drivers/scsi/atari_NCR5380.c

   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  * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
  31  * this file, too:
  32  *
  33  *  - Some of the debug statements were incorrect (undefined variables and the
  34  *    like). I fixed that.
  35  *
  36  *  - In information_transfer(), I think a #ifdef was wrong. Looking at the
  37  *    possible DMA transfer size should also happen for REAL_DMA. I added this
  38  *    in the #if statement.
  39  *
  40  *  - When using real DMA, information_transfer() should return in a DATAOUT
  41  *    phase after starting the DMA. It has nothing more to do.
  42  *
  43  *  - The interrupt service routine should run main after end of DMA, too (not
  44  *    only after RESELECTION interrupts). Additionally, it should _not_ test
  45  *    for more interrupts after running main, since a DMA process may have
  46  *    been started and interrupts are turned on now. The new int could happen
  47  *    inside the execution of NCR5380_intr(), leading to recursive
  48  *    calls.
  49  *
  50  *  - I've added a function merge_contiguous_buffers() that tries to
  51  *    merge scatter-gather buffers that are located at contiguous
  52  *    physical addresses and can be processed with the same DMA setup.
  53  *    Since most scatter-gather operations work on a page (4K) of
  54  *    4 buffers (1K), in more than 90% of all cases three interrupts and
  55  *    DMA setup actions are saved.
  56  *
  57  * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
  58  *    and USLEEP, because these were messing up readability and will never be
  59  *    needed for Atari SCSI.
  60  *
  61  * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
  62  *   stuff), and 'main' is executed in a bottom half if awoken by an
  63  *   interrupt.
  64  *
  65  * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
  66  *   constructs. In my eyes, this made the source rather unreadable, so I
  67  *   finally replaced that by the *_PRINTK() macros.
  68  *
  69  */
  70
  71 /*
  72  * Further development / testing that should be done :
  73  * 1.  Test linked command handling code after Eric is ready with
  74  *     the high level code.
  75  */
  76 #include <scsi/scsi_dbg.h>
  77 #include <scsi/scsi_transport_spi.h>
  78
  79 #if (NDEBUG & NDEBUG_LISTS)
  80 #define LIST(x, y)                                              \
  81         do {                                                    \
  82                 printk("LINE:%d   Adding %p to %p\n",           \
  83                        __LINE__, (void*)(x), (void*)(y));       \
  84                 if ((x) == (y))                                 \
  85                         udelay(5);                              \
  86         } while (0)
  87 #define REMOVE(w, x, y, z)                                      \
  88         do {                                                    \
  89                 printk("LINE:%d   Removing: %p->%p  %p->%p \n", \
  90                        __LINE__, (void*)(w), (void*)(x),        \
  91                        (void*)(y), (void*)(z));                 \
  92                 if ((x) == (y))                                 \
  93                         udelay(5);                              \
  94         } while (0)
  95 #else
  96 #define LIST(x,y)
  97 #define REMOVE(w,x,y,z)
  98 #endif
  99
 100 #ifndef notyet
 101 #undef LINKED
 102 #endif
 103
 104 /*
 105  * Design
 106  * Issues :
 107  *
 108  * The other Linux SCSI drivers were written when Linux was Intel PC-only,
 109  * and specifically for each board rather than each chip.  This makes their
 110  * adaptation to platforms like the Mac (Some of which use NCR5380's)
 111  * more difficult than it has to be.
 112  *
 113  * Also, many of the SCSI drivers were written before the command queuing
 114  * routines were implemented, meaning their implementations of queued
 115  * commands were hacked on rather than designed in from the start.
 116  *
 117  * When I designed the Linux SCSI drivers I figured that
 118  * while having two different SCSI boards in a system might be useful
 119  * for debugging things, two of the same type wouldn't be used.
 120  * Well, I was wrong and a number of users have mailed me about running
 121  * multiple high-performance SCSI boards in a server.
 122  *
 123  * Finally, when I get questions from users, I have no idea what
 124  * revision of my driver they are running.
 125  *
 126  * This driver attempts to address these problems :
 127  * This is a generic 5380 driver.  To use it on a different platform,
 128  * one simply writes appropriate system specific macros (ie, data
 129  * transfer - some PC's will use the I/O bus, 68K's must use
 130  * memory mapped) and drops this file in their 'C' wrapper.
 131  *
 132  * As far as command queueing, two queues are maintained for
 133  * each 5380 in the system - commands that haven't been issued yet,
 134  * and commands that are currently executing.  This means that an
 135  * unlimited number of commands may be queued, letting
 136  * more commands propagate from the higher driver levels giving higher
 137  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
 138  * allowing multiple commands to propagate all the way to a SCSI-II device
 139  * while a command is already executing.
 140  *
 141  * To solve the multiple-boards-in-the-same-system problem,
 142  * there is a separate instance structure for each instance
 143  * of a 5380 in the system.  So, multiple NCR5380 drivers will
 144  * be able to coexist with appropriate changes to the high level
 145  * SCSI code.
 146  *
 147  * A NCR5380_PUBLIC_REVISION macro is provided, with the release
 148  * number (updated for each public release) printed by the
 149  * NCR5380_print_options command, which should be called from the
 150  * wrapper detect function, so that I know what release of the driver
 151  * users are using.
 152  *
 153  * Issues specific to the NCR5380 :
 154  *
 155  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
 156  * piece of hardware that requires you to sit in a loop polling for
 157  * the REQ signal as long as you are connected.  Some devices are
 158  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
 159  * while doing long seek operations.
 160  *
 161  * The workaround for this is to keep track of devices that have
 162  * disconnected.  If the device hasn't disconnected, for commands that
 163  * should disconnect, we do something like
 164  *
 165  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
 166  *
 167  * Some tweaking of N and M needs to be done.  An algorithm based
 168  * on "time to data" would give the best results as long as short time
 169  * to datas (ie, on the same track) were considered, however these
 170  * broken devices are the exception rather than the rule and I'd rather
 171  * spend my time optimizing for the normal case.
 172  *
 173  * Architecture :
 174  *
 175  * At the heart of the design is a coroutine, NCR5380_main,
 176  * which is started when not running by the interrupt handler,
 177  * timer, and queue command function.  It attempts to establish
 178  * I_T_L or I_T_L_Q nexuses by removing the commands from the
 179  * issue queue and calling NCR5380_select() if a nexus
 180  * is not established.
 181  *
 182  * Once a nexus is established, the NCR5380_information_transfer()
 183  * phase goes through the various phases as instructed by the target.
 184  * if the target goes into MSG IN and sends a DISCONNECT message,
 185  * the command structure is placed into the per instance disconnected
 186  * queue, and NCR5380_main tries to find more work.  If USLEEP
 187  * was defined, and the target is idle for too long, the system
 188  * will try to sleep.
 189  *
 190  * If a command has disconnected, eventually an interrupt will trigger,
 191  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
 192  * to reestablish a nexus.  This will run main if necessary.
 193  *
 194  * On command termination, the done function will be called as
 195  * appropriate.
 196  *
 197  * SCSI pointers are maintained in the SCp field of SCSI command
 198  * structures, being initialized after the command is connected
 199  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
 200  * Note that in violation of the standard, an implicit SAVE POINTERS operation
 201  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
 202  */
 203
 204 /*
 205  * Using this file :
 206  * This file a skeleton Linux SCSI driver for the NCR 5380 series
 207  * of chips.  To use it, you write an architecture specific functions
 208  * and macros and include this file in your driver.
 209  *
 210  * These macros control options :
 211  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
 212  *      for commands that return with a CHECK CONDITION status.
 213  *
 214  * LINKED - if defined, linked commands are supported.
 215  *
 216  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
 217  *
 218  * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
 219  *
 220  * These macros MUST be defined :
 221  *
 222  * NCR5380_read(register)  - read from the specified register
 223  *
 224  * NCR5380_write(register, value) - write to the specific register
 225  *
 226  * Either real DMA *or* pseudo DMA may be implemented
 227  * REAL functions :
 228  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
 229  * Note that the DMA setup functions should return the number of bytes
 230  *      that they were able to program the controller for.
 231  *
 232  * Also note that generic i386/PC versions of these macros are
 233  *      available as NCR5380_i386_dma_write_setup,
 234  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
 235  *
 236  * NCR5380_dma_write_setup(instance, src, count) - initialize
 237  * NCR5380_dma_read_setup(instance, dst, count) - initialize
 238  * NCR5380_dma_residual(instance); - residual count
 239  *
 240  * PSEUDO functions :
 241  * NCR5380_pwrite(instance, src, count)
 242  * NCR5380_pread(instance, dst, count);
 243  *
 244  * If nothing specific to this implementation needs doing (ie, with external
 245  * hardware), you must also define
 246  *
 247  * NCR5380_queue_command
 248  * NCR5380_reset
 249  * NCR5380_abort
 250  * NCR5380_proc_info
 251  *
 252  * to be the global entry points into the specific driver, ie
 253  * #define NCR5380_queue_command t128_queue_command.
 254  *
 255  * If this is not done, the routines will be defined as static functions
 256  * with the NCR5380* names and the user must provide a globally
 257  * accessible wrapper function.
 258  *
 259  * The generic driver is initialized by calling NCR5380_init(instance),
 260  * after setting the appropriate host specific fields and ID.  If the
 261  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
 262  * possible) function may be used.  Before the specific driver initialization
 263  * code finishes, NCR5380_print_options should be called.
 264  */
 265
 266 static struct Scsi_Host *first_instance = NULL;
 267 static struct scsi_host_template *the_template = NULL;
 268
 269 /* Macros ease life... :-) */
 270 #define SETUP_HOSTDATA(in)                              \
 271     struct NCR5380_hostdata *hostdata =                 \
 272         (struct NCR5380_hostdata *)(in)->hostdata
 273 #define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
 274
 275 #define NEXT(cmd)               ((Scsi_Cmnd *)(cmd)->host_scribble)
 276 #define SET_NEXT(cmd,next)      ((cmd)->host_scribble = (void *)(next))
 277 #define NEXTADDR(cmd)           ((Scsi_Cmnd **)&(cmd)->host_scribble)
 278
 279 #define HOSTNO          instance->host_no
 280 #define H_NO(cmd)       (cmd)->device->host->host_no
 281
 282 #ifdef SUPPORT_TAGS
 283
 284 /*
 285  * Functions for handling tagged queuing
 286  * =====================================
 287  *
 288  * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
 289  *
 290  * Using consecutive numbers for the tags is no good idea in my eyes. There
 291  * could be wrong re-usings if the counter (8 bit!) wraps and some early
 292  * command has been preempted for a long time. My solution: a bitfield for
 293  * remembering used tags.
 294  *
 295  * There's also the problem that each target has a certain queue size, but we
 296  * cannot know it in advance :-( We just see a QUEUE_FULL status being
 297  * returned. So, in this case, the driver internal queue size assumption is
 298  * reduced to the number of active tags if QUEUE_FULL is returned by the
 299  * target. The command is returned to the mid-level, but with status changed
 300  * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
 301  * correctly.
 302  *
 303  * We're also not allowed running tagged commands as long as an untagged
 304  * command is active. And REQUEST SENSE commands after a contingent allegiance
 305  * condition _must_ be untagged. To keep track whether an untagged command has
 306  * been issued, the host->busy array is still employed, as it is without
 307  * support for tagged queuing.
 308  *
 309  * One could suspect that there are possible race conditions between
 310  * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
 311  * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
 312  * which already guaranteed to be running at most once. It is also the only
 313  * place where tags/LUNs are allocated. So no other allocation can slip
 314  * between that pair, there could only happen a reselection, which can free a
 315  * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
 316  * important: the tag bit must be cleared before 'nr_allocated' is decreased.
 317  */
 318
 319 /* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
 320 #undef TAG_NONE
 321 #define TAG_NONE 0xff
 322
 323 typedef struct {
 324         DECLARE_BITMAP(allocated, MAX_TAGS);
 325         int nr_allocated;
 326         int queue_size;
 327 } TAG_ALLOC;
 328
 329 static TAG_ALLOC TagAlloc[8][8];        /* 8 targets and 8 LUNs */
 330
 331
 332 static void __init init_tags(void)
 333 {
 334         int target, lun;
 335         TAG_ALLOC *ta;
 336
 337         if (!setup_use_tagged_queuing)
 338                 return;
 339
 340         for (target = 0; target < 8; ++target) {
 341                 for (lun = 0; lun < 8; ++lun) {
 342                         ta = &TagAlloc[target][lun];
 343                         bitmap_zero(ta->allocated, MAX_TAGS);
 344                         ta->nr_allocated = 0;
 345                         /* At the beginning, assume the maximum queue size we could
 346                          * support (MAX_TAGS). This value will be decreased if the target
 347                          * returns QUEUE_FULL status.
