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  * For more information, please consult
  15  *
  16  * NCR 5380 Family
  17  * SCSI Protocol Controller
  18  * Databook
  19  *
  20  * NCR Microelectronics
  21  * 1635 Aeroplaza Drive
  22  * Colorado Springs, CO 80916
  23  * 1+ (719) 578-3400
  24  * 1+ (800) 334-5454
  25  */
  26
  27 /*
  28  * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
  29  * this file, too:
  30  *
  31  *  - Some of the debug statements were incorrect (undefined variables and the
  32  *    like). I fixed that.
  33  *
  34  *  - In information_transfer(), I think a #ifdef was wrong. Looking at the
  35  *    possible DMA transfer size should also happen for REAL_DMA. I added this
  36  *    in the #if statement.
  37  *
  38  *  - When using real DMA, information_transfer() should return in a DATAOUT
  39  *    phase after starting the DMA. It has nothing more to do.
  40  *
  41  *  - The interrupt service routine should run main after end of DMA, too (not
  42  *    only after RESELECTION interrupts). Additionally, it should _not_ test
  43  *    for more interrupts after running main, since a DMA process may have
  44  *    been started and interrupts are turned on now. The new int could happen
  45  *    inside the execution of NCR5380_intr(), leading to recursive
  46  *    calls.
  47  *
  48  *  - I've added a function merge_contiguous_buffers() that tries to
  49  *    merge scatter-gather buffers that are located at contiguous
  50  *    physical addresses and can be processed with the same DMA setup.
  51  *    Since most scatter-gather operations work on a page (4K) of
  52  *    4 buffers (1K), in more than 90% of all cases three interrupts and
  53  *    DMA setup actions are saved.
  54  *
  55  * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
  56  *    and USLEEP, because these were messing up readability and will never be
  57  *    needed for Atari SCSI.
  58  *
  59  * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
  60  *   stuff), and 'main' is executed in a bottom half if awoken by an
  61  *   interrupt.
  62  *
  63  * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
  64  *   constructs. In my eyes, this made the source rather unreadable, so I
  65  *   finally replaced that by the *_PRINTK() macros.
  66  *
  67  */
  68
  69 /*
  70  * Further development / testing that should be done :
  71  * 1.  Test linked command handling code after Eric is ready with
  72  *     the high level code.
  73  */
  74
  75 /* Adapted for the sun3 by Sam Creasey. */
  76
  77 #include <scsi/scsi_dbg.h>
  78 #include <scsi/scsi_transport_spi.h>
  79
  80 #if (NDEBUG & NDEBUG_LISTS)
  81 #define LIST(x, y)                                              \
  82         do {                                                    \
  83                 printk("LINE:%d   Adding %p to %p\n",           \
  84                        __LINE__, (void*)(x), (void*)(y));       \
  85                 if ((x) == (y))                                 \
  86                         udelay(5);                              \
  87         } while (0)
  88 #define REMOVE(w, x, y, z)                                      \
  89         do {                                                    \
  90                 printk("LINE:%d   Removing: %p->%p  %p->%p \n", \
  91                        __LINE__, (void*)(w), (void*)(x),        \
  92                        (void*)(y), (void*)(z));                 \
  93                 if ((x) == (y))                                 \
  94                         udelay(5);                              \
  95         } while (0)
  96 #else
  97 #define LIST(x,y)
  98 #define REMOVE(w,x,y,z)
  99 #endif
 100
 101 #ifndef notyet
 102 #undef LINKED
 103 #endif
 104
 105 /*
 106  * Design
 107  *
 108  * This is a generic 5380 driver.  To use it on a different platform,
 109  * one simply writes appropriate system specific macros (ie, data
 110  * transfer - some PC's will use the I/O bus, 68K's must use
 111  * memory mapped) and drops this file in their 'C' wrapper.
 112  *
 113  * As far as command queueing, two queues are maintained for
 114  * each 5380 in the system - commands that haven't been issued yet,
 115  * and commands that are currently executing.  This means that an
 116  * unlimited number of commands may be queued, letting
 117  * more commands propagate from the higher driver levels giving higher
 118  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
 119  * allowing multiple commands to propagate all the way to a SCSI-II device
 120  * while a command is already executing.
 121  *
 122  *
 123  * Issues specific to the NCR5380 :
 124  *
 125  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
 126  * piece of hardware that requires you to sit in a loop polling for
 127  * the REQ signal as long as you are connected.  Some devices are
 128  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
 129  * while doing long seek operations.
 130  *
 131  * The workaround for this is to keep track of devices that have
 132  * disconnected.  If the device hasn't disconnected, for commands that
 133  * should disconnect, we do something like
 134  *
 135  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
 136  *
 137  * Some tweaking of N and M needs to be done.  An algorithm based
 138  * on "time to data" would give the best results as long as short time
 139  * to datas (ie, on the same track) were considered, however these
 140  * broken devices are the exception rather than the rule and I'd rather
 141  * spend my time optimizing for the normal case.
 142  *
 143  * Architecture :
 144  *
 145  * At the heart of the design is a coroutine, NCR5380_main,
 146  * which is started from a workqueue for each NCR5380 host in the
 147  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
 148  * removing the commands from the issue queue and calling
 149  * NCR5380_select() if a nexus is not established.
 150  *
 151  * Once a nexus is established, the NCR5380_information_transfer()
 152  * phase goes through the various phases as instructed by the target.
 153  * if the target goes into MSG IN and sends a DISCONNECT message,
 154  * the command structure is placed into the per instance disconnected
 155  * queue, and NCR5380_main tries to find more work.  If the target is
 156  * idle for too long, the system will try to sleep.
 157  *
 158  * If a command has disconnected, eventually an interrupt will trigger,
 159  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
 160  * to reestablish a nexus.  This will run main if necessary.
 161  *
 162  * On command termination, the done function will be called as
 163  * appropriate.
 164  *
 165  * SCSI pointers are maintained in the SCp field of SCSI command
 166  * structures, being initialized after the command is connected
 167  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
 168  * Note that in violation of the standard, an implicit SAVE POINTERS operation
 169  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
 170  */
 171
 172 /*
 173  * Using this file :
 174  * This file a skeleton Linux SCSI driver for the NCR 5380 series
 175  * of chips.  To use it, you write an architecture specific functions
 176  * and macros and include this file in your driver.
 177  *
 178  * These macros control options :
 179  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
 180  *      for commands that return with a CHECK CONDITION status.
 181  *
 182  * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
 183  *      transceivers.
 184  *
 185  * LINKED - if defined, linked commands are supported.
 186  *
 187  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
 188  *
 189  * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
 190  *
 191  * These macros MUST be defined :
 192  *
 193  * NCR5380_read(register)  - read from the specified register
 194  *
 195  * NCR5380_write(register, value) - write to the specific register
 196  *
 197  * NCR5380_implementation_fields  - additional fields needed for this
 198  *      specific implementation of the NCR5380
 199  *
 200  * Either real DMA *or* pseudo DMA may be implemented
 201  * REAL functions :
 202  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
 203  * Note that the DMA setup functions should return the number of bytes
 204  *      that they were able to program the controller for.
 205  *
 206  * Also note that generic i386/PC versions of these macros are
 207  *      available as NCR5380_i386_dma_write_setup,
 208  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
 209  *
 210  * NCR5380_dma_write_setup(instance, src, count) - initialize
 211  * NCR5380_dma_read_setup(instance, dst, count) - initialize
 212  * NCR5380_dma_residual(instance); - residual count
 213  *
 214  * PSEUDO functions :
 215  * NCR5380_pwrite(instance, src, count)
 216  * NCR5380_pread(instance, dst, count);
 217  *
 218  * The generic driver is initialized by calling NCR5380_init(instance),
 219  * after setting the appropriate host specific fields and ID.  If the
 220  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
 221  * possible) function may be used.
 222  */
 223
 224 /* Macros ease life... :-) */
 225 #define SETUP_HOSTDATA(in)                              \
 226     struct NCR5380_hostdata *hostdata =                 \
 227         (struct NCR5380_hostdata *)(in)->hostdata
 228 #define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
 229
 230 #define NEXT(cmd)               ((struct scsi_cmnd *)(cmd)->host_scribble)
 231 #define SET_NEXT(cmd,next)      ((cmd)->host_scribble = (void *)(next))
 232 #define NEXTADDR(cmd)           ((struct scsi_cmnd **)&(cmd)->host_scribble)
 233
 234 #define HOSTNO          instance->host_no
 235 #define H_NO(cmd)       (cmd)->device->host->host_no
 236
 237 static int do_abort(struct Scsi_Host *);
 238 static void do_reset(struct Scsi_Host *);
 239
 240 #ifdef SUPPORT_TAGS
 241
 242 /*
 243  * Functions for handling tagged queuing
 244  * =====================================
 245  *
 246  * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
 247  *
 248  * Using consecutive numbers for the tags is no good idea in my eyes. There
 249  * could be wrong re-usings if the counter (8 bit!) wraps and some early
 250  * command has been preempted for a long time. My solution: a bitfield for
 251  * remembering used tags.
 252  *
 253  * There's also the problem that each target has a certain queue size, but we
 254  * cannot know it in advance :-( We just see a QUEUE_FULL status being
 255  * returned. So, in this case, the driver internal queue size assumption is
 256  * reduced to the number of active tags if QUEUE_FULL is returned by the
 257  * target. The command is returned to the mid-level, but with status changed
 258  * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
 259  * correctly.
 260  *
 261  * We're also not allowed running tagged commands as long as an untagged
 262  * command is active. And REQUEST SENSE commands after a contingent allegiance
 263  * condition _must_ be untagged. To keep track whether an untagged command has
 264  * been issued, the host->busy array is still employed, as it is without
 265  * support for tagged queuing.
 266  *
 267  * One could suspect that there are possible race conditions between
 268  * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
 269  * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
 270  * which already guaranteed to be running at most once. It is also the only
 271  * place where tags/LUNs are allocated. So no other allocation can slip
 272  * between that pair, there could only happen a reselection, which can free a
 273  * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
 274  * important: the tag bit must be cleared before 'nr_allocated' is decreased.
 275  */
 276
 277 static void __init init_tags(struct NCR5380_hostdata *hostdata)
 278 {
 279         int target, lun;
 280         struct tag_alloc *ta;
 281
 282         if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
 283                 return;
 284
 285         for (target = 0; target < 8; ++target) {
 286                 for (lun = 0; lun < 8; ++lun) {
 287                         ta = &hostdata->TagAlloc[target][lun];
 288                         bitmap_zero(ta->allocated, MAX_TAGS);
 289                         ta->nr_allocated = 0;
 290                         /* At the beginning, assume the maximum queue size we could
 291                          * support (MAX_TAGS). This value will be decreased if the target
 292                          * returns QUEUE_FULL status.
 293                          */
 294                         ta->queue_size = MAX_TAGS;
 295                 }
 296         }
 297 }
 298
 299
 300 /* Check if we can issue a command to this LUN: First see if the LUN is marked
 301  * busy by an untagged command. If the command should use tagged queuing, also
 302  * check that there is a free tag and the target's queue won't overflow. This
 303  * function should be called with interrupts disabled to avoid race
 304  * conditions.
 305  */
 306
 307 static int is_lun_busy(struct scsi_cmnd *cmd, int should_be_tagged)
 308 {
 309         u8 lun = cmd->device->lun;
 310         SETUP_HOSTDATA(cmd->device->host);
 311
 312         if (hostdata->busy[cmd->device->id] & (1 << lun))
 313                 return 1;
 314         if (!should_be_tagged ||
 315             !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
 316             !cmd->device->tagged_supported)
 317                 return 0;
 318         if (hostdata->TagAlloc[scmd_id(cmd)][lun].nr_allocated >=
 319             hostdata->TagAlloc[scmd_id(cmd)][lun].queue_size) {
 320                 dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d: no free tags\n",
 321                            H_NO(cmd), cmd->device->id, lun);
 322                 return 1;
 323         }
 324         return 0;
 325 }
 326
 327
 328 /* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
 329  * must be called before!), or reserve the LUN in 'busy' if the command is
 330  * untagged.
 331  */
 332
 333 static void cmd_get_tag(struct scsi_cmnd *cmd, int should_be_tagged)
 334 {
 335         u8 lun = cmd->device->lun;
 336         SETUP_HOSTDATA(cmd->device->host);
 337
 338         /* If we or the target don't support tagged queuing, allocate the LUN for
 339          * an untagged command.
 340          */
 341         if (!should_be_tagged ||
 342             !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
 343             !cmd->device->tagged_supported) {
 344                 cmd->tag = TAG_NONE;
 345                 hostdata->busy[cmd->device->id] |= (1 << lun);
 346                 dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d now allocated by untagged "
 347                            "command\n", H_NO(cmd), cmd->device->id, lun);
 348         } else {
 349                 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
 350
 351                 cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
 352                 set_bit(cmd->tag, ta->allocated);
 353                 ta->nr_allocated++;
 354                 dprintk(NDEBUG_TAGS, "scsi%d: using tag %d for target %d lun %d "
 355                            "(now %d tags in use)\n",
 356                            H_NO(cmd), cmd->tag, cmd->device->id,
 357                            lun, ta->nr_allocated);
 358         }
 359 }
 360
 361
 362 /* Mark the tag of command 'cmd' as free, or in case of an untagged command,
 363  * unlock the LUN.
