linux/drivers/scsi/atari_NCR5380.c
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   1/*
   2 * NCR 5380 generic driver routines.  These should make it *trivial*
   3 *      to implement 5380 SCSI drivers under Linux with a non-trantor
   4 *      architecture.
   5 *
   6 *      Note that these routines also work with NR53c400 family chips.
   7 *
   8 * Copyright 1993, Drew Eckhardt
   9 *      Visionary Computing
  10 *      (Unix and Linux consulting and custom programming)
  11 *      drew@colorado.edu
  12 *      +1 (303) 666-5836
  13 *
  14 * DISTRIBUTION RELEASE 6.
  15 *
  16 * For more information, please consult
  17 *
  18 * NCR 5380 Family
  19 * SCSI Protocol Controller
  20 * Databook
  21 *
  22 * NCR Microelectronics
  23 * 1635 Aeroplaza Drive
  24 * Colorado Springs, CO 80916
  25 * 1+ (719) 578-3400
  26 * 1+ (800) 334-5454
  27 */
  28
  29/*
  30 * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
  31 * this file, too:
  32 *
  33 *  - Some of the debug statements were incorrect (undefined variables and the
  34 *    like). I fixed that.
  35 *
  36 *  - In information_transfer(), I think a #ifdef was wrong. Looking at the
  37 *    possible DMA transfer size should also happen for REAL_DMA. I added this
  38 *    in the #if statement.
  39 *
  40 *  - When using real DMA, information_transfer() should return in a DATAOUT
  41 *    phase after starting the DMA. It has nothing more to do.
  42 *
  43 *  - The interrupt service routine should run main after end of DMA, too (not
  44 *    only after RESELECTION interrupts). Additionally, it should _not_ test
  45 *    for more interrupts after running main, since a DMA process may have
  46 *    been started and interrupts are turned on now. The new int could happen
  47 *    inside the execution of NCR5380_intr(), leading to recursive
  48 *    calls.
  49 *
  50 *  - I've added a function merge_contiguous_buffers() that tries to
  51 *    merge scatter-gather buffers that are located at contiguous
  52 *    physical addresses and can be processed with the same DMA setup.
  53 *    Since most scatter-gather operations work on a page (4K) of
  54 *    4 buffers (1K), in more than 90% of all cases three interrupts and
  55 *    DMA setup actions are saved.
  56 *
  57 * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
  58 *    and USLEEP, because these were messing up readability and will never be
  59 *    needed for Atari SCSI.
  60 *
  61 * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
  62 *   stuff), and 'main' is executed in a bottom half if awoken by an
  63 *   interrupt.
  64 *
  65 * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
  66 *   constructs. In my eyes, this made the source rather unreadable, so I
  67 *   finally replaced that by the *_PRINTK() macros.
  68 *
  69 */
  70
  71/*
  72 * Further development / testing that should be done :
  73 * 1.  Test linked command handling code after Eric is ready with
  74 *     the high level code.
  75 */
  76#include <scsi/scsi_dbg.h>
  77#include <scsi/scsi_transport_spi.h>
  78
  79#if (NDEBUG & NDEBUG_LISTS)
  80#define LIST(x, y)                                              \
  81        do {                                                    \
  82                printk("LINE:%d   Adding %p to %p\n",           \
  83                       __LINE__, (void*)(x), (void*)(y));       \
  84                if ((x) == (y))                                 \
  85                        udelay(5);                              \
  86        } while (0)
  87#define REMOVE(w, x, y, z)                                      \
  88        do {                                                    \
  89                printk("LINE:%d   Removing: %p->%p  %p->%p \n", \
  90                       __LINE__, (void*)(w), (void*)(x),        \
  91                       (void*)(y), (void*)(z));                 \
  92                if ((x) == (y))                                 \
  93                        udelay(5);                              \
  94        } while (0)
  95#else
  96#define LIST(x,y)
  97#define REMOVE(w,x,y,z)
  98#endif
  99
 100#ifndef notyet
 101#undef LINKED
 102#endif
 103
 104/*
 105 * Design
 106 * Issues :
 107 *
 108 * The other Linux SCSI drivers were written when Linux was Intel PC-only,
 109 * and specifically for each board rather than each chip.  This makes their
 110 * adaptation to platforms like the Mac (Some of which use NCR5380's)
 111 * more difficult than it has to be.
 112 *
 113 * Also, many of the SCSI drivers were written before the command queuing
 114 * routines were implemented, meaning their implementations of queued
 115 * commands were hacked on rather than designed in from the start.
 116 *
 117 * When I designed the Linux SCSI drivers I figured that
 118 * while having two different SCSI boards in a system might be useful
 119 * for debugging things, two of the same type wouldn't be used.
 120 * Well, I was wrong and a number of users have mailed me about running
 121 * multiple high-performance SCSI boards in a server.
 122 *
 123 * Finally, when I get questions from users, I have no idea what
 124 * revision of my driver they are running.
 125 *
 126 * This driver attempts to address these problems :
 127 * This is a generic 5380 driver.  To use it on a different platform,
 128 * one simply writes appropriate system specific macros (ie, data
 129 * transfer - some PC's will use the I/O bus, 68K's must use
 130 * memory mapped) and drops this file in their 'C' wrapper.
 131 *
 132 * As far as command queueing, two queues are maintained for
 133 * each 5380 in the system - commands that haven't been issued yet,
 134 * and commands that are currently executing.  This means that an
 135 * unlimited number of commands may be queued, letting
 136 * more commands propagate from the higher driver levels giving higher
 137 * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
 138 * allowing multiple commands to propagate all the way to a SCSI-II device
 139 * while a command is already executing.
 140 *
 141 * To solve the multiple-boards-in-the-same-system problem,
 142 * there is a separate instance structure for each instance
 143 * of a 5380 in the system.  So, multiple NCR5380 drivers will
 144 * be able to coexist with appropriate changes to the high level
 145 * SCSI code.
 146 *
 147 * A NCR5380_PUBLIC_REVISION macro is provided, with the release
 148 * number (updated for each public release) printed by the
 149 * NCR5380_print_options command, which should be called from the
 150 * wrapper detect function, so that I know what release of the driver
 151 * users are using.
 152 *
 153 * Issues specific to the NCR5380 :
 154 *
 155 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
 156 * piece of hardware that requires you to sit in a loop polling for
 157 * the REQ signal as long as you are connected.  Some devices are
 158 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
 159 * while doing long seek operations.
 160 *
 161 * The workaround for this is to keep track of devices that have
 162 * disconnected.  If the device hasn't disconnected, for commands that
 163 * should disconnect, we do something like
 164 *
 165 * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
 166 *
 167 * Some tweaking of N and M needs to be done.  An algorithm based
 168 * on "time to data" would give the best results as long as short time
 169 * to datas (ie, on the same track) were considered, however these
 170 * broken devices are the exception rather than the rule and I'd rather
 171 * spend my time optimizing for the normal case.
 172 *
 173 * Architecture :
 174 *
 175 * At the heart of the design is a coroutine, NCR5380_main,
 176 * which is started when not running by the interrupt handler,
 177 * timer, and queue command function.  It attempts to establish
 178 * I_T_L or I_T_L_Q nexuses by removing the commands from the
 179 * issue queue and calling NCR5380_select() if a nexus
 180 * is not established.
 181 *
 182 * Once a nexus is established, the NCR5380_information_transfer()
 183 * phase goes through the various phases as instructed by the target.
 184 * if the target goes into MSG IN and sends a DISCONNECT message,
 185 * the command structure is placed into the per instance disconnected
 186 * queue, and NCR5380_main tries to find more work.  If USLEEP
 187 * was defined, and the target is idle for too long, the system
 188 * will try to sleep.
 189 *
 190 * If a command has disconnected, eventually an interrupt will trigger,
 191 * calling NCR5380_intr()  which will in turn call NCR5380_reselect
 192 * to reestablish a nexus.  This will run main if necessary.
 193 *
 194 * On command termination, the done function will be called as
 195 * appropriate.
 196 *
 197 * SCSI pointers are maintained in the SCp field of SCSI command
 198 * structures, being initialized after the command is connected
 199 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
 200 * Note that in violation of the standard, an implicit SAVE POINTERS operation
 201 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
 202 */
 203
 204/*
 205 * Using this file :
 206 * This file a skeleton Linux SCSI driver for the NCR 5380 series
 207 * of chips.  To use it, you write an architecture specific functions
 208 * and macros and include this file in your driver.
 209 *
 210 * These macros control options :
 211 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
 212 *      for commands that return with a CHECK CONDITION status.
 213 *
 214 * LINKED - if defined, linked commands are supported.
 215 *
 216 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
 217 *
 218 * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
 219 *
 220 * These macros MUST be defined :
 221 *
 222 * NCR5380_read(register)  - read from the specified register
 223 *
 224 * NCR5380_write(register, value) - write to the specific register
 225 *
 226 * Either real DMA *or* pseudo DMA may be implemented
 227 * REAL functions :
 228 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
 229 * Note that the DMA setup functions should return the number of bytes
 230 *      that they were able to program the controller for.
 231 *
 232 * Also note that generic i386/PC versions of these macros are
 233 *      available as NCR5380_i386_dma_write_setup,
 234 *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
 235 *
 236 * NCR5380_dma_write_setup(instance, src, count) - initialize
 237 * NCR5380_dma_read_setup(instance, dst, count) - initialize
 238 * NCR5380_dma_residual(instance); - residual count
 239 *
 240 * PSEUDO functions :
 241 * NCR5380_pwrite(instance, src, count)
 242 * NCR5380_pread(instance, dst, count);
 243 *
 244 * If nothing specific to this implementation needs doing (ie, with external
 245 * hardware), you must also define
 246 *
 247 * NCR5380_queue_command
 248 * NCR5380_reset
 249 * NCR5380_abort
 250 * NCR5380_proc_info
 251 *
 252 * to be the global entry points into the specific driver, ie
 253 * #define NCR5380_queue_command t128_queue_command.
 254 *
 255 * If this is not done, the routines will be defined as static functions
 256 * with the NCR5380* names and the user must provide a globally
 257 * accessible wrapper function.
 258 *
 259 * The generic driver is initialized by calling NCR5380_init(instance),
 260 * after setting the appropriate host specific fields and ID.  If the
 261 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
 262 * possible) function may be used.  Before the specific driver initialization
 263 * code finishes, NCR5380_print_options should be called.
 264 */
 265
 266static struct Scsi_Host *first_instance = NULL;
 267static struct scsi_host_template *the_template = NULL;
 268
 269/* Macros ease life... :-) */
 270#define SETUP_HOSTDATA(in)                              \
 271    struct NCR5380_hostdata *hostdata =                 \
 272        (struct NCR5380_hostdata *)(in)->hostdata
 273#define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
 274
 275#define NEXT(cmd)               ((Scsi_Cmnd *)(cmd)->host_scribble)
 276#define SET_NEXT(cmd,next)      ((cmd)->host_scribble = (void *)(next))
 277#define NEXTADDR(cmd)           ((Scsi_Cmnd **)&(cmd)->host_scribble)
 278
 279#define HOSTNO          instance->host_no
 280#define H_NO(cmd)       (cmd)->device->host->host_no
 281
 282#ifdef SUPPORT_TAGS
 283
 284/*
 285 * Functions for handling tagged queuing
 286 * =====================================
 287 *
 288 * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
 289 *
 290 * Using consecutive numbers for the tags is no good idea in my eyes. There
 291 * could be wrong re-usings if the counter (8 bit!) wraps and some early
 292 * command has been preempted for a long time. My solution: a bitfield for
 293 * remembering used tags.
 294 *
 295 * There's also the problem that each target has a certain queue size, but we
 296 * cannot know it in advance :-( We just see a QUEUE_FULL status being
 297 * returned. So, in this case, the driver internal queue size assumption is
 298 * reduced to the number of active tags if QUEUE_FULL is returned by the
 299 * target. The command is returned to the mid-level, but with status changed
 300 * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
 301 * correctly.
 302 *
 303 * We're also not allowed running tagged commands as long as an untagged
 304 * command is active. And REQUEST SENSE commands after a contingent allegiance
 305 * condition _must_ be untagged. To keep track whether an untagged command has
 306 * been issued, the host->busy array is still employed, as it is without
 307 * support for tagged queuing.
 308 *
 309 * One could suspect that there are possible race conditions between
 310 * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
 311 * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
 312 * which already guaranteed to be running at most once. It is also the only
 313 * place where tags/LUNs are allocated. So no other allocation can slip
 314 * between that pair, there could only happen a reselection, which can free a
 315 * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
 316 * important: the tag bit must be cleared before 'nr_allocated' is decreased.