 348                          */
 349                         ta->queue_size = MAX_TAGS;
 350                 }
 351         }
 352 }
 353
 354
 355 /* Check if we can issue a command to this LUN: First see if the LUN is marked
 356  * busy by an untagged command. If the command should use tagged queuing, also
 357  * check that there is a free tag and the target's queue won't overflow. This
 358  * function should be called with interrupts disabled to avoid race
 359  * conditions.
 360  */
 361
 362 static int is_lun_busy(Scsi_Cmnd *cmd, int should_be_tagged)
 363 {
 364         SETUP_HOSTDATA(cmd->device->host);
 365
 366         if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun))
 367                 return 1;
 368         if (!should_be_tagged ||
 369             !setup_use_tagged_queuing || !cmd->device->tagged_supported)
 370                 return 0;
 371         if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >=
 372             TagAlloc[cmd->device->id][cmd->device->lun].queue_size) {
 373                 TAG_PRINTK("scsi%d: target %d lun %d: no free tags\n",
 374                            H_NO(cmd), cmd->device->id, cmd->device->lun);
 375                 return 1;
 376         }
 377         return 0;
 378 }
 379
 380
 381 /* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
 382  * must be called before!), or reserve the LUN in 'busy' if the command is
 383  * untagged.
 384  */
 385
 386 static void cmd_get_tag(Scsi_Cmnd *cmd, int should_be_tagged)
 387 {
 388         SETUP_HOSTDATA(cmd->device->host);
 389
 390         /* If we or the target don't support tagged queuing, allocate the LUN for
 391          * an untagged command.
 392          */
 393         if (!should_be_tagged ||
 394             !setup_use_tagged_queuing || !cmd->device->tagged_supported) {
 395                 cmd->tag = TAG_NONE;
 396                 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
 397                 TAG_PRINTK("scsi%d: target %d lun %d now allocated by untagged "
 398                            "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun);
 399         } else {
 400                 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
 401
 402                 cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
 403                 set_bit(cmd->tag, ta->allocated);
 404                 ta->nr_allocated++;
 405                 TAG_PRINTK("scsi%d: using tag %d for target %d lun %d "
 406                            "(now %d tags in use)\n",
 407                            H_NO(cmd), cmd->tag, cmd->device->id,
 408                            cmd->device->lun, ta->nr_allocated);
 409         }
 410 }
 411
 412
 413 /* Mark the tag of command 'cmd' as free, or in case of an untagged command,
 414  * unlock the LUN.
 415  */
 416
 417 static void cmd_free_tag(Scsi_Cmnd *cmd)
 418 {
 419         SETUP_HOSTDATA(cmd->device->host);
 420
 421         if (cmd->tag == TAG_NONE) {
 422                 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
 423                 TAG_PRINTK("scsi%d: target %d lun %d untagged cmd finished\n",
 424                            H_NO(cmd), cmd->device->id, cmd->device->lun);
 425         } else if (cmd->tag >= MAX_TAGS) {
 426                 printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
 427                        H_NO(cmd), cmd->tag);
 428         } else {
 429                 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
 430                 clear_bit(cmd->tag, ta->allocated);
 431                 ta->nr_allocated--;
 432                 TAG_PRINTK("scsi%d: freed tag %d for target %d lun %d\n",
 433                            H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun);
 434         }
 435 }
 436
 437
 438 static void free_all_tags(void)
 439 {
 440         int target, lun;
 441         TAG_ALLOC *ta;
 442
 443         if (!setup_use_tagged_queuing)
 444                 return;
 445
 446         for (target = 0; target < 8; ++target) {
 447                 for (lun = 0; lun < 8; ++lun) {
 448                         ta = &TagAlloc[target][lun];
 449                         bitmap_zero(ta->allocated, MAX_TAGS);
 450                         ta->nr_allocated = 0;
 451                 }
 452         }
 453 }
 454
 455 #endif /* SUPPORT_TAGS */
 456
 457
 458 /*
 459  * Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd )
 460  *
 461  * Purpose: Try to merge several scatter-gather requests into one DMA
 462  *    transfer. This is possible if the scatter buffers lie on
 463  *    physical contiguous addresses.
 464  *
 465  * Parameters: Scsi_Cmnd *cmd
 466  *    The command to work on. The first scatter buffer's data are
 467  *    assumed to be already transferred into ptr/this_residual.
 468  */
 469
 470 static void merge_contiguous_buffers(Scsi_Cmnd *cmd)
 471 {
 472         unsigned long endaddr;
 473 #if (NDEBUG & NDEBUG_MERGING)
 474         unsigned long oldlen = cmd->SCp.this_residual;
 475         int cnt = 1;
 476 #endif
 477
 478         for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
 479              cmd->SCp.buffers_residual &&
 480              virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
 481                 MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
 482                            page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
 483 #if (NDEBUG & NDEBUG_MERGING)
 484                 ++cnt;
 485 #endif
 486                 ++cmd->SCp.buffer;
 487                 --cmd->SCp.buffers_residual;
 488                 cmd->SCp.this_residual += cmd->SCp.buffer->length;
 489                 endaddr += cmd->SCp.buffer->length;
 490         }
 491 #if (NDEBUG & NDEBUG_MERGING)
 492         if (oldlen != cmd->SCp.this_residual)
 493                 MER_PRINTK("merged %d buffers from %p, new length %08x\n",
 494                            cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
 495 #endif
 496 }
 497
 498 /*
 499  * Function : void initialize_SCp(Scsi_Cmnd *cmd)
 500  *
 501  * Purpose : initialize the saved data pointers for cmd to point to the
 502  *      start of the buffer.
 503  *
 504  * Inputs : cmd - Scsi_Cmnd structure to have pointers reset.
 505  */
 506
 507 static inline void initialize_SCp(Scsi_Cmnd *cmd)
 508 {
 509         /*
 510          * Initialize the Scsi Pointer field so that all of the commands in the
 511          * various queues are valid.
 512          */
 513
 514         if (scsi_bufflen(cmd)) {
 515                 cmd->SCp.buffer = scsi_sglist(cmd);
 516                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 517                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 518                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 519                 /* ++roman: Try to merge some scatter-buffers if they are at
 520                  * contiguous physical addresses.
 521                  */
 522                 merge_contiguous_buffers(cmd);
 523         } else {
 524                 cmd->SCp.buffer = NULL;
 525                 cmd->SCp.buffers_residual = 0;
 526                 cmd->SCp.ptr = NULL;
 527                 cmd->SCp.this_residual = 0;
 528         }
 529 }
 530
 531 #include <linux/delay.h>
 532
 533 #if NDEBUG
 534 static struct {
 535         unsigned char mask;
 536         const char *name;
 537 } signals[] = {
 538         { SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
 539         { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD,  "CD" }, { SR_IO, "IO" },
 540         { SR_SEL, "SEL" }, {0, NULL}
 541 }, basrs[] = {
 542         {BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
 543 }, icrs[] = {
 544         {ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
 545         {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
 546         {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
 547         {0, NULL}
 548 }, mrs[] = {
 549         {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
 550         {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
 551         "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
 552         {MR_MONITOR_BSY, "MODE MONITOR BSY"},
 553         {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
 554         {0, NULL}
 555 };
 556
 557 /*
 558  * Function : void NCR5380_print(struct Scsi_Host *instance)
 559  *
 560  * Purpose : print the SCSI bus signals for debugging purposes
 561  *
 562  * Input : instance - which NCR5380
 563  */
 564
 565 static void NCR5380_print(struct Scsi_Host *instance)
 566 {
 567         unsigned char status, data, basr, mr, icr, i;
 568         unsigned long flags;
 569
 570         local_irq_save(flags);
 571         data = NCR5380_read(CURRENT_SCSI_DATA_REG);
 572         status = NCR5380_read(STATUS_REG);
 573         mr = NCR5380_read(MODE_REG);
 574         icr = NCR5380_read(INITIATOR_COMMAND_REG);
 575         basr = NCR5380_read(BUS_AND_STATUS_REG);
 576         local_irq_restore(flags);
 577         printk("STATUS_REG: %02x ", status);
 578         for (i = 0; signals[i].mask; ++i)
 579                 if (status & signals[i].mask)
 580                         printk(",%s", signals[i].name);
 581         printk("\nBASR: %02x ", basr);
 582         for (i = 0; basrs[i].mask; ++i)
 583                 if (basr & basrs[i].mask)
 584                         printk(",%s", basrs[i].name);
 585         printk("\nICR: %02x ", icr);
 586         for (i = 0; icrs[i].mask; ++i)
 587                 if (icr & icrs[i].mask)
 588                         printk(",%s", icrs[i].name);
 589         printk("\nMODE: %02x ", mr);
 590         for (i = 0; mrs[i].mask; ++i)
 591                 if (mr & mrs[i].mask)
 592                         printk(",%s", mrs[i].name);
 593         printk("\n");
 594 }
 595
 596 static struct {
 597         unsigned char value;
 598         const char *name;
 599 } phases[] = {
 600         {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
 601         {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
 602         {PHASE_UNKNOWN, "UNKNOWN"}
 603 };
 604
 605 /*
 606  * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
 607  *
 608  * Purpose : print the current SCSI phase for debugging purposes
 609  *
 610  * Input : instance - which NCR5380
 611  */
 612
 613 static void NCR5380_print_phase(struct Scsi_Host *instance)
 614 {
 615         unsigned char status;
 616         int i;
 617
 618         status = NCR5380_read(STATUS_REG);
 619         if (!(status & SR_REQ))
 620                 printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
 621         else {
 622                 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
 623                      (phases[i].value != (status & PHASE_MASK)); ++i)
 624                         ;
 625                 printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
 626         }
 627 }
 628
 629 #else /* !NDEBUG */
 630
 631 /* dummies... */
 632 static inline void NCR5380_print(struct Scsi_Host *instance)
 633 {
 634 };
 635 static inline void NCR5380_print_phase(struct Scsi_Host *instance)
 636 {
 637 };
 638
 639 #endif
 640
 641 /*
 642  * ++roman: New scheme of calling NCR5380_main()
 643  *
 644  * If we're not in an interrupt, we can call our main directly, it cannot be
 645  * already running. Else, we queue it on a task queue, if not 'main_running'
 646  * tells us that a lower level is already executing it. This way,
 647  * 'main_running' needs not be protected in a special way.
 648  *
 649  * queue_main() is a utility function for putting our main onto the task
 650  * queue, if main_running is false. It should be called only from a
 651  * interrupt or bottom half.
 652  */
 653
 654 #include <linux/gfp.h>
 655 #include <linux/workqueue.h>
 656 #include <linux/interrupt.h>
 657
 658 static volatile int main_running;
 659 static DECLARE_WORK(NCR5380_tqueue, NCR5380_main);
 660
 661 static inline void queue_main(void)
 662 {
 663         if (!main_running) {
 664                 /* If in interrupt and NCR5380_main() not already running,
 665                    queue it on the 'immediate' task queue, to be processed
 666                    immediately after the current interrupt processing has
 667                    finished. */
 668                 schedule_work(&NCR5380_tqueue);
 669         }
 670         /* else: nothing to do: the running NCR5380_main() will pick up
 671            any newly queued command. */
 672 }
 673
 674
 675 static inline void NCR5380_all_init(void)
 676 {
 677         static int done = 0;
 678         if (!done) {
 679                 INI_PRINTK("scsi : NCR5380_all_init()\n");
 680                 done = 1;
 681         }
 682 }
 683
 684
 685 /*
 686  * Function : void NCR58380_print_options (struct Scsi_Host *instance)
 687  *
 688  * Purpose : called by probe code indicating the NCR5380 driver
 689  *           options that were selected.
 690  *
 691  * Inputs : instance, pointer to this instance.  Unused.
 692  */
 693
 694 static void __init NCR5380_print_options(struct Scsi_Host *instance)
 695 {
 696         printk(" generic options"
 697 #ifdef AUTOSENSE
 698                " AUTOSENSE"
 699 #endif
 700 #ifdef REAL_DMA
 701                " REAL DMA"
 702 #endif
 703 #ifdef PARITY
 704                " PARITY"
 705 #endif
 706 #ifdef SUPPORT_TAGS
 707                " SCSI-2 TAGGED QUEUING"
 708 #endif
 709                );
 710         printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
 711 }
 712
 713 /*
 714  * Function : void NCR5380_print_status (struct Scsi_Host *instance)
 715  *
 716  * Purpose : print commands in the various queues, called from
 717  *      NCR5380_abort and NCR5380_debug to aid debugging.