 364  */
 365
 366 static void cmd_free_tag(struct scsi_cmnd *cmd)
 367 {
 368         u8 lun = cmd->device->lun;
 369         SETUP_HOSTDATA(cmd->device->host);
 370
 371         if (cmd->tag == TAG_NONE) {
 372                 hostdata->busy[cmd->device->id] &= ~(1 << lun);
 373                 dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d untagged cmd finished\n",
 374                            H_NO(cmd), cmd->device->id, lun);
 375         } else if (cmd->tag >= MAX_TAGS) {
 376                 printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
 377                        H_NO(cmd), cmd->tag);
 378         } else {
 379                 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
 380                 clear_bit(cmd->tag, ta->allocated);
 381                 ta->nr_allocated--;
 382                 dprintk(NDEBUG_TAGS, "scsi%d: freed tag %d for target %d lun %d\n",
 383                            H_NO(cmd), cmd->tag, cmd->device->id, lun);
 384         }
 385 }
 386
 387
 388 static void free_all_tags(struct NCR5380_hostdata *hostdata)
 389 {
 390         int target, lun;
 391         struct tag_alloc *ta;
 392
 393         if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
 394                 return;
 395
 396         for (target = 0; target < 8; ++target) {
 397                 for (lun = 0; lun < 8; ++lun) {
 398                         ta = &hostdata->TagAlloc[target][lun];
 399                         bitmap_zero(ta->allocated, MAX_TAGS);
 400                         ta->nr_allocated = 0;
 401                 }
 402         }
 403 }
 404
 405 #endif /* SUPPORT_TAGS */
 406
 407
 408 /*
 409  * Function: void merge_contiguous_buffers( struct scsi_cmnd *cmd )
 410  *
 411  * Purpose: Try to merge several scatter-gather requests into one DMA
 412  *    transfer. This is possible if the scatter buffers lie on
 413  *    physical contiguous addresses.
 414  *
 415  * Parameters: struct scsi_cmnd *cmd
 416  *    The command to work on. The first scatter buffer's data are
 417  *    assumed to be already transferred into ptr/this_residual.
 418  */
 419
 420 static void merge_contiguous_buffers(struct scsi_cmnd *cmd)
 421 {
 422 #if !defined(CONFIG_SUN3)
 423         unsigned long endaddr;
 424 #if (NDEBUG & NDEBUG_MERGING)
 425         unsigned long oldlen = cmd->SCp.this_residual;
 426         int cnt = 1;
 427 #endif
 428
 429         for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
 430              cmd->SCp.buffers_residual &&
 431              virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
 432                 dprintk(NDEBUG_MERGING, "VTOP(%p) == %08lx -> merging\n",
 433                            page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
 434 #if (NDEBUG & NDEBUG_MERGING)
 435                 ++cnt;
 436 #endif
 437                 ++cmd->SCp.buffer;
 438                 --cmd->SCp.buffers_residual;
 439                 cmd->SCp.this_residual += cmd->SCp.buffer->length;
 440                 endaddr += cmd->SCp.buffer->length;
 441         }
 442 #if (NDEBUG & NDEBUG_MERGING)
 443         if (oldlen != cmd->SCp.this_residual)
 444                 dprintk(NDEBUG_MERGING, "merged %d buffers from %p, new length %08x\n",
 445                            cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
 446 #endif
 447 #endif /* !defined(CONFIG_SUN3) */
 448 }
 449
 450 /**
 451  * initialize_SCp - init the scsi pointer field
 452  * @cmd: command block to set up
 453  *
 454  * Set up the internal fields in the SCSI command.
 455  */
 456
 457 static inline void initialize_SCp(struct scsi_cmnd *cmd)
 458 {
 459         /*
 460          * Initialize the Scsi Pointer field so that all of the commands in the
 461          * various queues are valid.
 462          */
 463
 464         if (scsi_bufflen(cmd)) {
 465                 cmd->SCp.buffer = scsi_sglist(cmd);
 466                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 467                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 468                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
 469                 /* ++roman: Try to merge some scatter-buffers if they are at
 470                  * contiguous physical addresses.
 471                  */
 472                 merge_contiguous_buffers(cmd);
 473         } else {
 474                 cmd->SCp.buffer = NULL;
 475                 cmd->SCp.buffers_residual = 0;
 476                 cmd->SCp.ptr = NULL;
 477                 cmd->SCp.this_residual = 0;
 478         }
 479 }
 480
 481 /**
 482  * NCR5380_poll_politely - wait for NCR5380 status bits
 483  * @instance: controller to poll
 484  * @reg: 5380 register to poll
 485  * @bit: Bitmask to check
 486  * @val: Value required to exit
 487  *
 488  * Polls the NCR5380 in a reasonably efficient manner waiting for
 489  * an event to occur, after a short quick poll we begin giving the
 490  * CPU back in non IRQ contexts
 491  *
 492  * Returns the value of the register or a negative error code.
 493  */
 494
 495 static int NCR5380_poll_politely(struct Scsi_Host *instance,
 496                                  int reg, int bit, int val, int t)
 497 {
 498         int n = 500;
 499         unsigned long end = jiffies + t;
 500         int r;
 501
 502         while (n-- > 0) {
 503                 r = NCR5380_read(reg);
 504                 if ((r & bit) == val)
 505                         return 0;
 506                 cpu_relax();
 507         }
 508
 509         /* t time yet ? */
 510         while (time_before(jiffies, end)) {
 511                 r = NCR5380_read(reg);
 512                 if ((r & bit) == val)
 513                         return 0;
 514                 if (!in_interrupt())
 515                         cond_resched();
 516                 else
 517                         cpu_relax();
 518         }
 519         return -ETIMEDOUT;
 520 }
 521
 522 #include <linux/delay.h>
 523
 524 #if NDEBUG
 525 static struct {
 526         unsigned char mask;
 527         const char *name;
 528 } signals[] = {
 529         { SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
 530         { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD,  "CD" }, { SR_IO, "IO" },
 531         { SR_SEL, "SEL" }, {0, NULL}
 532 }, basrs[] = {
 533         {BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
 534 }, icrs[] = {
 535         {ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
 536         {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
 537         {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
 538         {0, NULL}
 539 }, mrs[] = {
 540         {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
 541         {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
 542         "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
 543         {MR_MONITOR_BSY, "MODE MONITOR BSY"},
 544         {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
 545         {0, NULL}
 546 };
 547
 548 /**
 549  * NCR5380_print - print scsi bus signals
 550  * @instance: adapter state to dump
 551  *
 552  * Print the SCSI bus signals for debugging purposes
 553  */
 554
 555 static void NCR5380_print(struct Scsi_Host *instance)
 556 {
 557         unsigned char status, data, basr, mr, icr, i;
 558         unsigned long flags;
 559
 560         local_irq_save(flags);
 561         data = NCR5380_read(CURRENT_SCSI_DATA_REG);
 562         status = NCR5380_read(STATUS_REG);
 563         mr = NCR5380_read(MODE_REG);
 564         icr = NCR5380_read(INITIATOR_COMMAND_REG);
 565         basr = NCR5380_read(BUS_AND_STATUS_REG);
 566         local_irq_restore(flags);
 567         printk("STATUS_REG: %02x ", status);
 568         for (i = 0; signals[i].mask; ++i)
 569                 if (status & signals[i].mask)
 570                         printk(",%s", signals[i].name);
 571         printk("\nBASR: %02x ", basr);
 572         for (i = 0; basrs[i].mask; ++i)
 573                 if (basr & basrs[i].mask)
 574                         printk(",%s", basrs[i].name);
 575         printk("\nICR: %02x ", icr);
 576         for (i = 0; icrs[i].mask; ++i)
 577                 if (icr & icrs[i].mask)
 578                         printk(",%s", icrs[i].name);
 579         printk("\nMODE: %02x ", mr);
 580         for (i = 0; mrs[i].mask; ++i)
 581                 if (mr & mrs[i].mask)
 582                         printk(",%s", mrs[i].name);
 583         printk("\n");
 584 }
 585
 586 static struct {
 587         unsigned char value;
 588         const char *name;
 589 } phases[] = {
 590         {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
 591         {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
 592         {PHASE_UNKNOWN, "UNKNOWN"}
 593 };
 594
 595 /**
 596  * NCR5380_print_phase - show SCSI phase
 597  * @instance: adapter to dump
 598  *
 599  * Print the current SCSI phase for debugging purposes
 600  *
 601  * Locks: none
 602  */
 603
 604 static void NCR5380_print_phase(struct Scsi_Host *instance)
 605 {
 606         unsigned char status;
 607         int i;
 608
 609         status = NCR5380_read(STATUS_REG);
 610         if (!(status & SR_REQ))
 611                 printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
 612         else {
 613                 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
 614                      (phases[i].value != (status & PHASE_MASK)); ++i)
 615                         ;
 616                 printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
 617         }
 618 }
 619
 620 #endif
 621
 622 /*
 623  * ++roman: New scheme of calling NCR5380_main()
 624  *
 625  * If we're not in an interrupt, we can call our main directly, it cannot be
 626  * already running. Else, we queue it on a task queue, if not 'main_running'
 627  * tells us that a lower level is already executing it. This way,
 628  * 'main_running' needs not be protected in a special way.
 629  *
 630  * queue_main() is a utility function for putting our main onto the task
 631  * queue, if main_running is false. It should be called only from a
 632  * interrupt or bottom half.
 633  */
 634
 635 #include <linux/gfp.h>
 636 #include <linux/workqueue.h>
 637 #include <linux/interrupt.h>
 638
 639 static inline void queue_main(struct NCR5380_hostdata *hostdata)
 640 {
 641         if (!hostdata->main_running) {
 642                 /* If in interrupt and NCR5380_main() not already running,
 643                    queue it on the 'immediate' task queue, to be processed
 644                    immediately after the current interrupt processing has
 645                    finished. */
 646                 schedule_work(&hostdata->main_task);
 647         }
 648         /* else: nothing to do: the running NCR5380_main() will pick up
 649            any newly queued command. */
 650 }
 651
 652 /**
 653  * NCR58380_info - report driver and host information
 654  * @instance: relevant scsi host instance
 655  *
 656  * For use as the host template info() handler.
 657  *
 658  * Locks: none
 659  */
 660
 661 static const char *NCR5380_info(struct Scsi_Host *instance)
 662 {
 663         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 664
 665         return hostdata->info;
 666 }
 667
 668 static void prepare_info(struct Scsi_Host *instance)
 669 {
 670         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 671
 672         snprintf(hostdata->info, sizeof(hostdata->info),
 673                  "%s, io_port 0x%lx, n_io_port %d, "
 674                  "base 0x%lx, irq %d, "
 675                  "can_queue %d, cmd_per_lun %d, "
 676                  "sg_tablesize %d, this_id %d, "
 677                  "flags { %s%s}, "
 678                  "options { %s} ",
 679                  instance->hostt->name, instance->io_port, instance->n_io_port,
 680                  instance->base, instance->irq,
 681                  instance->can_queue, instance->cmd_per_lun,
 682                  instance->sg_tablesize, instance->this_id,
 683                  hostdata->flags & FLAG_TAGGED_QUEUING ? "TAGGED_QUEUING " : "",
 684                  hostdata->flags & FLAG_TOSHIBA_DELAY  ? "TOSHIBA_DELAY "  : "",
 685 #ifdef DIFFERENTIAL
 686                  "DIFFERENTIAL "
 687 #endif
 688 #ifdef REAL_DMA
 689                  "REAL_DMA "
 690 #endif
 691 #ifdef PARITY
 692                  "PARITY "
 693 #endif
 694 #ifdef SUPPORT_TAGS
 695                  "SUPPORT_TAGS "
 696 #endif
 697                  "");
 698 }
 699
 700 /**
 701  * NCR5380_print_status - dump controller info
 702  * @instance: controller to dump
 703  *
 704  * Print commands in the various queues, called from NCR5380_abort
 705  * to aid debugging.