 317 */
 318
 319/* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
 320#undef TAG_NONE
 321#define TAG_NONE 0xff
 322
 323typedef struct {
 324        DECLARE_BITMAP(allocated, MAX_TAGS);
 325        int nr_allocated;
 326        int queue_size;
 327} TAG_ALLOC;
 328
 329static TAG_ALLOC TagAlloc[8][8];        /* 8 targets and 8 LUNs */
 330
 331
 332static void __init init_tags(void)
 333{
 334        int target, lun;
 335        TAG_ALLOC *ta;
 336
 337        if (!setup_use_tagged_queuing)
 338                return;
 339
 340        for (target = 0; target < 8; ++target) {
 341                for (lun = 0; lun < 8; ++lun) {
 342                        ta = &TagAlloc[target][lun];
 343                        bitmap_zero(ta->allocated, MAX_TAGS);
 344                        ta->nr_allocated = 0;
 345                        /* At the beginning, assume the maximum queue size we could
 346                         * support (MAX_TAGS). This value will be decreased if the target
 347                         * returns QUEUE_FULL status.
 348                         */
 349                        ta->queue_size = MAX_TAGS;
 350                }
 351        }
 352}
 353
 354
 355/* Check if we can issue a command to this LUN: First see if the LUN is marked
 356 * busy by an untagged command. If the command should use tagged queuing, also
 357 * check that there is a free tag and the target's queue won't overflow. This
 358 * function should be called with interrupts disabled to avoid race
 359 * conditions.
 360 */
 361
 362static int is_lun_busy(Scsi_Cmnd *cmd, int should_be_tagged)
 363{
 364        SETUP_HOSTDATA(cmd->device->host);
 365
 366        if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun))
 367                return 1;
 368        if (!should_be_tagged ||
 369            !setup_use_tagged_queuing || !cmd->device->tagged_supported)
 370                return 0;
 371        if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >=
 372            TagAlloc[cmd->device->id][cmd->device->lun].queue_size) {
 373                TAG_PRINTK("scsi%d: target %d lun %d: no free tags\n",
 374                           H_NO(cmd), cmd->device->id, cmd->device->lun);
 375                return 1;
 376        }
 377        return 0;
 378}
 379
 380
 381/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
 382 * must be called before!), or reserve the LUN in 'busy' if the command is
 383 * untagged.
 384 */
 385
 386static void cmd_get_tag(Scsi_Cmnd *cmd, int should_be_tagged)
 387{
 388        SETUP_HOSTDATA(cmd->device->host);
 389
 390        /* If we or the target don't support tagged queuing, allocate the LUN for
 391         * an untagged command.
 392         */
 393        if (!should_be_tagged ||
 394            !setup_use_tagged_queuing || !cmd->device->tagged_supported) {
 395                cmd->tag = TAG_NONE;
 396                hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
 397                TAG_PRINTK("scsi%d: target %d lun %d now allocated by untagged "
 398                           "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun);
 399        } else {
 400                TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
 401
 402                cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
 403                set_bit(cmd->tag, ta->allocated);
 404                ta->nr_allocated++;
 405                TAG_PRINTK("scsi%d: using tag %d for target %d lun %d "
 406                           "(now %d tags in use)\n",
 407                           H_NO(cmd), cmd->tag, cmd->device->id,
 408                           cmd->device->lun, ta->nr_allocated);
 409        }
 410}
 411
 412
 413/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
 414 * unlock the LUN.
 415 */
 416
 417static void cmd_free_tag(Scsi_Cmnd *cmd)
 418{
 419        SETUP_HOSTDATA(cmd->device->host);
 420
 421        if (cmd->tag == TAG_NONE) {
 422                hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
 423                TAG_PRINTK("scsi%d: target %d lun %d untagged cmd finished\n",
 424                           H_NO(cmd), cmd->device->id, cmd->device->lun);
 425        } else if (cmd->tag >= MAX_TAGS) {
 426                printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
 427                       H_NO(cmd), cmd->tag);
 428        } else {
 429                TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
 430                clear_bit(cmd->tag, ta->allocated);
 431                ta->nr_allocated--;
 432                TAG_PRINTK("scsi%d: freed tag %d for target %d lun %d\n",
 433                           H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun);
 434        }
 435}
 436
 437
 438static void free_all_tags(void)
 439{
 440        int target, lun;
 441        TAG_ALLOC *ta;
 442
 443        if (!setup_use_tagged_queuing)
 444                return;
 445
 446        for (target = 0; target < 8; ++target) {
 447                for (lun = 0; lun < 8; ++lun) {
 448                        ta = &TagAlloc[target][lun];
 449                        bitmap_zero(ta->allocated, MAX_TAGS);
 450                        ta->nr_allocated = 0;
 451                }
 452        }
 453}
 454
 455#endif /* SUPPORT_TAGS */
 456
 457
 458/*
 459 * Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd )
 460 *
 461 * Purpose: Try to merge several scatter-gather requests into one DMA
 462 *    transfer. This is possible if the scatter buffers lie on
 463 *    physical contiguous addresses.
 464 *
 465 * Parameters: Scsi_Cmnd *cmd
 466 *    The command to work on. The first scatter buffer's data are
 467 *    assumed to be already transferred into ptr/this_residual.
 468 */
 469
 470static void merge_contiguous_buffers(Scsi_Cmnd *cmd)
 471{
 472        unsigned long endaddr;
 473#if (NDEBUG & NDEBUG_MERGING)
 474        unsigned long oldlen = cmd->SCp.this_residual;
 475        int cnt = 1;
 476#endif
 477
 478        for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
 479             cmd->SCp.buffers_residual &&
 480             virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
 481                MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
 482                           page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
 483#if (NDEBUG & NDEBUG_MERGING)
 484                ++cnt;
 485#endif
 486                ++cmd->SCp.buffer;
 487                --cmd->SCp.buffers_residual;
 488                cmd->SCp.this_residual += cmd->SCp.buffer->length;
 489                endaddr += cmd->SCp.buffer->length;
 490        }
 491#if (NDEBUG & NDEBUG_MERGING)
 492        if (oldlen != cmd->SCp.this_residual)
 493                MER_PRINTK("merged %d buffers from %p, new length %08x\n",
 494                           cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
 495#endif
 496}
 497
 498/*
 499 * Function : void initialize_SCp(Scsi_Cmnd *cmd)
 500 *
 501 * Purpose : initialize the saved data pointers for cmd to point to the
 502 *      start of the buffer.
 503 *
 504 * Inputs : cmd - Scsi_Cmnd structure to have pointers reset.
 505 */
 506
 507static inline void initialize_SCp(Scsi_Cmnd *cmd)
 508{
 509        /*
 510         * Initialize the Scsi Pointer field so that all of the commands in the
 511         * various queues are valid.
 512         */
 513
 514        if (scsi_bufflen(cmd)) {
 515                cmd->SCp.buffer = scsi_sglist(cmd);
 516                cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 517                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 518                cmd->SCp.this_residual = cmd->SCp.buffer->length;
 519                /* ++roman: Try to merge some scatter-buffers if they are at
 520                 * contiguous physical addresses.
 521                 */
 522                merge_contiguous_buffers(cmd);
 523        } else {
 524                cmd->SCp.buffer = NULL;
 525                cmd->SCp.buffers_residual = 0;
 526                cmd->SCp.ptr = NULL;
 527                cmd->SCp.this_residual = 0;
 528        }
 529}
 530
 531#include <linux/delay.h>
 532
 533#if NDEBUG
 534static struct {
 535        unsigned char mask;
 536        const char *name;
 537} signals[] = {
 538        { SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
 539        { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD,  "CD" }, { SR_IO, "IO" },
 540        { SR_SEL, "SEL" }, {0, NULL}
 541}, basrs[] = {
 542        {BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
 543}, icrs[] = {
 544        {ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
 545        {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
 546        {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
 547        {0, NULL}
 548}, mrs[] = {
 549        {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
 550        {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
 551        "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
 552        {MR_MONITOR_BSY, "MODE MONITOR BSY"},
 553        {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
 554        {0, NULL}
 555};
 556
 557/*
 558 * Function : void NCR5380_print(struct Scsi_Host *instance)
 559 *
 560 * Purpose : print the SCSI bus signals for debugging purposes
 561 *
 562 * Input : instance - which NCR5380
 563 */
 564
 565static void NCR5380_print(struct Scsi_Host *instance)
 566{
 567        unsigned char status, data, basr, mr, icr, i;
 568        unsigned long flags;
 569
 570        local_irq_save(flags);
 571        data = NCR5380_read(CURRENT_SCSI_DATA_REG);
 572        status = NCR5380_read(STATUS_REG);
 573        mr = NCR5380_read(MODE_REG);
 574        icr = NCR5380_read(INITIATOR_COMMAND_REG);
 575        basr = NCR5380_read(BUS_AND_STATUS_REG);
 576        local_irq_restore(flags);
 577        printk("STATUS_REG: %02x ", status);
 578        for (i = 0; signals[i].mask; ++i)
 579                if (status & signals[i].mask)
 580                        printk(",%s", signals[i].name);
 581        printk("\nBASR: %02x ", basr);
 582        for (i = 0; basrs[i].mask; ++i)
 583                if (basr & basrs[i].mask)
 584                        printk(",%s", basrs[i].name);
 585        printk("\nICR: %02x ", icr);
 586        for (i = 0; icrs[i].mask; ++i)
 587                if (icr & icrs[i].mask)
 588                        printk(",%s", icrs[i].name);
 589        printk("\nMODE: %02x ", mr);
 590        for (i = 0; mrs[i].mask; ++i)
 591                if (mr & mrs[i].mask)
 592                        printk(",%s", mrs[i].name);
 593        printk("\n");
 594}
 595
 596static struct {
 597        unsigned char value;
 598        const char *name;
 599} phases[] = {
 600        {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
 601        {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
 602        {PHASE_UNKNOWN, "UNKNOWN"}
 603};
 604
 605/*
 606 * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
 607 *
 608 * Purpose : print the current SCSI phase for debugging purposes
 609 *
 610 * Input : instance - which NCR5380
 611 */
 612
 613static void NCR5380_print_phase(struct Scsi_Host *instance)
 614{
 615        unsigned char status;
 616        int i;
 617
 618        status = NCR5380_read(STATUS_REG);
 619        if (!(status & SR_REQ))
 620                printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
 621        else {
 622                for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
 623                     (phases[i].value != (status & PHASE_MASK)); ++i)
 624                        ;
 625                printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
 626        }
 627}
 628
 629#else /* !NDEBUG */
 630
 631/* dummies... */
 632static inline void NCR5380_print(struct Scsi_Host *instance)
 633{
 634};
 635static inline void NCR5380_print_phase(struct Scsi_Host *instance)
 636{
 637};
 638
 639#endif
 640
 641/*
 642 * ++roman: New scheme of calling NCR5380_main()
 643 *
 644 * If we're not in an interrupt, we can call our main directly, it cannot be
 645 * already running. Else, we queue it on a task queue, if not 'main_running'
 646 * tells us that a lower level is already executing it. This way,
 647 * 'main_running' needs not be protected in a special way.
 648 *
 649 * queue_main() is a utility function for putting our main onto the task
 650 * queue, if main_running is false. It should be called only from a
 651 * interrupt or bottom half.
 652 */
 653
 654#include <linux/gfp.h>
 655#include <linux/workqueue.h>
 656#include <linux/interrupt.h>
 657
 658static volatile int main_running;
 659static DECLARE_WORK(NCR5380_tqueue, NCR5380_main);
 660
 661static inline void queue_main(void)
 662{
 663        if (!main_running) {
 664                /* If in interrupt and NCR5380_main() not already running,
 665                   queue it on the 'immediate' task queue, to be processed
 666                   immediately after the current interrupt processing has
 667                   finished. */
 668                schedule_work(&NCR5380_tqueue);
 669        }
 670        /* else: nothing to do: the running NCR5380_main() will pick up
 671           any newly queued command. */
 672}
 673
 674
 675static inline void NCR5380_all_init(void)
 676{
 677        static int done = 0;
 678        if (!done) {
 679                INI_PRINTK("scsi : NCR5380_all_init()\n");
 680                done = 1;
 681        }
 682}
 683
 684
 685/*
 686 * Function : void NCR58380_print_options (struct Scsi_Host *instance)
 687 *
 688 * Purpose : called by probe code indicating the NCR5380 driver
 689 *           options that were selected.
 690 *
 691 * Inputs : instance, pointer to this instance.  Unused.
