linux/drivers/scsi/atari_NCR5380.c
<<
>>
Prefs
   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 lprint_Scsi_Cmnd(Scsi_Cmnd *cmd)
 723{
 724        int i, s;
 725        unsigned char *command;
 726        printk("scsi%d: destination target %d, lun %d\n",
 727                H_NO(cmd), cmd->device->id, cmd->device->lun);
 728        printk(KERN_CONT "        command = ");
 729        command = cmd->cmnd;
 730        printk(KERN_CONT "%2d (0x%02x)", command[0], command[0]);
 731        for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 732                printk(KERN_CONT " %02x", command[i]);
 733        printk("\n");
 734}
 735
 736static void NCR5380_print_status(struct Scsi_Host *instance)
 737{
 738        struct NCR5380_hostdata *hostdata;
 739        Scsi_Cmnd *ptr;
 740        unsigned long flags;
 741
 742        NCR_PRINT(NDEBUG_ANY);
 743        NCR_PRINT_PHASE(NDEBUG_ANY);
 744
 745        hostdata = (struct NCR5380_hostdata *)instance->hostdata;
 746
 747        printk("\nNCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
 748        local_irq_save(flags);
 749        printk("NCR5380: coroutine is%s running.\n",
 750                main_running ? "" : "n't");
 751        if (!hostdata->connected)
 752                printk("scsi%d: no currently connected command\n", HOSTNO);
 753        else
 754                lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected);
 755        printk("scsi%d: issue_queue\n", HOSTNO);
 756        for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
 757                lprint_Scsi_Cmnd(ptr);
 758
 759        printk("scsi%d: disconnected_queue\n", HOSTNO);
 760        for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
 761             ptr = NEXT(ptr))
 762                lprint_Scsi_Cmnd(ptr);
 763
 764        local_irq_restore(flags);
 765        printk("\n");
 766}
 767
 768static void show_Scsi_Cmnd(Scsi_Cmnd *cmd, struct seq_file *m)
 769{
 770        int i, s;
 771        unsigned char *command;
 772        seq_printf(m, "scsi%d: destination target %d, lun %d\n",
 773                H_NO(cmd), cmd->device->id, cmd->device->lun);
 774        seq_printf(m, "        command = ");
 775        command = cmd->cmnd;
 776        seq_printf(m, "%2d (0x%02x)", command[0], command[0]);
 777        for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
 778                seq_printf(m, " %02x", command[i]);
 779        seq_printf(m, "\n");
 780}
 781
 782static int NCR5380_show_info(struct seq_file *m, struct Scsi_Host *instance)
 783{
 784        struct NCR5380_hostdata *hostdata;
 785        Scsi_Cmnd *ptr;
 786        unsigned long flags;
 787
 788        hostdata = (struct NCR5380_hostdata *)instance->hostdata;
 789
 790        seq_printf(m, "NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
 791        local_irq_save(flags);
 792        seq_printf(m, "NCR5380: coroutine is%s running.\n",
 793                main_running ? "" : "n't");
 794        if (!hostdata->connected)
 795                seq_printf(m, "scsi%d: no currently connected command\n", HOSTNO);
 796        else
 797                show_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, m);
 798        seq_printf(m, "scsi%d: issue_queue\n", HOSTNO);
 799        for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
 800                show_Scsi_Cmnd(ptr, m);
 801
 802        seq_printf(m, "scsi%d: disconnected_queue\n", HOSTNO);
 803        for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
 804             ptr = NEXT(ptr))
 805                show_Scsi_Cmnd(ptr, m);
 806
 807        local_irq_restore(flags);
 808        return 0;
 809}
 810
 811/*
 812 * Function : void NCR5380_init (struct Scsi_Host *instance)
 813 *
 814 * Purpose : initializes *instance and corresponding 5380 chip.
 815 *
 816 * Inputs : instance - instantiation of the 5380 driver.
 817 *
 818 * Notes : I assume that the host, hostno, and id bits have been
 819 *      set correctly.  I don't care about the irq and other fields.