 706  */
 707
 708 static void lprint_Scsi_Cmnd(struct scsi_cmnd *cmd)
 709 {
 710         int i, s;
 711         unsigned char *command;
 712         printk("scsi%d: destination target %d, lun %llu\n",
 713                 H_NO(cmd), cmd->device->id, cmd->device->lun);
 714         printk(KERN_CONT "        command = ");
 715         command = cmd->cmnd;
 716         printk(KERN_CONT "%2d (0x%02x)", command[0], command[0]);
 717         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 718                 printk(KERN_CONT " %02x", command[i]);
 719         printk("\n");
 720 }
 721
 722 static void __maybe_unused NCR5380_print_status(struct Scsi_Host *instance)
 723 {
 724         struct NCR5380_hostdata *hostdata;
 725         struct scsi_cmnd *ptr;
 726         unsigned long flags;
 727
 728         NCR5380_dprint(NDEBUG_ANY, instance);
 729         NCR5380_dprint_phase(NDEBUG_ANY, instance);
 730
 731         hostdata = (struct NCR5380_hostdata *)instance->hostdata;
 732
 733         local_irq_save(flags);
 734         printk("NCR5380: coroutine is%s running.\n",
 735                 hostdata->main_running ? "" : "n't");
 736         if (!hostdata->connected)
 737                 printk("scsi%d: no currently connected command\n", HOSTNO);
 738         else
 739                 lprint_Scsi_Cmnd((struct scsi_cmnd *) hostdata->connected);
 740         printk("scsi%d: issue_queue\n", HOSTNO);
 741         for (ptr = (struct scsi_cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
 742                 lprint_Scsi_Cmnd(ptr);
 743
 744         printk("scsi%d: disconnected_queue\n", HOSTNO);
 745         for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
 746              ptr = NEXT(ptr))
 747                 lprint_Scsi_Cmnd(ptr);
 748
 749         local_irq_restore(flags);
 750         printk("\n");
 751 }
 752
 753 static void show_Scsi_Cmnd(struct scsi_cmnd *cmd, struct seq_file *m)
 754 {
 755         int i, s;
 756         unsigned char *command;
 757         seq_printf(m, "scsi%d: destination target %d, lun %llu\n",
 758                 H_NO(cmd), cmd->device->id, cmd->device->lun);
 759         seq_puts(m, "        command = ");
 760         command = cmd->cmnd;
 761         seq_printf(m, "%2d (0x%02x)", command[0], command[0]);
 762         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 763                 seq_printf(m, " %02x", command[i]);
 764         seq_putc(m, '\n');
 765 }
 766
 767 static int __maybe_unused NCR5380_show_info(struct seq_file *m,
 768                                             struct Scsi_Host *instance)
 769 {
 770         struct NCR5380_hostdata *hostdata;
 771         struct scsi_cmnd *ptr;
 772         unsigned long flags;
 773
 774         hostdata = (struct NCR5380_hostdata *)instance->hostdata;
 775
 776         local_irq_save(flags);
 777         seq_printf(m, "NCR5380: coroutine is%s running.\n",
 778                 hostdata->main_running ? "" : "n't");
 779         if (!hostdata->connected)
 780                 seq_printf(m, "scsi%d: no currently connected command\n", HOSTNO);
 781         else
 782                 show_Scsi_Cmnd((struct scsi_cmnd *) hostdata->connected, m);
 783         seq_printf(m, "scsi%d: issue_queue\n", HOSTNO);
 784         for (ptr = (struct scsi_cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
 785                 show_Scsi_Cmnd(ptr, m);
 786
 787         seq_printf(m, "scsi%d: disconnected_queue\n", HOSTNO);
 788         for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
 789              ptr = NEXT(ptr))
 790                 show_Scsi_Cmnd(ptr, m);
 791
 792         local_irq_restore(flags);
 793         return 0;
 794 }
 795
 796 /**
 797  * NCR5380_init - initialise an NCR5380
 798  * @instance: adapter to configure
 799  * @flags: control flags
 800  *
 801  * Initializes *instance and corresponding 5380 chip,
 802  * with flags OR'd into the initial flags value.
 803  *
 804  * Notes : I assume that the host, hostno, and id bits have been
 805  * set correctly. I don't care about the irq and other fields.
 806  *
 807  * Returns 0 for success
 808  */
 809
 810 static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
 811 {
 812         int i;
 813         SETUP_HOSTDATA(instance);
 814
 815         hostdata->host = instance;
 816         hostdata->aborted = 0;
 817         hostdata->id_mask = 1 << instance->this_id;
 818         hostdata->id_higher_mask = 0;
 819         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 820                 if (i > hostdata->id_mask)
 821                         hostdata->id_higher_mask |= i;
 822         for (i = 0; i < 8; ++i)
 823                 hostdata->busy[i] = 0;
 824 #ifdef SUPPORT_TAGS
 825         init_tags(hostdata);
 826 #endif
 827 #if defined (REAL_DMA)
 828         hostdata->dma_len = 0;
 829 #endif
 830         hostdata->targets_present = 0;
 831         hostdata->connected = NULL;
 832         hostdata->issue_queue = NULL;
 833         hostdata->disconnected_queue = NULL;
 834         hostdata->flags = flags;
 835
 836         INIT_WORK(&hostdata->main_task, NCR5380_main);
 837
 838         prepare_info(instance);
 839
 840         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 841         NCR5380_write(MODE_REG, MR_BASE);
 842         NCR5380_write(TARGET_COMMAND_REG, 0);
 843         NCR5380_write(SELECT_ENABLE_REG, 0);
 844
 845         return 0;
 846 }
 847
 848 /**
 849  * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
 850  * @instance: adapter to check
 851  *
 852  * If the system crashed, it may have crashed with a connected target and
 853  * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
 854  * currently established nexus, which we know nothing about. Failing that
 855  * do a bus reset.
 856  *
 857  * Note that a bus reset will cause the chip to assert IRQ.
 858  *
 859  * Returns 0 if successful, otherwise -ENXIO.
 860  */
 861
 862 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
 863 {
 864         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 865         int pass;
 866
 867         for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
 868                 switch (pass) {
 869                 case 1:
 870                 case 3:
 871                 case 5:
 872                         shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
 873                         NCR5380_poll_politely(instance,
 874                                               STATUS_REG, SR_BSY, 0, 5 * HZ);
 875                         break;
 876                 case 2:
 877                         shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
 878                         do_abort(instance);
 879                         break;
 880                 case 4:
 881                         shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
 882                         do_reset(instance);
 883                         /* Wait after a reset; the SCSI standard calls for
 884                          * 250ms, we wait 500ms to be on the safe side.
 885                          * But some Toshiba CD-ROMs need ten times that.
 886                          */
 887                         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
 888                                 msleep(2500);
 889                         else
 890                                 msleep(500);
 891                         break;
 892                 case 6:
 893                         shost_printk(KERN_ERR, instance, "bus locked solid\n");
 894                         return -ENXIO;
 895                 }
 896         }
 897         return 0;
 898 }
 899
 900 /**
 901  * NCR5380_exit - remove an NCR5380
 902  * @instance: adapter to remove
 903  *
 904  * Assumes that no more work can be queued (e.g. by NCR5380_intr).
 905  */
 906
 907 static void NCR5380_exit(struct Scsi_Host *instance)
 908 {
 909         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 910
 911         cancel_work_sync(&hostdata->main_task);
 912 }
 913
 914 /**
 915  * NCR5380_queue_command - queue a command
 916  * @instance: the relevant SCSI adapter
 917  * @cmd: SCSI command
 918  *
 919  * cmd is added to the per instance issue_queue, with minor
 920  * twiddling done to the host specific fields of cmd.  If the
 921  * main coroutine is not running, it is restarted.
 922  */
 923
 924 static int NCR5380_queue_command(struct Scsi_Host *instance,
 925                                  struct scsi_cmnd *cmd)
 926 {
 927         struct NCR5380_hostdata *hostdata = shost_priv(instance);
 928         struct scsi_cmnd *tmp;
 929         unsigned long flags;
 930
 931 #if (NDEBUG & NDEBUG_NO_WRITE)
 932         switch (cmd->cmnd[0]) {
 933         case WRITE_6:
 934         case WRITE_10:
 935                 printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
 936                        H_NO(cmd));
 937                 cmd->result = (DID_ERROR << 16);
 938                 cmd->scsi_done(cmd);
 939                 return 0;
 940         }
 941 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 942
 943         /*
 944          * We use the host_scribble field as a pointer to the next command
 945          * in a queue
 946          */
 947
 948         SET_NEXT(cmd, NULL);
 949         cmd->result = 0;
 950
 951         /*
 952          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 953          * commands are added to the head of the queue since any command will
 954          * clear the contingent allegiance condition that exists and the
 955          * sense data is only guaranteed to be valid while the condition exists.
 956          */
 957
 958         /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
 959          * Otherwise a running NCR5380_main may steal the lock.
 960          * Lock before actually inserting due to fairness reasons explained in
 961          * atari_scsi.c. If we insert first, then it's impossible for this driver
 962          * to release the lock.
 963          * Stop timer for this command while waiting for the lock, or timeouts
 964          * may happen (and they really do), and it's no good if the command doesn't
 965          * appear in any of the queues.
 966          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
 967          * because also a timer int can trigger an abort or reset, which would
 968          * alter queues and touch the lock.
 969          */
 970         if (!NCR5380_acquire_dma_irq(instance))
 971                 return SCSI_MLQUEUE_HOST_BUSY;
 972
 973         local_irq_save(flags);
 974
 975         /*
 976          * Insert the cmd into the issue queue. Note that REQUEST SENSE
 977          * commands are added to the head of the queue since any command will
 978          * clear the contingent allegiance condition that exists and the
 979          * sense data is only guaranteed to be valid while the condition exists.
 980          */
 981
 982         if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
 983                 LIST(cmd, hostdata->issue_queue);
 984                 SET_NEXT(cmd, hostdata->issue_queue);
 985                 hostdata->issue_queue = cmd;
 986         } else {
 987                 for (tmp = (struct scsi_cmnd *)hostdata->issue_queue;
 988                      NEXT(tmp); tmp = NEXT(tmp))
 989                         ;
 990                 LIST(cmd, tmp);
 991                 SET_NEXT(tmp, cmd);
 992         }
 993         local_irq_restore(flags);
 994
 995         dprintk(NDEBUG_QUEUES, "scsi%d: command added to %s of queue\n", H_NO(cmd),
 996                   (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 997
 998         /* If queue_command() is called from an interrupt (real one or bottom
 999          * half), we let queue_main() do the job of taking care about main. If it
1000          * is already running, this is a no-op, else main will be queued.
1001          *
1002          * If we're not in an interrupt, we can call NCR5380_main()
1003          * unconditionally, because it cannot be already running.
1004          */
1005         if (in_interrupt() || irqs_disabled())
1006                 queue_main(hostdata);
1007         else
1008                 NCR5380_main(&hostdata->main_task);
1009         return 0;
1010 }
1011
1012 static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
1013 {
1014         struct NCR5380_hostdata *hostdata = shost_priv(instance);
1015
1016         /* Caller does the locking needed to set & test these data atomically */
1017         if (!hostdata->disconnected_queue &&
1018             !hostdata->issue_queue &&
1019             !hostdata->connected &&
1020             !hostdata->retain_dma_intr)
1021                 NCR5380_release_dma_irq(instance);
1022 }
1023
1024 /**
1025  * NCR5380_main - NCR state machines
1026  *
1027  * NCR5380_main is a coroutine that runs as long as more work can
1028  * be done on the NCR5380 host adapters in a system.  Both
1029  * NCR5380_queue_command() and NCR5380_intr() will try to start it
1030  * in case it is not running.
1031  *
1032  * Locks: called as its own thread with no locks held.
1033  */
1034
1035 static void NCR5380_main(struct work_struct *work)
1036 {
1037         struct NCR5380_hostdata *hostdata =
1038                 container_of(work, struct NCR5380_hostdata, main_task);
1039         struct Scsi_Host *instance = hostdata->host;
1040         struct scsi_cmnd *tmp, *prev;
1041         int done;
1042         unsigned long flags;
1043
1044         /*
1045          * We run (with interrupts disabled) until we're sure that none of
1046          * the host adapters have anything that can be done, at which point
1047          * we set main_running to 0 and exit.
1048          *
1049          * Interrupts are enabled before doing various other internal
1050          * instructions, after we've decided that we need to run through
1051          * the loop again.
1052          *
1053          * this should prevent any race conditions.
1054          *
1055          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1056          * because also a timer int can trigger an abort or reset, which can
1057          * alter queues and touch the Falcon lock.
1058          */
1059
1060         /* Tell int handlers main() is now already executing.  Note that
1061            no races are possible here. If an int comes in before
1062            'main_running' is set here, and queues/executes main via the
1063            task queue, it doesn't do any harm, just this instance of main
1064            won't find any work left to do. */
1065         if (hostdata->main_running)
1066                 return;
1067         hostdata->main_running = 1;
1068
1069         local_save_flags(flags);
1070         do {
1071                 local_irq_disable();    /* Freeze request queues */
1072                 done = 1;
1073
1074                 if (!hostdata->connected) {
1075                         dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO);
1076                         /*
1077                          * Search through the issue_queue for a command destined
1078                          * for a target that's not busy.
1079                          */
1080 #if (NDEBUG & NDEBUG_LISTS)
1081                         for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL;
1082                              tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
1083                                 ;
1084                         /*printk("%p  ", tmp);*/
1085                         if ((tmp == prev) && tmp)
1086                                 printk(" LOOP\n");
1087                         /* else printk("\n"); */
1088 #endif
1089                         for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
1090                              prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
1091                                 u8 lun = tmp->device->lun;
1092
1093                                 dprintk(NDEBUG_LISTS,
1094                                         "MAIN tmp=%p target=%d busy=%d lun=%d\n",
1095                                         tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)],
1096                                         lun);
1097                                 /*  When we find one, remove it from the issue queue. */
1098                                 /* ++guenther: possible race with Falcon locking */
1099                                 if (
1100 #ifdef SUPPORT_TAGS
1101                                     !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
1102 #else
1103                                     !(hostdata->busy[tmp->device->id] & (1 << lun))
1104 #endif
1105                                     ) {
1106                                         /* ++guenther: just to be sure, this must be atomic */
1107                                         local_irq_disable();
1108                                         if (prev) {
1109                                                 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1110                                                 SET_NEXT(prev, NEXT(tmp));
1111                                         } else {
1112                                                 REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
1113                                                 hostdata->issue_queue = NEXT(tmp);
1114                                         }
1115                                         SET_NEXT(tmp, NULL);
1116                                         hostdata->retain_dma_intr++;
1117
1118                                         /* reenable interrupts after finding one */
1119                                         local_irq_restore(flags);
1120
1121                                         /*
1122                                          * Attempt to establish an I_T_L nexus here.