 718  *
 719  * Inputs : instance, pointer to this instance.
 720  */
 721
 722 static void lprint_Scsi_Cmnd(Scsi_Cmnd *cmd)
 723 {
 724         int i, s;
 725         unsigned char *command;
 726         printk("scsi%d: destination target %d, lun %d\n",
 727                 H_NO(cmd), cmd->device->id, cmd->device->lun);
 728         printk(KERN_CONT "        command = ");
 729         command = cmd->cmnd;
 730         printk(KERN_CONT "%2d (0x%02x)", command[0], command[0]);
 731         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 732                 printk(KERN_CONT " %02x", command[i]);
 733         printk("\n");
 734 }
 735
 736 static void NCR5380_print_status(struct Scsi_Host *instance)
 737 {
 738         struct NCR5380_hostdata *hostdata;
 739         Scsi_Cmnd *ptr;
 740         unsigned long flags;
 741
 742         NCR_PRINT(NDEBUG_ANY);
 743         NCR_PRINT_PHASE(NDEBUG_ANY);
 744
 745         hostdata = (struct NCR5380_hostdata *)instance->hostdata;
 746
 747         printk("\nNCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
 748         local_irq_save(flags);
 749         printk("NCR5380: coroutine is%s running.\n",
 750                 main_running ? "" : "n't");
 751         if (!hostdata->connected)
 752                 printk("scsi%d: no currently connected command\n", HOSTNO);
 753         else
 754                 lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected);
 755         printk("scsi%d: issue_queue\n", HOSTNO);
 756         for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
 757                 lprint_Scsi_Cmnd(ptr);
 758
 759         printk("scsi%d: disconnected_queue\n", HOSTNO);
 760         for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
 761              ptr = NEXT(ptr))
 762                 lprint_Scsi_Cmnd(ptr);
 763
 764         local_irq_restore(flags);
 765         printk("\n");
 766 }
 767
 768 static void show_Scsi_Cmnd(Scsi_Cmnd *cmd, struct seq_file *m)
 769 {
 770         int i, s;
 771         unsigned char *command;
 772         seq_printf(m, "scsi%d: destination target %d, lun %d\n",
 773                 H_NO(cmd), cmd->device->id, cmd->device->lun);
 774         seq_printf(m, "        command = ");
 775         command = cmd->cmnd;
 776         seq_printf(m, "%2d (0x%02x)", command[0], command[0]);
 777         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 778                 seq_printf(m, " %02x", command[i]);
 779         seq_printf(m, "\n");
 780 }
 781
 782 static int NCR5380_show_info(struct seq_file *m, struct Scsi_Host *instance)
 783 {
 784         struct NCR5380_hostdata *hostdata;
 785         Scsi_Cmnd *ptr;
 786         unsigned long flags;
 787
 788         hostdata = (struct NCR5380_hostdata *)instance->hostdata;
 789
 790         seq_printf(m, "NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
 791         local_irq_save(flags);
 792         seq_printf(m, "NCR5380: coroutine is%s running.\n",
 793                 main_running ? "" : "n't");
 794         if (!hostdata->connected)
 795                 seq_printf(m, "scsi%d: no currently connected command\n", HOSTNO);
 796         else
 797                 show_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, m);
 798         seq_printf(m, "scsi%d: issue_queue\n", HOSTNO);
 799         for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
 800                 show_Scsi_Cmnd(ptr, m);
 801
 802         seq_printf(m, "scsi%d: disconnected_queue\n", HOSTNO);
 803         for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
 804              ptr = NEXT(ptr))
 805                 show_Scsi_Cmnd(ptr, m);
 806
 807         local_irq_restore(flags);
 808         return 0;
 809 }
 810
 811 /*
 812  * Function : void NCR5380_init (struct Scsi_Host *instance)
 813  *
 814  * Purpose : initializes *instance and corresponding 5380 chip.
 815  *
 816  * Inputs : instance - instantiation of the 5380 driver.
 817  *
 818  * Notes : I assume that the host, hostno, and id bits have been
 819  *      set correctly.  I don't care about the irq and other fields.
 820  *
 821  */
 822
 823 static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
 824 {
 825         int i;
 826         SETUP_HOSTDATA(instance);
 827
 828         NCR5380_all_init();
 829
 830         hostdata->aborted = 0;
 831         hostdata->id_mask = 1 << instance->this_id;
 832         hostdata->id_higher_mask = 0;
 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 SUPPORT_TAGS
 839         init_tags();
 840 #endif
 841 #if defined (REAL_DMA)
 842         hostdata->dma_len = 0;
 843 #endif
 844         hostdata->targets_present = 0;
 845         hostdata->connected = NULL;
 846         hostdata->issue_queue = NULL;
 847         hostdata->disconnected_queue = NULL;
 848         hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
 849
 850         if (!the_template) {
 851                 the_template = instance->hostt;
 852                 first_instance = instance;
 853         }
 854
 855 #ifndef AUTOSENSE
 856         if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
 857                 printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
 858                        "        without AUTOSENSE option, contingent allegiance conditions may\n"
 859                        "        be incorrectly cleared.\n", HOSTNO);
 860 #endif /* def AUTOSENSE */
 861
 862         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 863         NCR5380_write(MODE_REG, MR_BASE);
 864         NCR5380_write(TARGET_COMMAND_REG, 0);
 865         NCR5380_write(SELECT_ENABLE_REG, 0);
 866
 867         return 0;
 868 }
 869
 870 static void NCR5380_exit(struct Scsi_Host *instance)
 871 {
 872         /* Empty, as we didn't schedule any delayed work */
 873 }
 874
 875 /*
 876  * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd,
 877  *      void (*done)(Scsi_Cmnd *))
 878  *
 879  * Purpose :  enqueues a SCSI command
 880  *
 881  * Inputs : cmd - SCSI command, done - function called on completion, with
 882  *      a pointer to the command descriptor.
 883  *
 884  * Returns : 0
 885  *
 886  * Side effects :
 887  *      cmd is added to the per instance issue_queue, with minor
 888  *      twiddling done to the host specific fields of cmd.  If the
 889  *      main coroutine is not running, it is restarted.
 890  *
 891  */
 892
 893 static int NCR5380_queue_command_lck(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
 894 {
 895         SETUP_HOSTDATA(cmd->device->host);
 896         Scsi_Cmnd *tmp;
 897         unsigned long flags;
 898
 899 #if (NDEBUG & NDEBUG_NO_WRITE)
 900         switch (cmd->cmnd[0]) {
 901         case WRITE_6:
 902         case WRITE_10:
 903                 printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
 904                        H_NO(cmd));
 905                 cmd->result = (DID_ERROR << 16);
 906                 done(cmd);
 907                 return 0;
 908         }
 909 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 910
 911 #ifdef NCR5380_STATS
 912 # if 0
 913         if (!hostdata->connected && !hostdata->issue_queue &&
 914             !hostdata->disconnected_queue) {
 915                 hostdata->timebase = jiffies;
 916         }
 917 # endif
 918 # ifdef NCR5380_STAT_LIMIT
 919         if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
 920 # endif
 921                 switch (cmd->cmnd[0]) {
 922                 case WRITE:
 923                 case WRITE_6:
 924                 case WRITE_10:
 925                         hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
 926                         hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
 927                         hostdata->pendingw++;
 928                         break;
 929                 case READ:
 930                 case READ_6:
 931                 case READ_10:
 932                         hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
 933                         hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
 934                         hostdata->pendingr++;
 935                         break;
 936                 }
 937 #endif
 938
 939         /*
 940          * We use the host_scribble field as a pointer to the next command
 941          * in a queue
 942          */
 943
 944         SET_NEXT(cmd, NULL);
 945         cmd->scsi_done = done;
 946
 947         cmd->result = 0;
 948
 949         /*
 950          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 951          * commands are added to the head of the queue since any command will
 952          * clear the contingent allegiance condition that exists and the
 953          * sense data is only guaranteed to be valid while the condition exists.
 954          */
 955
 956         local_irq_save(flags);
 957         /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
 958          * Otherwise a running NCR5380_main may steal the lock.
 959          * Lock before actually inserting due to fairness reasons explained in
 960          * atari_scsi.c. If we insert first, then it's impossible for this driver
 961          * to release the lock.
 962          * Stop timer for this command while waiting for the lock, or timeouts
 963          * may happen (and they really do), and it's no good if the command doesn't
 964          * appear in any of the queues.
 965          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
 966          * because also a timer int can trigger an abort or reset, which would
 967          * alter queues and touch the lock.
 968          */
 969         if (!IS_A_TT()) {
 970                 /* perhaps stop command timer here */
 971                 falcon_get_lock();
 972                 /* perhaps restart command timer here */
 973         }
 974         if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
 975                 LIST(cmd, hostdata->issue_queue);
 976                 SET_NEXT(cmd, hostdata->issue_queue);
 977                 hostdata->issue_queue = cmd;
 978         } else {
 979                 for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
 980                      NEXT(tmp); tmp = NEXT(tmp))
 981                         ;
 982                 LIST(cmd, tmp);
 983                 SET_NEXT(tmp, cmd);
 984         }
 985         local_irq_restore(flags);
 986
 987         QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
 988                   (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 989
 990         /* If queue_command() is called from an interrupt (real one or bottom
 991          * half), we let queue_main() do the job of taking care about main. If it
 992          * is already running, this is a no-op, else main will be queued.
 993          *
 994          * If we're not in an interrupt, we can call NCR5380_main()
 995          * unconditionally, because it cannot be already running.
 996          */
 997         if (in_interrupt() || ((flags >> 8) & 7) >= 6)
 998                 queue_main();
 999         else
1000                 NCR5380_main(NULL);
1001         return 0;
1002 }
1003
1004 static DEF_SCSI_QCMD(NCR5380_queue_command)
1005
1006 /*
1007  * Function : NCR5380_main (void)
1008  *
1009  * Purpose : NCR5380_main is a coroutine that runs as long as more work can
1010  *      be done on the NCR5380 host adapters in a system.  Both
1011  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1012  *      in case it is not running.
1013  *
1014  * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
1015  *  reenable them.  This prevents reentrancy and kernel stack overflow.
1016  */
1017
1018 static void NCR5380_main(struct work_struct *work)
1019 {
1020         Scsi_Cmnd *tmp, *prev;
1021         struct Scsi_Host *instance = first_instance;
1022         struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
1023         int done;
1024         unsigned long flags;
1025
1026         /*
1027          * We run (with interrupts disabled) until we're sure that none of
1028          * the host adapters have anything that can be done, at which point
1029          * we set main_running to 0 and exit.
1030          *
1031          * Interrupts are enabled before doing various other internal
1032          * instructions, after we've decided that we need to run through
1033          * the loop again.
1034          *
1035          * this should prevent any race conditions.
1036          *
1037          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1038          * because also a timer int can trigger an abort or reset, which can
1039          * alter queues and touch the Falcon lock.
1040          */
1041
1042         /* Tell int handlers main() is now already executing.  Note that
1043            no races are possible here. If an int comes in before
1044            'main_running' is set here, and queues/executes main via the
1045            task queue, it doesn't do any harm, just this instance of main
1046            won't find any work left to do. */
1047         if (main_running)
1048                 return;
1049         main_running = 1;
1050
1051         local_save_flags(flags);
1052         do {
1053                 local_irq_disable();    /* Freeze request queues */
1054                 done = 1;
1055
1056                 if (!hostdata->connected) {
1057                         MAIN_PRINTK("scsi%d: not connected\n", HOSTNO);
1058                         /*
1059                          * Search through the issue_queue for a command destined
1060                          * for a target that's not busy.