 820 *
 821 */
 822
 823static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
 824{
 825        int i;
 826        SETUP_HOSTDATA(instance);
 827
 828        NCR5380_all_init();
 829
 830        hostdata->aborted = 0;
 831        hostdata->id_mask = 1 << instance->this_id;
 832        hostdata->id_higher_mask = 0;
 833        for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
 834                if (i > hostdata->id_mask)
 835                        hostdata->id_higher_mask |= i;
 836        for (i = 0; i < 8; ++i)
 837                hostdata->busy[i] = 0;
 838#ifdef SUPPORT_TAGS
 839        init_tags();
 840#endif
 841#if defined (REAL_DMA)
 842        hostdata->dma_len = 0;
 843#endif
 844        hostdata->targets_present = 0;
 845        hostdata->connected = NULL;
 846        hostdata->issue_queue = NULL;
 847        hostdata->disconnected_queue = NULL;
 848        hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
 849
 850        if (!the_template) {
 851                the_template = instance->hostt;
 852                first_instance = instance;
 853        }
 854
 855#ifndef AUTOSENSE
 856        if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
 857                printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
 858                       "        without AUTOSENSE option, contingent allegiance conditions may\n"
 859                       "        be incorrectly cleared.\n", HOSTNO);
 860#endif /* def AUTOSENSE */
 861
 862        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 863        NCR5380_write(MODE_REG, MR_BASE);
 864        NCR5380_write(TARGET_COMMAND_REG, 0);
 865        NCR5380_write(SELECT_ENABLE_REG, 0);
 866
 867        return 0;
 868}
 869
 870static void NCR5380_exit(struct Scsi_Host *instance)
 871{
 872        /* Empty, as we didn't schedule any delayed work */
 873}
 874
 875/*
 876 * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd,
 877 *      void (*done)(Scsi_Cmnd *))
 878 *
 879 * Purpose :  enqueues a SCSI command
 880 *
 881 * Inputs : cmd - SCSI command, done - function called on completion, with
 882 *      a pointer to the command descriptor.
 883 *
 884 * Returns : 0
 885 *
 886 * Side effects :
 887 *      cmd is added to the per instance issue_queue, with minor
 888 *      twiddling done to the host specific fields of cmd.  If the
 889 *      main coroutine is not running, it is restarted.
 890 *
 891 */
 892
 893static int NCR5380_queue_command_lck(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
 894{
 895        SETUP_HOSTDATA(cmd->device->host);
 896        Scsi_Cmnd *tmp;
 897        unsigned long flags;
 898
 899#if (NDEBUG & NDEBUG_NO_WRITE)
 900        switch (cmd->cmnd[0]) {
 901        case WRITE_6:
 902        case WRITE_10:
 903                printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
 904                       H_NO(cmd));
 905                cmd->result = (DID_ERROR << 16);
 906                done(cmd);
 907                return 0;
 908        }
 909#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
 910
 911#ifdef NCR5380_STATS
 912# if 0
 913        if (!hostdata->connected && !hostdata->issue_queue &&
 914            !hostdata->disconnected_queue) {
 915                hostdata->timebase = jiffies;
 916        }
 917# endif
 918# ifdef NCR5380_STAT_LIMIT
 919        if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
 920# endif
 921                switch (cmd->cmnd[0]) {
 922                case WRITE:
 923                case WRITE_6:
 924                case WRITE_10:
 925                        hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
 926                        hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
 927                        hostdata->pendingw++;
 928                        break;
 929                case READ:
 930                case READ_6:
 931                case READ_10:
 932                        hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
 933                        hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
 934                        hostdata->pendingr++;
 935                        break;
 936                }
 937#endif
 938
 939        /*
 940         * We use the host_scribble field as a pointer to the next command
 941         * in a queue
 942         */
 943
 944        SET_NEXT(cmd, NULL);
 945        cmd->scsi_done = done;
 946
 947        cmd->result = 0;
 948
 949        /*
 950         * Insert the cmd into the issue queue. Note that REQUEST SENSE
 951         * commands are added to the head of the queue since any command will
 952         * clear the contingent allegiance condition that exists and the
 953         * sense data is only guaranteed to be valid while the condition exists.
 954         */
 955
 956        local_irq_save(flags);
 957        /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
 958         * Otherwise a running NCR5380_main may steal the lock.
 959         * Lock before actually inserting due to fairness reasons explained in
 960         * atari_scsi.c. If we insert first, then it's impossible for this driver
 961         * to release the lock.
 962         * Stop timer for this command while waiting for the lock, or timeouts
 963         * may happen (and they really do), and it's no good if the command doesn't
 964         * appear in any of the queues.
 965         * ++roman: Just disabling the NCR interrupt isn't sufficient here,
 966         * because also a timer int can trigger an abort or reset, which would
 967         * alter queues and touch the lock.