1123                                          * On success, instance->hostdata->connected is set.
1124                                          * On failure, we must add the command back to the
1125                                          *   issue queue so we can keep trying.
1126                                          */
1127                                         dprintk(NDEBUG_MAIN, "scsi%d: main(): command for target %d "
1128                                                     "lun %d removed from issue_queue\n",
1129                                                     HOSTNO, tmp->device->id, lun);
1130                                         /*
1131                                          * REQUEST SENSE commands are issued without tagged
1132                                          * queueing, even on SCSI-II devices because the
1133                                          * contingent allegiance condition exists for the
1134                                          * entire unit.
1135                                          */
1136                                         /* ++roman: ...and the standard also requires that
1137                                          * REQUEST SENSE command are untagged.
1138                                          */
1139
1140 #ifdef SUPPORT_TAGS
1141                                         cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
1142 #endif
1143                                         if (!NCR5380_select(instance, tmp)) {
1144                                                 local_irq_disable();
1145                                                 hostdata->retain_dma_intr--;
1146                                                 /* release if target did not response! */
1147                                                 maybe_release_dma_irq(instance);
1148                                                 local_irq_restore(flags);
1149                                                 break;
1150                                         } else {
1151                                                 local_irq_disable();
1152                                                 LIST(tmp, hostdata->issue_queue);
1153                                                 SET_NEXT(tmp, hostdata->issue_queue);
1154                                                 hostdata->issue_queue = tmp;
1155 #ifdef SUPPORT_TAGS
1156                                                 cmd_free_tag(tmp);
1157 #endif
1158                                                 hostdata->retain_dma_intr--;
1159                                                 local_irq_restore(flags);
1160                                                 dprintk(NDEBUG_MAIN, "scsi%d: main(): select() failed, "
1161                                                             "returned to issue_queue\n", HOSTNO);
1162                                                 if (hostdata->connected)
1163                                                         break;
1164                                         }
1165                                 } /* if target/lun/target queue is not busy */
1166                         } /* for issue_queue */
1167                 } /* if (!hostdata->connected) */
1168
1169                 if (hostdata->connected
1170 #ifdef REAL_DMA
1171                     && !hostdata->dma_len
1172 #endif
1173                     ) {
1174                         local_irq_restore(flags);
1175                         dprintk(NDEBUG_MAIN, "scsi%d: main: performing information transfer\n",
1176                                     HOSTNO);
1177                         NCR5380_information_transfer(instance);
1178                         dprintk(NDEBUG_MAIN, "scsi%d: main: done set false\n", HOSTNO);
1179                         done = 0;
1180                 }
1181         } while (!done);
1182
1183         /* Better allow ints _after_ 'main_running' has been cleared, else
1184            an interrupt could believe we'll pick up the work it left for
1185            us, but we won't see it anymore here... */
1186         hostdata->main_running = 0;
1187         local_irq_restore(flags);
1188 }
1189
1190
1191 #ifdef REAL_DMA
1192 /*
1193  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1194  *
1195  * Purpose : Called by interrupt handler when DMA finishes or a phase
1196  *      mismatch occurs (which would finish the DMA transfer).
1197  *
1198  * Inputs : instance - this instance of the NCR5380.
1199  *
1200  */
1201
1202 static void NCR5380_dma_complete(struct Scsi_Host *instance)
1203 {
1204         SETUP_HOSTDATA(instance);
1205         int transferred;
1206         unsigned char **data;
1207         volatile int *count;
1208         int saved_data = 0, overrun = 0;
1209         unsigned char p;
1210
1211         if (!hostdata->connected) {
1212                 printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
1213                        "no connected cmd\n", HOSTNO);
1214                 return;
1215         }
1216
1217         if (hostdata->read_overruns) {
1218                 p = hostdata->connected->SCp.phase;
1219                 if (p & SR_IO) {
1220                         udelay(10);
1221                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
1222                              (BASR_PHASE_MATCH|BASR_ACK)) ==
1223                             (BASR_PHASE_MATCH|BASR_ACK)) {
1224                                 saved_data = NCR5380_read(INPUT_DATA_REG);
1225                                 overrun = 1;
1226                                 dprintk(NDEBUG_DMA, "scsi%d: read overrun handled\n", HOSTNO);
1227                         }
1228                 }
1229         }
1230
1231         dprintk(NDEBUG_DMA, "scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1232                    HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
1233                    NCR5380_read(STATUS_REG));
1234
1235 #if defined(CONFIG_SUN3)
1236         if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
1237                 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
1238                        instance->host_no);
1239                 BUG();
1240         }
1241
1242         /* make sure we're not stuck in a data phase */
1243         if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
1244             (BASR_PHASE_MATCH | BASR_ACK)) {
1245                 pr_err("scsi%d: BASR %02x\n", instance->host_no,
1246                        NCR5380_read(BUS_AND_STATUS_REG));
1247                 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
1248                        instance->host_no);
1249                 BUG();
1250         }
1251 #endif
1252
1253         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1254         NCR5380_write(MODE_REG, MR_BASE);
1255         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1256
1257         transferred = hostdata->dma_len - NCR5380_dma_residual(instance);
1258         hostdata->dma_len = 0;
1259
1260         data = (unsigned char **)&hostdata->connected->SCp.ptr;
1261         count = &hostdata->connected->SCp.this_residual;
1262         *data += transferred;
1263         *count -= transferred;
1264
1265         if (hostdata->read_overruns) {
1266                 int cnt, toPIO;
1267
1268                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1269                         cnt = toPIO = hostdata->read_overruns;
1270                         if (overrun) {
1271                                 dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1272                                 *(*data)++ = saved_data;
1273                                 (*count)--;
1274                                 cnt--;
1275                                 toPIO--;
1276                         }
1277                         dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1278                         NCR5380_transfer_pio(instance, &p, &cnt, data);
1279                         *count -= toPIO - cnt;
1280                 }
1281         }
1282 }
1283 #endif /* REAL_DMA */
1284
1285
1286 /**
1287  * NCR5380_intr - generic NCR5380 irq handler
1288  * @irq: interrupt number
1289  * @dev_id: device info
1290  *
1291  * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1292  * from the disconnected queue, and restarting NCR5380_main()
1293  * as required.
1294  */
1295
1296 static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1297 {
1298         struct Scsi_Host *instance = dev_id;
1299         int done = 1, handled = 0;
1300         unsigned char basr;
1301
1302         dprintk(NDEBUG_INTR, "scsi%d: NCR5380 irq triggered\n", HOSTNO);
1303
1304         /* Look for pending interrupts */
1305         basr = NCR5380_read(BUS_AND_STATUS_REG);
1306         dprintk(NDEBUG_INTR, "scsi%d: BASR=%02x\n", HOSTNO, basr);
1307         /* dispatch to appropriate routine if found and done=0 */
1308         if (basr & BASR_IRQ) {
1309                 NCR5380_dprint(NDEBUG_INTR, instance);
1310                 if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
1311                         done = 0;
1312                         dprintk(NDEBUG_INTR, "scsi%d: SEL interrupt\n", HOSTNO);
1313                         NCR5380_reselect(instance);
1314                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1315                 } else if (basr & BASR_PARITY_ERROR) {
1316                         dprintk(NDEBUG_INTR, "scsi%d: PARITY interrupt\n", HOSTNO);
1317                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1318                 } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1319                         dprintk(NDEBUG_INTR, "scsi%d: RESET interrupt\n", HOSTNO);
1320                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1321                 } else {
1322                         /*
1323                          * The rest of the interrupt conditions can occur only during a
1324                          * DMA transfer
1325                          */
1326
1327 #if defined(REAL_DMA)
1328                         /*
1329                          * We should only get PHASE MISMATCH and EOP interrupts if we have
1330                          * DMA enabled, so do a sanity check based on the current setting
1331                          * of the MODE register.
1332                          */
1333
1334                         if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
1335                             ((basr & BASR_END_DMA_TRANSFER) ||
1336                              !(basr & BASR_PHASE_MATCH))) {
1337
1338                                 dprintk(NDEBUG_INTR, "scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1339                                 NCR5380_dma_complete( instance );
1340                                 done = 0;
1341                         } else
1342 #endif /* REAL_DMA */
1343                         {
1344 /* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1345                                 if (basr & BASR_PHASE_MATCH)
1346                                         dprintk(NDEBUG_INTR, "scsi%d: unknown interrupt, "
1347                                                "BASR 0x%x, MR 0x%x, SR 0x%x\n",
1348                                                HOSTNO, basr, NCR5380_read(MODE_REG),
1349                                                NCR5380_read(STATUS_REG));
1350                                 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1351 #ifdef SUN3_SCSI_VME
1352                                 dregs->csr |= CSR_DMA_ENABLE;
1353 #endif
1354                         }
1355                 } /* if !(SELECTION || PARITY) */
1356                 handled = 1;
1357         } /* BASR & IRQ */ else {
1358                 printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
1359                        "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
1360                        NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1361                 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1362 #ifdef SUN3_SCSI_VME
1363                 dregs->csr |= CSR_DMA_ENABLE;
1364 #endif
1365         }
1366
1367         if (!done) {
1368                 dprintk(NDEBUG_INTR, "scsi%d: in int routine, calling main\n", HOSTNO);
1369                 /* Put a call to NCR5380_main() on the queue... */
1370                 queue_main(shost_priv(instance));
1371         }
1372         return IRQ_RETVAL(handled);
1373 }
1374
1375 /*
1376  * Function : int NCR5380_select(struct Scsi_Host *instance,
1377  *                               struct scsi_cmnd *cmd)
1378  *
1379  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1380  *      including ARBITRATION, SELECTION, and initial message out for
1381  *      IDENTIFY and queue messages.
1382  *
1383  * Inputs : instance - instantiation of the 5380 driver on which this
1384  *      target lives, cmd - SCSI command to execute.
1385  *
1386  * Returns : -1 if selection could not execute for some reason,
1387  *      0 if selection succeeded or failed because the target
1388  *      did not respond.
1389  *
1390  * Side effects :
1391  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1392  *              with registers as they should have been on entry - ie
1393  *              SELECT_ENABLE will be set appropriately, the NCR5380
1394  *              will cease to drive any SCSI bus signals.
1395  *
1396  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1397  *              instance->connected will be set to cmd.
1398  *              SELECT interrupt will be disabled.
1399  *
1400  *      If failed (no target) : cmd->scsi_done() will be called, and the
1401  *              cmd->result host byte set to DID_BAD_TARGET.
1402  */
1403
1404 static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
1405 {
1406         SETUP_HOSTDATA(instance);
1407         unsigned char tmp[3], phase;
1408         unsigned char *data;
1409         int len;
1410         unsigned long timeout;
1411         unsigned long flags;
1412
1413         hostdata->restart_select = 0;
1414         NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1415         dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
1416                    instance->this_id);
1417
1418         /*
1419          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1420          * data bus during SELECTION.
1421          */
1422
1423         local_irq_save(flags);
1424         if (hostdata->connected) {
1425                 local_irq_restore(flags);
1426                 return -1;
1427         }
1428         NCR5380_write(TARGET_COMMAND_REG, 0);
1429
1430         /*
1431          * Start arbitration.
1432          */
1433
1434         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1435         NCR5380_write(MODE_REG, MR_ARBITRATE);
1436
1437         local_irq_restore(flags);
1438
1439         /* Wait for arbitration logic to complete */
1440 #if defined(NCR_TIMEOUT)
1441         {
1442                 unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
1443
1444                 while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1445                        time_before(jiffies, timeout) && !hostdata->connected)
1446                         ;
1447                 if (time_after_eq(jiffies, timeout)) {
1448                         printk("scsi : arbitration timeout at %d\n", __LINE__);
1449                         NCR5380_write(MODE_REG, MR_BASE);
1450                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1451                         return -1;
1452                 }
1453         }
1454 #else /* NCR_TIMEOUT */
1455         while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1456                !hostdata->connected)
1457                 ;
1458 #endif
1459
1460         dprintk(NDEBUG_ARBITRATION, "scsi%d: arbitration complete\n", HOSTNO);
1461
1462         if (hostdata->connected) {
1463                 NCR5380_write(MODE_REG, MR_BASE);
1464                 return -1;
1465         }
1466         /*
1467          * The arbitration delay is 2.2us, but this is a minimum and there is
1468          * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1469          * the integral nature of udelay().
1470          *
1471          */
1472
1473         udelay(3);
1474
1475         /* Check for lost arbitration */
1476         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1477             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1478             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1479             hostdata->connected) {
1480                 NCR5380_write(MODE_REG, MR_BASE);
1481                 dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1482                            HOSTNO);
1483                 return -1;
1484         }
1485
1486         /* after/during arbitration, BSY should be asserted.
1487            IBM DPES-31080 Version S31Q works now */
1488         /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
1489         NCR5380_write(INITIATOR_COMMAND_REG,
1490                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1491
1492         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1493             hostdata->connected) {
1494                 NCR5380_write(MODE_REG, MR_BASE);
1495                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1496                 dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1497                            HOSTNO);
1498                 return -1;
1499         }
1500
1501         /*
1502          * Again, bus clear + bus settle time is 1.2us, however, this is
1503          * a minimum so we'll udelay ceil(1.2)
1504          */
1505
1506         if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1507                 udelay(15);
1508         else
1509                 udelay(2);
1510
1511         if (hostdata->connected) {
1512                 NCR5380_write(MODE_REG, MR_BASE);
1513                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1514                 return -1;
1515         }
1516
1517         dprintk(NDEBUG_ARBITRATION, "scsi%d: won arbitration\n", HOSTNO);
1518
1519         /*
1520          * Now that we have won arbitration, start Selection process, asserting
1521          * the host and target ID's on the SCSI bus.
