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 transfered 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 NCR5380_print_status(struct Scsi_Host *instance)
 723 {
 724         char *pr_bfr;
 725         char *start;
 726         int len;
 727
 728         NCR_PRINT(NDEBUG_ANY);
 729         NCR_PRINT_PHASE(NDEBUG_ANY);
 730
 731         pr_bfr = (char *)__get_free_page(GFP_ATOMIC);
 732         if (!pr_bfr) {
 733                 printk("NCR5380_print_status: no memory for print buffer\n");
 734                 return;
 735         }
 736         len = NCR5380_proc_info(instance, pr_bfr, &start, 0, PAGE_SIZE, 0);
 737         pr_bfr[len] = 0;
 738         printk("\n%s\n", pr_bfr);
 739         free_page((unsigned long)pr_bfr);
 740 }
 741
 742
 743 /******************************************/
 744 /*
 745  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
 746  *
 747  * *buffer: I/O buffer
 748  * **start: if inout == FALSE pointer into buffer where user read should start
 749  * offset: current offset
 750  * length: length of buffer
 751  * hostno: Scsi_Host host_no
 752  * inout: TRUE - user is writing; FALSE - user is reading
 753  *
 754  * Return the number of bytes read from or written
 755 */
 756
 757 #undef SPRINTF
 758 #define SPRINTF(fmt,args...)                                                    \
 759         do {                                                                    \
 760                 if (pos + strlen(fmt) + 20 /* slop */ < buffer + length)        \
 761                         pos += sprintf(pos, fmt , ## args);                     \
 762         } while(0)
 763 static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length);
 764
 765 static int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer,
 766                              char **start, off_t offset, int length, int inout)
 767 {
 768         char *pos = buffer;
 769         struct NCR5380_hostdata *hostdata;
 770         Scsi_Cmnd *ptr;
 771         unsigned long flags;
 772         off_t begin = 0;
 773 #define check_offset()                                  \
 774         do {                                            \
 775                 if (pos - buffer < offset - begin) {    \
 776                         begin += pos - buffer;          \
 777                         pos = buffer;                   \
 778                 }                                       \
 779         } while (0)
 780
 781         hostdata = (struct NCR5380_hostdata *)instance->hostdata;
 782
 783         if (inout)                      /* Has data been written to the file ? */
 784                 return -ENOSYS;         /* Currently this is a no-op */
 785         SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
 786         check_offset();
 787         local_irq_save(flags);
 788         SPRINTF("NCR5380: coroutine is%s running.\n",
 789                 main_running ? "" : "n't");
 790         check_offset();
 791         if (!hostdata->connected)
 792                 SPRINTF("scsi%d: no currently connected command\n", HOSTNO);
 793         else
 794                 pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected,
 795                                        pos, buffer, length);
 796         SPRINTF("scsi%d: issue_queue\n", HOSTNO);
 797         check_offset();
 798         for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr)) {
 799                 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
 800                 check_offset();
 801         }
 802
 803         SPRINTF("scsi%d: disconnected_queue\n", HOSTNO);
 804         check_offset();
 805         for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
 806              ptr = NEXT(ptr)) {
 807                 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
 808                 check_offset();
 809         }
 810
 811         local_irq_restore(flags);
 812         *start = buffer + (offset - begin);
 813         if (pos - buffer < offset - begin)
 814                 return 0;
 815         else if (pos - buffer - (offset - begin) < length)
 816                 return pos - buffer - (offset - begin);
 817         return length;
 818 }
 819
 820 static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length)
 821 {
 822         int i, s;
 823         unsigned char *command;
 824         SPRINTF("scsi%d: destination target %d, lun %d\n",
 825                 H_NO(cmd), cmd->device->id, cmd->device->lun);
 826         SPRINTF("        command = ");
 827         command = cmd->cmnd;
 828         SPRINTF("%2d (0x%02x)", command[0], command[0]);
 829         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 830                 SPRINTF(" %02x", command[i]);
 831         SPRINTF("\n");
 832         return pos;
 833 }
 834
 835
 836 /*
 837  * Function : void NCR5380_init (struct Scsi_Host *instance)
 838  *
 839  * Purpose : initializes *instance and corresponding 5380 chip.
 840  *
 841  * Inputs : instance - instantiation of the 5380 driver.
 842  *
 843  * Notes : I assume that the host, hostno, and id bits have been
 844  *      set correctly.  I don't care about the irq and other fields.
 845  *
 846  */
 847
 848 static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
 849 {
 850         int i;
 851         SETUP_HOSTDATA(instance);
 852
 853         NCR5380_all_init();
 854
 855         hostdata->aborted = 0;
 856         hostdata->id_mask = 1 << instance->this_id;
 857         hostdata->id_higher_mask = 0;
 858         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 859                 if (i > hostdata->id_mask)
 860                         hostdata->id_higher_mask |= i;
 861         for (i = 0; i < 8; ++i)
 862                 hostdata->busy[i] = 0;
 863 #ifdef SUPPORT_TAGS
 864         init_tags();
 865 #endif
 866 #if defined (REAL_DMA)
 867         hostdata->dma_len = 0;
 868 #endif
 869         hostdata->targets_present = 0;
 870         hostdata->connected = NULL;
 871         hostdata->issue_queue = NULL;
 872         hostdata->disconnected_queue = NULL;
 873         hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
 874
 875         if (!the_template) {
 876                 the_template = instance->hostt;
 877                 first_instance = instance;
 878         }
 879
 880 #ifndef AUTOSENSE
 881         if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
 882                 printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
 883                        "        without AUTOSENSE option, contingent allegiance conditions may\n"
 884                        "        be incorrectly cleared.\n", HOSTNO);
 885 #endif /* def AUTOSENSE */
 886
 887         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 888         NCR5380_write(MODE_REG, MR_BASE);
 889         NCR5380_write(TARGET_COMMAND_REG, 0);
 890         NCR5380_write(SELECT_ENABLE_REG, 0);
 891
 892         return 0;
 893 }
 894
 895 /*
 896  * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd,
 897  *      void (*done)(Scsi_Cmnd *))
 898  *
 899  * Purpose :  enqueues a SCSI command
 900  *
 901  * Inputs : cmd - SCSI command, done - function called on completion, with
 902  *      a pointer to the command descriptor.
 903  *
 904  * Returns : 0
 905  *
 906  * Side effects :
 907  *      cmd is added to the per instance issue_queue, with minor
 908  *      twiddling done to the host specific fields of cmd.  If the
 909  *      main coroutine is not running, it is restarted.
 910  *
 911  */
 912
 913 static int NCR5380_queue_command_lck(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
 914 {
 915         SETUP_HOSTDATA(cmd->device->host);
 916         Scsi_Cmnd *tmp;
 917         int oldto;
 918         unsigned long flags;
 919
 920 #if (NDEBUG & NDEBUG_NO_WRITE)
 921         switch (cmd->cmnd[0]) {
 922         case WRITE_6:
 923         case WRITE_10:
 924                 printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
 925                        H_NO(cmd));
 926                 cmd->result = (DID_ERROR << 16);
 927                 done(cmd);
 928                 return 0;
 929         }
 930 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 931
 932 #ifdef NCR5380_STATS
 933 # if 0
 934         if (!hostdata->connected && !hostdata->issue_queue &&
 935             !hostdata->disconnected_queue) {
 936                 hostdata->timebase = jiffies;
 937         }
 938 # endif
 939 # ifdef NCR5380_STAT_LIMIT
 940         if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
 941 # endif
 942                 switch (cmd->cmnd[0]) {
 943                 case WRITE:
 944                 case WRITE_6:
 945                 case WRITE_10:
 946                         hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
 947                         hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
 948                         hostdata->pendingw++;
 949                         break;
 950                 case READ:
 951                 case READ_6:
 952                 case READ_10:
 953                         hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
 954                         hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
 955                         hostdata->pendingr++;
 956                         break;
 957                 }
 958 #endif
 959
 960         /*
 961          * We use the host_scribble field as a pointer to the next command
 962          * in a queue
 963          */
 964
 965         SET_NEXT(cmd, NULL);
 966         cmd->scsi_done = done;
 967
 968         cmd->result = 0;
 969
 970         /*
 971          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 972          * commands are added to the head of the queue since any command will
 973          * clear the contingent allegiance condition that exists and the
 974          * sense data is only guaranteed to be valid while the condition exists.
 975          */
 976
 977         local_irq_save(flags);
 978         /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
 979          * Otherwise a running NCR5380_main may steal the lock.
 980          * Lock before actually inserting due to fairness reasons explained in
 981          * atari_scsi.c. If we insert first, then it's impossible for this driver
 982          * to release the lock.
 983          * Stop timer for this command while waiting for the lock, or timeouts
 984          * may happen (and they really do), and it's no good if the command doesn't
 985          * appear in any of the queues.
 986          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
 987          * because also a timer int can trigger an abort or reset, which would
 988          * alter queues and touch the lock.
 989          */
 990         if (!IS_A_TT()) {
 991                 /* perhaps stop command timer here */
 992                 falcon_get_lock();
 993                 /* perhaps restart command timer here */
 994         }
 995         if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
 996                 LIST(cmd, hostdata->issue_queue);
 997                 SET_NEXT(cmd, hostdata->issue_queue);
 998                 hostdata->issue_queue = cmd;
 999         } else {
1000                 for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
1001                      NEXT(tmp); tmp = NEXT(tmp))
1002                         ;
1003                 LIST(cmd, tmp);
1004                 SET_NEXT(tmp, cmd);
1005         }
1006         local_irq_restore(flags);
1007
1008         QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
1009                   (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
1010
1011         /* If queue_command() is called from an interrupt (real one or bottom
1012          * half), we let queue_main() do the job of taking care about main. If it
1013          * is already running, this is a no-op, else main will be queued.