1061                          */
1062 #if (NDEBUG & NDEBUG_LISTS)
1063                         for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
1064                              tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
1065                                 ;
1066                         /*printk("%p  ", tmp);*/
1067                         if ((tmp == prev) && tmp)
1068                                 printk(" LOOP\n");
1069                         /* else printk("\n"); */
1070 #endif
1071                         for (tmp = (Scsi_Cmnd *) hostdata->issue_queue,
1072                              prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
1073
1074 #if (NDEBUG & NDEBUG_LISTS)
1075                                 if (prev != tmp)
1076                                         printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
1077                                                tmp, tmp->device->id, hostdata->busy[tmp->device->id],
1078                                                tmp->device->lun);
1079 #endif
1080                                 /*  When we find one, remove it from the issue queue. */
1081                                 /* ++guenther: possible race with Falcon locking */
1082                                 if (
1083 #ifdef SUPPORT_TAGS
1084                                     !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
1085 #else
1086                                     !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
1087 #endif
1088                                     ) {
1089                                         /* ++guenther: just to be sure, this must be atomic */
1090                                         local_irq_disable();
1091                                         if (prev) {
1092                                                 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1093                                                 SET_NEXT(prev, NEXT(tmp));
1094                                         } else {
1095                                                 REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
1096                                                 hostdata->issue_queue = NEXT(tmp);
1097                                         }
1098                                         SET_NEXT(tmp, NULL);
1099                                         falcon_dont_release++;
1100
1101                                         /* reenable interrupts after finding one */
1102                                         local_irq_restore(flags);
1103
1104                                         /*
1105                                          * Attempt to establish an I_T_L nexus here.
1106                                          * On success, instance->hostdata->connected is set.
1107                                          * On failure, we must add the command back to the
1108                                          *   issue queue so we can keep trying.
1109                                          */
1110                                         MAIN_PRINTK("scsi%d: main(): command for target %d "
1111                                                     "lun %d removed from issue_queue\n",
1112                                                     HOSTNO, tmp->device->id, tmp->device->lun);
1113                                         /*
1114                                          * REQUEST SENSE commands are issued without tagged
1115                                          * queueing, even on SCSI-II devices because the
1116                                          * contingent allegiance condition exists for the
1117                                          * entire unit.
1118                                          */
1119                                         /* ++roman: ...and the standard also requires that
1120                                          * REQUEST SENSE command are untagged.
1121                                          */
1122
1123 #ifdef SUPPORT_TAGS
1124                                         cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
1125 #endif
1126                                         if (!NCR5380_select(instance, tmp,
1127                                             (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE :
1128                                             TAG_NEXT)) {
1129                                                 falcon_dont_release--;
1130                                                 /* release if target did not response! */
1131                                                 falcon_release_lock_if_possible(hostdata);
1132                                                 break;
1133                                         } else {
1134                                                 local_irq_disable();
1135                                                 LIST(tmp, hostdata->issue_queue);
1136                                                 SET_NEXT(tmp, hostdata->issue_queue);
1137                                                 hostdata->issue_queue = tmp;
1138 #ifdef SUPPORT_TAGS
1139                                                 cmd_free_tag(tmp);
1140 #endif
1141                                                 falcon_dont_release--;
1142                                                 local_irq_restore(flags);
1143                                                 MAIN_PRINTK("scsi%d: main(): select() failed, "
1144                                                             "returned to issue_queue\n", HOSTNO);
1145                                                 if (hostdata->connected)
1146                                                         break;
1147                                         }
1148                                 } /* if target/lun/target queue is not busy */
1149                         } /* for issue_queue */
1150                 } /* if (!hostdata->connected) */
1151
1152                 if (hostdata->connected
1153 #ifdef REAL_DMA
1154                     && !hostdata->dma_len
1155 #endif
1156                     ) {
1157                         local_irq_restore(flags);
1158                         MAIN_PRINTK("scsi%d: main: performing information transfer\n",
1159                                     HOSTNO);
1160                         NCR5380_information_transfer(instance);
1161                         MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
1162                         done = 0;
1163                 }
1164         } while (!done);
1165
1166         /* Better allow ints _after_ 'main_running' has been cleared, else
1167            an interrupt could believe we'll pick up the work it left for
1168            us, but we won't see it anymore here... */
1169         main_running = 0;
1170         local_irq_restore(flags);
1171 }
1172
1173
1174 #ifdef REAL_DMA
1175 /*
1176  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1177  *
1178  * Purpose : Called by interrupt handler when DMA finishes or a phase
1179  *      mismatch occurs (which would finish the DMA transfer).
1180  *
1181  * Inputs : instance - this instance of the NCR5380.
1182  *
1183  */
1184
1185 static void NCR5380_dma_complete(struct Scsi_Host *instance)
1186 {
1187         SETUP_HOSTDATA(instance);
1188         int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
1189         unsigned char **data, p;
1190         volatile int *count;
1191
1192         if (!hostdata->connected) {
1193                 printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
1194                        "no connected cmd\n", HOSTNO);
1195                 return;
1196         }
1197
1198         if (atari_read_overruns) {
1199                 p = hostdata->connected->SCp.phase;
1200                 if (p & SR_IO) {
1201                         udelay(10);
1202                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
1203                              (BASR_PHASE_MATCH|BASR_ACK)) ==
1204                             (BASR_PHASE_MATCH|BASR_ACK)) {
1205                                 saved_data = NCR5380_read(INPUT_DATA_REG);
1206                                 overrun = 1;
1207                                 DMA_PRINTK("scsi%d: read overrun handled\n", HOSTNO);
1208                         }
1209                 }
1210         }
1211
1212         DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1213                    HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
1214                    NCR5380_read(STATUS_REG));
1215
1216         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1217         NCR5380_write(MODE_REG, MR_BASE);
1218         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1219
1220         transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
1221         hostdata->dma_len = 0;
1222
1223         data = (unsigned char **)&hostdata->connected->SCp.ptr;
1224         count = &hostdata->connected->SCp.this_residual;
1225         *data += transfered;
1226         *count -= transfered;
1227
1228         if (atari_read_overruns) {
1229                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1230                         cnt = toPIO = atari_read_overruns;
1231                         if (overrun) {
1232                                 DMA_PRINTK("Got an input overrun, using saved byte\n");
1233                                 *(*data)++ = saved_data;
1234                                 (*count)--;
1235                                 cnt--;
1236                                 toPIO--;
1237                         }
1238                         DMA_PRINTK("Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1239                         NCR5380_transfer_pio(instance, &p, &cnt, data);
1240                         *count -= toPIO - cnt;
1241                 }
1242         }
1243 }
1244 #endif /* REAL_DMA */
1245
1246
1247 /*
1248  * Function : void NCR5380_intr (int irq)
1249  *
1250  * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1251  *      from the disconnected queue, and restarting NCR5380_main()
1252  *      as required.
1253  *
1254  * Inputs : int irq, irq that caused this interrupt.
1255  *
1256  */
1257
1258 static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1259 {
1260         struct Scsi_Host *instance = first_instance;
1261         int done = 1, handled = 0;
1262         unsigned char basr;
1263
1264         INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);
1265
1266         /* Look for pending interrupts */
1267         basr = NCR5380_read(BUS_AND_STATUS_REG);
1268         INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
1269         /* dispatch to appropriate routine if found and done=0 */
1270         if (basr & BASR_IRQ) {
1271                 NCR_PRINT(NDEBUG_INTR);
1272                 if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
1273                         done = 0;
1274                         ENABLE_IRQ();
1275                         INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
1276                         NCR5380_reselect(instance);
1277                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1278                 } else if (basr & BASR_PARITY_ERROR) {
1279                         INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
1280                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1281                 } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1282                         INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
1283                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1284                 } else {
1285                         /*
1286                          * The rest of the interrupt conditions can occur only during a
1287                          * DMA transfer
1288                          */
1289
1290 #if defined(REAL_DMA)
1291                         /*
1292                          * We should only get PHASE MISMATCH and EOP interrupts if we have
1293                          * DMA enabled, so do a sanity check based on the current setting
1294                          * of the MODE register.
1295                          */
1296
1297                         if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
1298                             ((basr & BASR_END_DMA_TRANSFER) ||
1299                              !(basr & BASR_PHASE_MATCH))) {
1300
1301                                 INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1302                                 NCR5380_dma_complete( instance );
1303                                 done = 0;
1304                                 ENABLE_IRQ();
1305                         } else
1306 #endif /* REAL_DMA */
1307                         {
1308 /* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1309                                 if (basr & BASR_PHASE_MATCH)
1310                                         printk(KERN_NOTICE "scsi%d: unknown interrupt, "
1311                                                "BASR 0x%x, MR 0x%x, SR 0x%x\n",
1312                                                HOSTNO, basr, NCR5380_read(MODE_REG),
1313                                                NCR5380_read(STATUS_REG));
1314                                 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1315                         }
1316                 } /* if !(SELECTION || PARITY) */
1317                 handled = 1;
1318         } /* BASR & IRQ */ else {
1319                 printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
1320                        "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
1321                        NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1322                 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1323         }
1324
1325         if (!done) {
1326                 INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
1327                 /* Put a call to NCR5380_main() on the queue... */
1328                 queue_main();
1329         }
1330         return IRQ_RETVAL(handled);
1331 }
1332
1333 #ifdef NCR5380_STATS
1334 static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd *cmd)
1335 {
1336 # ifdef NCR5380_STAT_LIMIT
1337         if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
1338 # endif
1339                 switch (cmd->cmnd[0]) {
1340                 case WRITE:
1341                 case WRITE_6:
1342                 case WRITE_10:
1343                         hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
1344                         /*hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);*/
1345                         hostdata->pendingw--;
1346                         break;
1347                 case READ:
1348                 case READ_6:
1349                 case READ_10:
1350                         hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
1351                         /*hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);*/
1352                         hostdata->pendingr--;
1353                         break;
1354                 }
1355 }
1356 #endif
1357
1358 /*
1359  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1360  *      int tag);
1361  *
1362  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1363  *      including ARBITRATION, SELECTION, and initial message out for
1364  *      IDENTIFY and queue messages.
1365  *
1366  * Inputs : instance - instantiation of the 5380 driver on which this
1367  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1368  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1369  *      the command that is presently connected.
1370  *
1371  * Returns : -1 if selection could not execute for some reason,
1372  *      0 if selection succeeded or failed because the target
1373  *      did not respond.
1374  *
1375  * Side effects :
1376  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1377  *              with registers as they should have been on entry - ie
1378  *              SELECT_ENABLE will be set appropriately, the NCR5380
1379  *              will cease to drive any SCSI bus signals.
1380  *
1381  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1382  *              instance->connected will be set to cmd.
1383  *              SELECT interrupt will be disabled.
1384  *
1385  *      If failed (no target) : cmd->scsi_done() will be called, and the
1386  *              cmd->result host byte set to DID_BAD_TARGET.
1387  */
1388
1389 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
1390 {
1391         SETUP_HOSTDATA(instance);
1392         unsigned char tmp[3], phase;
1393         unsigned char *data;
1394         int len;
1395         unsigned long timeout;
1396         unsigned long flags;
1397
1398         hostdata->restart_select = 0;
1399         NCR_PRINT(NDEBUG_ARBITRATION);
1400         ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
1401                    instance->this_id);
1402
1403         /*
1404          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1405          * data bus during SELECTION.
1406          */
1407
1408         local_irq_save(flags);
1409         if (hostdata->connected) {
1410                 local_irq_restore(flags);
1411                 return -1;
1412         }
1413         NCR5380_write(TARGET_COMMAND_REG, 0);
1414
1415         /*
1416          * Start arbitration.
1417          */
1418
1419         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1420         NCR5380_write(MODE_REG, MR_ARBITRATE);
1421
1422         local_irq_restore(flags);
1423
1424         /* Wait for arbitration logic to complete */
1425 #if defined(NCR_TIMEOUT)
1426         {
1427                 unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
1428
1429                 while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1430                        time_before(jiffies, timeout) && !hostdata->connected)
1431                         ;
1432                 if (time_after_eq(jiffies, timeout)) {
1433                         printk("scsi : arbitration timeout at %d\n", __LINE__);
1434                         NCR5380_write(MODE_REG, MR_BASE);
1435                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1436                         return -1;
1437                 }
1438         }
1439 #else /* NCR_TIMEOUT */
1440         while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1441                !hostdata->connected)
1442                 ;
1443 #endif
1444
1445         ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);
1446
1447         if (hostdata->connected) {
1448                 NCR5380_write(MODE_REG, MR_BASE);
1449                 return -1;
1450         }
1451         /*
1452          * The arbitration delay is 2.2us, but this is a minimum and there is
1453          * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1454          * the integral nature of udelay().
1455          *
1456          */
1457
1458         udelay(3);
1459
1460         /* Check for lost arbitration */
1461         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1462             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1463             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1464             hostdata->connected) {
1465                 NCR5380_write(MODE_REG, MR_BASE);
1466                 ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1467                            HOSTNO);
1468                 return -1;
1469         }
1470
1471         /* after/during arbitration, BSY should be asserted.