1522          */
1523
1524         NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
1525
1526         /*
1527          * Raise ATN while SEL is true before BSY goes false from arbitration,
1528          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1529          * phase immediately after selection.
1530          */
1531
1532         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
1533                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1534         NCR5380_write(MODE_REG, MR_BASE);
1535
1536         /*
1537          * Reselect interrupts must be turned off prior to the dropping of BSY,
1538          * otherwise we will trigger an interrupt.
1539          */
1540
1541         if (hostdata->connected) {
1542                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1543                 return -1;
1544         }
1545
1546         NCR5380_write(SELECT_ENABLE_REG, 0);
1547
1548         /*
1549          * The initiator shall then wait at least two deskew delays and release
1550          * the BSY signal.
1551          */
1552         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1553
1554         /* Reset BSY */
1555         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
1556                       ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1557
1558         /*
1559          * Something weird happens when we cease to drive BSY - looks
1560          * like the board/chip is letting us do another read before the
1561          * appropriate propagation delay has expired, and we're confusing
1562          * a BSY signal from ourselves as the target's response to SELECTION.
1563          *
1564          * A small delay (the 'C++' frontend breaks the pipeline with an
1565          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1566          * tighter 'C' code breaks and requires this) solves the problem -
1567          * the 1 us delay is arbitrary, and only used because this delay will
1568          * be the same on other platforms and since it works here, it should
1569          * work there.
1570          *
1571          * wingel suggests that this could be due to failing to wait
1572          * one deskew delay.
1573          */
1574
1575         udelay(1);
1576
1577         dprintk(NDEBUG_SELECTION, "scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
1578
1579         /*
1580          * The SCSI specification calls for a 250 ms timeout for the actual
1581          * selection.
1582          */
1583
1584         timeout = jiffies + msecs_to_jiffies(250);
1585
1586         /*
1587          * XXX very interesting - we're seeing a bounce where the BSY we
1588          * asserted is being reflected / still asserted (propagation delay?)
1589          * and it's detecting as true.  Sigh.
1590          */
1591
1592 #if 0
1593         /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
1594          * IO while SEL is true. But again, there are some disks out the in the
1595          * world that do that nevertheless. (Somebody claimed that this announces
1596          * reselection capability of the target.) So we better skip that test and
1597          * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
1598          */
1599
1600         while (time_before(jiffies, timeout) &&
1601                !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
1602                 ;
1603
1604         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1605                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1606                 NCR5380_reselect(instance);
1607                 printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
1608                        HOSTNO);
1609                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1610                 return -1;
1611         }
1612 #else
1613         while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
1614                 ;
1615 #endif
1616
1617         /*
1618          * No less than two deskew delays after the initiator detects the
1619          * BSY signal is true, it shall release the SEL signal and may
1620          * change the DATA BUS.                                     -wingel
1621          */
1622
1623         udelay(1);
1624
1625         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1626
1627         if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1628                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1629                 if (hostdata->targets_present & (1 << cmd->device->id)) {
1630                         printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
1631                         if (hostdata->restart_select)
1632                                 printk(KERN_NOTICE "\trestart select\n");
1633                         NCR5380_dprint(NDEBUG_ANY, instance);
1634                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1635                         return -1;
1636                 }
1637                 cmd->result = DID_BAD_TARGET << 16;
1638 #ifdef SUPPORT_TAGS
1639                 cmd_free_tag(cmd);
1640 #endif
1641                 cmd->scsi_done(cmd);
1642                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1643                 dprintk(NDEBUG_SELECTION, "scsi%d: target did not respond within 250ms\n", HOSTNO);
1644                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1645                 return 0;
1646         }
1647
1648         hostdata->targets_present |= (1 << cmd->device->id);
1649
1650         /*
1651          * Since we followed the SCSI spec, and raised ATN while SEL
1652          * was true but before BSY was false during selection, the information
1653          * transfer phase should be a MESSAGE OUT phase so that we can send the
1654          * IDENTIFY message.
1655          *
1656          * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1657          * message (2 bytes) with a tag ID that we increment with every command
1658          * until it wraps back to 0.
1659          *
1660          * XXX - it turns out that there are some broken SCSI-II devices,
1661          *           which claim to support tagged queuing but fail when more than
1662          *           some number of commands are issued at once.
1663          */
1664
1665         /* Wait for start of REQ/ACK handshake */
1666         while (!(NCR5380_read(STATUS_REG) & SR_REQ))
1667                 ;
1668
1669         dprintk(NDEBUG_SELECTION, "scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1670                    HOSTNO, cmd->device->id);
1671         tmp[0] = IDENTIFY(1, cmd->device->lun);
1672
1673 #ifdef SUPPORT_TAGS
1674         if (cmd->tag != TAG_NONE) {
1675                 tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1676                 tmp[2] = cmd->tag;
1677                 len = 3;
1678         } else
1679                 len = 1;
1680 #else
1681         len = 1;
1682         cmd->tag = 0;
1683 #endif /* SUPPORT_TAGS */
1684
1685         /* Send message(s) */
1686         data = tmp;
1687         phase = PHASE_MSGOUT;
1688         NCR5380_transfer_pio(instance, &phase, &len, &data);
1689         dprintk(NDEBUG_SELECTION, "scsi%d: nexus established.\n", HOSTNO);
1690         /* XXX need to handle errors here */
1691         hostdata->connected = cmd;
1692 #ifndef SUPPORT_TAGS
1693         hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1694 #endif
1695 #ifdef SUN3_SCSI_VME
1696         dregs->csr |= CSR_INTR;
1697 #endif
1698
1699         initialize_SCp(cmd);
1700
1701         return 0;
1702 }
1703
1704 /*
1705  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1706  *      unsigned char *phase, int *count, unsigned char **data)
1707  *
1708  * Purpose : transfers data in given phase using polled I/O
1709  *
1710  * Inputs : instance - instance of driver, *phase - pointer to
1711  *      what phase is expected, *count - pointer to number of
1712  *      bytes to transfer, **data - pointer to data pointer.
1713  *
1714  * Returns : -1 when different phase is entered without transferring
1715  *      maximum number of bytes, 0 if all bytes are transferred or exit
1716  *      is in same phase.
1717  *
1718  *      Also, *phase, *count, *data are modified in place.
1719  *
1720  * XXX Note : handling for bus free may be useful.
1721  */
1722
1723 /*
1724  * Note : this code is not as quick as it could be, however it
1725  * IS 100% reliable, and for the actual data transfer where speed
1726  * counts, we will always do a pseudo DMA or DMA transfer.
1727  */
1728
1729 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1730                                 unsigned char *phase, int *count,
1731                                 unsigned char **data)
1732 {
1733         register unsigned char p = *phase, tmp;
1734         register int c = *count;
1735         register unsigned char *d = *data;
1736
1737         /*
1738          * The NCR5380 chip will only drive the SCSI bus when the
1739          * phase specified in the appropriate bits of the TARGET COMMAND
1740          * REGISTER match the STATUS REGISTER
1741          */
1742
1743         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1744
1745         do {
1746                 /*
1747                  * Wait for assertion of REQ, after which the phase bits will be
1748                  * valid
1749                  */
1750                 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1751                         ;
1752
1753                 dprintk(NDEBUG_HANDSHAKE, "scsi%d: REQ detected\n", HOSTNO);
1754
1755                 /* Check for phase mismatch */
1756                 if ((tmp & PHASE_MASK) != p) {
1757                         dprintk(NDEBUG_PIO, "scsi%d: phase mismatch\n", HOSTNO);
1758                         NCR5380_dprint_phase(NDEBUG_PIO, instance);
1759                         break;
1760                 }
1761
1762                 /* Do actual transfer from SCSI bus to / from memory */
1763                 if (!(p & SR_IO))
1764                         NCR5380_write(OUTPUT_DATA_REG, *d);
1765                 else
1766                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1767
1768                 ++d;
1769
1770                 /*
1771                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1772                  * should drop ATN on the last byte of the message phase
1773                  * after REQ has been asserted for the handshake but before
1774                  * the initiator raises ACK.
1775                  */
1776
1777                 if (!(p & SR_IO)) {
1778                         if (!((p & SR_MSG) && c > 1)) {
1779                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1780                                 NCR5380_dprint(NDEBUG_PIO, instance);
1781                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1782                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1783                         } else {
1784                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1785                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1786                                 NCR5380_dprint(NDEBUG_PIO, instance);
1787                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1788                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1789                         }
1790                 } else {
1791                         NCR5380_dprint(NDEBUG_PIO, instance);
1792                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1793                 }
1794
1795                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1796                         ;
1797
1798                 dprintk(NDEBUG_HANDSHAKE, "scsi%d: req false, handshake complete\n", HOSTNO);
1799
1800                 /*
1801                  * We have several special cases to consider during REQ/ACK handshaking :
1802                  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1803                  *      message.  ATN must be dropped as ACK is dropped.
1804                  *
1805                  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1806                  *      message.  We must exit with ACK asserted, so that the calling
1807                  *      code may raise ATN before dropping ACK to reject the message.
1808                  *
1809                  * 3.  ACK and ATN are clear and the target may proceed as normal.
1810                  */
1811                 if (!(p == PHASE_MSGIN && c == 1)) {
1812                         if (p == PHASE_MSGOUT && c > 1)
1813                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1814                         else
1815                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1816                 }
1817         } while (--c);
1818
1819         dprintk(NDEBUG_PIO, "scsi%d: residual %d\n", HOSTNO, c);
1820
1821         *count = c;
1822         *data = d;
1823         tmp = NCR5380_read(STATUS_REG);
1824         /* The phase read from the bus is valid if either REQ is (already)
1825          * asserted or if ACK hasn't been released yet. The latter is the case if
1826          * we're in MSGIN and all wanted bytes have been received.
1827          */
1828         if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
1829                 *phase = tmp & PHASE_MASK;
1830         else
1831                 *phase = PHASE_UNKNOWN;
1832
1833         if (!c || (*phase == p))
1834                 return 0;
1835         else
1836                 return -1;
1837 }
1838
1839 /**
1840  * do_reset - issue a reset command
1841  * @instance: adapter to reset
1842  *
1843  * Issue a reset sequence to the NCR5380 and try and get the bus
1844  * back into sane shape.
1845  *
1846  * This clears the reset interrupt flag because there may be no handler for
1847  * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1848  * been installed. And when in EH we may have released the ST DMA interrupt.
1849  */
1850
1851 static void do_reset(struct Scsi_Host *instance)
1852 {
1853         unsigned long flags;
1854
1855         local_irq_save(flags);
1856         NCR5380_write(TARGET_COMMAND_REG,
1857                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1858         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1859         udelay(50);
1860         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1861         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1862         local_irq_restore(flags);
1863 }
1864
1865 /*
1866  * Function : do_abort (Scsi_Host *host)
1867  *
1868  * Purpose : abort the currently established nexus.  Should only be
1869  *      called from a routine which can drop into a
1870  *
1871  * Returns : 0 on success, -1 on failure.
1872  */
1873
1874 static int do_abort(struct Scsi_Host *instance)
1875 {
1876         unsigned char tmp, *msgptr, phase;
1877         int len;
1878
1879         /* Request message out phase */
1880         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1881
1882         /*
1883          * Wait for the target to indicate a valid phase by asserting
1884          * REQ.  Once this happens, we'll have either a MSGOUT phase
1885          * and can immediately send the ABORT message, or we'll have some
1886          * other phase and will have to source/sink data.
1887          *
1888          * We really don't care what value was on the bus or what value
1889          * the target sees, so we just handshake.
1890          */
1891
1892         while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1893                 ;
1894
1895         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1896
1897         if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1898                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1899                               ICR_ASSERT_ACK);
1900                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1901                         ;
1902                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1903         }
1904
1905         tmp = ABORT;
1906         msgptr = &tmp;
1907         len = 1;
1908         phase = PHASE_MSGOUT;
1909         NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1910
1911         /*
1912          * If we got here, and the command completed successfully,
1913          * we're about to go into bus free state.
1914          */
1915
1916         return len ? -1 : 0;
1917 }
1918
1919 #if defined(REAL_DMA)
1920 /*
1921  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1922  *      unsigned char *phase, int *count, unsigned char **data)
1923  *
1924  * Purpose : transfers data in given phase using either real
1925  *      or pseudo DMA.
1926  *
1927  * Inputs : instance - instance of driver, *phase - pointer to
1928  *      what phase is expected, *count - pointer to number of
1929  *      bytes to transfer, **data - pointer to data pointer.
1930  *
1931  * Returns : -1 when different phase is entered without transferring
1932  *      maximum number of bytes, 0 if all bytes or transferred or exit
1933  *      is in same phase.
1934  *
1935  *      Also, *phase, *count, *data are modified in place.