1014          *
1015          * If we're not in an interrupt, we can call NCR5380_main()
1016          * unconditionally, because it cannot be already running.
1017          */
1018         if (in_interrupt() || ((flags >> 8) & 7) >= 6)
1019                 queue_main();
1020         else
1021                 NCR5380_main(NULL);
1022         return 0;
1023 }
1024
1025 static DEF_SCSI_QCMD(NCR5380_queue_command)
1026
1027 /*
1028  * Function : NCR5380_main (void)
1029  *
1030  * Purpose : NCR5380_main is a coroutine that runs as long as more work can
1031  *      be done on the NCR5380 host adapters in a system.  Both
1032  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1033  *      in case it is not running.
1034  *
1035  * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
1036  *  reenable them.  This prevents reentrancy and kernel stack overflow.
1037  */
1038
1039 static void NCR5380_main(struct work_struct *work)
1040 {
1041         Scsi_Cmnd *tmp, *prev;
1042         struct Scsi_Host *instance = first_instance;
1043         struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
1044         int done;
1045         unsigned long flags;
1046
1047         /*
1048          * We run (with interrupts disabled) until we're sure that none of
1049          * the host adapters have anything that can be done, at which point
1050          * we set main_running to 0 and exit.
1051          *
1052          * Interrupts are enabled before doing various other internal
1053          * instructions, after we've decided that we need to run through
1054          * the loop again.
1055          *
1056          * this should prevent any race conditions.
1057          *
1058          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1059          * because also a timer int can trigger an abort or reset, which can
1060          * alter queues and touch the Falcon lock.
1061          */
1062
1063         /* Tell int handlers main() is now already executing.  Note that
1064            no races are possible here. If an int comes in before
1065            'main_running' is set here, and queues/executes main via the
1066            task queue, it doesn't do any harm, just this instance of main
1067            won't find any work left to do. */
1068         if (main_running)
1069                 return;
1070         main_running = 1;
1071
1072         local_save_flags(flags);
1073         do {
1074                 local_irq_disable();    /* Freeze request queues */
1075                 done = 1;
1076
1077                 if (!hostdata->connected) {
1078                         MAIN_PRINTK("scsi%d: not connected\n", HOSTNO);
1079                         /*
1080                          * Search through the issue_queue for a command destined
1081                          * for a target that's not busy.
1082                          */
1083 #if (NDEBUG & NDEBUG_LISTS)
1084                         for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
1085                              tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
1086                                 ;
1087                         /*printk("%p  ", tmp);*/
1088                         if ((tmp == prev) && tmp)
1089                                 printk(" LOOP\n");
1090                         /* else printk("\n"); */
1091 #endif
1092                         for (tmp = (Scsi_Cmnd *) hostdata->issue_queue,
1093                              prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
1094
1095 #if (NDEBUG & NDEBUG_LISTS)
1096                                 if (prev != tmp)
1097                                         printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
1098                                                tmp, tmp->device->id, hostdata->busy[tmp->device->id],
1099                                                tmp->device->lun);
1100 #endif
1101                                 /*  When we find one, remove it from the issue queue. */
1102                                 /* ++guenther: possible race with Falcon locking */
1103                                 if (
1104 #ifdef SUPPORT_TAGS
1105                                     !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
1106 #else
1107                                     !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
1108 #endif
1109                                     ) {
1110                                         /* ++guenther: just to be sure, this must be atomic */
1111                                         local_irq_disable();
1112                                         if (prev) {
1113                                                 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1114                                                 SET_NEXT(prev, NEXT(tmp));
1115                                         } else {
1116                                                 REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
1117                                                 hostdata->issue_queue = NEXT(tmp);
1118                                         }
1119                                         SET_NEXT(tmp, NULL);
1120                                         falcon_dont_release++;
1121
1122                                         /* reenable interrupts after finding one */
1123                                         local_irq_restore(flags);
1124
1125                                         /*
1126                                          * Attempt to establish an I_T_L nexus here.
1127                                          * On success, instance->hostdata->connected is set.
1128                                          * On failure, we must add the command back to the
1129                                          *   issue queue so we can keep trying.
1130                                          */
1131                                         MAIN_PRINTK("scsi%d: main(): command for target %d "
1132                                                     "lun %d removed from issue_queue\n",
1133                                                     HOSTNO, tmp->device->id, tmp->device->lun);
1134                                         /*
1135                                          * REQUEST SENSE commands are issued without tagged
1136                                          * queueing, even on SCSI-II devices because the
1137                                          * contingent allegiance condition exists for the
1138                                          * entire unit.
1139                                          */
1140                                         /* ++roman: ...and the standard also requires that
1141                                          * REQUEST SENSE command are untagged.
1142                                          */
1143
1144 #ifdef SUPPORT_TAGS
1145                                         cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
1146 #endif
1147                                         if (!NCR5380_select(instance, tmp,
1148                                             (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE :
1149                                             TAG_NEXT)) {
1150                                                 falcon_dont_release--;
1151                                                 /* release if target did not response! */
1152                                                 falcon_release_lock_if_possible(hostdata);
1153                                                 break;
1154                                         } else {
1155                                                 local_irq_disable();
1156                                                 LIST(tmp, hostdata->issue_queue);
1157                                                 SET_NEXT(tmp, hostdata->issue_queue);
1158                                                 hostdata->issue_queue = tmp;
1159 #ifdef SUPPORT_TAGS
1160                                                 cmd_free_tag(tmp);
1161 #endif
1162                                                 falcon_dont_release--;
1163                                                 local_irq_restore(flags);
1164                                                 MAIN_PRINTK("scsi%d: main(): select() failed, "
1165                                                             "returned to issue_queue\n", HOSTNO);
1166                                                 if (hostdata->connected)
1167                                                         break;
1168                                         }
1169                                 } /* if target/lun/target queue is not busy */
1170                         } /* for issue_queue */
1171                 } /* if (!hostdata->connected) */
1172
1173                 if (hostdata->connected
1174 #ifdef REAL_DMA
1175                     && !hostdata->dma_len
1176 #endif
1177                     ) {
1178                         local_irq_restore(flags);
1179                         MAIN_PRINTK("scsi%d: main: performing information transfer\n",
1180                                     HOSTNO);
1181                         NCR5380_information_transfer(instance);
1182                         MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
1183                         done = 0;
1184                 }
1185         } while (!done);
1186
1187         /* Better allow ints _after_ 'main_running' has been cleared, else
1188            an interrupt could believe we'll pick up the work it left for
1189            us, but we won't see it anymore here... */
1190         main_running = 0;
1191         local_irq_restore(flags);
1192 }
1193
1194
1195 #ifdef REAL_DMA
1196 /*
1197  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1198  *
1199  * Purpose : Called by interrupt handler when DMA finishes or a phase
1200  *      mismatch occurs (which would finish the DMA transfer).
1201  *
1202  * Inputs : instance - this instance of the NCR5380.
1203  *
1204  */
1205
1206 static void NCR5380_dma_complete(struct Scsi_Host *instance)
1207 {
1208         SETUP_HOSTDATA(instance);
1209         int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
1210         unsigned char **data, p;
1211         volatile int *count;
1212
1213         if (!hostdata->connected) {
1214                 printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
1215                        "no connected cmd\n", HOSTNO);
1216                 return;
1217         }
1218
1219         if (atari_read_overruns) {
1220                 p = hostdata->connected->SCp.phase;
1221                 if (p & SR_IO) {
1222                         udelay(10);
1223                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
1224                              (BASR_PHASE_MATCH|BASR_ACK)) ==
1225                             (BASR_PHASE_MATCH|BASR_ACK)) {
1226                                 saved_data = NCR5380_read(INPUT_DATA_REG);
1227                                 overrun = 1;
1228                                 DMA_PRINTK("scsi%d: read overrun handled\n", HOSTNO);
1229                         }
1230                 }
1231         }
1232
1233         DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1234                    HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
1235                    NCR5380_read(STATUS_REG));
1236
1237         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1238         NCR5380_write(MODE_REG, MR_BASE);
1239         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1240
1241         transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
1242         hostdata->dma_len = 0;
1243
1244         data = (unsigned char **)&hostdata->connected->SCp.ptr;
1245         count = &hostdata->connected->SCp.this_residual;
1246         *data += transfered;
1247         *count -= transfered;
1248
1249         if (atari_read_overruns) {
1250                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1251                         cnt = toPIO = atari_read_overruns;
1252                         if (overrun) {
1253                                 DMA_PRINTK("Got an input overrun, using saved byte\n");
1254                                 *(*data)++ = saved_data;
1255                                 (*count)--;
1256                                 cnt--;
1257                                 toPIO--;
1258                         }
1259                         DMA_PRINTK("Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1260                         NCR5380_transfer_pio(instance, &p, &cnt, data);
1261                         *count -= toPIO - cnt;
1262                 }
1263         }
1264 }
1265 #endif /* REAL_DMA */
1266
1267
1268 /*
1269  * Function : void NCR5380_intr (int irq)
1270  *
1271  * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1272  *      from the disconnected queue, and restarting NCR5380_main()
1273  *      as required.
1274  *
1275  * Inputs : int irq, irq that caused this interrupt.