1472            IBM DPES-31080 Version S31Q works now */
1473         /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
1474         NCR5380_write(INITIATOR_COMMAND_REG,
1475                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1476
1477         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1478             hostdata->connected) {
1479                 NCR5380_write(MODE_REG, MR_BASE);
1480                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1481                 ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1482                            HOSTNO);
1483                 return -1;
1484         }
1485
1486         /*
1487          * Again, bus clear + bus settle time is 1.2us, however, this is
1488          * a minimum so we'll udelay ceil(1.2)
1489          */
1490
1491 #ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
1492         /* ++roman: But some targets (see above :-) seem to need a bit more... */
1493         udelay(15);
1494 #else
1495         udelay(2);
1496 #endif
1497
1498         if (hostdata->connected) {
1499                 NCR5380_write(MODE_REG, MR_BASE);
1500                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1501                 return -1;
1502         }
1503
1504         ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);
1505
1506         /*
1507          * Now that we have won arbitration, start Selection process, asserting
1508          * the host and target ID's on the SCSI bus.
1509          */
1510
1511         NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
1512
1513         /*
1514          * Raise ATN while SEL is true before BSY goes false from arbitration,
1515          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1516          * phase immediately after selection.
1517          */
1518
1519         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
1520                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1521         NCR5380_write(MODE_REG, MR_BASE);
1522
1523         /*
1524          * Reselect interrupts must be turned off prior to the dropping of BSY,
1525          * otherwise we will trigger an interrupt.
1526          */
1527
1528         if (hostdata->connected) {
1529                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1530                 return -1;
1531         }
1532
1533         NCR5380_write(SELECT_ENABLE_REG, 0);
1534
1535         /*
1536          * The initiator shall then wait at least two deskew delays and release
1537          * the BSY signal.
1538          */
1539         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1540
1541         /* Reset BSY */
1542         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
1543                       ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1544
1545         /*
1546          * Something weird happens when we cease to drive BSY - looks
1547          * like the board/chip is letting us do another read before the
1548          * appropriate propagation delay has expired, and we're confusing
1549          * a BSY signal from ourselves as the target's response to SELECTION.
1550          *
1551          * A small delay (the 'C++' frontend breaks the pipeline with an
1552          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1553          * tighter 'C' code breaks and requires this) solves the problem -
1554          * the 1 us delay is arbitrary, and only used because this delay will
1555          * be the same on other platforms and since it works here, it should
1556          * work there.
1557          *
1558          * wingel suggests that this could be due to failing to wait
1559          * one deskew delay.
1560          */
1561
1562         udelay(1);
1563
1564         SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
1565
1566         /*
1567          * The SCSI specification calls for a 250 ms timeout for the actual
1568          * selection.
1569          */
1570
1571         timeout = jiffies + 25;
1572
1573         /*
1574          * XXX very interesting - we're seeing a bounce where the BSY we
1575          * asserted is being reflected / still asserted (propagation delay?)
1576          * and it's detecting as true.  Sigh.
1577          */
1578
1579 #if 0
1580         /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
1581          * IO while SEL is true. But again, there are some disks out the in the
1582          * world that do that nevertheless. (Somebody claimed that this announces
1583          * reselection capability of the target.) So we better skip that test and
1584          * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
1585          */
1586
1587         while (time_before(jiffies, timeout) &&
1588                !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
1589                 ;
1590
1591         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1592                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1593                 NCR5380_reselect(instance);
1594                 printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
1595                        HOSTNO);
1596                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1597                 return -1;
1598         }
1599 #else
1600         while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
1601                 ;
1602 #endif
1603
1604         /*
1605          * No less than two deskew delays after the initiator detects the
1606          * BSY signal is true, it shall release the SEL signal and may
1607          * change the DATA BUS.                                     -wingel
1608          */
1609
1610         udelay(1);
1611
1612         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1613
1614         if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1615                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1616                 if (hostdata->targets_present & (1 << cmd->device->id)) {
1617                         printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
1618                         if (hostdata->restart_select)
1619                                 printk(KERN_NOTICE "\trestart select\n");
1620                         NCR_PRINT(NDEBUG_ANY);
1621                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1622                         return -1;
1623                 }
1624                 cmd->result = DID_BAD_TARGET << 16;
1625 #ifdef NCR5380_STATS
1626                 collect_stats(hostdata, cmd);
1627 #endif
1628 #ifdef SUPPORT_TAGS
1629                 cmd_free_tag(cmd);
1630 #endif
1631                 cmd->scsi_done(cmd);
1632                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1633                 SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
1634                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1635                 return 0;
1636         }
1637
1638         hostdata->targets_present |= (1 << cmd->device->id);
1639
1640         /*
1641          * Since we followed the SCSI spec, and raised ATN while SEL
1642          * was true but before BSY was false during selection, the information
1643          * transfer phase should be a MESSAGE OUT phase so that we can send the
1644          * IDENTIFY message.
1645          *
1646          * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1647          * message (2 bytes) with a tag ID that we increment with every command
1648          * until it wraps back to 0.
1649          *
1650          * XXX - it turns out that there are some broken SCSI-II devices,
1651          *           which claim to support tagged queuing but fail when more than
1652          *           some number of commands are issued at once.
1653          */
1654
1655         /* Wait for start of REQ/ACK handshake */
1656         while (!(NCR5380_read(STATUS_REG) & SR_REQ))
1657                 ;
1658
1659         SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1660                    HOSTNO, cmd->device->id);
1661         tmp[0] = IDENTIFY(1, cmd->device->lun);
1662
1663 #ifdef SUPPORT_TAGS
1664         if (cmd->tag != TAG_NONE) {
1665                 tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1666                 tmp[2] = cmd->tag;
1667                 len = 3;
1668         } else
1669                 len = 1;
1670 #else
1671         len = 1;
1672         cmd->tag = 0;
1673 #endif /* SUPPORT_TAGS */
1674
1675         /* Send message(s) */
1676         data = tmp;
1677         phase = PHASE_MSGOUT;
1678         NCR5380_transfer_pio(instance, &phase, &len, &data);
1679         SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
1680         /* XXX need to handle errors here */
1681         hostdata->connected = cmd;
1682 #ifndef SUPPORT_TAGS
1683         hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1684 #endif
1685
1686         initialize_SCp(cmd);
1687
1688         return 0;
1689 }
1690
1691 /*
1692  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1693  *      unsigned char *phase, int *count, unsigned char **data)
1694  *
1695  * Purpose : transfers data in given phase using polled I/O
1696  *
1697  * Inputs : instance - instance of driver, *phase - pointer to
1698  *      what phase is expected, *count - pointer to number of
1699  *      bytes to transfer, **data - pointer to data pointer.
1700  *
1701  * Returns : -1 when different phase is entered without transferring
1702  *      maximum number of bytes, 0 if all bytes are transferred or exit
1703  *      is in same phase.
1704  *
1705  *      Also, *phase, *count, *data are modified in place.
1706  *
1707  * XXX Note : handling for bus free may be useful.
1708  */
1709
1710 /*
1711  * Note : this code is not as quick as it could be, however it
1712  * IS 100% reliable, and for the actual data transfer where speed
1713  * counts, we will always do a pseudo DMA or DMA transfer.
1714  */
1715
1716 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1717                                 unsigned char *phase, int *count,
1718                                 unsigned char **data)
1719 {
1720         register unsigned char p = *phase, tmp;
1721         register int c = *count;
1722         register unsigned char *d = *data;
1723
1724         /*
1725          * The NCR5380 chip will only drive the SCSI bus when the
1726          * phase specified in the appropriate bits of the TARGET COMMAND
1727          * REGISTER match the STATUS REGISTER
1728          */
1729
1730         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1731
1732         do {
1733                 /*
1734                  * Wait for assertion of REQ, after which the phase bits will be
1735                  * valid
1736                  */
1737                 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1738                         ;
1739
1740                 HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);
1741
1742                 /* Check for phase mismatch */
1743                 if ((tmp & PHASE_MASK) != p) {
1744                         PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
1745                         NCR_PRINT_PHASE(NDEBUG_PIO);
1746                         break;
1747                 }
1748
1749                 /* Do actual transfer from SCSI bus to / from memory */
1750                 if (!(p & SR_IO))
1751                         NCR5380_write(OUTPUT_DATA_REG, *d);
1752                 else
1753                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1754
1755                 ++d;
1756
1757                 /*
1758                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1759                  * should drop ATN on the last byte of the message phase
1760                  * after REQ has been asserted for the handshake but before
1761                  * the initiator raises ACK.
1762                  */
1763
1764                 if (!(p & SR_IO)) {
1765                         if (!((p & SR_MSG) && c > 1)) {
1766                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1767                                 NCR_PRINT(NDEBUG_PIO);
1768                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1769                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1770                         } else {
1771                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1772                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1773                                 NCR_PRINT(NDEBUG_PIO);
1774                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1775                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1776                         }
1777                 } else {
1778                         NCR_PRINT(NDEBUG_PIO);
1779                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1780                 }
1781
1782                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1783                         ;
1784
1785                 HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);
1786
1787                 /*
1788                  * We have several special cases to consider during REQ/ACK handshaking :
1789                  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1790                  *      message.  ATN must be dropped as ACK is dropped.
1791                  *
1792                  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1793                  *      message.  We must exit with ACK asserted, so that the calling
1794                  *      code may raise ATN before dropping ACK to reject the message.
1795                  *
1796                  * 3.  ACK and ATN are clear and the target may proceed as normal.
1797                  */
1798                 if (!(p == PHASE_MSGIN && c == 1)) {
1799                         if (p == PHASE_MSGOUT && c > 1)
1800                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1801                         else
1802                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1803                 }
1804         } while (--c);
1805
1806         PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);
1807
1808         *count = c;
1809         *data = d;
1810         tmp = NCR5380_read(STATUS_REG);
1811         /* The phase read from the bus is valid if either REQ is (already)
1812          * asserted or if ACK hasn't been released yet. The latter is the case if
1813          * we're in MSGIN and all wanted bytes have been received.
1814          */
1815         if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
1816                 *phase = tmp & PHASE_MASK;
1817         else
1818                 *phase = PHASE_UNKNOWN;
1819
1820         if (!c || (*phase == p))
1821                 return 0;
1822         else
1823                 return -1;
1824 }
1825
1826 /*
1827  * Function : do_abort (Scsi_Host *host)
1828  *
1829  * Purpose : abort the currently established nexus.  Should only be
1830  *      called from a routine which can drop into a
1831  *
1832  * Returns : 0 on success, -1 on failure.
1833  */
1834
1835 static int do_abort(struct Scsi_Host *host)
1836 {
1837         unsigned char tmp, *msgptr, phase;
1838         int len;
1839
1840         /* Request message out phase */
1841         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1842
1843         /*
1844          * Wait for the target to indicate a valid phase by asserting
1845          * REQ.  Once this happens, we'll have either a MSGOUT phase
1846          * and can immediately send the ABORT message, or we'll have some
1847          * other phase and will have to source/sink data.
1848          *
1849          * We really don't care what value was on the bus or what value
1850          * the target sees, so we just handshake.
1851          */
1852
1853         while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1854                 ;
1855
1856         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1857
1858         if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1859                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1860                               ICR_ASSERT_ACK);
1861                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1862                         ;
1863                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1864         }
1865
1866         tmp = ABORT;
1867         msgptr = &tmp;
1868         len = 1;
1869         phase = PHASE_MSGOUT;
1870         NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1871
1872         /*
1873          * If we got here, and the command completed successfully,
1874          * we're about to go into bus free state.
1875          */
1876
1877         return len ? -1 : 0;
1878 }
1879
1880 #if defined(REAL_DMA)
1881 /*
1882  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1883  *      unsigned char *phase, int *count, unsigned char **data)
1884  *
1885  * Purpose : transfers data in given phase using either real
1886  *      or pseudo DMA.
1887  *
1888  * Inputs : instance - instance of driver, *phase - pointer to
1889  *      what phase is expected, *count - pointer to number of
1890  *      bytes to transfer, **data - pointer to data pointer.
1891  *
1892  * Returns : -1 when different phase is entered without transferring
1893  *      maximum number of bytes, 0 if all bytes or transferred or exit
1894  *      is in same phase.
1895  *
1896  *      Also, *phase, *count, *data are modified in place.