1936  *
1937  */
1938
1939
1940 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1941                                 unsigned char *phase, int *count,
1942                                 unsigned char **data)
1943 {
1944         SETUP_HOSTDATA(instance);
1945         register int c = *count;
1946         register unsigned char p = *phase;
1947         unsigned long flags;
1948
1949 #if defined(CONFIG_SUN3)
1950         /* sanity check */
1951         if (!sun3_dma_setup_done) {
1952                 pr_err("scsi%d: transfer_dma without setup!\n",
1953                        instance->host_no);
1954                 BUG();
1955         }
1956         hostdata->dma_len = c;
1957
1958         dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1959                 instance->host_no, (p & SR_IO) ? "reading" : "writing",
1960                 c, (p & SR_IO) ? "to" : "from", *data);
1961
1962         /* netbsd turns off ints here, why not be safe and do it too */
1963         local_irq_save(flags);
1964
1965         /* send start chain */
1966         sun3scsi_dma_start(c, *data);
1967
1968         if (p & SR_IO) {
1969                 NCR5380_write(TARGET_COMMAND_REG, 1);
1970                 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1971                 NCR5380_write(INITIATOR_COMMAND_REG, 0);
1972                 NCR5380_write(MODE_REG,
1973                               (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
1974                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1975         } else {
1976                 NCR5380_write(TARGET_COMMAND_REG, 0);
1977                 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1978                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
1979                 NCR5380_write(MODE_REG,
1980                               (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
1981                 NCR5380_write(START_DMA_SEND_REG, 0);
1982         }
1983
1984 #ifdef SUN3_SCSI_VME
1985         dregs->csr |= CSR_DMA_ENABLE;
1986 #endif
1987
1988         local_irq_restore(flags);
1989
1990         sun3_dma_active = 1;
1991
1992 #else /* !defined(CONFIG_SUN3) */
1993         register unsigned char *d = *data;
1994         unsigned char tmp;
1995
1996         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1997                 *phase = tmp;
1998                 return -1;
1999         }
2000
2001         if (hostdata->read_overruns && (p & SR_IO))
2002                 c -= hostdata->read_overruns;
2003
2004         dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
2005                    HOSTNO, (p & SR_IO) ? "reading" : "writing",
2006                    c, (p & SR_IO) ? "to" : "from", d);
2007
2008         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
2009
2010 #ifdef REAL_DMA
2011         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
2012 #endif /* def REAL_DMA  */
2013
2014         if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
2015                 /* On the Medusa, it is a must to initialize the DMA before
2016                  * starting the NCR. This is also the cleaner way for the TT.
2017                  */
2018                 local_irq_save(flags);
2019                 hostdata->dma_len = (p & SR_IO) ?
2020                         NCR5380_dma_read_setup(instance, d, c) :
2021                         NCR5380_dma_write_setup(instance, d, c);
2022                 local_irq_restore(flags);
2023         }
2024
2025         if (p & SR_IO)
2026                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
2027         else {
2028                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
2029                 NCR5380_write(START_DMA_SEND_REG, 0);
2030         }
2031
2032         if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
2033                 /* On the Falcon, the DMA setup must be done after the last */
2034                 /* NCR access, else the DMA setup gets trashed!
2035                  */
2036                 local_irq_save(flags);
2037                 hostdata->dma_len = (p & SR_IO) ?
2038                         NCR5380_dma_read_setup(instance, d, c) :
2039                         NCR5380_dma_write_setup(instance, d, c);
2040                 local_irq_restore(flags);
2041         }
2042 #endif /* !defined(CONFIG_SUN3) */
2043
2044         return 0;
2045 }
2046 #endif /* defined(REAL_DMA) */
2047
2048 /*
2049  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2050  *
2051  * Purpose : run through the various SCSI phases and do as the target
2052  *      directs us to.  Operates on the currently connected command,
2053  *      instance->connected.
2054  *
2055  * Inputs : instance, instance for which we are doing commands
2056  *
2057  * Side effects : SCSI things happen, the disconnected queue will be
2058  *      modified if a command disconnects, *instance->connected will
2059  *      change.
2060  *
2061  * XXX Note : we need to watch for bus free or a reset condition here
2062  *      to recover from an unexpected bus free condition.
2063  */
2064
2065 static void NCR5380_information_transfer(struct Scsi_Host *instance)
2066 {
2067         SETUP_HOSTDATA(instance);
2068         unsigned long flags;
2069         unsigned char msgout = NOP;
2070         int sink = 0;
2071         int len;
2072 #if defined(REAL_DMA)
2073         int transfersize;
2074 #endif
2075         unsigned char *data;
2076         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2077         struct scsi_cmnd *cmd = (struct scsi_cmnd *) hostdata->connected;
2078
2079 #ifdef SUN3_SCSI_VME
2080         dregs->csr |= CSR_INTR;
2081 #endif
2082
2083         while (1) {
2084                 tmp = NCR5380_read(STATUS_REG);
2085                 /* We only have a valid SCSI phase when REQ is asserted */
2086                 if (tmp & SR_REQ) {
2087                         phase = (tmp & PHASE_MASK);
2088                         if (phase != old_phase) {
2089                                 old_phase = phase;
2090                                 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2091                         }
2092 #if defined(CONFIG_SUN3)
2093                         if (phase == PHASE_CMDOUT) {
2094 #if defined(REAL_DMA)
2095                                 void *d;
2096                                 unsigned long count;
2097
2098                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2099                                         count = cmd->SCp.buffer->length;
2100                                         d = sg_virt(cmd->SCp.buffer);
2101                                 } else {
2102                                         count = cmd->SCp.this_residual;
2103                                         d = cmd->SCp.ptr;
2104                                 }
2105                                 /* this command setup for dma yet? */
2106                                 if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != cmd)) {
2107                                         if (cmd->request->cmd_type == REQ_TYPE_FS) {
2108                                                 sun3scsi_dma_setup(d, count,
2109                                                                    rq_data_dir(cmd->request));
2110                                                 sun3_dma_setup_done = cmd;
2111                                         }
2112                                 }
2113 #endif
2114 #ifdef SUN3_SCSI_VME
2115                                 dregs->csr |= CSR_INTR;
2116 #endif
2117                         }
2118 #endif /* CONFIG_SUN3 */
2119
2120                         if (sink && (phase != PHASE_MSGOUT)) {
2121                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2122
2123                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
2124                                               ICR_ASSERT_ACK);
2125                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
2126                                         ;
2127                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2128                                               ICR_ASSERT_ATN);
2129                                 sink = 0;
2130                                 continue;
2131                         }
2132
2133                         switch (phase) {
2134                         case PHASE_DATAOUT:
2135 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2136                                 printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
2137                                        "aborted\n", HOSTNO);
2138                                 sink = 1;
2139                                 do_abort(instance);
2140                                 cmd->result = DID_ERROR << 16;
2141                                 cmd->scsi_done(cmd);
2142                                 return;
2143 #endif
2144                         case PHASE_DATAIN:
2145                                 /*
2146                                  * If there is no room left in the current buffer in the
2147                                  * scatter-gather list, move onto the next one.
2148                                  */
2149
2150                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2151                                         ++cmd->SCp.buffer;
2152                                         --cmd->SCp.buffers_residual;
2153                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
2154                                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2155                                         /* ++roman: Try to merge some scatter-buffers if
2156                                          * they are at contiguous physical addresses.
2157                                          */
2158                                         merge_contiguous_buffers(cmd);
2159                                         dprintk(NDEBUG_INFORMATION, "scsi%d: %d bytes and %d buffers left\n",
2160                                                    HOSTNO, cmd->SCp.this_residual,
2161                                                    cmd->SCp.buffers_residual);
2162                                 }
2163
2164                                 /*
2165                                  * The preferred transfer method is going to be
2166                                  * PSEUDO-DMA for systems that are strictly PIO,
2167                                  * since we can let the hardware do the handshaking.
2168                                  *
2169                                  * For this to work, we need to know the transfersize
2170                                  * ahead of time, since the pseudo-DMA code will sit
2171                                  * in an unconditional loop.
2172                                  */
2173
2174                                 /* ++roman: I suggest, this should be
2175                                  *   #if def(REAL_DMA)
2176                                  * instead of leaving REAL_DMA out.
2177                                  */
2178
2179 #if defined(REAL_DMA)
2180                                 if (
2181 #if !defined(CONFIG_SUN3)
2182                                     !cmd->device->borken &&
2183 #endif
2184                                     (transfersize = NCR5380_dma_xfer_len(instance, cmd, phase)) >= DMA_MIN_SIZE) {
2185                                         len = transfersize;
2186                                         cmd->SCp.phase = phase;
2187                                         if (NCR5380_transfer_dma(instance, &phase,
2188                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
2189                                                 /*
2190                                                  * If the watchdog timer fires, all future
2191                                                  * accesses to this device will use the
2192                                                  * polled-IO. */
2193                                                 scmd_printk(KERN_INFO, cmd,
2194                                                         "switching to slow handshake\n");
2195                                                 cmd->device->borken = 1;
2196                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2197                                                         ICR_ASSERT_ATN);
2198                                                 sink = 1;
2199                                                 do_abort(instance);
2200                                                 cmd->result = DID_ERROR << 16;
2201                                                 cmd->scsi_done(cmd);
2202                                                 /* XXX - need to source or sink data here, as appropriate */
2203                                         } else {
2204 #ifdef REAL_DMA
2205                                                 /* ++roman: When using real DMA,
2206                                                  * information_transfer() should return after
2207                                                  * starting DMA since it has nothing more to
2208                                                  * do.
2209                                                  */
2210                                                 return;
2211 #else
2212                                                 cmd->SCp.this_residual -= transfersize - len;
2213 #endif
2214                                         }
2215                                 } else
2216 #endif /* defined(REAL_DMA) */
2217                                         NCR5380_transfer_pio(instance, &phase,
2218                                                              (int *)&cmd->SCp.this_residual,
2219                                                              (unsigned char **)&cmd->SCp.ptr);
2220 #if defined(CONFIG_SUN3) && defined(REAL_DMA)
2221                                 /* if we had intended to dma that command clear it */
2222                                 if (sun3_dma_setup_done == cmd)
2223                                         sun3_dma_setup_done = NULL;
2224 #endif
2225                                 break;
2226                         case PHASE_MSGIN:
2227                                 len = 1;
2228                                 data = &tmp;
2229                                 NCR5380_write(SELECT_ENABLE_REG, 0);    /* disable reselects */
2230                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2231                                 cmd->SCp.Message = tmp;
2232
2233                                 switch (tmp) {
2234                                 /*
2235                                  * Linking lets us reduce the time required to get the
2236                                  * next command out to the device, hopefully this will
2237                                  * mean we don't waste another revolution due to the delays
2238                                  * required by ARBITRATION and another SELECTION.
2239                                  *
2240                                  * In the current implementation proposal, low level drivers
2241                                  * merely have to start the next command, pointed to by
2242                                  * next_link, done() is called as with unlinked commands.
2243                                  */
2244 #ifdef LINKED
2245                                 case LINKED_CMD_COMPLETE:
2246                                 case LINKED_FLG_CMD_COMPLETE:
2247                                         /* Accept message by clearing ACK */
2248                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2249
2250                                         dprintk(NDEBUG_LINKED, "scsi%d: target %d lun %llu linked command "
2251                                                    "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
2252
2253                                         /* Enable reselect interrupts */
2254                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2255                                         /*
2256                                          * Sanity check : A linked command should only terminate
2257                                          * with one of these messages if there are more linked
2258                                          * commands available.
2259                                          */
2260
2261                                         if (!cmd->next_link) {
2262                                                  printk(KERN_NOTICE "scsi%d: target %d lun %llu "
2263                                                         "linked command complete, no next_link\n",
2264                                                         HOSTNO, cmd->device->id, cmd->device->lun);
2265                                                 sink = 1;
2266                                                 do_abort(instance);
2267                                                 return;
2268                                         }
2269
2270                                         initialize_SCp(cmd->next_link);
2271                                         /* The next command is still part of this process; copy it
2272                                          * and don't free it! */
2273                                         cmd->next_link->tag = cmd->tag;
2274                                         cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2275                                         dprintk(NDEBUG_LINKED, "scsi%d: target %d lun %llu linked request "
2276                                                    "done, calling scsi_done().\n",
2277                                                    HOSTNO, cmd->device->id, cmd->device->lun);
2278                                         cmd->scsi_done(cmd);
2279                                         cmd = hostdata->connected;
2280                                         break;
2281 #endif /* def LINKED */
2282                                 case ABORT:
2283                                 case COMMAND_COMPLETE:
2284                                         /* Accept message by clearing ACK */
2285                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2286                                         dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d, lun %llu "
2287                                                   "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2288
2289                                         local_irq_save(flags);
2290                                         hostdata->retain_dma_intr++;
2291                                         hostdata->connected = NULL;
2292 #ifdef SUPPORT_TAGS
2293                                         cmd_free_tag(cmd);
2294                                         if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2295                                                 /* Turn a QUEUE FULL status into BUSY, I think the
2296                                                  * mid level cannot handle QUEUE FULL :-( (The
2297                                                  * command is retried after BUSY). Also update our
2298                                                  * queue size to the number of currently issued
2299                                                  * commands now.