1276  *
1277  */
1278
1279 static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1280 {
1281         struct Scsi_Host *instance = first_instance;
1282         int done = 1, handled = 0;
1283         unsigned char basr;
1284
1285         INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);
1286
1287         /* Look for pending interrupts */
1288         basr = NCR5380_read(BUS_AND_STATUS_REG);
1289         INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
1290         /* dispatch to appropriate routine if found and done=0 */
1291         if (basr & BASR_IRQ) {
1292                 NCR_PRINT(NDEBUG_INTR);
1293                 if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
1294                         done = 0;
1295                         ENABLE_IRQ();
1296                         INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
1297                         NCR5380_reselect(instance);
1298                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1299                 } else if (basr & BASR_PARITY_ERROR) {
1300                         INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
1301                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1302                 } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1303                         INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
1304                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1305                 } else {
1306                         /*
1307                          * The rest of the interrupt conditions can occur only during a
1308                          * DMA transfer
1309                          */
1310
1311 #if defined(REAL_DMA)
1312                         /*
1313                          * We should only get PHASE MISMATCH and EOP interrupts if we have
1314                          * DMA enabled, so do a sanity check based on the current setting
1315                          * of the MODE register.
1316                          */
1317
1318                         if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
1319                             ((basr & BASR_END_DMA_TRANSFER) ||
1320                              !(basr & BASR_PHASE_MATCH))) {
1321
1322                                 INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1323                                 NCR5380_dma_complete( instance );
1324                                 done = 0;
1325                                 ENABLE_IRQ();
1326                         } else
1327 #endif /* REAL_DMA */
1328                         {
1329 /* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1330                                 if (basr & BASR_PHASE_MATCH)
1331                                         printk(KERN_NOTICE "scsi%d: unknown interrupt, "
1332                                                "BASR 0x%x, MR 0x%x, SR 0x%x\n",
1333                                                HOSTNO, basr, NCR5380_read(MODE_REG),
1334                                                NCR5380_read(STATUS_REG));
1335                                 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1336                         }
1337                 } /* if !(SELECTION || PARITY) */
1338                 handled = 1;
1339         } /* BASR & IRQ */ else {
1340                 printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
1341                        "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
1342                        NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1343                 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1344         }
1345
1346         if (!done) {
1347                 INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
1348                 /* Put a call to NCR5380_main() on the queue... */
1349                 queue_main();
1350         }
1351         return IRQ_RETVAL(handled);
1352 }
1353
1354 #ifdef NCR5380_STATS
1355 static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd *cmd)
1356 {
1357 # ifdef NCR5380_STAT_LIMIT
1358         if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
1359 # endif
1360                 switch (cmd->cmnd[0]) {
1361                 case WRITE:
1362                 case WRITE_6:
1363                 case WRITE_10:
1364                         hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
1365                         /*hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);*/
1366                         hostdata->pendingw--;
1367                         break;
1368                 case READ:
1369                 case READ_6:
1370                 case READ_10:
1371                         hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
1372                         /*hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);*/
1373                         hostdata->pendingr--;
1374                         break;
1375                 }
1376 }
1377 #endif
1378
1379 /*
1380  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1381  *      int tag);
1382  *
1383  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1384  *      including ARBITRATION, SELECTION, and initial message out for
1385  *      IDENTIFY and queue messages.
1386  *
1387  * Inputs : instance - instantiation of the 5380 driver on which this
1388  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1389  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1390  *      the command that is presently connected.
1391  *
1392  * Returns : -1 if selection could not execute for some reason,
1393  *      0 if selection succeeded or failed because the target
1394  *      did not respond.
1395  *
1396  * Side effects :
1397  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1398  *              with registers as they should have been on entry - ie
1399  *              SELECT_ENABLE will be set appropriately, the NCR5380
1400  *              will cease to drive any SCSI bus signals.
1401  *
1402  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1403  *              instance->connected will be set to cmd.
1404  *              SELECT interrupt will be disabled.
1405  *
1406  *      If failed (no target) : cmd->scsi_done() will be called, and the
1407  *              cmd->result host byte set to DID_BAD_TARGET.
1408  */
1409
1410 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
1411 {
1412         SETUP_HOSTDATA(instance);
1413         unsigned char tmp[3], phase;
1414         unsigned char *data;
1415         int len;
1416         unsigned long timeout;
1417         unsigned long flags;
1418
1419         hostdata->restart_select = 0;
1420         NCR_PRINT(NDEBUG_ARBITRATION);
1421         ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
1422                    instance->this_id);
1423
1424         /*
1425          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1426          * data bus during SELECTION.
1427          */
1428
1429         local_irq_save(flags);
1430         if (hostdata->connected) {
1431                 local_irq_restore(flags);
1432                 return -1;
1433         }
1434         NCR5380_write(TARGET_COMMAND_REG, 0);
1435
1436         /*
1437          * Start arbitration.
1438          */
1439
1440         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1441         NCR5380_write(MODE_REG, MR_ARBITRATE);
1442
1443         local_irq_restore(flags);
1444
1445         /* Wait for arbitration logic to complete */
1446 #if defined(NCR_TIMEOUT)
1447         {
1448                 unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
1449
1450                 while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1451                        time_before(jiffies, timeout) && !hostdata->connected)
1452                         ;
1453                 if (time_after_eq(jiffies, timeout)) {
1454                         printk("scsi : arbitration timeout at %d\n", __LINE__);
1455                         NCR5380_write(MODE_REG, MR_BASE);
1456                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1457                         return -1;
1458                 }
1459         }
1460 #else /* NCR_TIMEOUT */
1461         while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1462                !hostdata->connected)
1463                 ;
1464 #endif
1465
1466         ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);
1467
1468         if (hostdata->connected) {
1469                 NCR5380_write(MODE_REG, MR_BASE);
1470                 return -1;
1471         }
1472         /*
1473          * The arbitration delay is 2.2us, but this is a minimum and there is
1474          * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1475          * the integral nature of udelay().
1476          *
1477          */
1478
1479         udelay(3);
1480
1481         /* Check for lost arbitration */
1482         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1483             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1484             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1485             hostdata->connected) {
1486                 NCR5380_write(MODE_REG, MR_BASE);
1487                 ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1488                            HOSTNO);
1489                 return -1;
1490         }
1491
1492         /* after/during arbitration, BSY should be asserted.
1493            IBM DPES-31080 Version S31Q works now */
1494         /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
1495         NCR5380_write(INITIATOR_COMMAND_REG,
1496                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1497
1498         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1499             hostdata->connected) {
1500                 NCR5380_write(MODE_REG, MR_BASE);
1501                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1502                 ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1503                            HOSTNO);
1504                 return -1;
1505         }
1506
1507         /*
1508          * Again, bus clear + bus settle time is 1.2us, however, this is
1509          * a minimum so we'll udelay ceil(1.2)
1510          */
1511
1512 #ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
1513         /* ++roman: But some targets (see above :-) seem to need a bit more... */
1514         udelay(15);
1515 #else
1516         udelay(2);
1517 #endif
1518
1519         if (hostdata->connected) {
1520                 NCR5380_write(MODE_REG, MR_BASE);
1521                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1522                 return -1;
1523         }
1524
1525         ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);
1526
1527         /*
1528          * Now that we have won arbitration, start Selection process, asserting
1529          * the host and target ID's on the SCSI bus.
1530          */
1531
1532         NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
1533
1534         /*
1535          * Raise ATN while SEL is true before BSY goes false from arbitration,
1536          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1537          * phase immediately after selection.
1538          */
1539
1540         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
1541                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1542         NCR5380_write(MODE_REG, MR_BASE);
1543
1544         /*
1545          * Reselect interrupts must be turned off prior to the dropping of BSY,
1546          * otherwise we will trigger an interrupt.
1547          */
1548
1549         if (hostdata->connected) {
1550                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1551                 return -1;
1552         }
1553
1554         NCR5380_write(SELECT_ENABLE_REG, 0);
1555
1556         /*
1557          * The initiator shall then wait at least two deskew delays and release
1558          * the BSY signal.
1559          */
1560         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1561
1562         /* Reset BSY */
1563         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
1564                       ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1565
1566         /*
1567          * Something weird happens when we cease to drive BSY - looks
1568          * like the board/chip is letting us do another read before the
1569          * appropriate propagation delay has expired, and we're confusing
1570          * a BSY signal from ourselves as the target's response to SELECTION.
1571          *
1572          * A small delay (the 'C++' frontend breaks the pipeline with an
1573          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1574          * tighter 'C' code breaks and requires this) solves the problem -
1575          * the 1 us delay is arbitrary, and only used because this delay will
1576          * be the same on other platforms and since it works here, it should
1577          * work there.
1578          *
1579          * wingel suggests that this could be due to failing to wait
1580          * one deskew delay.
1581          */
1582
1583         udelay(1);
1584
1585         SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
1586
1587         /*
1588          * The SCSI specification calls for a 250 ms timeout for the actual
1589          * selection.
1590          */
1591
1592         timeout = jiffies + 25;
1593
1594         /*
1595          * XXX very interesting - we're seeing a bounce where the BSY we
1596          * asserted is being reflected / still asserted (propagation delay?)
1597          * and it's detecting as true.  Sigh.