 692 */
 693
 694static void __init NCR5380_print_options(struct Scsi_Host *instance)
 695{
 696        printk(" generic options"
 697#ifdef AUTOSENSE
 698               " AUTOSENSE"
 699#endif
 700#ifdef REAL_DMA
 701               " REAL DMA"
 702#endif
 703#ifdef PARITY
 704               " PARITY"
 705#endif
 706#ifdef SUPPORT_TAGS
 707               " SCSI-2 TAGGED QUEUING"
 708#endif
 709               );
 710        printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
 711}
 712
 713/*
 714 * Function : void NCR5380_print_status (struct Scsi_Host *instance)
 715 *
 716 * Purpose : print commands in the various queues, called from
 717 *      NCR5380_abort and NCR5380_debug to aid debugging.
 718 *
 719 * Inputs : instance, pointer to this instance.
 720 */
 721
 722static void NCR5380_print_status(struct Scsi_Host *instance)
 723{
 724        char *pr_bfr;
 725        char *start;
 726        int len;
 727
 728        NCR_PRINT(NDEBUG_ANY);
 729        NCR_PRINT_PHASE(NDEBUG_ANY);
 730
 731        pr_bfr = (char *)__get_free_page(GFP_ATOMIC);
 732        if (!pr_bfr) {
 733                printk("NCR5380_print_status: no memory for print buffer\n");
 734                return;
 735        }
 736        len = NCR5380_proc_info(instance, pr_bfr, &start, 0, PAGE_SIZE, 0);
 737        pr_bfr[len] = 0;
 738        printk("\n%s\n", pr_bfr);
 739        free_page((unsigned long)pr_bfr);
 740}
 741
 742
 743/******************************************/
 744/*
 745 * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
 746 *
 747 * *buffer: I/O buffer
 748 * **start: if inout == FALSE pointer into buffer where user read should start
 749 * offset: current offset
 750 * length: length of buffer
 751 * hostno: Scsi_Host host_no
 752 * inout: TRUE - user is writing; FALSE - user is reading
 753 *
 754 * Return the number of bytes read from or written
 755*/
 756
 757#undef SPRINTF
 758#define SPRINTF(fmt,args...)                                                    \
 759        do {                                                                    \
 760                if (pos + strlen(fmt) + 20 /* slop */ < buffer + length)        \
 761                        pos += sprintf(pos, fmt , ## args);                     \
 762        } while(0)
 763static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length);
 764
 765static int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer,
 766                             char **start, off_t offset, int length, int inout)
 767{
 768        char *pos = buffer;
 769        struct NCR5380_hostdata *hostdata;
 770        Scsi_Cmnd *ptr;
 771        unsigned long flags;
 772        off_t begin = 0;
 773#define check_offset()                                  \
 774        do {                                            \
 775                if (pos - buffer < offset - begin) {    \
 776                        begin += pos - buffer;          \
 777                        pos = buffer;                   \
 778                }                                       \
 779        } while (0)
 780
 781        hostdata = (struct NCR5380_hostdata *)instance->hostdata;
 782
 783        if (inout)                      /* Has data been written to the file ? */
 784                return -ENOSYS;         /* Currently this is a no-op */
 785        SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
 786        check_offset();
 787        local_irq_save(flags);
 788        SPRINTF("NCR5380: coroutine is%s running.\n",
 789                main_running ? "" : "n't");
 790        check_offset();
 791        if (!hostdata->connected)
 792                SPRINTF("scsi%d: no currently connected command\n", HOSTNO);
 793        else
 794                pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected,
 795                                       pos, buffer, length);
 796        SPRINTF("scsi%d: issue_queue\n", HOSTNO);
 797        check_offset();
 798        for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr)) {
 799                pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
 800                check_offset();
 801        }
 802
 803        SPRINTF("scsi%d: disconnected_queue\n", HOSTNO);
 804        check_offset();
 805        for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
 806             ptr = NEXT(ptr)) {
 807                pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
 808                check_offset();
 809        }
 810
 811        local_irq_restore(flags);
 812        *start = buffer + (offset - begin);
 813        if (pos - buffer < offset - begin)
 814                return 0;
 815        else if (pos - buffer - (offset - begin) < length)
 816                return pos - buffer - (offset - begin);
 817        return length;
 818}
 819
 820static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length)
 821{
 822        int i, s;
 823        unsigned char *command;
 824        SPRINTF("scsi%d: destination target %d, lun %d\n",
 825                H_NO(cmd), cmd->device->id, cmd->device->lun);
 826        SPRINTF("        command = ");
 827        command = cmd->cmnd;
 828        SPRINTF("%2d (0x%02x)", command[0], command[0]);
 829        for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 830                SPRINTF(" %02x", command[i]);
 831        SPRINTF("\n");
 832        return pos;
 833}
 834
 835
 836/*
 837 * Function : void NCR5380_init (struct Scsi_Host *instance)
 838 *
 839 * Purpose : initializes *instance and corresponding 5380 chip.
 840 *
 841 * Inputs : instance - instantiation of the 5380 driver.
 842 *
 843 * Notes : I assume that the host, hostno, and id bits have been
 844 *      set correctly.  I don't care about the irq and other fields.
 845 *
 846 */
 847
 848static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
 849{
 850        int i;
 851        SETUP_HOSTDATA(instance);
 852
 853        NCR5380_all_init();
 854
 855        hostdata->aborted = 0;
 856        hostdata->id_mask = 1 << instance->this_id;
 857        hostdata->id_higher_mask = 0;
 858        for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 859                if (i > hostdata->id_mask)
 860                        hostdata->id_higher_mask |= i;
 861        for (i = 0; i < 8; ++i)
 862                hostdata->busy[i] = 0;
 863#ifdef SUPPORT_TAGS
 864        init_tags();
 865#endif
 866#if defined (REAL_DMA)
 867        hostdata->dma_len = 0;
 868#endif
 869        hostdata->targets_present = 0;
 870        hostdata->connected = NULL;
 871        hostdata->issue_queue = NULL;
 872        hostdata->disconnected_queue = NULL;
 873        hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
 874
 875        if (!the_template) {
 876                the_template = instance->hostt;
 877                first_instance = instance;
 878        }
 879
 880#ifndef AUTOSENSE
 881        if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
 882                printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
 883                       "        without AUTOSENSE option, contingent allegiance conditions may\n"
 884                       "        be incorrectly cleared.\n", HOSTNO);
 885#endif /* def AUTOSENSE */
 886
 887        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 888        NCR5380_write(MODE_REG, MR_BASE);
 889        NCR5380_write(TARGET_COMMAND_REG, 0);
 890        NCR5380_write(SELECT_ENABLE_REG, 0);
 891
 892        return 0;
 893}
 894
 895static void NCR5380_exit(struct Scsi_Host *instance)
 896{
 897        /* Empty, as we didn't schedule any delayed work */
 898}
 899
 900/*
 901 * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd,
 902 *      void (*done)(Scsi_Cmnd *))
 903 *
 904 * Purpose :  enqueues a SCSI command
 905 *
 906 * Inputs : cmd - SCSI command, done - function called on completion, with
 907 *      a pointer to the command descriptor.
 908 *
 909 * Returns : 0
 910 *
 911 * Side effects :
 912 *      cmd is added to the per instance issue_queue, with minor
 913 *      twiddling done to the host specific fields of cmd.  If the
 914 *      main coroutine is not running, it is restarted.
 915 *
 916 */
 917
 918static int NCR5380_queue_command_lck(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
 919{
 920        SETUP_HOSTDATA(cmd->device->host);
 921        Scsi_Cmnd *tmp;
 922        unsigned long flags;
 923
 924#if (NDEBUG & NDEBUG_NO_WRITE)
 925        switch (cmd->cmnd[0]) {
 926        case WRITE_6:
 927        case WRITE_10:
 928                printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
 929                       H_NO(cmd));
 930                cmd->result = (DID_ERROR << 16);
 931                done(cmd);
 932                return 0;
 933        }
 934#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 935
 936#ifdef NCR5380_STATS
 937# if 0
 938        if (!hostdata->connected && !hostdata->issue_queue &&
 939            !hostdata->disconnected_queue) {
 940                hostdata->timebase = jiffies;
 941        }
 942# endif
 943# ifdef NCR5380_STAT_LIMIT
 944        if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
 945# endif
 946                switch (cmd->cmnd[0]) {
 947                case WRITE:
 948                case WRITE_6:
 949                case WRITE_10:
 950                        hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
 951                        hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
 952                        hostdata->pendingw++;
 953                        break;
 954                case READ:
 955                case READ_6:
 956                case READ_10:
 957                        hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
 958                        hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
 959                        hostdata->pendingr++;
 960                        break;
 961                }
 962#endif
 963
 964        /*
 965         * We use the host_scribble field as a pointer to the next command
 966         * in a queue
 967         */
 968
 969        SET_NEXT(cmd, NULL);
 970        cmd->scsi_done = done;
 971
 972        cmd->result = 0;
 973
 974        /*
 975         * Insert the cmd into the issue queue. Note that REQUEST SENSE
 976         * commands are added to the head of the queue since any command will
 977         * clear the contingent allegiance condition that exists and the
 978         * sense data is only guaranteed to be valid while the condition exists.
 979         */
 980
 981        local_irq_save(flags);
 982        /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
 983         * Otherwise a running NCR5380_main may steal the lock.
 984         * Lock before actually inserting due to fairness reasons explained in
 985         * atari_scsi.c. If we insert first, then it's impossible for this driver
 986         * to release the lock.
 987         * Stop timer for this command while waiting for the lock, or timeouts
 988         * may happen (and they really do), and it's no good if the command doesn't
 989         * appear in any of the queues.
 990         * ++roman: Just disabling the NCR interrupt isn't sufficient here,
 991         * because also a timer int can trigger an abort or reset, which would
 992         * alter queues and touch the lock.
 993         */
 994        if (!IS_A_TT()) {
 995                /* perhaps stop command timer here */
 996                falcon_get_lock();
 997                /* perhaps restart command timer here */
 998        }
 999        if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1000                LIST(cmd, hostdata->issue_queue);
1001                SET_NEXT(cmd, hostdata->issue_queue);
1002                hostdata->issue_queue = cmd;
1003        } else {
1004                for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
1005                     NEXT(tmp); tmp = NEXT(tmp))
1006                        ;
1007                LIST(cmd, tmp);
1008                SET_NEXT(tmp, cmd);
1009        }
1010        local_irq_restore(flags);
1011
1012        QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
1013                  (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
1014
1015        /* If queue_command() is called from an interrupt (real one or bottom
1016         * half), we let queue_main() do the job of taking care about main. If it
1017         * is already running, this is a no-op, else main will be queued.
1018         *
1019         * If we're not in an interrupt, we can call NCR5380_main()
1020         * unconditionally, because it cannot be already running.
1021         */
1022        if (in_interrupt() || ((flags >> 8) & 7) >= 6)
1023                queue_main();
1024        else
1025                NCR5380_main(NULL);
1026        return 0;
1027}
1028
1029static DEF_SCSI_QCMD(NCR5380_queue_command)
1030
1031/*
1032 * Function : NCR5380_main (void)
1033 *
1034 * Purpose : NCR5380_main is a coroutine that runs as long as more work can
1035 *      be done on the NCR5380 host adapters in a system.  Both
1036 *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1037 *      in case it is not running.
1038 *
1039 * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
1040 *  reenable them.  This prevents reentrancy and kernel stack overflow.
1041 */
1042
1043static void NCR5380_main(struct work_struct *work)
1044{
1045        Scsi_Cmnd *tmp, *prev;
1046        struct Scsi_Host *instance = first_instance;
1047        struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
1048        int done;
1049        unsigned long flags;
1050
1051        /*
1052         * We run (with interrupts disabled) until we're sure that none of
1053         * the host adapters have anything that can be done, at which point
1054         * we set main_running to 0 and exit.
1055         *
1056         * Interrupts are enabled before doing various other internal
1057         * instructions, after we've decided that we need to run through
1058         * the loop again.
1059         *
1060         * this should prevent any race conditions.
1061         *
1062         * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1063         * because also a timer int can trigger an abort or reset, which can
1064         * alter queues and touch the Falcon lock.
1065         */
1066
1067        /* Tell int handlers main() is now already executing.  Note that
1068           no races are possible here. If an int comes in before
1069           'main_running' is set here, and queues/executes main via the
1070           task queue, it doesn't do any harm, just this instance of main
1071           won't find any work left to do. */
1072        if (main_running)
1073                return;
1074        main_running = 1;
1075
1076        local_save_flags(flags);
1077        do {
1078                local_irq_disable();    /* Freeze request queues */
1079                done = 1;
1080
1081                if (!hostdata->connected) {
1082                        MAIN_PRINTK("scsi%d: not connected\n", HOSTNO);
1083                        /*
1084                         * Search through the issue_queue for a command destined
1085                         * for a target that's not busy.
