DMA mode.
1993                         * 
1994                         * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1995                         * REQ is deasserted when ACK is asserted, and not reasserted
1996                         * until ACK goes false.  Since the NCR5380 won't lower ACK
1997                         * until DACK is asserted, which won't happen unless we twiddle
1998                         * the DMA port or we take the NCR5380 out of DMA mode, we 
1999                         * can guarantee that we won't handshake another extra 
2000                         * byte.
2001                         */
2002
2003                        if (!(hostdata->flags & FLAG_NCR53C400)) {
2004                                while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
2005                                /* Wait for clean handshake */
2006                                while (NCR5380_read(STATUS_REG) & SR_REQ);
2007                                d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2008                        }
2009                }
2010#endif
2011        } else {
2012#ifdef DMA_WORKS_RIGHT
2013                foo = NCR5380_pwrite(instance, d, c);
2014#else
2015                int timeout;
2016                dprintk(NDEBUG_C400_PWRITE, ("About to pwrite %d bytes\n", c));
2017                if (!(foo = NCR5380_pwrite(instance, d, c))) {
2018                        /*
2019                         * Wait for the last byte to be sent.  If REQ is being asserted for 
2020                         * the byte we're interested, we'll ACK it and it will go false.  
2021                         */
2022                        if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2023                                timeout = 20000;
2024                                while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2025
2026                                if (!timeout)
2027                                        dprintk(NDEBUG_LAST_BYTE_SENT, ("scsi%d : timed out on last byte\n", instance->host_no));
2028
2029                                if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2030                                        hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2031                                        if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2032                                                hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2033                                                dprintk(NDEBUG_LAST_WRITE_SENT, ("scsi%d : last bit sent works\n", instance->host_no));
2034                                        }
2035                                }
2036                        } else {
2037                                dprintk(NDEBUG_C400_PWRITE, ("Waiting for LASTBYTE\n"));
2038                                while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2039                                dprintk(NDEBUG_C400_PWRITE, ("Got LASTBYTE\n"));
2040                        }
2041                }
2042#endif
2043        }
2044        NCR5380_write(MODE_REG, MR_BASE);
2045        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2046
2047        if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2048                dprintk(NDEBUG_C400_PWRITE, ("53C400w: Checking for IRQ\n"));
2049                if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2050                        dprintk(NDEBUG_C400_PWRITE, ("53C400w:    got it, reading reset interrupt reg\n"));
2051                        NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2052                } else {
2053                        printk("53C400w:    IRQ NOT THERE!\n");
2054                }
2055        }
2056        *data = d + c;
2057        *count = 0;
2058        *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2059#if defined(PSEUDO_DMA) && defined(UNSAFE)
2060        spin_lock_irq(instance->host_lock);
2061#endif                          /* defined(REAL_DMA_POLL) */
2062        return foo;
2063#endif                          /* def REAL_DMA */
2064}
2065#endif                          /* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2066
2067/*
2068 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2069 *
2070 * Purpose : run through the various SCSI phases and do as the target 
2071 *      directs us to.  Operates on the currently connected command, 
2072 *      instance->connected.
2073 *
2074 * Inputs : instance, instance for which we are doing commands
2075 *
2076 * Side effects : SCSI things happen, the disconnected queue will be 
2077 *      modified if a command disconnects, *instance->connected will
2078 *      change.
2079 *
2080 * XXX Note : we need to watch for bus free or a reset condition here 
2081 *      to recover from an unexpected bus free condition.
2082 *
2083 * Locks: io_request_lock held by caller in IRQ mode
2084 */
2085
2086static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2087        NCR5380_local_declare();
2088        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2089        unsigned char msgout = NOP;
2090        int sink = 0;
2091        int len;
2092#if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2093        int transfersize;
2094#endif
2095        unsigned char *data;
2096        unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2097        Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2098        /* RvC: we need to set the end of the polling time */
2099        unsigned long poll_time = jiffies + USLEEP_POLL;
2100
2101        NCR5380_setup(instance);
2102
2103        while (1) {
2104                tmp = NCR5380_read(STATUS_REG);
2105                /* We only have a valid SCSI phase when REQ is asserted */
2106                if (tmp & SR_REQ) {
2107                        phase = (tmp & PHASE_MASK);
2108                        if (phase != old_phase) {
2109                                old_phase = phase;
2110                                NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2111                        }
2112                        if (sink && (phase != PHASE_MSGOUT)) {
2113                                NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2114
2115                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2116                                while (NCR5380_read(STATUS_REG) & SR_REQ);
2117                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2118                                sink = 0;
2119                                continue;
2120                        }
2121                        switch (phase) {
2122                        case PHASE_DATAIN:
2123                        case PHASE_DATAOUT:
2124#if (NDEBUG & NDEBUG_NO_DATAOUT)
2125                                printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2126                                sink = 1;
2127                                do_abort(instance);
2128                                cmd->result = DID_ERROR << 16;
2129                                cmd->scsi_done(cmd);
2130                                return;
2131#endif
2132                                /* 
2133                                 * If there is no room left in the current buffer in the
2134                                 * scatter-gather list, move onto the next one.