1598          */
1599
1600 #if 0
1601         /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
1602          * IO while SEL is true. But again, there are some disks out the in the
1603          * world that do that nevertheless. (Somebody claimed that this announces
1604          * reselection capability of the target.) So we better skip that test and
1605          * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
1606          */
1607
1608         while (time_before(jiffies, timeout) &&
1609                !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
1610                 ;
1611
1612         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1613                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1614                 NCR5380_reselect(instance);
1615                 printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
1616                        HOSTNO);
1617                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1618                 return -1;
1619         }
1620 #else
1621         while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
1622                 ;
1623 #endif
1624
1625         /*
1626          * No less than two deskew delays after the initiator detects the
1627          * BSY signal is true, it shall release the SEL signal and may
1628          * change the DATA BUS.                                     -wingel
1629          */
1630
1631         udelay(1);
1632
1633         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1634
1635         if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1636                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1637                 if (hostdata->targets_present & (1 << cmd->device->id)) {
1638                         printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
1639                         if (hostdata->restart_select)
1640                                 printk(KERN_NOTICE "\trestart select\n");
1641                         NCR_PRINT(NDEBUG_ANY);
1642                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1643                         return -1;
1644                 }
1645                 cmd->result = DID_BAD_TARGET << 16;
1646 #ifdef NCR5380_STATS
1647                 collect_stats(hostdata, cmd);
1648 #endif
1649 #ifdef SUPPORT_TAGS
1650                 cmd_free_tag(cmd);
1651 #endif
1652                 cmd->scsi_done(cmd);
1653                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1654                 SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
1655                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1656                 return 0;
1657         }
1658
1659         hostdata->targets_present |= (1 << cmd->device->id);
1660
1661         /*
1662          * Since we followed the SCSI spec, and raised ATN while SEL
1663          * was true but before BSY was false during selection, the information
1664          * transfer phase should be a MESSAGE OUT phase so that we can send the
1665          * IDENTIFY message.
1666          *
1667          * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1668          * message (2 bytes) with a tag ID that we increment with every command
1669          * until it wraps back to 0.
1670          *
1671          * XXX - it turns out that there are some broken SCSI-II devices,
1672          *           which claim to support tagged queuing but fail when more than
1673          *           some number of commands are issued at once.
1674          */
1675
1676         /* Wait for start of REQ/ACK handshake */
1677         while (!(NCR5380_read(STATUS_REG) & SR_REQ))
1678                 ;
1679
1680         SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1681                    HOSTNO, cmd->device->id);
1682         tmp[0] = IDENTIFY(1, cmd->device->lun);
1683
1684 #ifdef SUPPORT_TAGS
1685         if (cmd->tag != TAG_NONE) {
1686                 tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1687                 tmp[2] = cmd->tag;
1688                 len = 3;
1689         } else
1690                 len = 1;
1691 #else
1692         len = 1;
1693         cmd->tag = 0;
1694 #endif /* SUPPORT_TAGS */
1695
1696         /* Send message(s) */
1697         data = tmp;
1698         phase = PHASE_MSGOUT;
1699         NCR5380_transfer_pio(instance, &phase, &len, &data);
1700         SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
1701         /* XXX need to handle errors here */
1702         hostdata->connected = cmd;
1703 #ifndef SUPPORT_TAGS
1704         hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1705 #endif
1706
1707         initialize_SCp(cmd);
1708
1709         return 0;
1710 }
1711
1712 /*
1713  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1714  *      unsigned char *phase, int *count, unsigned char **data)
1715  *
1716  * Purpose : transfers data in given phase using polled I/O
1717  *
1718  * Inputs : instance - instance of driver, *phase - pointer to
1719  *      what phase is expected, *count - pointer to number of
1720  *      bytes to transfer, **data - pointer to data pointer.
1721  *
1722  * Returns : -1 when different phase is entered without transferring
1723  *      maximum number of bytes, 0 if all bytes are transfered or exit
1724  *      is in same phase.
1725  *
1726  *      Also, *phase, *count, *data are modified in place.
1727  *
1728  * XXX Note : handling for bus free may be useful.
1729  */
1730
1731 /*
1732  * Note : this code is not as quick as it could be, however it
1733  * IS 100% reliable, and for the actual data transfer where speed
1734  * counts, we will always do a pseudo DMA or DMA transfer.
1735  */
1736
1737 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1738                                 unsigned char *phase, int *count,
1739                                 unsigned char **data)
1740 {
1741         register unsigned char p = *phase, tmp;
1742         register int c = *count;
1743         register unsigned char *d = *data;
1744
1745         /*
1746          * The NCR5380 chip will only drive the SCSI bus when the
1747          * phase specified in the appropriate bits of the TARGET COMMAND
1748          * REGISTER match the STATUS REGISTER
1749          */
1750
1751         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1752
1753         do {
1754                 /*
1755                  * Wait for assertion of REQ, after which the phase bits will be
1756                  * valid
1757                  */
1758                 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1759                         ;
1760
1761                 HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);
1762
1763                 /* Check for phase mismatch */
1764                 if ((tmp & PHASE_MASK) != p) {
1765                         PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
1766                         NCR_PRINT_PHASE(NDEBUG_PIO);
1767                         break;
1768                 }
1769
1770                 /* Do actual transfer from SCSI bus to / from memory */
1771                 if (!(p & SR_IO))
1772                         NCR5380_write(OUTPUT_DATA_REG, *d);
1773                 else
1774                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1775
1776                 ++d;
1777
1778                 /*
1779                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1780                  * should drop ATN on the last byte of the message phase
1781                  * after REQ has been asserted for the handshake but before
1782                  * the initiator raises ACK.
1783                  */
1784
1785                 if (!(p & SR_IO)) {
1786                         if (!((p & SR_MSG) && c > 1)) {
1787                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1788                                 NCR_PRINT(NDEBUG_PIO);
1789                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1790                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1791                         } else {
1792                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1793                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1794                                 NCR_PRINT(NDEBUG_PIO);
1795                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1796                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1797                         }
1798                 } else {
1799                         NCR_PRINT(NDEBUG_PIO);
1800                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1801                 }
1802
1803                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1804                         ;
1805
1806                 HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);
1807
1808                 /*
1809                  * We have several special cases to consider during REQ/ACK handshaking :
1810                  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1811                  *      message.  ATN must be dropped as ACK is dropped.
1812                  *
1813                  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1814                  *      message.  We must exit with ACK asserted, so that the calling
1815                  *      code may raise ATN before dropping ACK to reject the message.
1816                  *
1817                  * 3.  ACK and ATN are clear and the target may proceed as normal.
1818                  */
1819                 if (!(p == PHASE_MSGIN && c == 1)) {
1820                         if (p == PHASE_MSGOUT && c > 1)
1821                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1822                         else
1823                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1824                 }
1825         } while (--c);
1826
1827         PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);
1828
1829         *count = c;
1830         *data = d;
1831         tmp = NCR5380_read(STATUS_REG);
1832         /* The phase read from the bus is valid if either REQ is (already)
1833          * asserted or if ACK hasn't been released yet. The latter is the case if
1834          * we're in MSGIN and all wanted bytes have been received.
1835          */
1836         if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
1837                 *phase = tmp & PHASE_MASK;
1838         else
1839                 *phase = PHASE_UNKNOWN;
1840
1841         if (!c || (*phase == p))
1842                 return 0;
1843         else
1844                 return -1;
1845 }
1846
1847 /*
1848  * Function : do_abort (Scsi_Host *host)
1849  *
1850  * Purpose : abort the currently established nexus.  Should only be
1851  *      called from a routine which can drop into a
1852  *
1853  * Returns : 0 on success, -1 on failure.
1854  */
1855
1856 static int do_abort(struct Scsi_Host *host)
1857 {
1858         unsigned char tmp, *msgptr, phase;
1859         int len;
1860
1861         /* Request message out phase */
1862         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1863
1864         /*
1865          * Wait for the target to indicate a valid phase by asserting
1866          * REQ.  Once this happens, we'll have either a MSGOUT phase
1867          * and can immediately send the ABORT message, or we'll have some
1868          * other phase and will have to source/sink data.
1869          *
1870          * We really don't care what value was on the bus or what value
1871          * the target sees, so we just handshake.
1872          */
1873
1874         while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1875                 ;
1876
1877         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1878
1879         if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1880                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1881                               ICR_ASSERT_ACK);
1882                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1883                         ;
1884                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1885         }
1886
1887         tmp = ABORT;
1888         msgptr = &tmp;
1889         len = 1;
1890         phase = PHASE_MSGOUT;
1891         NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1892
1893         /*
1894          * If we got here, and the command completed successfully,
1895          * we're about to go into bus free state.
1896          */
1897
1898         return len ? -1 : 0;
1899 }
1900
1901 #if defined(REAL_DMA)
1902 /*
1903  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1904  *      unsigned char *phase, int *count, unsigned char **data)
1905  *
1906  * Purpose : transfers data in given phase using either real
1907  *      or pseudo DMA.
1908  *
1909  * Inputs : instance - instance of driver, *phase - pointer to
1910  *      what phase is expected, *count - pointer to number of
1911  *      bytes to transfer, **data - pointer to data pointer.
1912  *
1913  * Returns : -1 when different phase is entered without transferring
1914  *      maximum number of bytes, 0 if all bytes or transfered or exit
1915  *      is in same phase.
1916  *
1917  *      Also, *phase, *count, *data are modified in place.