1086                         */
1087#if (NDEBUG & NDEBUG_LISTS)
1088                        for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
1089                             tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
1090                                ;
1091                        /*printk("%p  ", tmp);*/
1092                        if ((tmp == prev) && tmp)
1093                                printk(" LOOP\n");
1094                        /* else printk("\n"); */
1095#endif
1096                        for (tmp = (Scsi_Cmnd *) hostdata->issue_queue,
1097                             prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
1098
1099#if (NDEBUG & NDEBUG_LISTS)
1100                                if (prev != tmp)
1101                                        printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
1102                                               tmp, tmp->device->id, hostdata->busy[tmp->device->id],
1103                                               tmp->device->lun);
1104#endif
1105                                /*  When we find one, remove it from the issue queue. */
1106                                /* ++guenther: possible race with Falcon locking */
1107                                if (
1108#ifdef SUPPORT_TAGS
1109                                    !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
1110#else
1111                                    !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
1112#endif
1113                                    ) {
1114                                        /* ++guenther: just to be sure, this must be atomic */
1115                                        local_irq_disable();
1116                                        if (prev) {
1117                                                REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1118                                                SET_NEXT(prev, NEXT(tmp));
1119                                        } else {
1120                                                REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
1121                                                hostdata->issue_queue = NEXT(tmp);
1122                                        }
1123                                        SET_NEXT(tmp, NULL);
1124                                        falcon_dont_release++;
1125
1126                                        /* reenable interrupts after finding one */
1127                                        local_irq_restore(flags);
1128
1129                                        /*
1130                                         * Attempt to establish an I_T_L nexus here.
1131                                         * On success, instance->hostdata->connected is set.
1132                                         * On failure, we must add the command back to the
1133                                         *   issue queue so we can keep trying.
1134                                         */
1135                                        MAIN_PRINTK("scsi%d: main(): command for target %d "
1136                                                    "lun %d removed from issue_queue\n",
1137                                                    HOSTNO, tmp->device->id, tmp->device->lun);
1138                                        /*
1139                                         * REQUEST SENSE commands are issued without tagged
1140                                         * queueing, even on SCSI-II devices because the
1141                                         * contingent allegiance condition exists for the
1142                                         * entire unit.
1143                                         */
1144                                        /* ++roman: ...and the standard also requires that
1145                                         * REQUEST SENSE command are untagged.
1146                                         */
1147
1148#ifdef SUPPORT_TAGS
1149                                        cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
1150#endif
1151                                        if (!NCR5380_select(instance, tmp,
1152                                            (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE :
1153                                            TAG_NEXT)) {
1154                                                falcon_dont_release--;
1155                                                /* release if target did not response! */
1156                                                falcon_release_lock_if_possible(hostdata);
1157                                                break;
1158                                        } else {
1159                                                local_irq_disable();
1160                                                LIST(tmp, hostdata->issue_queue);
1161                                                SET_NEXT(tmp, hostdata->issue_queue);
1162                                                hostdata->issue_queue = tmp;
1163#ifdef SUPPORT_TAGS
1164                                                cmd_free_tag(tmp);
1165#endif
1166                                                falcon_dont_release--;
1167                                                local_irq_restore(flags);
1168                                                MAIN_PRINTK("scsi%d: main(): select() failed, "
1169                                                            "returned to issue_queue\n", HOSTNO);
1170                                                if (hostdata->connected)
1171                                                        break;
1172                                        }
1173                                } /* if target/lun/target queue is not busy */
1174                        } /* for issue_queue */
1175                } /* if (!hostdata->connected) */
1176
1177                if (hostdata->connected
1178#ifdef REAL_DMA
1179                    && !hostdata->dma_len
1180#endif
1181                    ) {
1182                        local_irq_restore(flags);
1183                        MAIN_PRINTK("scsi%d: main: performing information transfer\n",
1184                                    HOSTNO);
1185                        NCR5380_information_transfer(instance);
1186                        MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
1187                        done = 0;
1188                }
1189        } while (!done);
1190
1191        /* Better allow ints _after_ 'main_running' has been cleared, else
1192           an interrupt could believe we'll pick up the work it left for
1193           us, but we won't see it anymore here... */
1194        main_running = 0;
1195        local_irq_restore(flags);
1196}
1197
1198
1199#ifdef REAL_DMA
1200/*
1201 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1202 *
1203 * Purpose : Called by interrupt handler when DMA finishes or a phase
1204 *      mismatch occurs (which would finish the DMA transfer).
1205 *
1206 * Inputs : instance - this instance of the NCR5380.
1207 *
1208 */
1209
1210static void NCR5380_dma_complete(struct Scsi_Host *instance)
1211{
1212        SETUP_HOSTDATA(instance);
1213        int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
1214        unsigned char **data, p;
1215        volatile int *count;
1216
1217        if (!hostdata->connected) {
1218                printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
1219                       "no connected cmd\n", HOSTNO);
1220                return;
1221        }
1222
1223        if (atari_read_overruns) {
1224                p = hostdata->connected->SCp.phase;
1225                if (p & SR_IO) {
1226                        udelay(10);
1227                        if ((NCR5380_read(BUS_AND_STATUS_REG) &
1228                             (BASR_PHASE_MATCH|BASR_ACK)) ==
1229                            (BASR_PHASE_MATCH|BASR_ACK)) {
1230                                saved_data = NCR5380_read(INPUT_DATA_REG);
1231                                overrun = 1;
1232                                DMA_PRINTK("scsi%d: read overrun handled\n", HOSTNO);
1233                        }
1234                }
1235        }
1236
1237        DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1238                   HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
1239                   NCR5380_read(STATUS_REG));
1240
1241        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1242        NCR5380_write(MODE_REG, MR_BASE);
1243        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1244
1245        transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
1246        hostdata->dma_len = 0;
1247
1248        data = (unsigned char **)&hostdata->connected->SCp.ptr;
1249        count = &hostdata->connected->SCp.this_residual;
1250        *data += transfered;
1251        *count -= transfered;
1252
1253        if (atari_read_overruns) {
1254                if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1255                        cnt = toPIO = atari_read_overruns;
1256                        if (overrun) {
1257                                DMA_PRINTK("Got an input overrun, using saved byte\n");
1258                                *(*data)++ = saved_data;
1259                                (*count)--;
1260                                cnt--;
1261                                toPIO--;
1262                        }
1263                        DMA_PRINTK("Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1264                        NCR5380_transfer_pio(instance, &p, &cnt, data);
1265                        *count -= toPIO - cnt;
1266                }
1267        }
1268}
1269#endif /* REAL_DMA */
1270
1271
1272/*
1273 * Function : void NCR5380_intr (int irq)
1274 *
1275 * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1276 *      from the disconnected queue, and restarting NCR5380_main()
1277 *      as required.
1278 *
1279 * Inputs : int irq, irq that caused this interrupt.
1280 *
1281 */
1282
1283static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1284{
1285        struct Scsi_Host *instance = first_instance;
1286        int done = 1, handled = 0;
1287        unsigned char basr;
1288
1289        INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);
1290
1291        /* Look for pending interrupts */
1292        basr = NCR5380_read(BUS_AND_STATUS_REG);
1293        INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
1294        /* dispatch to appropriate routine if found and done=0 */
1295        if (basr & BASR_IRQ) {
1296                NCR_PRINT(NDEBUG_INTR);
1297                if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
1298                        done = 0;
1299                        ENABLE_IRQ();
1300                        INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
1301                        NCR5380_reselect(instance);
1302                        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1303                } else if (basr & BASR_PARITY_ERROR) {
1304                        INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
1305                        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1306                } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1307                        INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
1308                        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1309                } else {
1310                        /*
1311                         * The rest of the interrupt conditions can occur only during a
1312                         * DMA transfer
1313                         */
1314
1315#if defined(REAL_DMA)
1316                        /*
1317                         * We should only get PHASE MISMATCH and EOP interrupts if we have
1318                         * DMA enabled, so do a sanity check based on the current setting
1319                         * of the MODE register.
1320                         */
1321
1322                        if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
1323                            ((basr & BASR_END_DMA_TRANSFER) ||
1324                             !(basr & BASR_PHASE_MATCH))) {
1325
1326                                INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1327                                NCR5380_dma_complete( instance );
1328                                done = 0;
1329                                ENABLE_IRQ();
1330                        } else
1331#endif /* REAL_DMA */
1332                        {
1333/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1334                                if (basr & BASR_PHASE_MATCH)
1335                                        printk(KERN_NOTICE "scsi%d: unknown interrupt, "
1336                                               "BASR 0x%x, MR 0x%x, SR 0x%x\n",
1337                                               HOSTNO, basr, NCR5380_read(MODE_REG),
1338                                               NCR5380_read(STATUS_REG));
1339                                (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1340                        }
1341                } /* if !(SELECTION || PARITY) */
1342                handled = 1;
1343        } /* BASR & IRQ */ else {
1344                printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
1345                       "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
1346                       NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1347                (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1348        }
1349
1350        if (!done) {
1351                INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
1352                /* Put a call to NCR5380_main() on the queue... */
1353                queue_main();
1354        }
1355        return IRQ_RETVAL(handled);
1356}
1357
1358#ifdef NCR5380_STATS
1359static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd *cmd)
1360{
1361# ifdef NCR5380_STAT_LIMIT
1362        if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
1363# endif
1364                switch (cmd->cmnd[0]) {
1365                case WRITE:
1366                case WRITE_6:
1367                case WRITE_10:
1368                        hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
1369                        /*hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);*/
1370                        hostdata->pendingw--;
1371                        break;
1372                case READ:
1373                case READ_6:
1374                case READ_10:
1375                        hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
1376                        /*hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);*/
1377                        hostdata->pendingr--;
1378                        break;
1379                }
1380}
1381#endif
1382
1383/*
1384 * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1385 *      int tag);
1386 *
1387 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1388 *      including ARBITRATION, SELECTION, and initial message out for
1389 *      IDENTIFY and queue messages.
1390 *
1391 * Inputs : instance - instantiation of the 5380 driver on which this
1392 *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1393 *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1394 *      the command that is presently connected.
1395 *
1396 * Returns : -1 if selection could not execute for some reason,
1397 *      0 if selection succeeded or failed because the target
1398 *      did not respond.
1399 *
1400 * Side effects :
1401 *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1402 *              with registers as they should have been on entry - ie
1403 *              SELECT_ENABLE will be set appropriately, the NCR5380
1404 *              will cease to drive any SCSI bus signals.
1405 *
1406 *      If successful : I_T_L or I_T_L_Q nexus will be established,
1407 *              instance->connected will be set to cmd.
1408 *              SELECT interrupt will be disabled.
1409 *
1410 *      If failed (no target) : cmd->scsi_done() will be called, and the
1411 *              cmd->result host byte set to DID_BAD_TARGET.
1412 */
1413
1414static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
1415{
1416        SETUP_HOSTDATA(instance);
1417        unsigned char tmp[3], phase;
1418        unsigned char *data;
1419        int len;
1420        unsigned long timeout;
1421        unsigned long flags;
1422
1423        hostdata->restart_select = 0;
1424        NCR_PRINT(NDEBUG_ARBITRATION);
1425        ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
1426                   instance->this_id);
1427
1428        /*
1429         * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1430         * data bus during SELECTION.
1431         */
1432
1433        local_irq_save(flags);
1434        if (hostdata->connected) {
1435                local_irq_restore(flags);
1436                return -1;
1437        }
1438        NCR5380_write(TARGET_COMMAND_REG, 0);
1439
1440        /*
1441         * Start arbitration.
1442         */
1443
1444        NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1445        NCR5380_write(MODE_REG, MR_ARBITRATE);
1446
1447        local_irq_restore(flags);
1448
1449        /* Wait for arbitration logic to complete */
1450#if defined(NCR_TIMEOUT)
1451        {
1452                unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
1453
1454                while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1455                       time_before(jiffies, timeout) && !hostdata->connected)
1456                        ;
1457                if (time_after_eq(jiffies, timeout)) {
1458                        printk("scsi : arbitration timeout at %d\n", __LINE__);
1459                        NCR5380_write(MODE_REG, MR_BASE);
1460                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1461                        return -1;
1462                }
1463        }
1464#else /* NCR_TIMEOUT */
1465        while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1466               !hostdata->connected)
1467                ;
1468#endif
1469
1470        ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);
1471
1472        if (hostdata->connected) {
1473                NCR5380_write(MODE_REG, MR_BASE);
1474                return -1;
1475        }
1476        /*
1477         * The arbitration delay is 2.2us, but this is a minimum and there is
1478         * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1479         * the integral nature of udelay().
1480         *
1481         */
1482
1483        udelay(3);
1484
1485        /* Check for lost arbitration */
1486        if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1487            (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1488            (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1489            hostdata->connected) {
1490                NCR5380_write(MODE_REG, MR_BASE);
1491                ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1492                           HOSTNO);
1493                return -1;
1494        }
1495
1496        /* after/during arbitration, BSY should be asserted.