2135                                 */
2136
2137                                if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2138                                        ++cmd->SCp.buffer;
2139                                        --cmd->SCp.buffers_residual;
2140                                        cmd->SCp.this_residual = cmd->SCp.buffer->length;
2141                                        cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2142                                        dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
2143                                }
2144                                /*
2145                                 * The preferred transfer method is going to be 
2146                                 * PSEUDO-DMA for systems that are strictly PIO,
2147                                 * since we can let the hardware do the handshaking.
2148                                 *
2149                                 * For this to work, we need to know the transfersize
2150                                 * ahead of time, since the pseudo-DMA code will sit
2151                                 * in an unconditional loop.
2152                                 */
2153
2154#if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2155                                /* KLL
2156                                 * PSEUDO_DMA is defined here. If this is the g_NCR5380
2157                                 * driver then it will always be defined, so the
2158                                 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2159                                 * NCR5380 case.  I think this is a fairly clean solution.
2160                                 * We supplement these 2 if's with the flag.
2161                                 */
2162#ifdef NCR5380_dma_xfer_len
2163                                if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2164#else
2165                                transfersize = cmd->transfersize;
2166
2167#ifdef LIMIT_TRANSFERSIZE       /* If we have problems with interrupt service */
2168                                if (transfersize > 512)
2169                                        transfersize = 512;
2170#endif                          /* LIMIT_TRANSFERSIZE */
2171
2172                                if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2173                                        /* Limit transfers to 32K, for xx400 & xx406
2174                                         * pseudoDMA that transfers in 128 bytes blocks. */
2175                                        if (transfersize > 32 * 1024)
2176                                                transfersize = 32 * 1024;
2177#endif
2178                                        len = transfersize;
2179                                        if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2180                                                /*
2181                                                 * If the watchdog timer fires, all future accesses to this
2182                                                 * device will use the polled-IO.
2183                                                 */
2184                                                scmd_printk(KERN_INFO, cmd,
2185                                                            "switching to slow handshake\n");
2186                                                cmd->device->borken = 1;
2187                                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2188                                                sink = 1;
2189                                                do_abort(instance);
2190                                                cmd->result = DID_ERROR << 16;
2191                                                cmd->scsi_done(cmd);
2192                                                /* XXX - need to source or sink data here, as appropriate */
2193                                        } else
2194                                                cmd->SCp.this_residual -= transfersize - len;
2195                                } else
2196#endif                          /* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2197                                        NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2198                                                             &cmd->SCp.ptr);
2199                                break;
2200                        case PHASE_MSGIN:
2201                                len = 1;
2202                                data = &tmp;
2203                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2204                                cmd->SCp.Message = tmp;
2205
2206                                switch (tmp) {
2207                                        /*
2208                                         * Linking lets us reduce the time required to get the 
2209                                         * next command out to the device, hopefully this will
2210                                         * mean we don't waste another revolution due to the delays
2211                                         * required by ARBITRATION and another SELECTION.
2212                                         *
2213                                         * In the current implementation proposal, low level drivers
2214                                         * merely have to start the next command, pointed to by 
2215                                         * next_link, done() is called as with unlinked commands.
2216                                         */
2217#ifdef LINKED
2218                                case LINKED_CMD_COMPLETE:
2219                                case LINKED_FLG_CMD_COMPLETE:
2220                                        /* Accept message by clearing ACK */
2221                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2222                                        dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun));
2223                                        /* 
2224                                         * Sanity check : A linked command should only terminate with
2225                                         * one of these messages if there are more linked commands
2226                                         * available.