 968         */
 969        if (!IS_A_TT()) {
 970                /* perhaps stop command timer here */
 971                falcon_get_lock();
 972                /* perhaps restart command timer here */
 973        }
 974        if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
 975                LIST(cmd, hostdata->issue_queue);
 976                SET_NEXT(cmd, hostdata->issue_queue);
 977                hostdata->issue_queue = cmd;
 978        } else {
 979                for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
 980                     NEXT(tmp); tmp = NEXT(tmp))
 981                        ;
 982                LIST(cmd, tmp);
 983                SET_NEXT(tmp, cmd);
 984        }
 985        local_irq_restore(flags);
 986
 987        QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
 988                  (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
 989
 990        /* If queue_command() is called from an interrupt (real one or bottom
 991         * half), we let queue_main() do the job of taking care about main. If it
 992         * is already running, this is a no-op, else main will be queued.
 993         *
 994         * If we're not in an interrupt, we can call NCR5380_main()
 995         * unconditionally, because it cannot be already running.
 996         */
 997        if (in_interrupt() || ((flags >> 8) & 7) >= 6)
 998                queue_main();
 999        else
1000                NCR5380_main(NULL);
1001        return 0;
1002}
1003
1004static DEF_SCSI_QCMD(NCR5380_queue_command)
1005
1006/*
1007 * Function : NCR5380_main (void)
1008 *
1009 * Purpose : NCR5380_main is a coroutine that runs as long as more work can
1010 *      be done on the NCR5380 host adapters in a system.  Both
1011 *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1012 *      in case it is not running.
1013 *
1014 * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
1015 *  reenable them.  This prevents reentrancy and kernel stack overflow.
1016 */
1017
1018static void NCR5380_main(struct work_struct *work)
1019{
1020        Scsi_Cmnd *tmp, *prev;
1021        struct Scsi_Host *instance = first_instance;
1022        struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
1023        int done;
1024        unsigned long flags;
1025
1026        /*
1027         * We run (with interrupts disabled) until we're sure that none of
1028         * the host adapters have anything that can be done, at which point
1029         * we set main_running to 0 and exit.
1030         *
1031         * Interrupts are enabled before doing various other internal
1032         * instructions, after we've decided that we need to run through
1033         * the loop again.
1034         *
1035         * this should prevent any race conditions.
1036         *
1037         * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1038         * because also a timer int can trigger an abort or reset, which can
1039         * alter queues and touch the Falcon lock.
1040         */
1041
1042        /* Tell int handlers main() is now already executing.  Note that
1043           no races are possible here. If an int comes in before
1044           'main_running' is set here, and queues/executes main via the
1045           task queue, it doesn't do any harm, just this instance of main
1046           won't find any work left to do. */
1047        if (main_running)
1048                return;
1049        main_running = 1;
1050
1051        local_save_flags(flags);
1052        do {
1053                local_irq_disable();    /* Freeze request queues */
1054                done = 1;
1055
1056                if (!hostdata->connected) {
1057                        MAIN_PRINTK("scsi%d: not connected\n", HOSTNO);
1058                        /*
1059                         * Search through the issue_queue for a command destined
1060                         * for a target that's not busy.
1061                         */
1062#if (NDEBUG & NDEBUG_LISTS)
1063                        for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
1064                             tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
1065                                ;
1066                        /*printk("%p  ", tmp);*/
1067                        if ((tmp == prev) && tmp)
1068                                printk(" LOOP\n");
1069                        /* else printk("\n"); */
1070#endif
1071                        for (tmp = (Scsi_Cmnd *) hostdata->issue_queue,
1072                             prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
1073
1074#if (NDEBUG & NDEBUG_LISTS)
1075                                if (prev != tmp)
1076                                        printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
1077                                               tmp, tmp->device->id, hostdata->busy[tmp->device->id],
1078                                               tmp->device->lun);
1079#endif
1080                                /*  When we find one, remove it from the issue queue. */
1081                                /* ++guenther: possible race with Falcon locking */
1082                                if (
1083#ifdef SUPPORT_TAGS
1084                                    !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
1085#else
1086                                    !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
1087#endif
1088                                    ) {
1089                                        /* ++guenther: just to be sure, this must be atomic */
1090                                        local_irq_disable();
1091                                        if (prev) {
1092                                                REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1093                                                SET_NEXT(prev, NEXT(tmp));
1094                                        } else {
1095                                                REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
1096                                                hostdata->issue_queue = NEXT(tmp);
1097                                        }
1098                                        SET_NEXT(tmp, NULL);
1099                                        falcon_dont_release++;
1100
1101                                        /* reenable interrupts after finding one */
1102                                        local_irq_restore(flags);
1103
1104                                        /*
1105                                         * Attempt to establish an I_T_L nexus here.