1497           IBM DPES-31080 Version S31Q works now */
1498        /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
1499        NCR5380_write(INITIATOR_COMMAND_REG,
1500                      ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1501
1502        if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1503            hostdata->connected) {
1504                NCR5380_write(MODE_REG, MR_BASE);
1505                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1506                ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1507                           HOSTNO);
1508                return -1;
1509        }
1510
1511        /*
1512         * Again, bus clear + bus settle time is 1.2us, however, this is
1513         * a minimum so we'll udelay ceil(1.2)
1514         */
1515
1516#ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
1517        /* ++roman: But some targets (see above :-) seem to need a bit more... */
1518        udelay(15);
1519#else
1520        udelay(2);
1521#endif
1522
1523        if (hostdata->connected) {
1524                NCR5380_write(MODE_REG, MR_BASE);
1525                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1526                return -1;
1527        }
1528
1529        ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);
1530
1531        /*
1532         * Now that we have won arbitration, start Selection process, asserting
1533         * the host and target ID's on the SCSI bus.
1534         */
1535
1536        NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
1537
1538        /*
1539         * Raise ATN while SEL is true before BSY goes false from arbitration,
1540         * since this is the only way to guarantee that we'll get a MESSAGE OUT
1541         * phase immediately after selection.
1542         */
1543
1544        NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
1545                      ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1546        NCR5380_write(MODE_REG, MR_BASE);
1547
1548        /*
1549         * Reselect interrupts must be turned off prior to the dropping of BSY,
1550         * otherwise we will trigger an interrupt.
1551         */
1552
1553        if (hostdata->connected) {
1554                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1555                return -1;
1556        }
1557
1558        NCR5380_write(SELECT_ENABLE_REG, 0);
1559
1560        /*
1561         * The initiator shall then wait at least two deskew delays and release
1562         * the BSY signal.
1563         */
1564        udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1565
1566        /* Reset BSY */
1567        NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
1568                      ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1569
1570        /*
1571         * Something weird happens when we cease to drive BSY - looks
1572         * like the board/chip is letting us do another read before the
1573         * appropriate propagation delay has expired, and we're confusing
1574         * a BSY signal from ourselves as the target's response to SELECTION.
1575         *
1576         * A small delay (the 'C++' frontend breaks the pipeline with an
1577         * unnecessary jump, making it work on my 386-33/Trantor T128, the
1578         * tighter 'C' code breaks and requires this) solves the problem -
1579         * the 1 us delay is arbitrary, and only used because this delay will
1580         * be the same on other platforms and since it works here, it should
1581         * work there.
1582         *
1583         * wingel suggests that this could be due to failing to wait
1584         * one deskew delay.
1585         */
1586
1587        udelay(1);
1588
1589        SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
1590
1591        /*
1592         * The SCSI specification calls for a 250 ms timeout for the actual
1593         * selection.
1594         */
1595
1596        timeout = jiffies + 25;
1597
1598        /*
1599         * XXX very interesting - we're seeing a bounce where the BSY we
1600         * asserted is being reflected / still asserted (propagation delay?)
1601         * and it's detecting as true.  Sigh.
1602         */
1603
1604#if 0
1605        /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
1606         * IO while SEL is true. But again, there are some disks out the in the
1607         * world that do that nevertheless. (Somebody claimed that this announces
1608         * reselection capability of the target.) So we better skip that test and
1609         * only wait for BSY... (Famous german words: Der Kl├╝gere gibt nach :-)
1610         */
1611
1612        while (time_before(jiffies, timeout) &&
1613               !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
1614                ;
1615
1616        if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1617                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1618                NCR5380_reselect(instance);
1619                printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
1620                       HOSTNO);
1621                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1622                return -1;
1623        }
1624#else
1625        while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
1626                ;
1627#endif
1628
1629        /*
1630         * No less than two deskew delays after the initiator detects the
1631         * BSY signal is true, it shall release the SEL signal and may
1632         * change the DATA BUS.                                     -wingel
1633         */
1634
1635        udelay(1);
1636
1637        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1638
1639        if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1640                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1641                if (hostdata->targets_present & (1 << cmd->device->id)) {
1642                        printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
1643                        if (hostdata->restart_select)
1644                                printk(KERN_NOTICE "\trestart select\n");
1645                        NCR_PRINT(NDEBUG_ANY);
1646                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1647                        return -1;
1648                }
1649                cmd->result = DID_BAD_TARGET << 16;
1650#ifdef NCR5380_STATS
1651                collect_stats(hostdata, cmd);
1652#endif
1653#ifdef SUPPORT_TAGS
1654                cmd_free_tag(cmd);
1655#endif
1656                cmd->scsi_done(cmd);
1657                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1658                SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
1659                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1660                return 0;
1661        }
1662
1663        hostdata->targets_present |= (1 << cmd->device->id);
1664
1665        /*
1666         * Since we followed the SCSI spec, and raised ATN while SEL
1667         * was true but before BSY was false during selection, the information
1668         * transfer phase should be a MESSAGE OUT phase so that we can send the
1669         * IDENTIFY message.
1670         *
1671         * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1672         * message (2 bytes) with a tag ID that we increment with every command
1673         * until it wraps back to 0.
1674         *
1675         * XXX - it turns out that there are some broken SCSI-II devices,
1676         *           which claim to support tagged queuing but fail when more than
1677         *           some number of commands are issued at once.
1678         */
1679
1680        /* Wait for start of REQ/ACK handshake */
1681        while (!(NCR5380_read(STATUS_REG) & SR_REQ))
1682                ;
1683
1684        SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1685                   HOSTNO, cmd->device->id);
1686        tmp[0] = IDENTIFY(1, cmd->device->lun);
1687
1688#ifdef SUPPORT_TAGS
1689        if (cmd->tag != TAG_NONE) {
1690                tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1691                tmp[2] = cmd->tag;
1692                len = 3;
1693        } else
1694                len = 1;
1695#else
1696        len = 1;
1697        cmd->tag = 0;
1698#endif /* SUPPORT_TAGS */
1699
1700        /* Send message(s) */
1701        data = tmp;
1702        phase = PHASE_MSGOUT;
1703        NCR5380_transfer_pio(instance, &phase, &len, &data);
1704        SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
1705        /* XXX need to handle errors here */
1706        hostdata->connected = cmd;
1707#ifndef SUPPORT_TAGS
1708        hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1709#endif
1710
1711        initialize_SCp(cmd);
1712
1713        return 0;
1714}
1715
1716/*
1717 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1718 *      unsigned char *phase, int *count, unsigned char **data)
1719 *
1720 * Purpose : transfers data in given phase using polled I/O
1721 *
1722 * Inputs : instance - instance of driver, *phase - pointer to
1723 *      what phase is expected, *count - pointer to number of
1724 *      bytes to transfer, **data - pointer to data pointer.
1725 *
1726 * Returns : -1 when different phase is entered without transferring
1727 *      maximum number of bytes, 0 if all bytes are transferred or exit
1728 *      is in same phase.
1729 *
1730 *      Also, *phase, *count, *data are modified in place.
1731 *
1732 * XXX Note : handling for bus free may be useful.
1733 */
1734
1735/*
1736 * Note : this code is not as quick as it could be, however it
1737 * IS 100% reliable, and for the actual data transfer where speed
1738 * counts, we will always do a pseudo DMA or DMA transfer.
1739 */
1740
1741static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1742                                unsigned char *phase, int *count,
1743                                unsigned char **data)
1744{
1745        register unsigned char p = *phase, tmp;
1746        register int c = *count;
1747        register unsigned char *d = *data;
1748
1749        /*
1750         * The NCR5380 chip will only drive the SCSI bus when the
1751         * phase specified in the appropriate bits of the TARGET COMMAND
1752         * REGISTER match the STATUS REGISTER
1753         */
1754
1755        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1756
1757        do {
1758                /*
1759                 * Wait for assertion of REQ, after which the phase bits will be
1760                 * valid
1761                 */
1762                while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1763                        ;
1764
1765                HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);
1766
1767                /* Check for phase mismatch */
1768                if ((tmp & PHASE_MASK) != p) {
1769                        PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
1770                        NCR_PRINT_PHASE(NDEBUG_PIO);
1771                        break;
1772                }
1773
1774                /* Do actual transfer from SCSI bus to / from memory */
1775                if (!(p & SR_IO))
1776                        NCR5380_write(OUTPUT_DATA_REG, *d);
1777                else
1778                        *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1779
1780                ++d;
1781
1782                /*
1783                 * The SCSI standard suggests that in MSGOUT phase, the initiator
1784                 * should drop ATN on the last byte of the message phase
1785                 * after REQ has been asserted for the handshake but before
1786                 * the initiator raises ACK.
1787                 */
1788
1789                if (!(p & SR_IO)) {
1790                        if (!((p & SR_MSG) && c > 1)) {
1791                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1792                                NCR_PRINT(NDEBUG_PIO);
1793                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1794                                              ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1795                        } else {
1796                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1797                                              ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1798                                NCR_PRINT(NDEBUG_PIO);
1799                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1800                                              ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1801                        }
1802                } else {
1803                        NCR_PRINT(NDEBUG_PIO);
1804                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1805                }
1806
1807                while (NCR5380_read(STATUS_REG) & SR_REQ)
1808                        ;
1809
1810                HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);
1811
1812                /*
1813                 * We have several special cases to consider during REQ/ACK handshaking :
1814                 * 1.  We were in MSGOUT phase, and we are on the last byte of the
1815                 *      message.  ATN must be dropped as ACK is dropped.
1816                 *
1817                 * 2.  We are in a MSGIN phase, and we are on the last byte of the
1818                 *      message.  We must exit with ACK asserted, so that the calling
1819                 *      code may raise ATN before dropping ACK to reject the message.
1820                 *
1821                 * 3.  ACK and ATN are clear and the target may proceed as normal.
1822                 */
1823                if (!(p == PHASE_MSGIN && c == 1)) {
1824                        if (p == PHASE_MSGOUT && c > 1)
1825                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1826                        else
1827                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1828                }
1829        } while (--c);
1830
1831        PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);
1832
1833        *count = c;
1834        *data = d;
1835        tmp = NCR5380_read(STATUS_REG);
1836        /* The phase read from the bus is valid if either REQ is (already)
1837         * asserted or if ACK hasn't been released yet. The latter is the case if
1838         * we're in MSGIN and all wanted bytes have been received.
1839         */
1840        if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
1841                *phase = tmp & PHASE_MASK;
1842        else
1843                *phase = PHASE_UNKNOWN;
1844
1845        if (!c || (*phase == p))
1846                return 0;
1847        else
1848                return -1;
1849}
1850
1851/*
1852 * Function : do_abort (Scsi_Host *host)
1853 *
1854 * Purpose : abort the currently established nexus.  Should only be
1855 *      called from a routine which can drop into a
1856 *
1857 * Returns : 0 on success, -1 on failure.
1858 */
1859
1860static int do_abort(struct Scsi_Host *host)
1861{
1862        unsigned char tmp, *msgptr, phase;
1863        int len;
1864
1865        /* Request message out phase */
1866        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1867
1868        /*
1869         * Wait for the target to indicate a valid phase by asserting
1870         * REQ.  Once this happens, we'll have either a MSGOUT phase
1871         * and can immediately send the ABORT message, or we'll have some
1872         * other phase and will have to source/sink data.
1873         *
1874         * We really don't care what value was on the bus or what value
1875         * the target sees, so we just handshake.
1876         */
1877
1878        while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1879                ;
1880
1881        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1882
1883        if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1884                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1885                              ICR_ASSERT_ACK);
1886                while (NCR5380_read(STATUS_REG) & SR_REQ)
1887                        ;
1888                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1889        }
1890
1891        tmp = ABORT;
1892        msgptr = &tmp;
1893        len = 1;
1894        phase = PHASE_MSGOUT;
1895        NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1896
1897        /*
1898         * If we got here, and the command completed successfully,
1899         * we're about to go into bus free state.
1900         */
1901
1902        return len ? -1 : 0;
1903}
1904
1905#if defined(REAL_DMA)
1906/*
1907 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1908 *      unsigned char *phase, int *count, unsigned char **data)
1909 *
1910 * Purpose : transfers data in given phase using either real
1911 *      or pseudo DMA.
1912 *
1913 * Inputs : instance - instance of driver, *phase - pointer to
1914 *      what phase is expected, *count - pointer to number of
1915 *      bytes to transfer, **data - pointer to data pointer.
1916 *
1917 * Returns : -1 when different phase is entered without transferring
1918 *      maximum number of bytes, 0 if all bytes or transferred or exit
1919 *      is in same phase.