2300                                                  */
2301                                                 /* ++Andreas: the mid level code knows about
2302                                                    QUEUE_FULL now. */
2303                                                 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][cmd->device->lun];
2304                                                 dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu returned "
2305                                                            "QUEUE_FULL after %d commands\n",
2306                                                            HOSTNO, cmd->device->id, cmd->device->lun,
2307                                                            ta->nr_allocated);
2308                                                 if (ta->queue_size > ta->nr_allocated)
2309                                                         ta->nr_allocated = ta->queue_size;
2310                                         }
2311 #else
2312                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2313 #endif
2314                                         /* Enable reselect interrupts */
2315                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2316
2317                                         /*
2318                                          * I'm not sure what the correct thing to do here is :
2319                                          *
2320                                          * If the command that just executed is NOT a request
2321                                          * sense, the obvious thing to do is to set the result
2322                                          * code to the values of the stored parameters.
2323                                          *
2324                                          * If it was a REQUEST SENSE command, we need some way to
2325                                          * differentiate between the failure code of the original
2326                                          * and the failure code of the REQUEST sense - the obvious
2327                                          * case is success, where we fall through and leave the
2328                                          * result code unchanged.
2329                                          *
2330                                          * The non-obvious place is where the REQUEST SENSE failed
2331                                          */
2332
2333                                         if (cmd->cmnd[0] != REQUEST_SENSE)
2334                                                 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2335                                         else if (status_byte(cmd->SCp.Status) != GOOD)
2336                                                 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2337
2338                                         if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2339                                                 hostdata->ses.cmd_len) {
2340                                                 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2341                                                 hostdata->ses.cmd_len = 0 ;
2342                                         }
2343
2344                                         if ((cmd->cmnd[0] != REQUEST_SENSE) &&
2345                                             (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2346                                                 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2347
2348                                                 dprintk(NDEBUG_AUTOSENSE, "scsi%d: performing request sense\n", HOSTNO);
2349
2350                                                 LIST(cmd,hostdata->issue_queue);
2351                                                 SET_NEXT(cmd, hostdata->issue_queue);
2352                                                 hostdata->issue_queue = (struct scsi_cmnd *) cmd;
2353                                                 dprintk(NDEBUG_QUEUES, "scsi%d: REQUEST SENSE added to head of "
2354                                                           "issue queue\n", H_NO(cmd));
2355                                         } else {
2356                                                 cmd->scsi_done(cmd);
2357                                         }
2358
2359                                         local_irq_restore(flags);
2360
2361                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2362                                         /*
2363                                          * Restore phase bits to 0 so an interrupted selection,
2364                                          * arbitration can resume.
2365                                          */
2366                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2367
2368                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2369                                                 barrier();
2370
2371                                         local_irq_save(flags);
2372                                         hostdata->retain_dma_intr--;
2373                                         /* ++roman: For Falcon SCSI, release the lock on the
2374                                          * ST-DMA here if no other commands are waiting on the
2375                                          * disconnected queue.
2376                                          */
2377                                         maybe_release_dma_irq(instance);
2378                                         local_irq_restore(flags);
2379                                         return;
2380                                 case MESSAGE_REJECT:
2381                                         /* Accept message by clearing ACK */
2382                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2383                                         /* Enable reselect interrupts */
2384                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2385                                         switch (hostdata->last_message) {
2386                                         case HEAD_OF_QUEUE_TAG:
2387                                         case ORDERED_QUEUE_TAG:
2388                                         case SIMPLE_QUEUE_TAG:
2389                                                 /* The target obviously doesn't support tagged
2390                                                  * queuing, even though it announced this ability in
2391                                                  * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2392                                                  * clear 'tagged_supported' and lock the LUN, since
2393                                                  * the command is treated as untagged further on.
2394                                                  */
2395                                                 cmd->device->tagged_supported = 0;
2396                                                 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2397                                                 cmd->tag = TAG_NONE;
2398                                                 dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu rejected "
2399                                                            "QUEUE_TAG message; tagged queuing "
2400                                                            "disabled\n",
2401                                                            HOSTNO, cmd->device->id, cmd->device->lun);
2402                                                 break;
2403                                         }
2404                                         break;
2405                                 case DISCONNECT:
2406                                         /* Accept message by clearing ACK */
2407                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2408                                         local_irq_save(flags);
2409                                         cmd->device->disconnect = 1;
2410                                         LIST(cmd,hostdata->disconnected_queue);
2411                                         SET_NEXT(cmd, hostdata->disconnected_queue);
2412                                         hostdata->connected = NULL;
2413                                         hostdata->disconnected_queue = cmd;
2414                                         local_irq_restore(flags);
2415                                         dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d lun %llu was "
2416                                                   "moved from connected to the "
2417                                                   "disconnected_queue\n", HOSTNO,
2418                                                   cmd->device->id, cmd->device->lun);
2419                                         /*
2420                                          * Restore phase bits to 0 so an interrupted selection,
2421                                          * arbitration can resume.
2422                                          */
2423                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2424
2425                                         /* Enable reselect interrupts */
2426                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2427                                         /* Wait for bus free to avoid nasty timeouts */
2428                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2429                                                 barrier();
2430 #ifdef SUN3_SCSI_VME
2431                                         dregs->csr |= CSR_DMA_ENABLE;
2432 #endif
2433                                         return;
2434                                         /*
2435                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2436                                          * operation, in violation of the SCSI spec so we can safely
2437                                          * ignore SAVE/RESTORE pointers calls.
2438                                          *
2439                                          * Unfortunately, some disks violate the SCSI spec and
2440                                          * don't issue the required SAVE_POINTERS message before
2441                                          * disconnecting, and we have to break spec to remain
2442                                          * compatible.
2443                                          */
2444                                 case SAVE_POINTERS:
2445                                 case RESTORE_POINTERS:
2446                                         /* Accept message by clearing ACK */
2447                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2448                                         /* Enable reselect interrupts */
2449                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2450                                         break;
2451                                 case EXTENDED_MESSAGE:
2452                                         /*
2453                                          * Extended messages are sent in the following format :
2454                                          * Byte
2455                                          * 0            EXTENDED_MESSAGE == 1
2456                                          * 1            length (includes one byte for code, doesn't
2457                                          *              include first two bytes)
2458                                          * 2            code
2459                                          * 3..length+1  arguments
2460                                          *
2461                                          * Start the extended message buffer with the EXTENDED_MESSAGE
2462                                          * byte, since spi_print_msg() wants the whole thing.
2463                                          */
2464                                         extended_msg[0] = EXTENDED_MESSAGE;
2465                                         /* Accept first byte by clearing ACK */
2466                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2467
2468                                         dprintk(NDEBUG_EXTENDED, "scsi%d: receiving extended message\n", HOSTNO);
2469
2470                                         len = 2;
2471                                         data = extended_msg + 1;
2472                                         phase = PHASE_MSGIN;
2473                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
2474                                         dprintk(NDEBUG_EXTENDED, "scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2475                                                    (int)extended_msg[1], (int)extended_msg[2]);
2476
2477                                         if (!len && extended_msg[1] <=
2478                                             (sizeof(extended_msg) - 1)) {
2479                                                 /* Accept third byte by clearing ACK */
2480                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2481                                                 len = extended_msg[1] - 1;
2482                                                 data = extended_msg + 3;
2483                                                 phase = PHASE_MSGIN;
2484
2485                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2486                                                 dprintk(NDEBUG_EXTENDED, "scsi%d: message received, residual %d\n",
2487                                                            HOSTNO, len);
2488
2489                                                 switch (extended_msg[2]) {
2490                                                 case EXTENDED_SDTR:
2491                                                 case EXTENDED_WDTR:
2492                                                 case EXTENDED_MODIFY_DATA_POINTER:
2493                                                 case EXTENDED_EXTENDED_IDENTIFY:
2494                                                         tmp = 0;
2495                                                 }
2496                                         } else if (len) {
2497                                                 printk(KERN_NOTICE "scsi%d: error receiving "
2498                                                        "extended message\n", HOSTNO);
2499                                                 tmp = 0;
2500                                         } else {
2501                                                 printk(KERN_NOTICE "scsi%d: extended message "
2502                                                            "code %02x length %d is too long\n",
2503                                                            HOSTNO, extended_msg[2], extended_msg[1]);
2504                                                 tmp = 0;
2505                                         }
2506                                         /* Fall through to reject message */
2507
2508                                         /*
2509                                          * If we get something weird that we aren't expecting,
2510                                          * reject it.
2511                                          */
2512                                 default:
2513                                         if (!tmp) {
2514                                                 printk(KERN_INFO "scsi%d: rejecting message ",
2515                                                        instance->host_no);
2516                                                 spi_print_msg(extended_msg);
2517                                                 printk("\n");
2518                                         } else if (tmp != EXTENDED_MESSAGE)
2519                                                 scmd_printk(KERN_INFO, cmd,
2520                                                             "rejecting unknown message %02x\n",
2521                                                             tmp);
2522                                         else
2523                                                 scmd_printk(KERN_INFO, cmd,
2524                                                             "rejecting unknown extended message code %02x, length %d\n",
2525                                                             extended_msg[1], extended_msg[0]);
2526
2527                                         msgout = MESSAGE_REJECT;
2528                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2529                                         break;
2530                                 } /* switch (tmp) */
2531                                 break;
2532                         case PHASE_MSGOUT:
2533                                 len = 1;
2534                                 data = &msgout;
2535                                 hostdata->last_message = msgout;
2536                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2537                                 if (msgout == ABORT) {
2538                                         local_irq_save(flags);
2539 #ifdef SUPPORT_TAGS
2540                                         cmd_free_tag(cmd);
2541 #else
2542                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2543 #endif
2544                                         hostdata->connected = NULL;
2545                                         cmd->result = DID_ERROR << 16;
2546                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2547                                         maybe_release_dma_irq(instance);
2548                                         local_irq_restore(flags);
2549                                         cmd->scsi_done(cmd);
2550                                         return;
2551                                 }
2552                                 msgout = NOP;
2553                                 break;
2554                         case PHASE_CMDOUT:
2555                                 len = cmd->cmd_len;
2556                                 data = cmd->cmnd;
2557                                 /*
2558                                  * XXX for performance reasons, on machines with a
2559                                  * PSEUDO-DMA architecture we should probably
2560                                  * use the dma transfer function.
2561                                  */
2562                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2563                                 break;
2564                         case PHASE_STATIN:
2565                                 len = 1;
2566                                 data = &tmp;
2567                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2568                                 cmd->SCp.Status = tmp;
2569                                 break;
2570                         default:
2571                                 printk("scsi%d: unknown phase\n", HOSTNO);
2572                                 NCR5380_dprint(NDEBUG_ANY, instance);
2573                         } /* switch(phase) */
2574                 } /* if (tmp * SR_REQ) */
2575         } /* while (1) */
2576 }
2577
2578 /*
2579  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2580  *
2581  * Purpose : does reselection, initializing the instance->connected
2582  *      field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2583  *      nexus has been reestablished,
2584  *
2585  * Inputs : instance - this instance of the NCR5380.
2586  *
2587  */
2588
2589
2590 /* it might eventually prove necessary to do a dma setup on
2591    reselection, but it doesn't seem to be needed now -- sam */
2592
2593 static void NCR5380_reselect(struct Scsi_Host *instance)
2594 {
2595         SETUP_HOSTDATA(instance);
2596         unsigned char target_mask;
2597         unsigned char lun;
2598 #ifdef SUPPORT_TAGS
2599         unsigned char tag;
2600 #endif
2601         unsigned char msg[3];
2602         int __maybe_unused len;
2603         unsigned char __maybe_unused *data, __maybe_unused phase;
2604         struct scsi_cmnd *tmp = NULL, *prev;
2605
2606         /*
2607          * Disable arbitration, etc. since the host adapter obviously
2608          * lost, and tell an interrupted NCR5380_select() to restart.
2609          */
2610
2611         NCR5380_write(MODE_REG, MR_BASE);
2612         hostdata->restart_select = 1;
2613
2614         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2615
2616         dprintk(NDEBUG_RESELECTION, "scsi%d: reselect\n", HOSTNO);
2617
2618         /*
2619          * At this point, we have detected that our SCSI ID is on the bus,
2620          * SEL is true and BSY was false for at least one bus settle delay
2621          * (400 ns).
2622          *
2623          * We must assert BSY ourselves, until the target drops the SEL
2624          * signal.
2625          */
2626
2627         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2628
2629         while (NCR5380_read(STATUS_REG) & SR_SEL)
2630                 ;
2631         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2632
2633         /*
2634          * Wait for target to go into MSGIN.
2635          */
2636
2637         while (!(NCR5380_read(STATUS_REG) & SR_REQ))
2638                 ;
2639
2640 #if defined(CONFIG_SUN3) && defined(REAL_DMA)
2641         /* acknowledge toggle to MSGIN */
2642         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2643
2644         /* peek at the byte without really hitting the bus */
2645         msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2646 #else
2647         len = 1;
2648         data = msg;
2649         phase = PHASE_MSGIN;
2650         NCR5380_transfer_pio(instance, &phase, &len, &data);
2651 #endif
2652
2653         if (!(msg[0] & 0x80)) {
2654                 printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2655                 spi_print_msg(msg);
2656                 do_abort(instance);
2657                 return;
2658         }
2659         lun = (msg[0] & 0x07);
2660
2661 #if defined(SUPPORT_TAGS) && !defined(CONFIG_SUN3)
2662         /* If the phase is still MSGIN, the target wants to send some more
2663          * messages. In case it supports tagged queuing, this is probably a
2664          * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2665          */
2666         tag = TAG_NONE;
2667         if (phase == PHASE_MSGIN && (hostdata->flags & FLAG_TAGGED_QUEUING)) {
2668                 /* Accept previous IDENTIFY message by clearing ACK */
2669                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2670                 len = 2;
2671                 data = msg + 1;
2672                 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2673                     msg[1] == SIMPLE_QUEUE_TAG)
2674                         tag = msg[2];
2675                 dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at "
2676                            "reselection\n", HOSTNO, target_mask, lun, tag);
2677         }
2678 #endif
2679
2680         /*
2681          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2682          * just reestablished, and remove it from the disconnected queue.