1897  *
1898  */
1899
1900
1901 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1902                                 unsigned char *phase, int *count,
1903                                 unsigned char **data)
1904 {
1905         SETUP_HOSTDATA(instance);
1906         register int c = *count;
1907         register unsigned char p = *phase;
1908         register unsigned char *d = *data;
1909         unsigned char tmp;
1910         unsigned long flags;
1911
1912         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1913                 *phase = tmp;
1914                 return -1;
1915         }
1916
1917         if (atari_read_overruns && (p & SR_IO))
1918                 c -= atari_read_overruns;
1919
1920         DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1921                    HOSTNO, (p & SR_IO) ? "reading" : "writing",
1922                    c, (p & SR_IO) ? "to" : "from", d);
1923
1924         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1925
1926 #ifdef REAL_DMA
1927         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1928 #endif /* def REAL_DMA  */
1929
1930         if (IS_A_TT()) {
1931                 /* On the Medusa, it is a must to initialize the DMA before
1932                  * starting the NCR. This is also the cleaner way for the TT.
1933                  */
1934                 local_irq_save(flags);
1935                 hostdata->dma_len = (p & SR_IO) ?
1936                         NCR5380_dma_read_setup(instance, d, c) :
1937                         NCR5380_dma_write_setup(instance, d, c);
1938                 local_irq_restore(flags);
1939         }
1940
1941         if (p & SR_IO)
1942                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1943         else {
1944                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1945                 NCR5380_write(START_DMA_SEND_REG, 0);
1946         }
1947
1948         if (!IS_A_TT()) {
1949                 /* On the Falcon, the DMA setup must be done after the last */
1950                 /* NCR access, else the DMA setup gets trashed!
1951                  */
1952                 local_irq_save(flags);
1953                 hostdata->dma_len = (p & SR_IO) ?
1954                         NCR5380_dma_read_setup(instance, d, c) :
1955                         NCR5380_dma_write_setup(instance, d, c);
1956                 local_irq_restore(flags);
1957         }
1958         return 0;
1959 }
1960 #endif /* defined(REAL_DMA) */
1961
1962 /*
1963  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1964  *
1965  * Purpose : run through the various SCSI phases and do as the target
1966  *      directs us to.  Operates on the currently connected command,
1967  *      instance->connected.
1968  *
1969  * Inputs : instance, instance for which we are doing commands
1970  *
1971  * Side effects : SCSI things happen, the disconnected queue will be
1972  *      modified if a command disconnects, *instance->connected will
1973  *      change.
1974  *
1975  * XXX Note : we need to watch for bus free or a reset condition here
1976  *      to recover from an unexpected bus free condition.
1977  */
1978
1979 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1980 {
1981         SETUP_HOSTDATA(instance);
1982         unsigned long flags;
1983         unsigned char msgout = NOP;
1984         int sink = 0;
1985         int len;
1986 #if defined(REAL_DMA)
1987         int transfersize;
1988 #endif
1989         unsigned char *data;
1990         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1991         Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
1992
1993         while (1) {
1994                 tmp = NCR5380_read(STATUS_REG);
1995                 /* We only have a valid SCSI phase when REQ is asserted */
1996                 if (tmp & SR_REQ) {
1997                         phase = (tmp & PHASE_MASK);
1998                         if (phase != old_phase) {
1999                                 old_phase = phase;
2000                                 NCR_PRINT_PHASE(NDEBUG_INFORMATION);
2001                         }
2002
2003                         if (sink && (phase != PHASE_MSGOUT)) {
2004                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2005
2006                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
2007                                               ICR_ASSERT_ACK);
2008                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
2009                                         ;
2010                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2011                                               ICR_ASSERT_ATN);
2012                                 sink = 0;
2013                                 continue;
2014                         }
2015
2016                         switch (phase) {
2017                         case PHASE_DATAOUT:
2018 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2019                                 printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
2020                                        "aborted\n", HOSTNO);
2021                                 sink = 1;
2022                                 do_abort(instance);
2023                                 cmd->result = DID_ERROR << 16;
2024                                 cmd->scsi_done(cmd);
2025                                 return;
2026 #endif
2027                         case PHASE_DATAIN:
2028                                 /*
2029                                  * If there is no room left in the current buffer in the
2030                                  * scatter-gather list, move onto the next one.
2031                                  */
2032
2033                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2034                                         ++cmd->SCp.buffer;
2035                                         --cmd->SCp.buffers_residual;
2036                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
2037                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2038                                         /* ++roman: Try to merge some scatter-buffers if
2039                                          * they are at contiguous physical addresses.
2040                                          */
2041                                         merge_contiguous_buffers(cmd);
2042                                         INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
2043                                                    HOSTNO, cmd->SCp.this_residual,
2044                                                    cmd->SCp.buffers_residual);
2045                                 }
2046
2047                                 /*
2048                                  * The preferred transfer method is going to be
2049                                  * PSEUDO-DMA for systems that are strictly PIO,
2050                                  * since we can let the hardware do the handshaking.
2051                                  *
2052                                  * For this to work, we need to know the transfersize
2053                                  * ahead of time, since the pseudo-DMA code will sit
2054                                  * in an unconditional loop.
2055                                  */
2056
2057                                 /* ++roman: I suggest, this should be
2058                                  *   #if def(REAL_DMA)
2059                                  * instead of leaving REAL_DMA out.
2060                                  */
2061
2062 #if defined(REAL_DMA)
2063                                 if (!cmd->device->borken &&
2064                                     (transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
2065                                         len = transfersize;
2066                                         cmd->SCp.phase = phase;
2067                                         if (NCR5380_transfer_dma(instance, &phase,
2068                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
2069                                                 /*
2070                                                  * If the watchdog timer fires, all future
2071                                                  * accesses to this device will use the
2072                                                  * polled-IO. */
2073                                                 printk(KERN_NOTICE "scsi%d: switching target %d "
2074                                                            "lun %d to slow handshake\n", HOSTNO,
2075                                                            cmd->device->id, cmd->device->lun);
2076                                                 cmd->device->borken = 1;
2077                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2078                                                         ICR_ASSERT_ATN);
2079                                                 sink = 1;
2080                                                 do_abort(instance);
2081                                                 cmd->result = DID_ERROR << 16;
2082                                                 cmd->scsi_done(cmd);
2083                                                 /* XXX - need to source or sink data here, as appropriate */
2084                                         } else {
2085 #ifdef REAL_DMA
2086                                                 /* ++roman: When using real DMA,
2087                                                  * information_transfer() should return after
2088                                                  * starting DMA since it has nothing more to
2089                                                  * do.
2090                                                  */
2091                                                 return;
2092 #else
2093                                                 cmd->SCp.this_residual -= transfersize - len;
2094 #endif
2095                                         }
2096                                 } else
2097 #endif /* defined(REAL_DMA) */
2098                                         NCR5380_transfer_pio(instance, &phase,
2099                                                              (int *)&cmd->SCp.this_residual,
2100                                                              (unsigned char **)&cmd->SCp.ptr);
2101                                 break;
2102                         case PHASE_MSGIN:
2103                                 len = 1;
2104                                 data = &tmp;
2105                                 NCR5380_write(SELECT_ENABLE_REG, 0);    /* disable reselects */
2106                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2107                                 cmd->SCp.Message = tmp;
2108
2109                                 switch (tmp) {
2110                                 /*
2111                                  * Linking lets us reduce the time required to get the
2112                                  * next command out to the device, hopefully this will
2113                                  * mean we don't waste another revolution due to the delays
2114                                  * required by ARBITRATION and another SELECTION.
2115                                  *
2116                                  * In the current implementation proposal, low level drivers
2117                                  * merely have to start the next command, pointed to by
2118                                  * next_link, done() is called as with unlinked commands.
2119                                  */
2120 #ifdef LINKED
2121                                 case LINKED_CMD_COMPLETE:
2122                                 case LINKED_FLG_CMD_COMPLETE:
2123                                         /* Accept message by clearing ACK */
2124                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2125
2126                                         LNK_PRINTK("scsi%d: target %d lun %d linked command "
2127                                                    "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
2128
2129                                         /* Enable reselect interrupts */
2130                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2131                                         /*
2132                                          * Sanity check : A linked command should only terminate
2133                                          * with one of these messages if there are more linked
2134                                          * commands available.
2135                                          */
2136
2137                                         if (!cmd->next_link) {
2138                                                  printk(KERN_NOTICE "scsi%d: target %d lun %d "
2139                                                         "linked command complete, no next_link\n",
2140                                                         HOSTNO, cmd->device->id, cmd->device->lun);
2141                                                 sink = 1;
2142                                                 do_abort(instance);
2143                                                 return;
2144                                         }
2145
2146                                         initialize_SCp(cmd->next_link);
2147                                         /* The next command is still part of this process; copy it
2148                                          * and don't free it! */
2149                                         cmd->next_link->tag = cmd->tag;
2150                                         cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2151                                         LNK_PRINTK("scsi%d: target %d lun %d linked request "
2152                                                    "done, calling scsi_done().\n",
2153                                                    HOSTNO, cmd->device->id, cmd->device->lun);
2154 #ifdef NCR5380_STATS
2155                                         collect_stats(hostdata, cmd);
2156 #endif
2157                                         cmd->scsi_done(cmd);
2158                                         cmd = hostdata->connected;
2159                                         break;
2160 #endif /* def LINKED */
2161                                 case ABORT:
2162                                 case COMMAND_COMPLETE:
2163                                         /* Accept message by clearing ACK */
2164                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2165                                         /* ++guenther: possible race with Falcon locking */
2166                                         falcon_dont_release++;
2167                                         hostdata->connected = NULL;
2168                                         QU_PRINTK("scsi%d: command for target %d, lun %d "
2169                                                   "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2170 #ifdef SUPPORT_TAGS
2171                                         cmd_free_tag(cmd);
2172                                         if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2173                                                 /* Turn a QUEUE FULL status into BUSY, I think the
2174                                                  * mid level cannot handle QUEUE FULL :-( (The
2175                                                  * command is retried after BUSY). Also update our
2176                                                  * queue size to the number of currently issued
2177                                                  * commands now.
2178                                                  */
2179                                                 /* ++Andreas: the mid level code knows about
2180                                                    QUEUE_FULL now. */
2181                                                 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
2182                                                 TAG_PRINTK("scsi%d: target %d lun %d returned "
2183                                                            "QUEUE_FULL after %d commands\n",
2184                                                            HOSTNO, cmd->device->id, cmd->device->lun,
2185                                                            ta->nr_allocated);
2186                                                 if (ta->queue_size > ta->nr_allocated)
2187                                                         ta->nr_allocated = ta->queue_size;
2188                                         }
2189 #else
2190                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2191 #endif
2192                                         /* Enable reselect interrupts */
2193                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2194
2195                                         /*
2196                                          * I'm not sure what the correct thing to do here is :
2197                                          *
2198                                          * If the command that just executed is NOT a request
2199                                          * sense, the obvious thing to do is to set the result
2200                                          * code to the values of the stored parameters.
2201                                          *
2202                                          * If it was a REQUEST SENSE command, we need some way to
2203                                          * differentiate between the failure code of the original
2204                                          * and the failure code of the REQUEST sense - the obvious
2205                                          * case is success, where we fall through and leave the
2206                                          * result code unchanged.
2207                                          *
2208                                          * The non-obvious place is where the REQUEST SENSE failed
2209                                          */
2210
2211                                         if (cmd->cmnd[0] != REQUEST_SENSE)
2212                                                 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2213                                         else if (status_byte(cmd->SCp.Status) != GOOD)
2214                                                 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2215
2216 #ifdef AUTOSENSE
2217                                         if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2218                                                 hostdata->ses.cmd_len) {
2219                                                 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2220                                                 hostdata->ses.cmd_len = 0 ;
2221                                         }
2222
2223                                         if ((cmd->cmnd[0] != REQUEST_SENSE) &&
2224                                             (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2225                                                 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2226
2227                                                 ASEN_PRINTK("scsi%d: performing request sense\n", HOSTNO);
2228
2229                                                 local_irq_save(flags);
2230                                                 LIST(cmd,hostdata->issue_queue);
2231                                                 SET_NEXT(cmd, hostdata->issue_queue);
2232                                                 hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2233                                                 local_irq_restore(flags);
2234                                                 QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
2235                                                           "issue queue\n", H_NO(cmd));
2236                                         } else
2237 #endif /* def AUTOSENSE */
2238                                         {
2239 #ifdef NCR5380_STATS
2240                                                 collect_stats(hostdata, cmd);
2241 #endif
2242                                                 cmd->scsi_done(cmd);
2243                                         }
2244
2245                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2246                                         /*
2247                                          * Restore phase bits to 0 so an interrupted selection,
2248                                          * arbitration can resume.
2249                                          */
2250                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2251
2252                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2253                                                 barrier();
2254
2255                                         falcon_dont_release--;
2256                                         /* ++roman: For Falcon SCSI, release the lock on the
2257                                          * ST-DMA here if no other commands are waiting on the
2258                                          * disconnected queue.