1918  *
1919  */
1920
1921
1922 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1923                                 unsigned char *phase, int *count,
1924                                 unsigned char **data)
1925 {
1926         SETUP_HOSTDATA(instance);
1927         register int c = *count;
1928         register unsigned char p = *phase;
1929         register unsigned char *d = *data;
1930         unsigned char tmp;
1931         unsigned long flags;
1932
1933         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1934                 *phase = tmp;
1935                 return -1;
1936         }
1937
1938         if (atari_read_overruns && (p & SR_IO))
1939                 c -= atari_read_overruns;
1940
1941         DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1942                    HOSTNO, (p & SR_IO) ? "reading" : "writing",
1943                    c, (p & SR_IO) ? "to" : "from", d);
1944
1945         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1946
1947 #ifdef REAL_DMA
1948         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1949 #endif /* def REAL_DMA  */
1950
1951         if (IS_A_TT()) {
1952                 /* On the Medusa, it is a must to initialize the DMA before
1953                  * starting the NCR. This is also the cleaner way for the TT.
1954                  */
1955                 local_irq_save(flags);
1956                 hostdata->dma_len = (p & SR_IO) ?
1957                         NCR5380_dma_read_setup(instance, d, c) :
1958                         NCR5380_dma_write_setup(instance, d, c);
1959                 local_irq_restore(flags);
1960         }
1961
1962         if (p & SR_IO)
1963                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1964         else {
1965                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1966                 NCR5380_write(START_DMA_SEND_REG, 0);
1967         }
1968
1969         if (!IS_A_TT()) {
1970                 /* On the Falcon, the DMA setup must be done after the last */
1971                 /* NCR access, else the DMA setup gets trashed!
1972                  */
1973                 local_irq_save(flags);
1974                 hostdata->dma_len = (p & SR_IO) ?
1975                         NCR5380_dma_read_setup(instance, d, c) :
1976                         NCR5380_dma_write_setup(instance, d, c);
1977                 local_irq_restore(flags);
1978         }
1979         return 0;
1980 }
1981 #endif /* defined(REAL_DMA) */
1982
1983 /*
1984  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1985  *
1986  * Purpose : run through the various SCSI phases and do as the target
1987  *      directs us to.  Operates on the currently connected command,
1988  *      instance->connected.
1989  *
1990  * Inputs : instance, instance for which we are doing commands
1991  *
1992  * Side effects : SCSI things happen, the disconnected queue will be
1993  *      modified if a command disconnects, *instance->connected will
1994  *      change.
1995  *
1996  * XXX Note : we need to watch for bus free or a reset condition here
1997  *      to recover from an unexpected bus free condition.
1998  */
1999
2000 static void NCR5380_information_transfer(struct Scsi_Host *instance)
2001 {
2002         SETUP_HOSTDATA(instance);
2003         unsigned long flags;
2004         unsigned char msgout = NOP;
2005         int sink = 0;
2006         int len;
2007 #if defined(REAL_DMA)
2008         int transfersize;
2009 #endif
2010         unsigned char *data;
2011         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2012         Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2013
2014         while (1) {
2015                 tmp = NCR5380_read(STATUS_REG);
2016                 /* We only have a valid SCSI phase when REQ is asserted */
2017                 if (tmp & SR_REQ) {
2018                         phase = (tmp & PHASE_MASK);
2019                         if (phase != old_phase) {
2020                                 old_phase = phase;
2021                                 NCR_PRINT_PHASE(NDEBUG_INFORMATION);
2022                         }
2023
2024                         if (sink && (phase != PHASE_MSGOUT)) {
2025                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2026
2027                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
2028                                               ICR_ASSERT_ACK);
2029                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
2030                                         ;
2031                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2032                                               ICR_ASSERT_ATN);
2033                                 sink = 0;
2034                                 continue;
2035                         }
2036
2037                         switch (phase) {
2038                         case PHASE_DATAOUT:
2039 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2040                                 printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
2041                                        "aborted\n", HOSTNO);
2042                                 sink = 1;
2043                                 do_abort(instance);
2044                                 cmd->result = DID_ERROR << 16;
2045                                 cmd->scsi_done(cmd);
2046                                 return;
2047 #endif
2048                         case PHASE_DATAIN:
2049                                 /*
2050                                  * If there is no room left in the current buffer in the
2051                                  * scatter-gather list, move onto the next one.
2052                                  */
2053
2054                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2055                                         ++cmd->SCp.buffer;
2056                                         --cmd->SCp.buffers_residual;
2057                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
2058                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2059                                         /* ++roman: Try to merge some scatter-buffers if
2060                                          * they are at contiguous physical addresses.
2061                                          */
2062                                         merge_contiguous_buffers(cmd);
2063                                         INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
2064                                                    HOSTNO, cmd->SCp.this_residual,
2065                                                    cmd->SCp.buffers_residual);
2066                                 }
2067
2068                                 /*
2069                                  * The preferred transfer method is going to be
2070                                  * PSEUDO-DMA for systems that are strictly PIO,
2071                                  * since we can let the hardware do the handshaking.
2072                                  *
2073                                  * For this to work, we need to know the transfersize
2074                                  * ahead of time, since the pseudo-DMA code will sit
2075                                  * in an unconditional loop.
2076                                  */
2077
2078                                 /* ++roman: I suggest, this should be
2079                                  *   #if def(REAL_DMA)
2080                                  * instead of leaving REAL_DMA out.
2081                                  */
2082
2083 #if defined(REAL_DMA)
2084                                 if (!cmd->device->borken &&
2085                                     (transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
2086                                         len = transfersize;
2087                                         cmd->SCp.phase = phase;
2088                                         if (NCR5380_transfer_dma(instance, &phase,
2089                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
2090                                                 /*
2091                                                  * If the watchdog timer fires, all future
2092                                                  * accesses to this device will use the
2093                                                  * polled-IO. */
2094                                                 printk(KERN_NOTICE "scsi%d: switching target %d "
2095                                                            "lun %d to slow handshake\n", HOSTNO,
2096                                                            cmd->device->id, cmd->device->lun);
2097                                                 cmd->device->borken = 1;
2098                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2099                                                         ICR_ASSERT_ATN);
2100                                                 sink = 1;
2101                                                 do_abort(instance);
2102                                                 cmd->result = DID_ERROR << 16;
2103                                                 cmd->scsi_done(cmd);
2104                                                 /* XXX - need to source or sink data here, as appropriate */
2105                                         } else {
2106 #ifdef REAL_DMA
2107                                                 /* ++roman: When using real DMA,
2108                                                  * information_transfer() should return after
2109                                                  * starting DMA since it has nothing more to
2110                                                  * do.
2111                                                  */
2112                                                 return;
2113 #else
2114                                                 cmd->SCp.this_residual -= transfersize - len;
2115 #endif
2116                                         }
2117                                 } else
2118 #endif /* defined(REAL_DMA) */
2119                                         NCR5380_transfer_pio(instance, &phase,
2120                                                              (int *)&cmd->SCp.this_residual,
2121                                                              (unsigned char **)&cmd->SCp.ptr);
2122                                 break;
2123                         case PHASE_MSGIN:
2124                                 len = 1;
2125                                 data = &tmp;
2126                                 NCR5380_write(SELECT_ENABLE_REG, 0);    /* disable reselects */
2127                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2128                                 cmd->SCp.Message = tmp;
2129
2130                                 switch (tmp) {
2131                                 /*
2132                                  * Linking lets us reduce the time required to get the
2133                                  * next command out to the device, hopefully this will
2134                                  * mean we don't waste another revolution due to the delays
2135                                  * required by ARBITRATION and another SELECTION.
2136                                  *
2137                                  * In the current implementation proposal, low level drivers
2138                                  * merely have to start the next command, pointed to by
2139                                  * next_link, done() is called as with unlinked commands.
2140                                  */
2141 #ifdef LINKED
2142                                 case LINKED_CMD_COMPLETE:
2143                                 case LINKED_FLG_CMD_COMPLETE:
2144                                         /* Accept message by clearing ACK */
2145                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2146
2147                                         LNK_PRINTK("scsi%d: target %d lun %d linked command "
2148                                                    "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
2149
2150                                         /* Enable reselect interrupts */
2151                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2152                                         /*
2153                                          * Sanity check : A linked command should only terminate
2154                                          * with one of these messages if there are more linked
2155                                          * commands available.
2156                                          */
2157
2158                                         if (!cmd->next_link) {
2159                                                  printk(KERN_NOTICE "scsi%d: target %d lun %d "
2160                                                         "linked command complete, no next_link\n",
2161                                                         HOSTNO, cmd->device->id, cmd->device->lun);
2162                                                 sink = 1;
2163                                                 do_abort(instance);
2164                                                 return;
2165                                         }
2166
2167                                         initialize_SCp(cmd->next_link);
2168                                         /* The next command is still part of this process; copy it
2169                                          * and don't free it! */
2170                                         cmd->next_link->tag = cmd->tag;
2171                                         cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2172                                         LNK_PRINTK("scsi%d: target %d lun %d linked request "
2173                                                    "done, calling scsi_done().\n",
2174                                                    HOSTNO, cmd->device->id, cmd->device->lun);
2175 #ifdef NCR5380_STATS
2176                                         collect_stats(hostdata, cmd);
2177 #endif
2178                                         cmd->scsi_done(cmd);
2179                                         cmd = hostdata->connected;
2180                                         break;
2181 #endif /* def LINKED */
2182                                 case ABORT:
2183                                 case COMMAND_COMPLETE:
2184                                         /* Accept message by clearing ACK */
2185                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2186                                         /* ++guenther: possible race with Falcon locking */
2187                                         falcon_dont_release++;
2188                                         hostdata->connected = NULL;
2189                                         QU_PRINTK("scsi%d: command for target %d, lun %d "
2190                                                   "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2191 #ifdef SUPPORT_TAGS
2192                                         cmd_free_tag(cmd);
2193                                         if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2194                                                 /* Turn a QUEUE FULL status into BUSY, I think the
2195                                                  * mid level cannot handle QUEUE FULL :-( (The
2196                                                  * command is retried after BUSY). Also update our
2197                                                  * queue size to the number of currently issued
2198                                                  * commands now.