2227                                         */
2228                                        if (!cmd->next_link) {
2229                                                printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2230                                                sink = 1;
2231                                                do_abort(instance);
2232                                                return;
2233                                        }
2234                                        initialize_SCp(cmd->next_link);
2235                                        /* The next command is still part of this process */
2236                                        cmd->next_link->tag = cmd->tag;
2237                                        cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2238                                        dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked request done, calling scsi_done().\n", instance->host_no, cmd->device->id, cmd->device->lun));
2239                                        collect_stats(hostdata, cmd);
2240                                        cmd->scsi_done(cmd);
2241                                        cmd = hostdata->connected;
2242                                        break;
2243#endif                          /* def LINKED */
2244                                case ABORT:
2245                                case COMMAND_COMPLETE:
2246                                        /* Accept message by clearing ACK */
2247                                        sink = 1;
2248                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2249                                        hostdata->connected = NULL;
2250                                        dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun));
2251                                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2252
2253                                        /* 
2254                                         * I'm not sure what the correct thing to do here is : 
2255                                         * 
2256                                         * If the command that just executed is NOT a request 
2257                                         * sense, the obvious thing to do is to set the result
2258                                         * code to the values of the stored parameters.
2259                                         * 
2260                                         * If it was a REQUEST SENSE command, we need some way 
2261                                         * to differentiate between the failure code of the original
2262                                         * and the failure code of the REQUEST sense - the obvious
2263                                         * case is success, where we fall through and leave the result
2264                                         * code unchanged.
2265                                         * 
2266                                         * The non-obvious place is where the REQUEST SENSE failed 
2267                                         */
2268
2269                                        if (cmd->cmnd[0] != REQUEST_SENSE)
2270                                                cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2271                                        else if (status_byte(cmd->SCp.Status) != GOOD)
2272                                                cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2273
2274#ifdef AUTOSENSE
2275                                        if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2276                                                hostdata->ses.cmd_len) {
2277                                                scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2278                                                hostdata->ses.cmd_len = 0 ;
2279                                        }
2280
2281                                        if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2282                                                scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2283
2284                                                dprintk(NDEBUG_AUTOSENSE, ("scsi%d : performing request sense\n", instance->host_no));
2285
2286                                                LIST(cmd, hostdata->issue_queue);
2287                                                cmd->host_scribble = (unsigned char *)
2288                                                    hostdata->issue_queue;
2289                                                hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2290                                                dprintk(NDEBUG_QUEUES, ("scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no));
2291                                        } else
2292#endif                          /* def AUTOSENSE */
2293                                        {
2294                                                collect_stats(hostdata, cmd);
2295                                                cmd->scsi_done(cmd);
2296                                        }
2297
2298                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2299                                        /* 
2300                                         * Restore phase bits to 0 so an interrupted selection, 
2301                                         * arbitration can resume.
2302                                         */
2303                                        NCR5380_write(TARGET_COMMAND_REG, 0);
2304
2305                                        while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2306                                                barrier();
2307                                        return;
2308                                case MESSAGE_REJECT:
2309                                        /* Accept message by clearing ACK */
2310                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2311                                        switch (hostdata->last_message) {
2312                                        case HEAD_OF_QUEUE_TAG:
2313                                        case ORDERED_QUEUE_TAG:
2314                                        case SIMPLE_QUEUE_TAG:
2315                                                cmd->device->simple_tags = 0;
2316                                                hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2317                                                break;
2318                                        default:
2319                                                break;
2320                                        }
2321                                case DISCONNECT:{
2322                                                /* Accept message by clearing ACK */
2323                                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2324                                                cmd->device->disconnect = 1;
2325                                                LIST(cmd, hostdata->disconnected_queue);
2326                                                cmd->host_scribble = (unsigned char *)
2327                                                    hostdata->disconnected_queue;
2328                                                hostdata->connected = NULL;
2329                                                hostdata->disconnected_queue = cmd;
2330                                                dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d lun %d was moved from connected to" "  the disconnected_queue\n", instance->host_no, cmd->device->id, cmd->device->lun));
2331                                                /* 
2332                                                 * Restore phase bits to 0 so an interrupted selection, 
2333                                                 * arbitration can resume.