2259                                          */
2260                                         falcon_release_lock_if_possible(hostdata);
2261                                         return;
2262                                 case MESSAGE_REJECT:
2263                                         /* Accept message by clearing ACK */
2264                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2265                                         /* Enable reselect interrupts */
2266                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2267                                         switch (hostdata->last_message) {
2268                                         case HEAD_OF_QUEUE_TAG:
2269                                         case ORDERED_QUEUE_TAG:
2270                                         case SIMPLE_QUEUE_TAG:
2271                                                 /* The target obviously doesn't support tagged
2272                                                  * queuing, even though it announced this ability in
2273                                                  * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2274                                                  * clear 'tagged_supported' and lock the LUN, since
2275                                                  * the command is treated as untagged further on.
2276                                                  */
2277                                                 cmd->device->tagged_supported = 0;
2278                                                 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2279                                                 cmd->tag = TAG_NONE;
2280                                                 TAG_PRINTK("scsi%d: target %d lun %d rejected "
2281                                                            "QUEUE_TAG message; tagged queuing "
2282                                                            "disabled\n",
2283                                                            HOSTNO, cmd->device->id, cmd->device->lun);
2284                                                 break;
2285                                         }
2286                                         break;
2287                                 case DISCONNECT:
2288                                         /* Accept message by clearing ACK */
2289                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2290                                         local_irq_save(flags);
2291                                         cmd->device->disconnect = 1;
2292                                         LIST(cmd,hostdata->disconnected_queue);
2293                                         SET_NEXT(cmd, hostdata->disconnected_queue);
2294                                         hostdata->connected = NULL;
2295                                         hostdata->disconnected_queue = cmd;
2296                                         local_irq_restore(flags);
2297                                         QU_PRINTK("scsi%d: command for target %d lun %d was "
2298                                                   "moved from connected to the "
2299                                                   "disconnected_queue\n", HOSTNO,
2300                                                   cmd->device->id, cmd->device->lun);
2301                                         /*
2302                                          * Restore phase bits to 0 so an interrupted selection,
2303                                          * arbitration can resume.
2304                                          */
2305                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2306
2307                                         /* Enable reselect interrupts */
2308                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2309                                         /* Wait for bus free to avoid nasty timeouts */
2310                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2311                                                 barrier();
2312                                         return;
2313                                         /*
2314                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2315                                          * operation, in violation of the SCSI spec so we can safely
2316                                          * ignore SAVE/RESTORE pointers calls.
2317                                          *
2318                                          * Unfortunately, some disks violate the SCSI spec and
2319                                          * don't issue the required SAVE_POINTERS message before
2320                                          * disconnecting, and we have to break spec to remain
2321                                          * compatible.
2322                                          */
2323                                 case SAVE_POINTERS:
2324                                 case RESTORE_POINTERS:
2325                                         /* Accept message by clearing ACK */
2326                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2327                                         /* Enable reselect interrupts */
2328                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2329                                         break;
2330                                 case EXTENDED_MESSAGE:
2331                                         /*
2332                                          * Extended messages are sent in the following format :
2333                                          * Byte
2334                                          * 0            EXTENDED_MESSAGE == 1
2335                                          * 1            length (includes one byte for code, doesn't
2336                                          *              include first two bytes)
2337                                          * 2            code
2338                                          * 3..length+1  arguments
2339                                          *
2340                                          * Start the extended message buffer with the EXTENDED_MESSAGE
2341                                          * byte, since spi_print_msg() wants the whole thing.
2342                                          */
2343                                         extended_msg[0] = EXTENDED_MESSAGE;
2344                                         /* Accept first byte by clearing ACK */
2345                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2346
2347                                         EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);
2348
2349                                         len = 2;
2350                                         data = extended_msg + 1;
2351                                         phase = PHASE_MSGIN;
2352                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
2353                                         EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2354                                                    (int)extended_msg[1], (int)extended_msg[2]);
2355
2356                                         if (!len && extended_msg[1] <=
2357                                             (sizeof(extended_msg) - 1)) {
2358                                                 /* Accept third byte by clearing ACK */
2359                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2360                                                 len = extended_msg[1] - 1;
2361                                                 data = extended_msg + 3;
2362                                                 phase = PHASE_MSGIN;
2363
2364                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2365                                                 EXT_PRINTK("scsi%d: message received, residual %d\n",
2366                                                            HOSTNO, len);
2367
2368                                                 switch (extended_msg[2]) {
2369                                                 case EXTENDED_SDTR:
2370                                                 case EXTENDED_WDTR:
2371                                                 case EXTENDED_MODIFY_DATA_POINTER:
2372                                                 case EXTENDED_EXTENDED_IDENTIFY:
2373                                                         tmp = 0;
2374                                                 }
2375                                         } else if (len) {
2376                                                 printk(KERN_NOTICE "scsi%d: error receiving "
2377                                                        "extended message\n", HOSTNO);
2378                                                 tmp = 0;
2379                                         } else {
2380                                                 printk(KERN_NOTICE "scsi%d: extended message "
2381                                                            "code %02x length %d is too long\n",
2382                                                            HOSTNO, extended_msg[2], extended_msg[1]);
2383                                                 tmp = 0;
2384                                         }
2385                                         /* Fall through to reject message */
2386
2387                                         /*
2388                                          * If we get something weird that we aren't expecting,
2389                                          * reject it.
2390                                          */
2391                                 default:
2392                                         if (!tmp) {
2393                                                 printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
2394                                                 spi_print_msg(extended_msg);
2395                                                 printk("\n");
2396                                         } else if (tmp != EXTENDED_MESSAGE)
2397                                                 printk(KERN_DEBUG "scsi%d: rejecting unknown "
2398                                                        "message %02x from target %d, lun %d\n",
2399                                                        HOSTNO, tmp, cmd->device->id, cmd->device->lun);
2400                                         else
2401                                                 printk(KERN_DEBUG "scsi%d: rejecting unknown "
2402                                                        "extended message "
2403                                                        "code %02x, length %d from target %d, lun %d\n",
2404                                                        HOSTNO, extended_msg[1], extended_msg[0],
2405                                                        cmd->device->id, cmd->device->lun);
2406
2407
2408                                         msgout = MESSAGE_REJECT;
2409                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2410                                         break;
2411                                 } /* switch (tmp) */
2412                                 break;
2413                         case PHASE_MSGOUT:
2414                                 len = 1;
2415                                 data = &msgout;
2416                                 hostdata->last_message = msgout;
2417                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2418                                 if (msgout == ABORT) {
2419 #ifdef SUPPORT_TAGS
2420                                         cmd_free_tag(cmd);
2421 #else
2422                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2423 #endif
2424                                         hostdata->connected = NULL;
2425                                         cmd->result = DID_ERROR << 16;
2426 #ifdef NCR5380_STATS
2427                                         collect_stats(hostdata, cmd);
2428 #endif
2429                                         cmd->scsi_done(cmd);
2430                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2431                                         falcon_release_lock_if_possible(hostdata);
2432                                         return;
2433                                 }
2434                                 msgout = NOP;
2435                                 break;
2436                         case PHASE_CMDOUT:
2437                                 len = cmd->cmd_len;
2438                                 data = cmd->cmnd;
2439                                 /*
2440                                  * XXX for performance reasons, on machines with a
2441                                  * PSEUDO-DMA architecture we should probably
2442                                  * use the dma transfer function.
2443                                  */
2444                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2445                                 break;
2446                         case PHASE_STATIN:
2447                                 len = 1;
2448                                 data = &tmp;
2449                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2450                                 cmd->SCp.Status = tmp;
2451                                 break;
2452                         default:
2453                                 printk("scsi%d: unknown phase\n", HOSTNO);
2454                                 NCR_PRINT(NDEBUG_ANY);
2455                         } /* switch(phase) */
2456                 } /* if (tmp * SR_REQ) */
2457         } /* while (1) */
2458 }
2459
2460 /*
2461  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2462  *
2463  * Purpose : does reselection, initializing the instance->connected
2464  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2465  *      nexus has been reestablished,
2466  *
2467  * Inputs : instance - this instance of the NCR5380.
2468  *
2469  */
2470
2471
2472 static void NCR5380_reselect(struct Scsi_Host *instance)
2473 {
2474         SETUP_HOSTDATA(instance);
2475         unsigned char target_mask;
2476         unsigned char lun, phase;
2477         int len;
2478 #ifdef SUPPORT_TAGS
2479         unsigned char tag;
2480 #endif
2481         unsigned char msg[3];
2482         unsigned char *data;
2483         Scsi_Cmnd *tmp = NULL, *prev;
2484 /*      unsigned long flags; */
2485
2486         /*
2487          * Disable arbitration, etc. since the host adapter obviously
2488          * lost, and tell an interrupted NCR5380_select() to restart.
2489          */
2490
2491         NCR5380_write(MODE_REG, MR_BASE);
2492         hostdata->restart_select = 1;
2493
2494         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2495
2496         RSL_PRINTK("scsi%d: reselect\n", HOSTNO);
2497
2498         /*
2499          * At this point, we have detected that our SCSI ID is on the bus,
2500          * SEL is true and BSY was false for at least one bus settle delay
2501          * (400 ns).
2502          *
2503          * We must assert BSY ourselves, until the target drops the SEL
2504          * signal.
2505          */
2506
2507         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2508
2509         while (NCR5380_read(STATUS_REG) & SR_SEL)
2510                 ;
2511         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2512
2513         /*
2514          * Wait for target to go into MSGIN.
2515          */
2516
2517         while (!(NCR5380_read(STATUS_REG) & SR_REQ))
2518                 ;
2519
2520         len = 1;
2521         data = msg;
2522         phase = PHASE_MSGIN;
2523         NCR5380_transfer_pio(instance, &phase, &len, &data);
2524
2525         if (!(msg[0] & 0x80)) {
2526                 printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2527                 spi_print_msg(msg);
2528                 do_abort(instance);
2529                 return;
2530         }
2531         lun = (msg[0] & 0x07);
2532
2533 #ifdef SUPPORT_TAGS
2534         /* If the phase is still MSGIN, the target wants to send some more
2535          * messages. In case it supports tagged queuing, this is probably a
2536          * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2537          */
2538         tag = TAG_NONE;
2539         if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2540                 /* Accept previous IDENTIFY message by clearing ACK */
2541                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2542                 len = 2;
2543                 data = msg + 1;
2544                 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2545                     msg[1] == SIMPLE_QUEUE_TAG)
2546                         tag = msg[2];
2547                 TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
2548                            "reselection\n", HOSTNO, target_mask, lun, tag);
2549         }
2550 #endif
2551
2552         /*
2553          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2554          * just reestablished, and remove it from the disconnected queue.
2555          */
2556
2557         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL;
2558              tmp; prev = tmp, tmp = NEXT(tmp)) {
2559                 if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2560 #ifdef SUPPORT_TAGS
2561                     && (tag == tmp->tag)
2562 #endif
2563                     ) {
2564                         /* ++guenther: prevent race with falcon_release_lock */
2565                         falcon_dont_release++;
2566                         if (prev) {
2567                                 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2568                                 SET_NEXT(prev, NEXT(tmp));
2569                         } else {
2570                                 REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
2571                                 hostdata->disconnected_queue = NEXT(tmp);
2572                         }
2573                         SET_NEXT(tmp, NULL);
2574                         break;
2575                 }
2576         }
2577
2578         if (!tmp) {
2579                 printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
2580 #ifdef SUPPORT_TAGS
2581                        "tag %d "
2582 #endif
2583                        "not in disconnected_queue.\n",
2584                        HOSTNO, target_mask, lun
2585 #ifdef SUPPORT_TAGS
2586                        , tag
2587 #endif
2588                         );
2589                 /*
2590                  * Since we have an established nexus that we can't do anything
2591                  * with, we must abort it.
2592                  */
2593                 do_abort(instance);
2594                 return;
2595         }
2596
2597         /* Accept message by clearing ACK */
2598         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2599
2600         hostdata->connected = tmp;
2601         RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
2602                    HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
2603         falcon_dont_release--;
2604 }
2605
2606
2607 /*
2608  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2609  *
2610  * Purpose : abort a command
2611  *
2612  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2613  *      host byte of the result field to, if zero DID_ABORTED is
2614  *      used.
2615  *
2616  * Returns : 0 - success, -1 on failure.
2617  *
2618  * XXX - there is no way to abort the command that is currently
2619  *       connected, you have to wait for it to complete.  If this is
2620  *       a problem, we could implement longjmp() / setjmp(), setjmp()
2621  *       called where the loop started in NCR5380_main().