1920 *
1921 *      Also, *phase, *count, *data are modified in place.
1922 *
1923 */
1924
1925
1926static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1927                                unsigned char *phase, int *count,
1928                                unsigned char **data)
1929{
1930        SETUP_HOSTDATA(instance);
1931        register int c = *count;
1932        register unsigned char p = *phase;
1933        register unsigned char *d = *data;
1934        unsigned char tmp;
1935        unsigned long flags;
1936
1937        if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1938                *phase = tmp;
1939                return -1;
1940        }
1941
1942        if (atari_read_overruns && (p & SR_IO))
1943                c -= atari_read_overruns;
1944
1945        DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1946                   HOSTNO, (p & SR_IO) ? "reading" : "writing",
1947                   c, (p & SR_IO) ? "to" : "from", d);
1948
1949        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1950
1951#ifdef REAL_DMA
1952        NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1953#endif /* def REAL_DMA  */
1954
1955        if (IS_A_TT()) {
1956                /* On the Medusa, it is a must to initialize the DMA before
1957                 * starting the NCR. This is also the cleaner way for the TT.
1958                 */
1959                local_irq_save(flags);
1960                hostdata->dma_len = (p & SR_IO) ?
1961                        NCR5380_dma_read_setup(instance, d, c) :
1962                        NCR5380_dma_write_setup(instance, d, c);
1963                local_irq_restore(flags);
1964        }
1965
1966        if (p & SR_IO)
1967                NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1968        else {
1969                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1970                NCR5380_write(START_DMA_SEND_REG, 0);
1971        }
1972
1973        if (!IS_A_TT()) {
1974                /* On the Falcon, the DMA setup must be done after the last */
1975                /* NCR access, else the DMA setup gets trashed!
1976                 */
1977                local_irq_save(flags);
1978                hostdata->dma_len = (p & SR_IO) ?
1979                        NCR5380_dma_read_setup(instance, d, c) :
1980                        NCR5380_dma_write_setup(instance, d, c);
1981                local_irq_restore(flags);
1982        }
1983        return 0;
1984}
1985#endif /* defined(REAL_DMA) */
1986
1987/*
1988 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1989 *
1990 * Purpose : run through the various SCSI phases and do as the target
1991 *      directs us to.  Operates on the currently connected command,
1992 *      instance->connected.
1993 *
1994 * Inputs : instance, instance for which we are doing commands
1995 *
1996 * Side effects : SCSI things happen, the disconnected queue will be
1997 *      modified if a command disconnects, *instance->connected will
1998 *      change.
1999 *
2000 * XXX Note : we need to watch for bus free or a reset condition here
2001 *      to recover from an unexpected bus free condition.
2002 */
2003
2004static void NCR5380_information_transfer(struct Scsi_Host *instance)
2005{
2006        SETUP_HOSTDATA(instance);
2007        unsigned long flags;
2008        unsigned char msgout = NOP;
2009        int sink = 0;
2010        int len;
2011#if defined(REAL_DMA)
2012        int transfersize;
2013#endif
2014        unsigned char *data;
2015        unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2016        Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2017
2018        while (1) {
2019                tmp = NCR5380_read(STATUS_REG);
2020                /* We only have a valid SCSI phase when REQ is asserted */
2021                if (tmp & SR_REQ) {
2022                        phase = (tmp & PHASE_MASK);
2023                        if (phase != old_phase) {
2024                                old_phase = phase;
2025                                NCR_PRINT_PHASE(NDEBUG_INFORMATION);
2026                        }
2027
2028                        if (sink && (phase != PHASE_MSGOUT)) {
2029                                NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2030
2031                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
2032                                              ICR_ASSERT_ACK);
2033                                while (NCR5380_read(STATUS_REG) & SR_REQ)
2034                                        ;
2035                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2036                                              ICR_ASSERT_ATN);
2037                                sink = 0;
2038                                continue;
2039                        }
2040
2041                        switch (phase) {
2042                        case PHASE_DATAOUT:
2043#if (NDEBUG & NDEBUG_NO_DATAOUT)
2044                                printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
2045                                       "aborted\n", HOSTNO);
2046                                sink = 1;
2047                                do_abort(instance);
2048                                cmd->result = DID_ERROR << 16;
2049                                cmd->scsi_done(cmd);
2050                                return;
2051#endif
2052                        case PHASE_DATAIN:
2053                                /*
2054                                 * If there is no room left in the current buffer in the
2055                                 * scatter-gather list, move onto the next one.
2056                                 */
2057
2058                                if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2059                                        ++cmd->SCp.buffer;
2060                                        --cmd->SCp.buffers_residual;
2061                                        cmd->SCp.this_residual = cmd->SCp.buffer->length;
2062                                        cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2063                                        /* ++roman: Try to merge some scatter-buffers if
2064                                         * they are at contiguous physical addresses.
2065                                         */
2066                                        merge_contiguous_buffers(cmd);
2067                                        INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
2068                                                   HOSTNO, cmd->SCp.this_residual,
2069                                                   cmd->SCp.buffers_residual);
2070                                }
2071
2072                                /*
2073                                 * The preferred transfer method is going to be
2074                                 * PSEUDO-DMA for systems that are strictly PIO,
2075                                 * since we can let the hardware do the handshaking.
2076                                 *
2077                                 * For this to work, we need to know the transfersize
2078                                 * ahead of time, since the pseudo-DMA code will sit
2079                                 * in an unconditional loop.
2080                                 */
2081
2082                                /* ++roman: I suggest, this should be
2083                                 *   #if def(REAL_DMA)
2084                                 * instead of leaving REAL_DMA out.
2085                                 */
2086
2087#if defined(REAL_DMA)
2088                                if (!cmd->device->borken &&
2089                                    (transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
2090                                        len = transfersize;
2091                                        cmd->SCp.phase = phase;
2092                                        if (NCR5380_transfer_dma(instance, &phase,
2093                                            &len, (unsigned char **)&cmd->SCp.ptr)) {
2094                                                /*
2095                                                 * If the watchdog timer fires, all future
2096                                                 * accesses to this device will use the
2097                                                 * polled-IO. */
2098                                                printk(KERN_NOTICE "scsi%d: switching target %d "
2099                                                           "lun %d to slow handshake\n", HOSTNO,
2100                                                           cmd->device->id, cmd->device->lun);
2101                                                cmd->device->borken = 1;
2102                                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2103                                                        ICR_ASSERT_ATN);
2104                                                sink = 1;
2105                                                do_abort(instance);
2106                                                cmd->result = DID_ERROR << 16;
2107                                                cmd->scsi_done(cmd);
2108                                                /* XXX - need to source or sink data here, as appropriate */
2109                                        } else {
2110#ifdef REAL_DMA
2111                                                /* ++roman: When using real DMA,
2112                                                 * information_transfer() should return after
2113                                                 * starting DMA since it has nothing more to
2114                                                 * do.
2115                                                 */
2116                                                return;
2117#else
2118                                                cmd->SCp.this_residual -= transfersize - len;
2119#endif
2120                                        }
2121                                } else
2122#endif /* defined(REAL_DMA) */
2123                                        NCR5380_transfer_pio(instance, &phase,
2124                                                             (int *)&cmd->SCp.this_residual,
2125                                                             (unsigned char **)&cmd->SCp.ptr);
2126                                break;
2127                        case PHASE_MSGIN:
2128                                len = 1;
2129                                data = &tmp;
2130                                NCR5380_write(SELECT_ENABLE_REG, 0);    /* disable reselects */
2131                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2132                                cmd->SCp.Message = tmp;
2133
2134                                switch (tmp) {
2135                                /*
2136                                 * Linking lets us reduce the time required to get the
2137                                 * next command out to the device, hopefully this will
2138                                 * mean we don't waste another revolution due to the delays
2139                                 * required by ARBITRATION and another SELECTION.
2140                                 *
2141                                 * In the current implementation proposal, low level drivers
2142                                 * merely have to start the next command, pointed to by
2143                                 * next_link, done() is called as with unlinked commands.
2144                                 */
2145#ifdef LINKED
2146                                case LINKED_CMD_COMPLETE:
2147                                case LINKED_FLG_CMD_COMPLETE:
2148                                        /* Accept message by clearing ACK */
2149                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2150
2151                                        LNK_PRINTK("scsi%d: target %d lun %d linked command "
2152                                                   "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
2153
2154                                        /* Enable reselect interrupts */
2155                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2156                                        /*
2157                                         * Sanity check : A linked command should only terminate
2158                                         * with one of these messages if there are more linked
2159                                         * commands available.
2160                                         */
2161
2162                                        if (!cmd->next_link) {
2163                                                 printk(KERN_NOTICE "scsi%d: target %d lun %d "
2164                                                        "linked command complete, no next_link\n",
2165                                                        HOSTNO, cmd->device->id, cmd->device->lun);
2166                                                sink = 1;
2167                                                do_abort(instance);
2168                                                return;
2169                                        }
2170
2171                                        initialize_SCp(cmd->next_link);
2172                                        /* The next command is still part of this process; copy it
2173                                         * and don't free it! */
2174                                        cmd->next_link->tag = cmd->tag;
2175                                        cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2176                                        LNK_PRINTK("scsi%d: target %d lun %d linked request "
2177                                                   "done, calling scsi_done().\n",
2178                                                   HOSTNO, cmd->device->id, cmd->device->lun);
2179#ifdef NCR5380_STATS
2180                                        collect_stats(hostdata, cmd);
2181#endif
2182                                        cmd->scsi_done(cmd);
2183                                        cmd = hostdata->connected;
2184                                        break;
2185#endif /* def LINKED */
2186                                case ABORT:
2187                                case COMMAND_COMPLETE:
2188                                        /* Accept message by clearing ACK */
2189                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2190                                        /* ++guenther: possible race with Falcon locking */
2191                                        falcon_dont_release++;
2192                                        hostdata->connected = NULL;
2193                                        QU_PRINTK("scsi%d: command for target %d, lun %d "
2194                                                  "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2195#ifdef SUPPORT_TAGS
2196                                        cmd_free_tag(cmd);
2197                                        if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2198                                                /* Turn a QUEUE FULL status into BUSY, I think the
2199                                                 * mid level cannot handle QUEUE FULL :-( (The
2200                                                 * command is retried after BUSY). Also update our
2201                                                 * queue size to the number of currently issued
2202                                                 * commands now.
2203                                                 */
2204                                                /* ++Andreas: the mid level code knows about
2205                                                   QUEUE_FULL now. */
2206                                                TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
2207                                                TAG_PRINTK("scsi%d: target %d lun %d returned "
2208                                                           "QUEUE_FULL after %d commands\n",
2209                                                           HOSTNO, cmd->device->id, cmd->device->lun,
2210                                                           ta->nr_allocated);
2211                                                if (ta->queue_size > ta->nr_allocated)
2212                                                        ta->nr_allocated = ta->queue_size;
2213                                        }
2214#else
2215                                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2216#endif
2217                                        /* Enable reselect interrupts */
2218                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2219
2220                                        /*
2221                                         * I'm not sure what the correct thing to do here is :
2222                                         *
2223                                         * If the command that just executed is NOT a request
2224                                         * sense, the obvious thing to do is to set the result
2225                                         * code to the values of the stored parameters.
2226                                         *
2227                                         * If it was a REQUEST SENSE command, we need some way to
2228                                         * differentiate between the failure code of the original
2229                                         * and the failure code of the REQUEST sense - the obvious
2230                                         * case is success, where we fall through and leave the
2231                                         * result code unchanged.
2232                                         *
2233                                         * The non-obvious place is where the REQUEST SENSE failed
2234                                         */
2235
2236                                        if (cmd->cmnd[0] != REQUEST_SENSE)
2237                                                cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2238                                        else if (status_byte(cmd->SCp.Status) != GOOD)
2239                                                cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2240
2241#ifdef AUTOSENSE
2242                                        if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2243                                                hostdata->ses.cmd_len) {
2244                                                scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2245                                                hostdata->ses.cmd_len = 0 ;
2246                                        }
2247
2248                                        if ((cmd->cmnd[0] != REQUEST_SENSE) &&
2249                                            (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2250                                                scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2251
2252                                                ASEN_PRINTK("scsi%d: performing request sense\n", HOSTNO);
2253
2254                                                local_irq_save(flags);
2255                                                LIST(cmd,hostdata->issue_queue);
2256                                                SET_NEXT(cmd, hostdata->issue_queue);
2257                                                hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2258                                                local_irq_restore(flags);
2259                                                QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
2260                                                          "issue queue\n", H_NO(cmd));
2261                                        } else
2262#endif /* def AUTOSENSE */
2263                                        {
2264#ifdef NCR5380_STATS
2265                                                collect_stats(hostdata, cmd);
2266#endif
2267                                                cmd->scsi_done(cmd);
2268                                        }
2269
2270                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2271                                        /*
2272                                         * Restore phase bits to 0 so an interrupted selection,
2273                                         * arbitration can resume.