2334                                                 */
2335                                                NCR5380_write(TARGET_COMMAND_REG, 0);
2336
2337                                                /* Enable reselect interrupts */
2338                                                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2339                                                /* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2340                                                /* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2341                                                while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2342                                                        barrier();
2343                                                return;
2344                                        }
2345                                        /* 
2346                                         * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2347                                         * operation, in violation of the SCSI spec so we can safely 
2348                                         * ignore SAVE/RESTORE pointers calls.
2349                                         *
2350                                         * Unfortunately, some disks violate the SCSI spec and 
2351                                         * don't issue the required SAVE_POINTERS message before
2352                                         * disconnecting, and we have to break spec to remain 
2353                                         * compatible.
2354                                         */
2355                                case SAVE_POINTERS:
2356                                case RESTORE_POINTERS:
2357                                        /* Accept message by clearing ACK */
2358                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2359                                        break;
2360                                case EXTENDED_MESSAGE:
2361/* 
2362 * Extended messages are sent in the following format :
2363 * Byte         
2364 * 0            EXTENDED_MESSAGE == 1
2365 * 1            length (includes one byte for code, doesn't 
2366 *              include first two bytes)
2367 * 2            code
2368 * 3..length+1  arguments
2369 *
2370 * Start the extended message buffer with the EXTENDED_MESSAGE
2371 * byte, since spi_print_msg() wants the whole thing.  
2372 */
2373                                        extended_msg[0] = EXTENDED_MESSAGE;
2374                                        /* Accept first byte by clearing ACK */
2375                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2376                                        dprintk(NDEBUG_EXTENDED, ("scsi%d : receiving extended message\n", instance->host_no));
2377
2378                                        len = 2;
2379                                        data = extended_msg + 1;
2380                                        phase = PHASE_MSGIN;
2381                                        NCR5380_transfer_pio(instance, &phase, &len, &data);
2382
2383                                        dprintk(NDEBUG_EXTENDED, ("scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]));
2384
2385                                        if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2386                                                /* Accept third byte by clearing ACK */
2387                                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2388                                                len = extended_msg[1] - 1;
2389                                                data = extended_msg + 3;
2390                                                phase = PHASE_MSGIN;
2391
2392                                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2393                                                dprintk(NDEBUG_EXTENDED, ("scsi%d : message received, residual %d\n", instance->host_no, len));
2394
2395                                                switch (extended_msg[2]) {
2396                                                case EXTENDED_SDTR:
2397                                                case EXTENDED_WDTR:
2398                                                case EXTENDED_MODIFY_DATA_POINTER:
2399                                                case EXTENDED_EXTENDED_IDENTIFY:
2400                                                        tmp = 0;
2401                                                }
2402                                        } else if (len) {
2403                                                printk("scsi%d: error receiving extended message\n", instance->host_no);
2404                                                tmp = 0;
2405                                        } else {
2406                                                printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2407                                                tmp = 0;
2408                                        }
2409                                        /* Fall through to reject message */
2410
2411                                        /* 
2412                                         * If we get something weird that we aren't expecting, 
2413                                         * reject it.
2414                                         */
2415                                default:
2416                                        if (!tmp) {
2417                                                printk("scsi%d: rejecting message ", instance->host_no);
2418                                                spi_print_msg(extended_msg);
2419                                                printk("\n");
2420                                        } else if (tmp != EXTENDED_MESSAGE)
2421                                                scmd_printk(KERN_INFO, cmd,
2422                                                        "rejecting unknown message %02x\n",tmp);
2423                                        else
2424                                                scmd_printk(KERN_INFO, cmd,
2425                                                        "rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2426
2427                                        msgout = MESSAGE_REJECT;
2428                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2429                                        break;
2430                                }       /* switch (tmp) */
2431                                break;
2432                        case PHASE_MSGOUT:
2433                                len = 1;
2434                                data = &msgout;
2435                                hostdata->last_message = msgout;
2436                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2437                                if (msgout == ABORT) {
2438                                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2439                                        hostdata->connected = NULL;
2440                                        cmd->result = DID_ERROR << 16;
2441                                        collect_stats(hostdata, cmd);
2442                                        cmd->scsi_done(cmd);
2443                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2444                                        return;
2445                                }
2446                                msgout = NOP;
2447                                break;
2448                        case PHASE_CMDOUT:
2449                                len = cmd->cmd_len;
2450                                data = cmd->cmnd;
2451                                /* 
2452                                 * XXX for performance reasons, on machines with a 
2453                                 * PSEUDO-DMA architecture we should probably 
2454                                 * use the dma transfer function.  