2199                                                  */
2200                                                 /* ++Andreas: the mid level code knows about
2201                                                    QUEUE_FULL now. */
2202                                                 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
2203                                                 TAG_PRINTK("scsi%d: target %d lun %d returned "
2204                                                            "QUEUE_FULL after %d commands\n",
2205                                                            HOSTNO, cmd->device->id, cmd->device->lun,
2206                                                            ta->nr_allocated);
2207                                                 if (ta->queue_size > ta->nr_allocated)
2208                                                         ta->nr_allocated = ta->queue_size;
2209                                         }
2210 #else
2211                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2212 #endif
2213                                         /* Enable reselect interrupts */
2214                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2215
2216                                         /*
2217                                          * I'm not sure what the correct thing to do here is :
2218                                          *
2219                                          * If the command that just executed is NOT a request
2220                                          * sense, the obvious thing to do is to set the result
2221                                          * code to the values of the stored parameters.
2222                                          *
2223                                          * If it was a REQUEST SENSE command, we need some way to
2224                                          * differentiate between the failure code of the original
2225                                          * and the failure code of the REQUEST sense - the obvious
2226                                          * case is success, where we fall through and leave the
2227                                          * result code unchanged.
2228                                          *
2229                                          * The non-obvious place is where the REQUEST SENSE failed
2230                                          */
2231
2232                                         if (cmd->cmnd[0] != REQUEST_SENSE)
2233                                                 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2234                                         else if (status_byte(cmd->SCp.Status) != GOOD)
2235                                                 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2236
2237 #ifdef AUTOSENSE
2238                                         if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2239                                                 hostdata->ses.cmd_len) {
2240                                                 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2241                                                 hostdata->ses.cmd_len = 0 ;
2242                                         }
2243
2244                                         if ((cmd->cmnd[0] != REQUEST_SENSE) &&
2245                                             (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2246                                                 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2247
2248                                                 ASEN_PRINTK("scsi%d: performing request sense\n", HOSTNO);
2249
2250                                                 local_irq_save(flags);
2251                                                 LIST(cmd,hostdata->issue_queue);
2252                                                 SET_NEXT(cmd, hostdata->issue_queue);
2253                                                 hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2254                                                 local_irq_restore(flags);
2255                                                 QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
2256                                                           "issue queue\n", H_NO(cmd));
2257                                         } else
2258 #endif /* def AUTOSENSE */
2259                                         {
2260 #ifdef NCR5380_STATS
2261                                                 collect_stats(hostdata, cmd);
2262 #endif
2263                                                 cmd->scsi_done(cmd);
2264                                         }
2265
2266                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2267                                         /*
2268                                          * Restore phase bits to 0 so an interrupted selection,
2269                                          * arbitration can resume.
2270                                          */
2271                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2272
2273                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2274                                                 barrier();
2275
2276                                         falcon_dont_release--;
2277                                         /* ++roman: For Falcon SCSI, release the lock on the
2278                                          * ST-DMA here if no other commands are waiting on the
2279                                          * disconnected queue.
2280                                          */
2281                                         falcon_release_lock_if_possible(hostdata);
2282                                         return;
2283                                 case MESSAGE_REJECT:
2284                                         /* Accept message by clearing ACK */
2285                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2286                                         /* Enable reselect interrupts */
2287                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2288                                         switch (hostdata->last_message) {
2289                                         case HEAD_OF_QUEUE_TAG:
2290                                         case ORDERED_QUEUE_TAG:
2291                                         case SIMPLE_QUEUE_TAG:
2292                                                 /* The target obviously doesn't support tagged
2293                                                  * queuing, even though it announced this ability in
2294                                                  * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2295                                                  * clear 'tagged_supported' and lock the LUN, since
2296                                                  * the command is treated as untagged further on.
2297                                                  */
2298                                                 cmd->device->tagged_supported = 0;
2299                                                 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2300                                                 cmd->tag = TAG_NONE;
2301                                                 TAG_PRINTK("scsi%d: target %d lun %d rejected "
2302                                                            "QUEUE_TAG message; tagged queuing "
2303                                                            "disabled\n",
2304                                                            HOSTNO, cmd->device->id, cmd->device->lun);
2305                                                 break;
2306                                         }
2307                                         break;
2308                                 case DISCONNECT:
2309                                         /* Accept message by clearing ACK */
2310                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2311                                         local_irq_save(flags);
2312                                         cmd->device->disconnect = 1;
2313                                         LIST(cmd,hostdata->disconnected_queue);
2314                                         SET_NEXT(cmd, hostdata->disconnected_queue);
2315                                         hostdata->connected = NULL;
2316                                         hostdata->disconnected_queue = cmd;
2317                                         local_irq_restore(flags);
2318                                         QU_PRINTK("scsi%d: command for target %d lun %d was "
2319                                                   "moved from connected to the "
2320                                                   "disconnected_queue\n", HOSTNO,
2321                                                   cmd->device->id, cmd->device->lun);
2322                                         /*
2323                                          * Restore phase bits to 0 so an interrupted selection,
2324                                          * arbitration can resume.
2325                                          */
2326                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2327
2328                                         /* Enable reselect interrupts */
2329                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2330                                         /* Wait for bus free to avoid nasty timeouts */
2331                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2332                                                 barrier();
2333                                         return;
2334                                         /*
2335                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2336                                          * operation, in violation of the SCSI spec so we can safely
2337                                          * ignore SAVE/RESTORE pointers calls.
2338                                          *
2339                                          * Unfortunately, some disks violate the SCSI spec and
2340                                          * don't issue the required SAVE_POINTERS message before
2341                                          * disconnecting, and we have to break spec to remain
2342                                          * compatible.
2343                                          */
2344                                 case SAVE_POINTERS:
2345                                 case RESTORE_POINTERS:
2346                                         /* Accept message by clearing ACK */
2347                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2348                                         /* Enable reselect interrupts */
2349                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2350                                         break;
2351                                 case EXTENDED_MESSAGE:
2352                                         /*
2353                                          * Extended messages are sent in the following format :
2354                                          * Byte
2355                                          * 0            EXTENDED_MESSAGE == 1
2356                                          * 1            length (includes one byte for code, doesn't
2357                                          *              include first two bytes)
2358                                          * 2            code
2359                                          * 3..length+1  arguments
2360                                          *
2361                                          * Start the extended message buffer with the EXTENDED_MESSAGE
2362                                          * byte, since spi_print_msg() wants the whole thing.
2363                                          */
2364                                         extended_msg[0] = EXTENDED_MESSAGE;
2365                                         /* Accept first byte by clearing ACK */
2366                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2367
2368                                         EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);
2369
2370                                         len = 2;
2371                                         data = extended_msg + 1;
2372                                         phase = PHASE_MSGIN;
2373                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
2374                                         EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2375                                                    (int)extended_msg[1], (int)extended_msg[2]);
2376
2377                                         if (!len && extended_msg[1] <=
2378                                             (sizeof(extended_msg) - 1)) {
2379                                                 /* Accept third byte by clearing ACK */
2380                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2381                                                 len = extended_msg[1] - 1;
2382                                                 data = extended_msg + 3;
2383                                                 phase = PHASE_MSGIN;
2384
2385                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2386                                                 EXT_PRINTK("scsi%d: message received, residual %d\n",
2387                                                            HOSTNO, len);
2388
2389                                                 switch (extended_msg[2]) {
2390                                                 case EXTENDED_SDTR:
2391                                                 case EXTENDED_WDTR:
2392                                                 case EXTENDED_MODIFY_DATA_POINTER:
2393                                                 case EXTENDED_EXTENDED_IDENTIFY:
2394                                                         tmp = 0;
2395                                                 }
2396                                         } else if (len) {
2397                                                 printk(KERN_NOTICE "scsi%d: error receiving "
2398                                                        "extended message\n", HOSTNO);
2399                                                 tmp = 0;
2400                                         } else {
2401                                                 printk(KERN_NOTICE "scsi%d: extended message "
2402                                                            "code %02x length %d is too long\n",
2403                                                            HOSTNO, extended_msg[2], extended_msg[1]);
2404                                                 tmp = 0;
2405                                         }
2406                                         /* Fall through to reject message */
2407
2408                                         /*
2409                                          * If we get something weird that we aren't expecting,
2410                                          * reject it.