2683          */
2684
2685         for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
2686              tmp; prev = tmp, tmp = NEXT(tmp)) {
2687                 if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2688 #ifdef SUPPORT_TAGS
2689                     && (tag == tmp->tag)
2690 #endif
2691                     ) {
2692                         if (prev) {
2693                                 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2694                                 SET_NEXT(prev, NEXT(tmp));
2695                         } else {
2696                                 REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
2697                                 hostdata->disconnected_queue = NEXT(tmp);
2698                         }
2699                         SET_NEXT(tmp, NULL);
2700                         break;
2701                 }
2702         }
2703
2704         if (!tmp) {
2705                 printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
2706 #ifdef SUPPORT_TAGS
2707                        "tag %d "
2708 #endif
2709                        "not in disconnected_queue.\n",
2710                        HOSTNO, target_mask, lun
2711 #ifdef SUPPORT_TAGS
2712                        , tag
2713 #endif
2714                         );
2715                 /*
2716                  * Since we have an established nexus that we can't do anything
2717                  * with, we must abort it.
2718                  */
2719                 do_abort(instance);
2720                 return;
2721         }
2722
2723 #if defined(CONFIG_SUN3) && defined(REAL_DMA)
2724         /* engage dma setup for the command we just saw */
2725         {
2726                 void *d;
2727                 unsigned long count;
2728
2729                 if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
2730                         count = tmp->SCp.buffer->length;
2731                         d = sg_virt(tmp->SCp.buffer);
2732                 } else {
2733                         count = tmp->SCp.this_residual;
2734                         d = tmp->SCp.ptr;
2735                 }
2736                 /* setup this command for dma if not already */
2737                 if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != tmp)) {
2738                         sun3scsi_dma_setup(d, count, rq_data_dir(tmp->request));
2739                         sun3_dma_setup_done = tmp;
2740                 }
2741         }
2742
2743         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2744 #endif
2745
2746         /* Accept message by clearing ACK */
2747         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2748
2749 #if defined(SUPPORT_TAGS) && defined(CONFIG_SUN3)
2750         /* If the phase is still MSGIN, the target wants to send some more
2751          * messages. In case it supports tagged queuing, this is probably a
2752          * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2753          */
2754         tag = TAG_NONE;
2755         if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2756                 /* Accept previous IDENTIFY message by clearing ACK */
2757                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2758                 len = 2;
2759                 data = msg + 1;
2760                 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2761                     msg[1] == SIMPLE_QUEUE_TAG)
2762                         tag = msg[2];
2763                 dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at reselection\n"
2764                         HOSTNO, target_mask, lun, tag);
2765         }
2766 #endif
2767
2768         hostdata->connected = tmp;
2769         dprintk(NDEBUG_RESELECTION, "scsi%d: nexus established, target = %d, lun = %llu, tag = %d\n",
2770                    HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
2771 }
2772
2773
2774 /*
2775  * Function : int NCR5380_abort (struct scsi_cmnd *cmd)
2776  *
2777  * Purpose : abort a command
2778  *
2779  * Inputs : cmd - the scsi_cmnd to abort, code - code to set the
2780  *      host byte of the result field to, if zero DID_ABORTED is
2781  *      used.
2782  *
2783  * Returns : SUCCESS - success, FAILED on failure.
2784  *
2785  * XXX - there is no way to abort the command that is currently
2786  *       connected, you have to wait for it to complete.  If this is
2787  *       a problem, we could implement longjmp() / setjmp(), setjmp()
2788  *       called where the loop started in NCR5380_main().
2789  */
2790
2791 static
2792 int NCR5380_abort(struct scsi_cmnd *cmd)
2793 {
2794         struct Scsi_Host *instance = cmd->device->host;
2795         SETUP_HOSTDATA(instance);
2796         struct scsi_cmnd *tmp, **prev;
2797         unsigned long flags;
2798
2799         scmd_printk(KERN_NOTICE, cmd, "aborting command\n");
2800
2801         NCR5380_print_status(instance);
2802
2803         local_irq_save(flags);
2804
2805         dprintk(NDEBUG_ABORT, "scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2806                     NCR5380_read(BUS_AND_STATUS_REG),
2807                     NCR5380_read(STATUS_REG));
2808
2809 #if 1
2810         /*
2811          * Case 1 : If the command is the currently executing command,
2812          * we'll set the aborted flag and return control so that
2813          * information transfer routine can exit cleanly.
2814          */
2815
2816         if (hostdata->connected == cmd) {
2817
2818                 dprintk(NDEBUG_ABORT, "scsi%d: aborting connected command\n", HOSTNO);
2819                 /*
2820                  * We should perform BSY checking, and make sure we haven't slipped
2821                  * into BUS FREE.
2822                  */
2823
2824                 /*      NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2825                 /*
2826                  * Since we can't change phases until we've completed the current
2827                  * handshake, we have to source or sink a byte of data if the current
2828                  * phase is not MSGOUT.
2829                  */
2830
2831                 /*
2832                  * Return control to the executing NCR drive so we can clear the
2833                  * aborted flag and get back into our main loop.
2834                  */
2835
2836                 if (do_abort(instance) == 0) {
2837                         hostdata->aborted = 1;
2838                         hostdata->connected = NULL;
2839                         cmd->result = DID_ABORT << 16;
2840 #ifdef SUPPORT_TAGS
2841                         cmd_free_tag(cmd);
2842 #else
2843                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2844 #endif
2845                         maybe_release_dma_irq(instance);
2846                         local_irq_restore(flags);
2847                         cmd->scsi_done(cmd);
2848                         return SUCCESS;
2849                 } else {
2850                         local_irq_restore(flags);
2851                         printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2852                         return FAILED;
2853                 }
2854         }
2855 #endif
2856
2857         /*
2858          * Case 2 : If the command hasn't been issued yet, we simply remove it
2859          *          from the issue queue.
2860          */
2861         for (prev = (struct scsi_cmnd **)&(hostdata->issue_queue),
2862              tmp = (struct scsi_cmnd *)hostdata->issue_queue;
2863              tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2864                 if (cmd == tmp) {
2865                         REMOVE(5, *prev, tmp, NEXT(tmp));
2866                         (*prev) = NEXT(tmp);
2867                         SET_NEXT(tmp, NULL);
2868                         tmp->result = DID_ABORT << 16;
2869                         maybe_release_dma_irq(instance);
2870                         local_irq_restore(flags);
2871                         dprintk(NDEBUG_ABORT, "scsi%d: abort removed command from issue queue.\n",
2872                                     HOSTNO);
2873                         /* Tagged queuing note: no tag to free here, hasn't been assigned
2874                          * yet... */
2875                         tmp->scsi_done(tmp);
2876                         return SUCCESS;
2877                 }
2878         }
2879
2880         /*
2881          * Case 3 : If any commands are connected, we're going to fail the abort
2882          *          and let the high level SCSI driver retry at a later time or
2883          *          issue a reset.
2884          *
2885          *          Timeouts, and therefore aborted commands, will be highly unlikely
2886          *          and handling them cleanly in this situation would make the common
2887          *          case of noresets less efficient, and would pollute our code.  So,
2888          *          we fail.
2889          */
2890
2891         if (hostdata->connected) {
2892                 local_irq_restore(flags);
2893                 dprintk(NDEBUG_ABORT, "scsi%d: abort failed, command connected.\n", HOSTNO);
2894                 return FAILED;
2895         }
2896
2897         /*
2898          * Case 4: If the command is currently disconnected from the bus, and
2899          *      there are no connected commands, we reconnect the I_T_L or
2900          *      I_T_L_Q nexus associated with it, go into message out, and send
2901          *      an abort message.
2902          *
2903          * This case is especially ugly. In order to reestablish the nexus, we
2904          * need to call NCR5380_select().  The easiest way to implement this
2905          * function was to abort if the bus was busy, and let the interrupt
2906          * handler triggered on the SEL for reselect take care of lost arbitrations
2907          * where necessary, meaning interrupts need to be enabled.
2908          *
2909          * When interrupts are enabled, the queues may change - so we
2910          * can't remove it from the disconnected queue before selecting it
2911          * because that could cause a failure in hashing the nexus if that
2912          * device reselected.
2913          *
2914          * Since the queues may change, we can't use the pointers from when we
2915          * first locate it.
2916          *
2917          * So, we must first locate the command, and if NCR5380_select()
2918          * succeeds, then issue the abort, relocate the command and remove
2919          * it from the disconnected queue.
2920          */
2921
2922         for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp;
2923              tmp = NEXT(tmp)) {
2924                 if (cmd == tmp) {
2925                         local_irq_restore(flags);
2926                         dprintk(NDEBUG_ABORT, "scsi%d: aborting disconnected command.\n", HOSTNO);
2927
2928                         if (NCR5380_select(instance, cmd))
2929                                 return FAILED;
2930
2931                         dprintk(NDEBUG_ABORT, "scsi%d: nexus reestablished.\n", HOSTNO);
2932
2933                         do_abort(instance);
2934
2935                         local_irq_save(flags);
2936                         for (prev = (struct scsi_cmnd **)&(hostdata->disconnected_queue),
2937                              tmp = (struct scsi_cmnd *)hostdata->disconnected_queue;
2938                              tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2939                                 if (cmd == tmp) {
2940                                         REMOVE(5, *prev, tmp, NEXT(tmp));
2941                                         *prev = NEXT(tmp);
2942                                         SET_NEXT(tmp, NULL);
2943                                         tmp->result = DID_ABORT << 16;
2944                                         /* We must unlock the tag/LUN immediately here, since the
2945                                          * target goes to BUS FREE and doesn't send us another
2946                                          * message (COMMAND_COMPLETE or the like)
2947                                          */
2948 #ifdef SUPPORT_TAGS
2949                                         cmd_free_tag(tmp);
2950 #else
2951                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2952 #endif
2953                                         maybe_release_dma_irq(instance);
2954                                         local_irq_restore(flags);
2955                                         tmp->scsi_done(tmp);
2956                                         return SUCCESS;
2957                                 }
2958                         }
2959                 }
2960         }
2961
2962         /* Maybe it is sufficient just to release the ST-DMA lock... (if
2963          * possible at all) At least, we should check if the lock could be
2964          * released after the abort, in case it is kept due to some bug.
2965          */
2966         maybe_release_dma_irq(instance);
2967         local_irq_restore(flags);
2968
2969         /*
2970          * Case 5 : If we reached this point, the command was not found in any of
2971          *          the queues.
2972          *
2973          * We probably reached this point because of an unlikely race condition
2974          * between the command completing successfully and the abortion code,
2975          * so we won't panic, but we will notify the user in case something really
2976          * broke.
2977          */
2978
2979         printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
2980
2981         return FAILED;
2982 }
2983
2984
2985 /**
2986  * NCR5380_bus_reset - reset the SCSI bus
2987  * @cmd: SCSI command undergoing EH
2988  *
2989  * Returns SUCCESS
2990  */
2991
2992 static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
2993 {
2994         struct Scsi_Host *instance = cmd->device->host;
2995         struct NCR5380_hostdata *hostdata = shost_priv(instance);
2996         int i;
2997         unsigned long flags;
2998
2999         local_irq_save(flags);
3000
3001 #if (NDEBUG & NDEBUG_ANY)
3002         scmd_printk(KERN_INFO, cmd, "performing bus reset\n");
3003         NCR5380_print_status(instance);
3004 #endif
3005
3006         do_reset(instance);
3007
3008         /* reset NCR registers */
3009         NCR5380_write(MODE_REG, MR_BASE);
3010         NCR5380_write(TARGET_COMMAND_REG, 0);
3011         NCR5380_write(SELECT_ENABLE_REG, 0);
3012
3013         /* After the reset, there are no more connected or disconnected commands
3014          * and no busy units; so clear the low-level status here to avoid
3015          * conflicts when the mid-level code tries to wake up the affected
3016          * commands!
3017          */
3018
3019         if (hostdata->issue_queue)
3020                 dprintk(NDEBUG_ABORT, "scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
3021         if (hostdata->connected)
3022                 dprintk(NDEBUG_ABORT, "scsi%d: reset aborted a connected command\n", H_NO(cmd));
3023         if (hostdata->disconnected_queue)
3024                 dprintk(NDEBUG_ABORT, "scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
3025
3026         hostdata->issue_queue = NULL;
3027         hostdata->connected = NULL;
3028         hostdata->disconnected_queue = NULL;
3029 #ifdef SUPPORT_TAGS
3030         free_all_tags(hostdata);
3031 #endif
3032         for (i = 0; i < 8; ++i)
3033                 hostdata->busy[i] = 0;
3034 #ifdef REAL_DMA
3035         hostdata->dma_len = 0;
3036 #endif
3037
3038         maybe_release_dma_irq(instance);
3039         local_irq_restore(flags);
3040
3041         return SUCCESS;
3042 }