2455                                 */
2456                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2457                                if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2458                                        NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2459                                        dprintk(NDEBUG_USLEEP, ("scsi%d : issued command, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2460                                        return;
2461                                }
2462                                break;
2463                        case PHASE_STATIN:
2464                                len = 1;
2465                                data = &tmp;
2466                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2467                                cmd->SCp.Status = tmp;
2468                                break;
2469                        default:
2470                                printk("scsi%d : unknown phase\n", instance->host_no);
2471                                NCR5380_dprint(NDEBUG_ALL, instance);
2472                        }       /* switch(phase) */
2473                }               /* if (tmp * SR_REQ) */
2474                else {
2475                        /* RvC: go to sleep if polling time expired
2476                         */
2477                        if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2478                                NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2479                                dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2480                                return;
2481                        }
2482                }
2483        }                       /* while (1) */
2484}
2485
2486/*
2487 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2488 *
2489 * Purpose : does reselection, initializing the instance->connected 
2490 *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q 
2491 *      nexus has been reestablished,
2492 *      
2493 * Inputs : instance - this instance of the NCR5380.
2494 *
2495 * Locks: io_request_lock held by caller if IRQ driven
2496 */
2497
2498static void NCR5380_reselect(struct Scsi_Host *instance) {
2499        NCR5380_local_declare();
2500        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2501         instance->hostdata;
2502        unsigned char target_mask;
2503        unsigned char lun, phase;
2504        int len;
2505        unsigned char msg[3];
2506        unsigned char *data;
2507        Scsi_Cmnd *tmp = NULL, *prev;
2508        int abort = 0;
2509        NCR5380_setup(instance);
2510
2511        /*
2512         * Disable arbitration, etc. since the host adapter obviously
2513         * lost, and tell an interrupted NCR5380_select() to restart.
2514         */
2515
2516        NCR5380_write(MODE_REG, MR_BASE);
2517        hostdata->restart_select = 1;
2518
2519        target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2520        dprintk(NDEBUG_SELECTION, ("scsi%d : reselect\n", instance->host_no));
2521
2522        /* 
2523         * At this point, we have detected that our SCSI ID is on the bus,
2524         * SEL is true and BSY was false for at least one bus settle delay
2525         * (400 ns).
2526         *
2527         * We must assert BSY ourselves, until the target drops the SEL
2528         * signal.
2529         */
2530
2531        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2532
2533        /* FIXME: timeout too long, must fail to workqueue */   
2534        if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2535                abort = 1;
2536                
2537        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2538
2539        /*
2540         * Wait for target to go into MSGIN.
2541         * FIXME: timeout needed and fail to work queeu
2542         */
2543
2544        if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2545                abort = 1;
2546
2547        len = 1;
2548        data = msg;
2549        phase = PHASE_MSGIN;
2550        NCR5380_transfer_pio(instance, &phase, &len, &data);
2551
2552        if (!(msg[0] & 0x80)) {
2553                printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2554                spi_print_msg(msg);
2555                abort = 1;
2556        } else {
2557                /* Accept message by clearing ACK */
2558                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2559                lun = (msg[0] & 0x07);
2560
2561                /* 
2562                 * We need to add code for SCSI-II to track which devices have
2563                 * I_T_L_Q nexuses established, and which have simple I_T_L
2564                 * nexuses so we can chose to do additional data transfer.
2565                 */
2566
2567                /* 
2568                 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we 
2569                 * just reestablished, and remove it from the disconnected queue.
2570                 */
2571
2572
2573                for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2574                        if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2575                            ) {
2576                                if (prev) {
2577                                        REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2578                                        prev->host_scribble = tmp->host_scribble;
2579                                } else {
2580                                        REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2581                                        hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2582                                }
2583                                tmp->host_scribble = NULL;
2584                                break;
2585                        }
2586                if (!tmp) {
2587                        printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2588                        /* 
2589                         * Since we have an established nexus that we can't do anything with,
2590                         * we must abort it.  
2591                         */
2592                        abort = 1;
2593                }
2594        }
2595
2596        if (abort) {
2597                do_abort(instance);
2598        } else {
2599                hostdata->connected = tmp;
2600                dprintk(NDEBUG_RESELECTION, ("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->target, tmp->lun, tmp->tag));
2601        }
2602}
2603
2604/*
2605 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2606 *
2607 * Purpose : called by interrupt handler when DMA finishes or a phase
2608 *      mismatch occurs (which would finish the DMA transfer).  