2411                                          */
2412                                 default:
2413                                         if (!tmp) {
2414                                                 printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
2415                                                 spi_print_msg(extended_msg);
2416                                                 printk("\n");
2417                                         } else if (tmp != EXTENDED_MESSAGE)
2418                                                 printk(KERN_DEBUG "scsi%d: rejecting unknown "
2419                                                        "message %02x from target %d, lun %d\n",
2420                                                        HOSTNO, tmp, cmd->device->id, cmd->device->lun);
2421                                         else
2422                                                 printk(KERN_DEBUG "scsi%d: rejecting unknown "
2423                                                        "extended message "
2424                                                        "code %02x, length %d from target %d, lun %d\n",
2425                                                        HOSTNO, extended_msg[1], extended_msg[0],
2426                                                        cmd->device->id, cmd->device->lun);
2427
2428
2429                                         msgout = MESSAGE_REJECT;
2430                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2431                                         break;
2432                                 } /* switch (tmp) */
2433                                 break;
2434                         case PHASE_MSGOUT:
2435                                 len = 1;
2436                                 data = &msgout;
2437                                 hostdata->last_message = msgout;
2438                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2439                                 if (msgout == ABORT) {
2440 #ifdef SUPPORT_TAGS
2441                                         cmd_free_tag(cmd);
2442 #else
2443                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2444 #endif
2445                                         hostdata->connected = NULL;
2446                                         cmd->result = DID_ERROR << 16;
2447 #ifdef NCR5380_STATS
2448                                         collect_stats(hostdata, cmd);
2449 #endif
2450                                         cmd->scsi_done(cmd);
2451                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2452                                         falcon_release_lock_if_possible(hostdata);
2453                                         return;
2454                                 }
2455                                 msgout = NOP;
2456                                 break;
2457                         case PHASE_CMDOUT:
2458                                 len = cmd->cmd_len;
2459                                 data = cmd->cmnd;
2460                                 /*
2461                                  * XXX for performance reasons, on machines with a
2462                                  * PSEUDO-DMA architecture we should probably
2463                                  * use the dma transfer function.
2464                                  */
2465                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2466                                 break;
2467                         case PHASE_STATIN:
2468                                 len = 1;
2469                                 data = &tmp;
2470                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2471                                 cmd->SCp.Status = tmp;
2472                                 break;
2473                         default:
2474                                 printk("scsi%d: unknown phase\n", HOSTNO);
2475                                 NCR_PRINT(NDEBUG_ANY);
2476                         } /* switch(phase) */
2477                 } /* if (tmp * SR_REQ) */
2478         } /* while (1) */
2479 }
2480
2481 /*
2482  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2483  *
2484  * Purpose : does reselection, initializing the instance->connected
2485  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2486  *      nexus has been reestablished,
2487  *
2488  * Inputs : instance - this instance of the NCR5380.
2489  *
2490  */
2491
2492
2493 static void NCR5380_reselect(struct Scsi_Host *instance)
2494 {
2495         SETUP_HOSTDATA(instance);
2496         unsigned char target_mask;
2497         unsigned char lun, phase;
2498         int len;
2499 #ifdef SUPPORT_TAGS
2500         unsigned char tag;
2501 #endif
2502         unsigned char msg[3];
2503         unsigned char *data;
2504         Scsi_Cmnd *tmp = NULL, *prev;
2505 /*      unsigned long flags; */
2506
2507         /*
2508          * Disable arbitration, etc. since the host adapter obviously
2509          * lost, and tell an interrupted NCR5380_select() to restart.
2510          */
2511
2512         NCR5380_write(MODE_REG, MR_BASE);
2513         hostdata->restart_select = 1;
2514
2515         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2516
2517         RSL_PRINTK("scsi%d: reselect\n", HOSTNO);
2518
2519         /*
2520          * At this point, we have detected that our SCSI ID is on the bus,
2521          * SEL is true and BSY was false for at least one bus settle delay
2522          * (400 ns).
2523          *
2524          * We must assert BSY ourselves, until the target drops the SEL
2525          * signal.
2526          */
2527
2528         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2529
2530         while (NCR5380_read(STATUS_REG) & SR_SEL)
2531                 ;
2532         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2533
2534         /*
2535          * Wait for target to go into MSGIN.
2536          */
2537
2538         while (!(NCR5380_read(STATUS_REG) & SR_REQ))
2539                 ;
2540
2541         len = 1;
2542         data = msg;
2543         phase = PHASE_MSGIN;
2544         NCR5380_transfer_pio(instance, &phase, &len, &data);
2545
2546         if (!(msg[0] & 0x80)) {
2547                 printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2548                 spi_print_msg(msg);
2549                 do_abort(instance);
2550                 return;
2551         }
2552         lun = (msg[0] & 0x07);
2553
2554 #ifdef SUPPORT_TAGS
2555         /* If the phase is still MSGIN, the target wants to send some more
2556          * messages. In case it supports tagged queuing, this is probably a
2557          * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2558          */
2559         tag = TAG_NONE;
2560         if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2561                 /* Accept previous IDENTIFY message by clearing ACK */
2562                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2563                 len = 2;
2564                 data = msg + 1;
2565                 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2566                     msg[1] == SIMPLE_QUEUE_TAG)
2567                         tag = msg[2];
2568                 TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
2569                            "reselection\n", HOSTNO, target_mask, lun, tag);
2570         }
2571 #endif
2572
2573         /*
2574          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2575          * just reestablished, and remove it from the disconnected queue.
2576          */
2577
2578         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL;
2579              tmp; prev = tmp, tmp = NEXT(tmp)) {
2580                 if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2581 #ifdef SUPPORT_TAGS
2582                     && (tag == tmp->tag)
2583 #endif
2584                     ) {
2585                         /* ++guenther: prevent race with falcon_release_lock */
2586                         falcon_dont_release++;
2587                         if (prev) {
2588                                 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2589                                 SET_NEXT(prev, NEXT(tmp));
2590                         } else {
2591                                 REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
2592                                 hostdata->disconnected_queue = NEXT(tmp);
2593                         }
2594                         SET_NEXT(tmp, NULL);
2595                         break;
2596                 }
2597         }
2598
2599         if (!tmp) {
2600                 printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
2601 #ifdef SUPPORT_TAGS
2602                        "tag %d "
2603 #endif
2604                        "not in disconnected_queue.\n",
2605                        HOSTNO, target_mask, lun
2606 #ifdef SUPPORT_TAGS
2607                        , tag
2608 #endif
2609                         );
2610                 /*
2611                  * Since we have an established nexus that we can't do anything
2612                  * with, we must abort it.
2613                  */
2614                 do_abort(instance);
2615                 return;
2616         }
2617
2618         /* Accept message by clearing ACK */
2619         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2620
2621         hostdata->connected = tmp;
2622         RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
2623                    HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
2624         falcon_dont_release--;
2625 }
2626
2627
2628 /*
2629  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2630  *
2631  * Purpose : abort a command
2632  *
2633  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2634  *      host byte of the result field to, if zero DID_ABORTED is
2635  *      used.
2636  *
2637  * Returns : 0 - success, -1 on failure.
2638  *
2639  * XXX - there is no way to abort the command that is currently
2640  *       connected, you have to wait for it to complete.  If this is
2641  *       a problem, we could implement longjmp() / setjmp(), setjmp()
2642  *       called where the loop started in NCR5380_main().
2643  */
2644
2645 static
2646 int NCR5380_abort(Scsi_Cmnd *cmd)
2647 {
2648         struct Scsi_Host *instance = cmd->device->host;
2649         SETUP_HOSTDATA(instance);
2650         Scsi_Cmnd *tmp, **prev;
2651         unsigned long flags;
2652
2653         printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
2654         scsi_print_command(cmd);
2655
2656         NCR5380_print_status(instance);
2657
2658         local_irq_save(flags);
2659
2660         if (!IS_A_TT() && !falcon_got_lock)
2661                 printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
2662                        HOSTNO);
2663
2664         ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2665                     NCR5380_read(BUS_AND_STATUS_REG),
2666                     NCR5380_read(STATUS_REG));
2667
2668 #if 1
2669         /*
2670          * Case 1 : If the command is the currently executing command,
2671          * we'll set the aborted flag and return control so that
2672          * information transfer routine can exit cleanly.
2673          */
2674
2675         if (hostdata->connected == cmd) {
2676
2677                 ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
2678                 /*
2679                  * We should perform BSY checking, and make sure we haven't slipped
2680                  * into BUS FREE.
2681                  */
2682
2683                 /*      NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2684                 /*
2685                  * Since we can't change phases until we've completed the current
2686                  * handshake, we have to source or sink a byte of data if the current
2687                  * phase is not MSGOUT.
2688                  */
2689
2690                 /*
2691                  * Return control to the executing NCR drive so we can clear the
2692                  * aborted flag and get back into our main loop.
2693                  */
2694
2695                 if (do_abort(instance) == 0) {
2696                         hostdata->aborted = 1;
2697                         hostdata->connected = NULL;
2698                         cmd->result = DID_ABORT << 16;
2699 #ifdef SUPPORT_TAGS
2700                         cmd_free_tag(cmd);
2701 #else
2702                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2703 #endif
2704                         local_irq_restore(flags);
2705                         cmd->scsi_done(cmd);
2706                         falcon_release_lock_if_possible(hostdata);
2707                         return SCSI_ABORT_SUCCESS;
2708                 } else {
2709 /*                      local_irq_restore(flags); */
2710                         printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2711                         return SCSI_ABORT_ERROR;
2712                 }
2713         }
2714 #endif
2715
2716         /*
2717          * Case 2 : If the command hasn't been issued yet, we simply remove it
2718          *          from the issue queue.
2719          */
2720         for (prev = (Scsi_Cmnd **)&(hostdata->issue_queue),
2721              tmp = (Scsi_Cmnd *)hostdata->issue_queue;
2722              tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2723                 if (cmd == tmp) {
2724                         REMOVE(5, *prev, tmp, NEXT(tmp));
2725                         (*prev) = NEXT(tmp);
2726                         SET_NEXT(tmp, NULL);
2727                         tmp->result = DID_ABORT << 16;
2728                         local_irq_restore(flags);
2729                         ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
2730                                     HOSTNO);
2731                         /* Tagged queuing note: no tag to free here, hasn't been assigned
2732                          * yet... */
2733                         tmp->scsi_done(tmp);
2734                         falcon_release_lock_if_possible(hostdata);
2735                         return SCSI_ABORT_SUCCESS;
2736                 }
2737         }
2738
2739         /*
2740          * Case 3 : If any commands are connected, we're going to fail the abort
2741          *          and let the high level SCSI driver retry at a later time or
2742          *          issue a reset.