2622  */
2623
2624 static
2625 int NCR5380_abort(Scsi_Cmnd *cmd)
2626 {
2627         struct Scsi_Host *instance = cmd->device->host;
2628         SETUP_HOSTDATA(instance);
2629         Scsi_Cmnd *tmp, **prev;
2630         unsigned long flags;
2631
2632         printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
2633         scsi_print_command(cmd);
2634
2635         NCR5380_print_status(instance);
2636
2637         local_irq_save(flags);
2638
2639         if (!IS_A_TT() && !falcon_got_lock)
2640                 printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
2641                        HOSTNO);
2642
2643         ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2644                     NCR5380_read(BUS_AND_STATUS_REG),
2645                     NCR5380_read(STATUS_REG));
2646
2647 #if 1
2648         /*
2649          * Case 1 : If the command is the currently executing command,
2650          * we'll set the aborted flag and return control so that
2651          * information transfer routine can exit cleanly.
2652          */
2653
2654         if (hostdata->connected == cmd) {
2655
2656                 ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
2657                 /*
2658                  * We should perform BSY checking, and make sure we haven't slipped
2659                  * into BUS FREE.
2660                  */
2661
2662                 /*      NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2663                 /*
2664                  * Since we can't change phases until we've completed the current
2665                  * handshake, we have to source or sink a byte of data if the current
2666                  * phase is not MSGOUT.
2667                  */
2668
2669                 /*
2670                  * Return control to the executing NCR drive so we can clear the
2671                  * aborted flag and get back into our main loop.
2672                  */
2673
2674                 if (do_abort(instance) == 0) {
2675                         hostdata->aborted = 1;
2676                         hostdata->connected = NULL;
2677                         cmd->result = DID_ABORT << 16;
2678 #ifdef SUPPORT_TAGS
2679                         cmd_free_tag(cmd);
2680 #else
2681                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2682 #endif
2683                         local_irq_restore(flags);
2684                         cmd->scsi_done(cmd);
2685                         falcon_release_lock_if_possible(hostdata);
2686                         return SCSI_ABORT_SUCCESS;
2687                 } else {
2688 /*                      local_irq_restore(flags); */
2689                         printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2690                         return SCSI_ABORT_ERROR;
2691                 }
2692         }
2693 #endif
2694
2695         /*
2696          * Case 2 : If the command hasn't been issued yet, we simply remove it
2697          *          from the issue queue.
2698          */
2699         for (prev = (Scsi_Cmnd **)&(hostdata->issue_queue),
2700              tmp = (Scsi_Cmnd *)hostdata->issue_queue;
2701              tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2702                 if (cmd == tmp) {
2703                         REMOVE(5, *prev, tmp, NEXT(tmp));
2704                         (*prev) = NEXT(tmp);
2705                         SET_NEXT(tmp, NULL);
2706                         tmp->result = DID_ABORT << 16;
2707                         local_irq_restore(flags);
2708                         ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
2709                                     HOSTNO);
2710                         /* Tagged queuing note: no tag to free here, hasn't been assigned
2711                          * yet... */
2712                         tmp->scsi_done(tmp);
2713                         falcon_release_lock_if_possible(hostdata);
2714                         return SCSI_ABORT_SUCCESS;
2715                 }
2716         }
2717
2718         /*
2719          * Case 3 : If any commands are connected, we're going to fail the abort
2720          *          and let the high level SCSI driver retry at a later time or
2721          *          issue a reset.
2722          *
2723          *          Timeouts, and therefore aborted commands, will be highly unlikely
2724          *          and handling them cleanly in this situation would make the common
2725          *          case of noresets less efficient, and would pollute our code.  So,
2726          *          we fail.
2727          */
2728
2729         if (hostdata->connected) {
2730                 local_irq_restore(flags);
2731                 ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
2732                 return SCSI_ABORT_SNOOZE;
2733         }
2734
2735         /*
2736          * Case 4: If the command is currently disconnected from the bus, and
2737          *      there are no connected commands, we reconnect the I_T_L or
2738          *      I_T_L_Q nexus associated with it, go into message out, and send
2739          *      an abort message.
2740          *
2741          * This case is especially ugly. In order to reestablish the nexus, we
2742          * need to call NCR5380_select().  The easiest way to implement this
2743          * function was to abort if the bus was busy, and let the interrupt
2744          * handler triggered on the SEL for reselect take care of lost arbitrations
2745          * where necessary, meaning interrupts need to be enabled.
2746          *
2747          * When interrupts are enabled, the queues may change - so we
2748          * can't remove it from the disconnected queue before selecting it
2749          * because that could cause a failure in hashing the nexus if that
2750          * device reselected.
2751          *
2752          * Since the queues may change, we can't use the pointers from when we
2753          * first locate it.
2754          *
2755          * So, we must first locate the command, and if NCR5380_select()
2756          * succeeds, then issue the abort, relocate the command and remove
2757          * it from the disconnected queue.
2758          */
2759
2760         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
2761              tmp = NEXT(tmp)) {
2762                 if (cmd == tmp) {
2763                         local_irq_restore(flags);
2764                         ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
2765
2766                         if (NCR5380_select(instance, cmd, (int)cmd->tag))
2767                                 return SCSI_ABORT_BUSY;
2768
2769                         ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);
2770
2771                         do_abort(instance);
2772
2773                         local_irq_save(flags);
2774                         for (prev = (Scsi_Cmnd **)&(hostdata->disconnected_queue),
2775                              tmp = (Scsi_Cmnd *)hostdata->disconnected_queue;
2776                              tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2777                                 if (cmd == tmp) {
2778                                         REMOVE(5, *prev, tmp, NEXT(tmp));
2779                                         *prev = NEXT(tmp);
2780                                         SET_NEXT(tmp, NULL);
2781                                         tmp->result = DID_ABORT << 16;
2782                                         /* We must unlock the tag/LUN immediately here, since the
2783                                          * target goes to BUS FREE and doesn't send us another
2784                                          * message (COMMAND_COMPLETE or the like)
2785                                          */
2786 #ifdef SUPPORT_TAGS
2787                                         cmd_free_tag(tmp);
2788 #else
2789                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2790 #endif
2791                                         local_irq_restore(flags);
2792                                         tmp->scsi_done(tmp);
2793                                         falcon_release_lock_if_possible(hostdata);
2794                                         return SCSI_ABORT_SUCCESS;
2795                                 }
2796                         }
2797                 }
2798         }
2799
2800         /*
2801          * Case 5 : If we reached this point, the command was not found in any of
2802          *          the queues.
2803          *
2804          * We probably reached this point because of an unlikely race condition
2805          * between the command completing successfully and the abortion code,
2806          * so we won't panic, but we will notify the user in case something really
2807          * broke.
2808          */
2809
2810         local_irq_restore(flags);
2811         printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
2812
2813         /* Maybe it is sufficient just to release the ST-DMA lock... (if
2814          * possible at all) At least, we should check if the lock could be
2815          * released after the abort, in case it is kept due to some bug.
2816          */
2817         falcon_release_lock_if_possible(hostdata);
2818
2819         return SCSI_ABORT_NOT_RUNNING;
2820 }
2821
2822
2823 /*
2824  * Function : int NCR5380_reset (Scsi_Cmnd *cmd)
2825  *
2826  * Purpose : reset the SCSI bus.
2827  *
2828  * Returns : SCSI_RESET_WAKEUP
2829  *
2830  */
2831
2832 static int NCR5380_bus_reset(Scsi_Cmnd *cmd)
2833 {
2834         SETUP_HOSTDATA(cmd->device->host);
2835         int i;
2836         unsigned long flags;
2837 #if 1
2838         Scsi_Cmnd *connected, *disconnected_queue;
2839 #endif
2840
2841         if (!IS_A_TT() && !falcon_got_lock)
2842                 printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
2843                        H_NO(cmd));
2844
2845         NCR5380_print_status(cmd->device->host);
2846
2847         /* get in phase */
2848         NCR5380_write(TARGET_COMMAND_REG,
2849                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
2850         /* assert RST */
2851         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
2852         udelay(40);
2853         /* reset NCR registers */
2854         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2855         NCR5380_write(MODE_REG, MR_BASE);
2856         NCR5380_write(TARGET_COMMAND_REG, 0);
2857         NCR5380_write(SELECT_ENABLE_REG, 0);
2858         /* ++roman: reset interrupt condition! otherwise no interrupts don't get
2859          * through anymore ... */
2860         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2861
2862 #if 1   /* XXX Should now be done by midlevel code, but it's broken XXX */
2863         /* XXX see below                                            XXX */
2864
2865         /* MSch: old-style reset: actually abort all command processing here */
2866
2867         /* After the reset, there are no more connected or disconnected commands
2868          * and no busy units; to avoid problems with re-inserting the commands
2869          * into the issue_queue (via scsi_done()), the aborted commands are
2870          * remembered in local variables first.
2871          */
2872         local_irq_save(flags);
2873         connected = (Scsi_Cmnd *)hostdata->connected;
2874         hostdata->connected = NULL;
2875         disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
2876         hostdata->disconnected_queue = NULL;
2877 #ifdef SUPPORT_TAGS
2878         free_all_tags();
2879 #endif
2880         for (i = 0; i < 8; ++i)
2881                 hostdata->busy[i] = 0;
2882 #ifdef REAL_DMA
2883         hostdata->dma_len = 0;
2884 #endif
2885         local_irq_restore(flags);
2886
2887         /* In order to tell the mid-level code which commands were aborted,
2888          * set the command status to DID_RESET and call scsi_done() !!!
2889          * This ultimately aborts processing of these commands in the mid-level.
2890          */
2891
2892         if ((cmd = connected)) {
2893                 ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2894                 cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2895                 cmd->scsi_done(cmd);
2896         }
2897
2898         for (i = 0; (cmd = disconnected_queue); ++i) {
2899                 disconnected_queue = NEXT(cmd);
2900                 SET_NEXT(cmd, NULL);
2901                 cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2902                 cmd->scsi_done(cmd);
2903         }
2904         if (i > 0)
2905                 ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);
2906
2907         /* The Falcon lock should be released after a reset...
2908          */
2909         /* ++guenther: moved to atari_scsi_reset(), to prevent a race between
2910          * unlocking and enabling dma interrupt.
2911          */
2912 /*      falcon_release_lock_if_possible( hostdata );*/
2913
2914         /* since all commands have been explicitly terminated, we need to tell
2915          * the midlevel code that the reset was SUCCESSFUL, and there is no
2916          * need to 'wake up' the commands by a request_sense
2917          */
2918         return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
2919 #else /* 1 */
2920
2921         /* MSch: new-style reset handling: let the mid-level do what it can */
2922
2923         /* ++guenther: MID-LEVEL IS STILL BROKEN.
2924          * Mid-level is supposed to requeue all commands that were active on the
2925          * various low-level queues. In fact it does this, but that's not enough
2926          * because all these commands are subject to timeout. And if a timeout
2927          * happens for any removed command, *_abort() is called but all queues
2928          * are now empty. Abort then gives up the falcon lock, which is fatal,
2929          * since the mid-level will queue more commands and must have the lock
2930          * (it's all happening inside timer interrupt handler!!).
2931          * Even worse, abort will return NOT_RUNNING for all those commands not
2932          * on any queue, so they won't be retried ...
2933          *
2934          * Conclusion: either scsi.c disables timeout for all resetted commands
2935          * immediately, or we lose!  As of linux-2.0.20 it doesn't.
2936          */
2937
2938         /* After the reset, there are no more connected or disconnected commands
2939          * and no busy units; so clear the low-level status here to avoid
2940          * conflicts when the mid-level code tries to wake up the affected
2941          * commands!
2942          */
2943
2944         if (hostdata->issue_queue)
2945                 ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
2946         if (hostdata->connected)
2947                 ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2948         if (hostdata->disconnected_queue)
2949                 ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
2950
2951         local_irq_save(flags);
2952         hostdata->issue_queue = NULL;
2953         hostdata->connected = NULL;
2954         hostdata->disconnected_queue = NULL;
2955 #ifdef SUPPORT_TAGS
2956         free_all_tags();
2957 #endif
2958         for (i = 0; i < 8; ++i)
2959                 hostdata->busy[i] = 0;
2960 #ifdef REAL_DMA
2961         hostdata->dma_len = 0;
2962 #endif
2963         local_irq_restore(flags);
2964
2965         /* we did no complete reset of all commands, so a wakeup is required */
2966         return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
2967 #endif /* 1 */
2968 }