2609 *
2610 * Inputs : instance - this instance of the NCR5380.
2611 *
2612 * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2613 *      nexus has been reestablished, on failure NULL is returned.
2614 */
2615
2616#ifdef REAL_DMA
2617static void NCR5380_dma_complete(NCR5380_instance * instance) {
2618        NCR5380_local_declare();
2619        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2620        int transferred;
2621        NCR5380_setup(instance);
2622
2623        /*
2624         * XXX this might not be right.
2625         *
2626         * Wait for final byte to transfer, ie wait for ACK to go false.
2627         *
2628         * We should use the Last Byte Sent bit, unfortunately this is 
2629         * not available on the 5380/5381 (only the various CMOS chips)
2630         *
2631         * FIXME: timeout, and need to handle long timeout/irq case
2632         */
2633
2634        NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2635
2636        NCR5380_write(MODE_REG, MR_BASE);
2637        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2638
2639        /*
2640         * The only places we should see a phase mismatch and have to send
2641         * data from the same set of pointers will be the data transfer
2642         * phases.  So, residual, requested length are only important here.
2643         */
2644
2645        if (!(hostdata->connected->SCp.phase & SR_CD)) {
2646                transferred = instance->dmalen - NCR5380_dma_residual();
2647                hostdata->connected->SCp.this_residual -= transferred;
2648                hostdata->connected->SCp.ptr += transferred;
2649        }
2650}
2651#endif                          /* def REAL_DMA */
2652
2653/*
2654 * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2655 *
2656 * Purpose : abort a command
2657 *
2658 * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the 
2659 *      host byte of the result field to, if zero DID_ABORTED is 
2660 *      used.
2661 *
2662 * Returns : 0 - success, -1 on failure.
2663 *
2664 *      XXX - there is no way to abort the command that is currently 
2665 *      connected, you have to wait for it to complete.  If this is 
2666 *      a problem, we could implement longjmp() / setjmp(), setjmp()
2667 *      called where the loop started in NCR5380_main().
2668 *
2669 * Locks: host lock taken by caller
2670 */
2671
2672static int NCR5380_abort(Scsi_Cmnd * cmd) {
2673        NCR5380_local_declare();
2674        struct Scsi_Host *instance = cmd->device->host;
2675        struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2676        Scsi_Cmnd *tmp, **prev;
2677        
2678        printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2679        scsi_print_command(cmd);
2680
2681        NCR5380_print_status(instance);
2682
2683        NCR5380_setup(instance);
2684
2685        dprintk(NDEBUG_ABORT, ("scsi%d : abort called\n", instance->host_no));
2686        dprintk(NDEBUG_ABORT, ("        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)));
2687
2688#if 0
2689/*
2690 * Case 1 : If the command is the currently executing command, 
2691 * we'll set the aborted flag and return control so that 
2692 * information transfer routine can exit cleanly.
2693 */
2694
2695        if (hostdata->connected == cmd) {
2696                dprintk(NDEBUG_ABORT, ("scsi%d : aborting connected command\n", instance->host_no));
2697                hostdata->aborted = 1;
2698/*
2699 * We should perform BSY checking, and make sure we haven't slipped
2700 * into BUS FREE.
2701 */
2702
2703                NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2704/* 
2705 * Since we can't change phases until we've completed the current 
2706 * handshake, we have to source or sink a byte of data if the current
2707 * phase is not MSGOUT.
2708 */
2709
2710/* 
2711 * Return control to the executing NCR drive so we can clear the
2712 * aborted flag and get back into our main loop.
2713 */
2714
2715                return 0;
2716        }
2717#endif
2718
2719/* 
2720 * Case 2 : If the command hasn't been issued yet, we simply remove it 
2721 *          from the issue queue.