2274                                         */
2275                                        NCR5380_write(TARGET_COMMAND_REG, 0);
2276
2277                                        while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2278                                                barrier();
2279
2280                                        falcon_dont_release--;
2281                                        /* ++roman: For Falcon SCSI, release the lock on the
2282                                         * ST-DMA here if no other commands are waiting on the
2283                                         * disconnected queue.
2284                                         */
2285                                        falcon_release_lock_if_possible(hostdata);
2286                                        return;
2287                                case MESSAGE_REJECT:
2288                                        /* Accept message by clearing ACK */
2289                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2290                                        /* Enable reselect interrupts */
2291                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2292                                        switch (hostdata->last_message) {
2293                                        case HEAD_OF_QUEUE_TAG:
2294                                        case ORDERED_QUEUE_TAG:
2295                                        case SIMPLE_QUEUE_TAG:
2296                                                /* The target obviously doesn't support tagged
2297                                                 * queuing, even though it announced this ability in
2298                                                 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2299                                                 * clear 'tagged_supported' and lock the LUN, since
2300                                                 * the command is treated as untagged further on.
2301                                                 */
2302                                                cmd->device->tagged_supported = 0;
2303                                                hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2304                                                cmd->tag = TAG_NONE;
2305                                                TAG_PRINTK("scsi%d: target %d lun %d rejected "
2306                                                           "QUEUE_TAG message; tagged queuing "
2307                                                           "disabled\n",
2308                                                           HOSTNO, cmd->device->id, cmd->device->lun);
2309                                                break;
2310                                        }
2311                                        break;
2312                                case DISCONNECT:
2313                                        /* Accept message by clearing ACK */
2314                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2315                                        local_irq_save(flags);
2316                                        cmd->device->disconnect = 1;
2317                                        LIST(cmd,hostdata->disconnected_queue);
2318                                        SET_NEXT(cmd, hostdata->disconnected_queue);
2319                                        hostdata->connected = NULL;
2320                                        hostdata->disconnected_queue = cmd;
2321                                        local_irq_restore(flags);
2322                                        QU_PRINTK("scsi%d: command for target %d lun %d was "
2323                                                  "moved from connected to the "
2324                                                  "disconnected_queue\n", HOSTNO,
2325                                                  cmd->device->id, cmd->device->lun);
2326                                        /*
2327                                         * Restore phase bits to 0 so an interrupted selection,
2328                                         * arbitration can resume.
2329                                         */
2330                                        NCR5380_write(TARGET_COMMAND_REG, 0);
2331
2332                                        /* Enable reselect interrupts */
2333                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2334                                        /* Wait for bus free to avoid nasty timeouts */
2335                                        while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2336                                                barrier();
2337                                        return;
2338                                        /*
2339                                         * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2340                                         * operation, in violation of the SCSI spec so we can safely
2341                                         * ignore SAVE/RESTORE pointers calls.
2342                                         *
2343                                         * Unfortunately, some disks violate the SCSI spec and
2344                                         * don't issue the required SAVE_POINTERS message before
2345                                         * disconnecting, and we have to break spec to remain
2346                                         * compatible.
2347                                         */
2348                                case SAVE_POINTERS:
2349                                case RESTORE_POINTERS:
2350                                        /* Accept message by clearing ACK */
2351                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2352                                        /* Enable reselect interrupts */
2353                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2354                                        break;
2355                                case EXTENDED_MESSAGE:
2356                                        /*
2357                                         * Extended messages are sent in the following format :
2358                                         * Byte
2359                                         * 0            EXTENDED_MESSAGE == 1
2360                                         * 1            length (includes one byte for code, doesn't
2361                                         *              include first two bytes)
2362                                         * 2            code
2363                                         * 3..length+1  arguments
2364                                         *
2365                                         * Start the extended message buffer with the EXTENDED_MESSAGE
2366                                         * byte, since spi_print_msg() wants the whole thing.
2367                                         */
2368                                        extended_msg[0] = EXTENDED_MESSAGE;
2369                                        /* Accept first byte by clearing ACK */
2370                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2371
2372                                        EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);
2373
2374                                        len = 2;
2375                                        data = extended_msg + 1;
2376                                        phase = PHASE_MSGIN;
2377                                        NCR5380_transfer_pio(instance, &phase, &len, &data);
2378                                        EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2379                                                   (int)extended_msg[1], (int)extended_msg[2]);
2380
2381                                        if (!len && extended_msg[1] <=
2382                                            (sizeof(extended_msg) - 1)) {
2383                                                /* Accept third byte by clearing ACK */
2384                                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2385                                                len = extended_msg[1] - 1;
2386                                                data = extended_msg + 3;
2387                                                phase = PHASE_MSGIN;
2388
2389                                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2390                                                EXT_PRINTK("scsi%d: message received, residual %d\n",
2391                                                           HOSTNO, len);
2392
2393                                                switch (extended_msg[2]) {
2394                                                case EXTENDED_SDTR:
2395                                                case EXTENDED_WDTR:
2396                                                case EXTENDED_MODIFY_DATA_POINTER:
2397                                                case EXTENDED_EXTENDED_IDENTIFY:
2398                                                        tmp = 0;
2399                                                }
2400                                        } else if (len) {
2401                                                printk(KERN_NOTICE "scsi%d: error receiving "
2402                                                       "extended message\n", HOSTNO);
2403                                                tmp = 0;
2404                                        } else {
2405                                                printk(KERN_NOTICE "scsi%d: extended message "
2406                                                           "code %02x length %d is too long\n",
2407                                                           HOSTNO, extended_msg[2], extended_msg[1]);
2408                                                tmp = 0;
2409                                        }
2410                                        /* Fall through to reject message */
2411
2412                                        /*
2413                                         * If we get something weird that we aren't expecting,
2414                                         * reject it.
2415                                         */
2416                                default:
2417                                        if (!tmp) {
2418                                                printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
2419                                                spi_print_msg(extended_msg);
2420                                                printk("\n");
2421                                        } else if (tmp != EXTENDED_MESSAGE)
2422                                                printk(KERN_DEBUG "scsi%d: rejecting unknown "
2423                                                       "message %02x from target %d, lun %d\n",
2424                                                       HOSTNO, tmp, cmd->device->id, cmd->device->lun);
2425                                        else
2426                                                printk(KERN_DEBUG "scsi%d: rejecting unknown "
2427                                                       "extended message "
2428                                                       "code %02x, length %d from target %d, lun %d\n",
2429                                                       HOSTNO, extended_msg[1], extended_msg[0],
2430                                                       cmd->device->id, cmd->device->lun);
2431
2432
2433                                        msgout = MESSAGE_REJECT;
2434                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2435                                        break;
2436                                } /* switch (tmp) */
2437                                break;
2438                        case PHASE_MSGOUT:
2439                                len = 1;
2440                                data = &msgout;
2441                                hostdata->last_message = msgout;
2442                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2443                                if (msgout == ABORT) {
2444#ifdef SUPPORT_TAGS
2445                                        cmd_free_tag(cmd);
2446#else
2447                                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2448#endif
2449                                        hostdata->connected = NULL;
2450                                        cmd->result = DID_ERROR << 16;
2451#ifdef NCR5380_STATS
2452                                        collect_stats(hostdata, cmd);
2453#endif
2454                                        cmd->scsi_done(cmd);
2455                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2456                                        falcon_release_lock_if_possible(hostdata);
2457                                        return;
2458                                }
2459                                msgout = NOP;
2460                                break;
2461                        case PHASE_CMDOUT:
2462                                len = cmd->cmd_len;
2463                                data = cmd->cmnd;
2464                                /*
2465                                 * XXX for performance reasons, on machines with a
2466                                 * PSEUDO-DMA architecture we should probably
2467                                 * use the dma transfer function.
2468                                 */
2469                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2470                                break;
2471                        case PHASE_STATIN:
2472                                len = 1;
2473                                data = &tmp;
2474                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2475                                cmd->SCp.Status = tmp;
2476                                break;
2477                        default:
2478                                printk("scsi%d: unknown phase\n", HOSTNO);
2479                                NCR_PRINT(NDEBUG_ANY);
2480                        } /* switch(phase) */
2481                } /* if (tmp * SR_REQ) */
2482        } /* while (1) */
2483}
2484
2485/*
2486 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2487 *
2488 * Purpose : does reselection, initializing the instance->connected
2489 *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2490 *      nexus has been reestablished,
2491 *
2492 * Inputs : instance - this instance of the NCR5380.
2493 *
2494 */
2495
2496
2497static void NCR5380_reselect(struct Scsi_Host *instance)
2498{
2499        SETUP_HOSTDATA(instance);
2500        unsigned char target_mask;
2501        unsigned char lun, phase;
2502        int len;
2503#ifdef SUPPORT_TAGS
2504        unsigned char tag;
2505#endif
2506        unsigned char msg[3];
2507        unsigned char *data;
2508        Scsi_Cmnd *tmp = NULL, *prev;
2509/*      unsigned long flags; */
2510
2511        /*
2512         * Disable arbitration, etc. since the host adapter obviously
2513         * lost, and tell an interrupted NCR5380_select() to restart.
2514         */
2515
2516        NCR5380_write(MODE_REG, MR_BASE);
2517        hostdata->restart_select = 1;
2518
2519        target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2520
2521        RSL_PRINTK("scsi%d: reselect\n", HOSTNO);
2522
2523        /*
2524         * At this point, we have detected that our SCSI ID is on the bus,
2525         * SEL is true and BSY was false for at least one bus settle delay
2526         * (400 ns).
2527         *
2528         * We must assert BSY ourselves, until the target drops the SEL
2529         * signal.
2530         */
2531
2532        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2533
2534        while (NCR5380_read(STATUS_REG) & SR_SEL)
2535                ;
2536        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2537
2538        /*
2539         * Wait for target to go into MSGIN.
2540         */
2541
2542        while (!(NCR5380_read(STATUS_REG) & SR_REQ))
2543                ;
2544
2545        len = 1;
2546        data = msg;
2547        phase = PHASE_MSGIN;
2548        NCR5380_transfer_pio(instance, &phase, &len, &data);
2549
2550        if (!(msg[0] & 0x80)) {
2551                printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2552                spi_print_msg(msg);
2553                do_abort(instance);
2554                return;
2555        }
2556        lun = (msg[0] & 0x07);
2557
2558#ifdef SUPPORT_TAGS
2559        /* If the phase is still MSGIN, the target wants to send some more
2560         * messages. In case it supports tagged queuing, this is probably a
2561         * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2562         */
2563        tag = TAG_NONE;
2564        if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2565                /* Accept previous IDENTIFY message by clearing ACK */
2566                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2567                len = 2;
2568                data = msg + 1;
2569                if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2570                    msg[1] == SIMPLE_QUEUE_TAG)
2571                        tag = msg[2];
2572                TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
2573                           "reselection\n", HOSTNO, target_mask, lun, tag);
2574        }
2575#endif
2576
2577        /*
2578         * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2579         * just reestablished, and remove it from the disconnected queue.
2580         */
2581
2582        for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL;
2583             tmp; prev = tmp, tmp = NEXT(tmp)) {
2584                if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2585#ifdef SUPPORT_TAGS
2586                    && (tag == tmp->tag)
2587#endif
2588                    ) {
2589                        /* ++guenther: prevent race with falcon_release_lock */
2590                        falcon_dont_release++;
2591                        if (prev) {
2592                                REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2593                                SET_NEXT(prev, NEXT(tmp));
2594                        } else {
2595                                REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
2596                                hostdata->disconnected_queue = NEXT(tmp);
2597                        }
2598                        SET_NEXT(tmp, NULL);
2599                        break;
2600                }
2601        }
2602
2603        if (!tmp) {
2604                printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
2605#ifdef SUPPORT_TAGS
2606                       "tag %d "
2607#endif
2608                       "not in disconnected_queue.\n",
2609                       HOSTNO, target_mask, lun
2610#ifdef SUPPORT_TAGS
2611                       , tag
2612#endif
2613                        );
2614                /*
2615                 * Since we have an established nexus that we can't do anything
2616                 * with, we must abort it.
2617                 */
2618                do_abort(instance);
2619                return;
2620        }
2621
2622        /* Accept message by clearing ACK */
2623        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2624
2625        hostdata->connected = tmp;
2626        RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
2627                   HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
2628        falcon_dont_release--;
2629}
2630
2631
2632/*
2633 * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2634 *
2635 * Purpose : abort a command
2636 *
2637 * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2638 *      host byte of the result field to, if zero DID_ABORTED is
2639 *      used.