2743          *
2744          *          Timeouts, and therefore aborted commands, will be highly unlikely
2745          *          and handling them cleanly in this situation would make the common
2746          *          case of noresets less efficient, and would pollute our code.  So,
2747          *          we fail.
2748          */
2749
2750         if (hostdata->connected) {
2751                 local_irq_restore(flags);
2752                 ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
2753                 return SCSI_ABORT_SNOOZE;
2754         }
2755
2756         /*
2757          * Case 4: If the command is currently disconnected from the bus, and
2758          *      there are no connected commands, we reconnect the I_T_L or
2759          *      I_T_L_Q nexus associated with it, go into message out, and send
2760          *      an abort message.
2761          *
2762          * This case is especially ugly. In order to reestablish the nexus, we
2763          * need to call NCR5380_select().  The easiest way to implement this
2764          * function was to abort if the bus was busy, and let the interrupt
2765          * handler triggered on the SEL for reselect take care of lost arbitrations
2766          * where necessary, meaning interrupts need to be enabled.
2767          *
2768          * When interrupts are enabled, the queues may change - so we
2769          * can't remove it from the disconnected queue before selecting it
2770          * because that could cause a failure in hashing the nexus if that
2771          * device reselected.
2772          *
2773          * Since the queues may change, we can't use the pointers from when we
2774          * first locate it.
2775          *
2776          * So, we must first locate the command, and if NCR5380_select()
2777          * succeeds, then issue the abort, relocate the command and remove
2778          * it from the disconnected queue.
2779          */
2780
2781         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
2782              tmp = NEXT(tmp)) {
2783                 if (cmd == tmp) {
2784                         local_irq_restore(flags);
2785                         ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
2786
2787                         if (NCR5380_select(instance, cmd, (int)cmd->tag))
2788                                 return SCSI_ABORT_BUSY;
2789
2790                         ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);
2791
2792                         do_abort(instance);
2793
2794                         local_irq_save(flags);
2795                         for (prev = (Scsi_Cmnd **)&(hostdata->disconnected_queue),
2796                              tmp = (Scsi_Cmnd *)hostdata->disconnected_queue;
2797                              tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2798                                 if (cmd == tmp) {
2799                                         REMOVE(5, *prev, tmp, NEXT(tmp));
2800                                         *prev = NEXT(tmp);
2801                                         SET_NEXT(tmp, NULL);
2802                                         tmp->result = DID_ABORT << 16;
2803                                         /* We must unlock the tag/LUN immediately here, since the
2804                                          * target goes to BUS FREE and doesn't send us another
2805                                          * message (COMMAND_COMPLETE or the like)
2806                                          */
2807 #ifdef SUPPORT_TAGS
2808                                         cmd_free_tag(tmp);
2809 #else
2810                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2811 #endif
2812                                         local_irq_restore(flags);
2813                                         tmp->scsi_done(tmp);
2814                                         falcon_release_lock_if_possible(hostdata);
2815                                         return SCSI_ABORT_SUCCESS;
2816                                 }
2817                         }
2818                 }
2819         }
2820
2821         /*
2822          * Case 5 : If we reached this point, the command was not found in any of
2823          *          the queues.
2824          *
2825          * We probably reached this point because of an unlikely race condition
2826          * between the command completing successfully and the abortion code,
2827          * so we won't panic, but we will notify the user in case something really
2828          * broke.
2829          */
2830
2831         local_irq_restore(flags);
2832         printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
2833
2834         /* Maybe it is sufficient just to release the ST-DMA lock... (if
2835          * possible at all) At least, we should check if the lock could be
2836          * released after the abort, in case it is kept due to some bug.
2837          */
2838         falcon_release_lock_if_possible(hostdata);
2839
2840         return SCSI_ABORT_NOT_RUNNING;
2841 }
2842
2843
2844 /*
2845  * Function : int NCR5380_reset (Scsi_Cmnd *cmd)
2846  *
2847  * Purpose : reset the SCSI bus.
2848  *
2849  * Returns : SCSI_RESET_WAKEUP
2850  *
2851  */
2852
2853 static int NCR5380_bus_reset(Scsi_Cmnd *cmd)
2854 {
2855         SETUP_HOSTDATA(cmd->device->host);
2856         int i;
2857         unsigned long flags;
2858 #if 1
2859         Scsi_Cmnd *connected, *disconnected_queue;
2860 #endif
2861
2862         if (!IS_A_TT() && !falcon_got_lock)
2863                 printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
2864                        H_NO(cmd));
2865
2866         NCR5380_print_status(cmd->device->host);
2867
2868         /* get in phase */
2869         NCR5380_write(TARGET_COMMAND_REG,
2870                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
2871         /* assert RST */
2872         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
2873         udelay(40);
2874         /* reset NCR registers */
2875         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2876         NCR5380_write(MODE_REG, MR_BASE);
2877         NCR5380_write(TARGET_COMMAND_REG, 0);
2878         NCR5380_write(SELECT_ENABLE_REG, 0);
2879         /* ++roman: reset interrupt condition! otherwise no interrupts don't get
2880          * through anymore ... */
2881         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2882
2883 #if 1   /* XXX Should now be done by midlevel code, but it's broken XXX */
2884         /* XXX see below                                            XXX */
2885
2886         /* MSch: old-style reset: actually abort all command processing here */
2887
2888         /* After the reset, there are no more connected or disconnected commands
2889          * and no busy units; to avoid problems with re-inserting the commands
2890          * into the issue_queue (via scsi_done()), the aborted commands are
2891          * remembered in local variables first.
2892          */
2893         local_irq_save(flags);
2894         connected = (Scsi_Cmnd *)hostdata->connected;
2895         hostdata->connected = NULL;
2896         disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
2897         hostdata->disconnected_queue = NULL;
2898 #ifdef SUPPORT_TAGS
2899         free_all_tags();
2900 #endif
2901         for (i = 0; i < 8; ++i)
2902                 hostdata->busy[i] = 0;
2903 #ifdef REAL_DMA
2904         hostdata->dma_len = 0;
2905 #endif
2906         local_irq_restore(flags);
2907
2908         /* In order to tell the mid-level code which commands were aborted,
2909          * set the command status to DID_RESET and call scsi_done() !!!
2910          * This ultimately aborts processing of these commands in the mid-level.
2911          */
2912
2913         if ((cmd = connected)) {
2914                 ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2915                 cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2916                 cmd->scsi_done(cmd);
2917         }
2918
2919         for (i = 0; (cmd = disconnected_queue); ++i) {
2920                 disconnected_queue = NEXT(cmd);
2921                 SET_NEXT(cmd, NULL);
2922                 cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2923                 cmd->scsi_done(cmd);
2924         }
2925         if (i > 0)
2926                 ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);
2927
2928         /* The Falcon lock should be released after a reset...
2929          */
2930         /* ++guenther: moved to atari_scsi_reset(), to prevent a race between
2931          * unlocking and enabling dma interrupt.
2932          */
2933 /*      falcon_release_lock_if_possible( hostdata );*/
2934
2935         /* since all commands have been explicitly terminated, we need to tell
2936          * the midlevel code that the reset was SUCCESSFUL, and there is no
2937          * need to 'wake up' the commands by a request_sense
2938          */
2939         return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
2940 #else /* 1 */
2941
2942         /* MSch: new-style reset handling: let the mid-level do what it can */
2943
2944         /* ++guenther: MID-LEVEL IS STILL BROKEN.
2945          * Mid-level is supposed to requeue all commands that were active on the
2946          * various low-level queues. In fact it does this, but that's not enough
2947          * because all these commands are subject to timeout. And if a timeout
2948          * happens for any removed command, *_abort() is called but all queues
2949          * are now empty. Abort then gives up the falcon lock, which is fatal,
2950          * since the mid-level will queue more commands and must have the lock
2951          * (it's all happening inside timer interrupt handler!!).
2952          * Even worse, abort will return NOT_RUNNING for all those commands not
2953          * on any queue, so they won't be retried ...
2954          *
2955          * Conclusion: either scsi.c disables timeout for all resetted commands
2956          * immediately, or we lose!  As of linux-2.0.20 it doesn't.
2957          */
2958
2959         /* After the reset, there are no more connected or disconnected commands
2960          * and no busy units; so clear the low-level status here to avoid
2961          * conflicts when the mid-level code tries to wake up the affected
2962          * commands!
2963          */
2964
2965         if (hostdata->issue_queue)
2966                 ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
2967         if (hostdata->connected)
2968                 ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2969         if (hostdata->disconnected_queue)
2970                 ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
2971
2972         local_irq_save(flags);
2973         hostdata->issue_queue = NULL;
2974         hostdata->connected = NULL;
2975         hostdata->disconnected_queue = NULL;
2976 #ifdef SUPPORT_TAGS
2977         free_all_tags();
2978 #endif
2979         for (i = 0; i < 8; ++i)
2980                 hostdata->busy[i] = 0;
2981 #ifdef REAL_DMA
2982         hostdata->dma_len = 0;
2983 #endif
2984         local_irq_restore(flags);
2985
2986         /* we did no complete reset of all commands, so a wakeup is required */
2987         return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
2988 #endif /* 1 */
2989 }