2722 */
2723 
2724        dprintk(NDEBUG_ABORT, ("scsi%d : abort going into loop.\n", instance->host_no));
2725        for (prev = (Scsi_Cmnd **) & (hostdata->issue_queue), tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp; prev = (Scsi_Cmnd **) & (tmp->host_scribble), tmp = (Scsi_Cmnd *) tmp->host_scribble)
2726                if (cmd == tmp) {
2727                        REMOVE(5, *prev, tmp, tmp->host_scribble);
2728                        (*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2729                        tmp->host_scribble = NULL;
2730                        tmp->result = DID_ABORT << 16;
2731                        dprintk(NDEBUG_ABORT, ("scsi%d : abort removed command from issue queue.\n", instance->host_no));
2732                        tmp->scsi_done(tmp);
2733                        return SUCCESS;
2734                }
2735#if (NDEBUG  & NDEBUG_ABORT)
2736        /* KLL */
2737                else if (prev == tmp)
2738                        printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2739#endif
2740
2741/* 
2742 * Case 3 : If any commands are connected, we're going to fail the abort
2743 *          and let the high level SCSI driver retry at a later time or 
2744 *          issue a reset.
2745 *
2746 *          Timeouts, and therefore aborted commands, will be highly unlikely
2747 *          and handling them cleanly in this situation would make the common
2748 *          case of noresets less efficient, and would pollute our code.  So,
2749 *          we fail.
2750 */
2751
2752        if (hostdata->connected) {
2753                dprintk(NDEBUG_ABORT, ("scsi%d : abort failed, command connected.\n", instance->host_no));
2754                return FAILED;
2755        }
2756/*
2757 * Case 4: If the command is currently disconnected from the bus, and 
2758 *      there are no connected commands, we reconnect the I_T_L or 
2759 *      I_T_L_Q nexus associated with it, go into message out, and send 
2760 *      an abort message.
2761 *
2762 * This case is especially ugly. In order to reestablish the nexus, we
2763 * need to call NCR5380_select().  The easiest way to implement this 
2764 * function was to abort if the bus was busy, and let the interrupt
2765 * handler triggered on the SEL for reselect take care of lost arbitrations
2766 * where necessary, meaning interrupts need to be enabled.
2767 *
2768 * When interrupts are enabled, the queues may change - so we 
2769 * can't remove it from the disconnected queue before selecting it
2770 * because that could cause a failure in hashing the nexus if that 
2771 * device reselected.
2772 * 
2773 * Since the queues may change, we can't use the pointers from when we
2774 * first locate it.
2775 *
2776 * So, we must first locate the command, and if NCR5380_select()
2777 * succeeds, then issue the abort, relocate the command and remove
2778 * it from the disconnected queue.
2779 */
2780
2781        for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2782                if (cmd == tmp) {
2783                        dprintk(NDEBUG_ABORT, ("scsi%d : aborting disconnected command.\n", instance->host_no));
2784
2785                        if (NCR5380_select(instance, cmd, (int) cmd->tag))
2786                                return FAILED;
2787                        dprintk(NDEBUG_ABORT, ("scsi%d : nexus reestablished.\n", instance->host_no));
2788
2789                        do_abort(instance);
2790
2791                        for (prev = (Scsi_Cmnd **) & (hostdata->disconnected_queue), tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; prev = (Scsi_Cmnd **) & (tmp->host_scribble), tmp = (Scsi_Cmnd *) tmp->host_scribble)
2792                                if (cmd == tmp) {
2793                                        REMOVE(5, *prev, tmp, tmp->host_scribble);
2794                                        *prev = (Scsi_Cmnd *) tmp->host_scribble;
2795                                        tmp->host_scribble = NULL;
2796                                        tmp->result = DID_ABORT << 16;
2797                                        tmp->scsi_done(tmp);
2798                                        return SUCCESS;
2799                                }
2800                }
2801/*
2802 * Case 5 : If we reached this point, the command was not found in any of 
2803 *          the queues.
2804 *
2805 * We probably reached this point because of an unlikely race condition
2806 * between the command completing successfully and the abortion code,
2807 * so we won't panic, but we will notify the user in case something really
2808 * broke.
2809 */
2810        printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2811                        "         before abortion\n", instance->host_no);
2812        return FAILED;
2813}
2814
2815
2816/* 
2817 * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2818 * 
2819 * Purpose : reset the SCSI bus.
2820 *
2821 * Returns : SUCCESS
2822 *
2823 * Locks: host lock taken by caller
2824 */
2825
2826static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2827{
2828        struct Scsi_Host *instance = cmd->device->host;
2829
2830        NCR5380_local_declare();
2831        NCR5380_setup(instance);
2832        NCR5380_print_status(instance);
2833
2834        spin_lock_irq(instance->host_lock);
2835        do_reset(instance);
2836        spin_unlock_irq(instance->host_lock);
2837
2838        return SUCCESS;
2839}
2840
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