2640 *
2641 * Returns : 0 - success, -1 on failure.
2642 *
2643 * XXX - there is no way to abort the command that is currently
2644 *       connected, you have to wait for it to complete.  If this is
2645 *       a problem, we could implement longjmp() / setjmp(), setjmp()
2646 *       called where the loop started in NCR5380_main().
2647 */
2648
2649static
2650int NCR5380_abort(Scsi_Cmnd *cmd)
2651{
2652        struct Scsi_Host *instance = cmd->device->host;
2653        SETUP_HOSTDATA(instance);
2654        Scsi_Cmnd *tmp, **prev;
2655        unsigned long flags;
2656
2657        printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
2658        scsi_print_command(cmd);
2659
2660        NCR5380_print_status(instance);
2661
2662        local_irq_save(flags);
2663
2664        if (!IS_A_TT() && !falcon_got_lock)
2665                printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
2666                       HOSTNO);
2667
2668        ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2669                    NCR5380_read(BUS_AND_STATUS_REG),
2670                    NCR5380_read(STATUS_REG));
2671
2672#if 1
2673        /*
2674         * Case 1 : If the command is the currently executing command,
2675         * we'll set the aborted flag and return control so that
2676         * information transfer routine can exit cleanly.
2677         */
2678
2679        if (hostdata->connected == cmd) {
2680
2681                ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
2682                /*
2683                 * We should perform BSY checking, and make sure we haven't slipped
2684                 * into BUS FREE.
2685                 */
2686
2687                /*      NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2688                /*
2689                 * Since we can't change phases until we've completed the current
2690                 * handshake, we have to source or sink a byte of data if the current
2691                 * phase is not MSGOUT.
2692                 */
2693
2694                /*
2695                 * Return control to the executing NCR drive so we can clear the
2696                 * aborted flag and get back into our main loop.
2697                 */
2698
2699                if (do_abort(instance) == 0) {
2700                        hostdata->aborted = 1;
2701                        hostdata->connected = NULL;
2702                        cmd->result = DID_ABORT << 16;
2703#ifdef SUPPORT_TAGS
2704                        cmd_free_tag(cmd);
2705#else
2706                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2707#endif
2708                        local_irq_restore(flags);
2709                        cmd->scsi_done(cmd);
2710                        falcon_release_lock_if_possible(hostdata);
2711                        return SCSI_ABORT_SUCCESS;
2712                } else {
2713/*                      local_irq_restore(flags); */
2714                        printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2715                        return SCSI_ABORT_ERROR;
2716                }
2717        }
2718#endif
2719
2720        /*
2721         * Case 2 : If the command hasn't been issued yet, we simply remove it
2722         *          from the issue queue.
2723         */
2724        for (prev = (Scsi_Cmnd **)&(hostdata->issue_queue),
2725             tmp = (Scsi_Cmnd *)hostdata->issue_queue;
2726             tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2727                if (cmd == tmp) {
2728                        REMOVE(5, *prev, tmp, NEXT(tmp));
2729                        (*prev) = NEXT(tmp);
2730                        SET_NEXT(tmp, NULL);
2731                        tmp->result = DID_ABORT << 16;
2732                        local_irq_restore(flags);
2733                        ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
2734                                    HOSTNO);
2735                        /* Tagged queuing note: no tag to free here, hasn't been assigned
2736                         * yet... */
2737                        tmp->scsi_done(tmp);
2738                        falcon_release_lock_if_possible(hostdata);
2739                        return SCSI_ABORT_SUCCESS;
2740                }
2741        }
2742
2743        /*
2744         * Case 3 : If any commands are connected, we're going to fail the abort
2745         *          and let the high level SCSI driver retry at a later time or
2746         *          issue a reset.
2747         *
2748         *          Timeouts, and therefore aborted commands, will be highly unlikely
2749         *          and handling them cleanly in this situation would make the common
2750         *          case of noresets less efficient, and would pollute our code.  So,
2751         *          we fail.
2752         */
2753
2754        if (hostdata->connected) {
2755                local_irq_restore(flags);
2756                ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
2757                return SCSI_ABORT_SNOOZE;
2758        }
2759
2760        /*
2761         * Case 4: If the command is currently disconnected from the bus, and
2762         *      there are no connected commands, we reconnect the I_T_L or
2763         *      I_T_L_Q nexus associated with it, go into message out, and send
2764         *      an abort message.
2765         *
2766         * This case is especially ugly. In order to reestablish the nexus, we
2767         * need to call NCR5380_select().  The easiest way to implement this
2768         * function was to abort if the bus was busy, and let the interrupt
2769         * handler triggered on the SEL for reselect take care of lost arbitrations
2770         * where necessary, meaning interrupts need to be enabled.
2771         *
2772         * When interrupts are enabled, the queues may change - so we
2773         * can't remove it from the disconnected queue before selecting it
2774         * because that could cause a failure in hashing the nexus if that
2775         * device reselected.
2776         *
2777         * Since the queues may change, we can't use the pointers from when we
2778         * first locate it.
2779         *
2780         * So, we must first locate the command, and if NCR5380_select()
2781         * succeeds, then issue the abort, relocate the command and remove
2782         * it from the disconnected queue.
2783         */
2784
2785        for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
2786             tmp = NEXT(tmp)) {
2787                if (cmd == tmp) {
2788                        local_irq_restore(flags);
2789                        ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
2790
2791                        if (NCR5380_select(instance, cmd, (int)cmd->tag))
2792                                return SCSI_ABORT_BUSY;
2793
2794                        ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);
2795
2796                        do_abort(instance);
2797
2798                        local_irq_save(flags);
2799                        for (prev = (Scsi_Cmnd **)&(hostdata->disconnected_queue),
2800                             tmp = (Scsi_Cmnd *)hostdata->disconnected_queue;
2801                             tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2802                                if (cmd == tmp) {
2803                                        REMOVE(5, *prev, tmp, NEXT(tmp));
2804                                        *prev = NEXT(tmp);
2805                                        SET_NEXT(tmp, NULL);
2806                                        tmp->result = DID_ABORT << 16;
2807                                        /* We must unlock the tag/LUN immediately here, since the
2808                                         * target goes to BUS FREE and doesn't send us another
2809                                         * message (COMMAND_COMPLETE or the like)
2810                                         */
2811#ifdef SUPPORT_TAGS
2812                                        cmd_free_tag(tmp);
2813#else
2814                                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2815#endif
2816                                        local_irq_restore(flags);
2817                                        tmp->scsi_done(tmp);
2818                                        falcon_release_lock_if_possible(hostdata);
2819                                        return SCSI_ABORT_SUCCESS;
2820                                }
2821                        }
2822                }
2823        }
2824
2825        /*
2826         * Case 5 : If we reached this point, the command was not found in any of
2827         *          the queues.
2828         *
2829         * We probably reached this point because of an unlikely race condition
2830         * between the command completing successfully and the abortion code,
2831         * so we won't panic, but we will notify the user in case something really
2832         * broke.
2833         */
2834
2835        local_irq_restore(flags);
2836        printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
2837
2838        /* Maybe it is sufficient just to release the ST-DMA lock... (if
2839         * possible at all) At least, we should check if the lock could be
2840         * released after the abort, in case it is kept due to some bug.
2841         */
2842        falcon_release_lock_if_possible(hostdata);
2843
2844        return SCSI_ABORT_NOT_RUNNING;
2845}
2846
2847
2848/*
2849 * Function : int NCR5380_reset (Scsi_Cmnd *cmd)
2850 *
2851 * Purpose : reset the SCSI bus.
2852 *
2853 * Returns : SCSI_RESET_WAKEUP
2854 *
2855 */
2856
2857static int NCR5380_bus_reset(Scsi_Cmnd *cmd)
2858{
2859        SETUP_HOSTDATA(cmd->device->host);
2860        int i;
2861        unsigned long flags;
2862#if 1
2863        Scsi_Cmnd *connected, *disconnected_queue;
2864#endif
2865
2866        if (!IS_A_TT() && !falcon_got_lock)
2867                printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
2868                       H_NO(cmd));
2869
2870        NCR5380_print_status(cmd->device->host);
2871
2872        /* get in phase */
2873        NCR5380_write(TARGET_COMMAND_REG,
2874                      PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
2875        /* assert RST */
2876        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
2877        udelay(40);
2878        /* reset NCR registers */
2879        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2880        NCR5380_write(MODE_REG, MR_BASE);
2881        NCR5380_write(TARGET_COMMAND_REG, 0);
2882        NCR5380_write(SELECT_ENABLE_REG, 0);
2883        /* ++roman: reset interrupt condition! otherwise no interrupts don't get
2884         * through anymore ... */
2885        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2886
2887#if 1   /* XXX Should now be done by midlevel code, but it's broken XXX */
2888        /* XXX see below                                            XXX */
2889
2890        /* MSch: old-style reset: actually abort all command processing here */
2891
2892        /* After the reset, there are no more connected or disconnected commands
2893         * and no busy units; to avoid problems with re-inserting the commands
2894         * into the issue_queue (via scsi_done()), the aborted commands are
2895         * remembered in local variables first.
2896         */
2897        local_irq_save(flags);
2898        connected = (Scsi_Cmnd *)hostdata->connected;
2899        hostdata->connected = NULL;
2900        disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
2901        hostdata->disconnected_queue = NULL;
2902#ifdef SUPPORT_TAGS
2903        free_all_tags();
2904#endif
2905        for (i = 0; i < 8; ++i)
2906                hostdata->busy[i] = 0;
2907#ifdef REAL_DMA
2908        hostdata->dma_len = 0;
2909#endif
2910        local_irq_restore(flags);
2911
2912        /* In order to tell the mid-level code which commands were aborted,
2913         * set the command status to DID_RESET and call scsi_done() !!!
2914         * This ultimately aborts processing of these commands in the mid-level.
2915         */
2916
2917        if ((cmd = connected)) {
2918                ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2919                cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2920                cmd->scsi_done(cmd);
2921        }
2922
2923        for (i = 0; (cmd = disconnected_queue); ++i) {
2924                disconnected_queue = NEXT(cmd);
2925                SET_NEXT(cmd, NULL);
2926                cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2927                cmd->scsi_done(cmd);
2928        }
2929        if (i > 0)
2930                ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);
2931
2932        /* The Falcon lock should be released after a reset...
2933         */
2934        /* ++guenther: moved to atari_scsi_reset(), to prevent a race between
2935         * unlocking and enabling dma interrupt.
2936         */
2937/*      falcon_release_lock_if_possible( hostdata );*/
2938
2939        /* since all commands have been explicitly terminated, we need to tell
2940         * the midlevel code that the reset was SUCCESSFUL, and there is no
2941         * need to 'wake up' the commands by a request_sense
2942         */
2943        return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
2944#else /* 1 */
2945
2946        /* MSch: new-style reset handling: let the mid-level do what it can */
2947
2948        /* ++guenther: MID-LEVEL IS STILL BROKEN.
2949         * Mid-level is supposed to requeue all commands that were active on the
2950         * various low-level queues. In fact it does this, but that's not enough
2951         * because all these commands are subject to timeout. And if a timeout
2952         * happens for any removed command, *_abort() is called but all queues
2953         * are now empty. Abort then gives up the falcon lock, which is fatal,
2954         * since the mid-level will queue more commands and must have the lock
2955         * (it's all happening inside timer interrupt handler!!).
2956         * Even worse, abort will return NOT_RUNNING for all those commands not
2957         * on any queue, so they won't be retried ...
2958         *
2959         * Conclusion: either scsi.c disables timeout for all resetted commands
2960         * immediately, or we lose!  As of linux-2.0.20 it doesn't.
2961         */
2962
2963        /* After the reset, there are no more connected or disconnected commands
2964         * and no busy units; so clear the low-level status here to avoid
2965         * conflicts when the mid-level code tries to wake up the affected
2966         * commands!
2967         */
2968
2969        if (hostdata->issue_queue)
2970                ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
2971        if (hostdata->connected)
2972                ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2973        if (hostdata->disconnected_queue)
2974                ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
2975
2976        local_irq_save(flags);
2977        hostdata->issue_queue = NULL;
2978        hostdata->connected = NULL;
2979        hostdata->disconnected_queue = NULL;
2980#ifdef SUPPORT_TAGS
2981        free_all_tags();
2982#endif
2983        for (i = 0; i < 8; ++i)
2984                hostdata->busy[i] = 0;
2985#ifdef REAL_DMA
2986        hostdata->dma_len = 0;
2987#endif
2988        local_irq_restore(flags);
2989
2990        /* we did no complete reset of all commands, so a wakeup is required */
2991        return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
2992#endif /* 1 */
2993}
2994
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