1106                                         * On success, instance->hostdata->connected is set.
1107                                         * On failure, we must add the command back to the
1108                                         *   issue queue so we can keep trying.
1109                                         */
1110                                        MAIN_PRINTK("scsi%d: main(): command for target %d "
1111                                                    "lun %d removed from issue_queue\n",
1112                                                    HOSTNO, tmp->device->id, tmp->device->lun);
1113                                        /*
1114                                         * REQUEST SENSE commands are issued without tagged
1115                                         * queueing, even on SCSI-II devices because the
1116                                         * contingent allegiance condition exists for the
1117                                         * entire unit.
1118                                         */
1119                                        /* ++roman: ...and the standard also requires that
1120                                         * REQUEST SENSE command are untagged.
1121                                         */
1122
1123#ifdef SUPPORT_TAGS
1124                                        cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
1125#endif
1126                                        if (!NCR5380_select(instance, tmp,
1127                                            (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE :
1128                                            TAG_NEXT)) {
1129                                                falcon_dont_release--;
1130                                                /* release if target did not response! */
1131                                                falcon_release_lock_if_possible(hostdata);
1132                                                break;
1133                                        } else {
1134                                                local_irq_disable();
1135                                                LIST(tmp, hostdata->issue_queue);
1136                                                SET_NEXT(tmp, hostdata->issue_queue);
1137                                                hostdata->issue_queue = tmp;
1138#ifdef SUPPORT_TAGS
1139                                                cmd_free_tag(tmp);
1140#endif
1141                                                falcon_dont_release--;
1142                                                local_irq_restore(flags);
1143                                                MAIN_PRINTK("scsi%d: main(): select() failed, "
1144                                                            "returned to issue_queue\n", HOSTNO);
1145                                                if (hostdata->connected)
1146                                                        break;
1147                                        }
1148                                } /* if target/lun/target queue is not busy */
1149                        } /* for issue_queue */
1150                } /* if (!hostdata->connected) */
1151
1152                if (hostdata->connected
1153#ifdef REAL_DMA
1154                    && !hostdata->dma_len
1155#endif
1156                    ) {
1157                        local_irq_restore(flags);
1158                        MAIN_PRINTK("scsi%d: main: performing information transfer\n",
1159                                    HOSTNO);
1160                        NCR5380_information_transfer(instance);
1161                        MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
1162                        done = 0;
1163                }
1164        } while (!done);
1165
1166        /* Better allow ints _after_ 'main_running' has been cleared, else
1167           an interrupt could believe we'll pick up the work it left for
1168           us, but we won't see it anymore here... */
1169        main_running = 0;
1170        local_irq_restore(flags);
1171}
1172
1173
1174#ifdef REAL_DMA
1175/*
1176 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1177 *
1178 * Purpose : Called by interrupt handler when DMA finishes or a phase
1179 *      mismatch occurs (which would finish the DMA transfer).
1180 *
1181 * Inputs : instance - this instance of the NCR5380.
1182 *
1183 */
1184
1185static void NCR5380_dma_complete(struct Scsi_Host *instance)
1186{
1187        SETUP_HOSTDATA(instance);
1188        int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
1189        unsigned char **data, p;
1190        volatile int *count;
1191
1192        if (!hostdata->connected) {
1193                printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
1194                       "no connected cmd\n", HOSTNO);
1195                return;
1196        }
1197
1198        if (atari_read_overruns) {
1199                p = hostdata->connected->SCp.phase;
1200                if (p & SR_IO) {
1201                        udelay(10);
1202                        if ((NCR5380_read(BUS_AND_STATUS_REG) &
1203                             (BASR_PHASE_MATCH|BASR_ACK)) ==
1204                            (BASR_PHASE_MATCH|BASR_ACK)) {
1205                                saved_data = NCR5380_read(INPUT_DATA_REG);
1206                                overrun = 1;
1207                                DMA_PRINTK("scsi%d: read overrun handled\n", HOSTNO);
1208                        }
1209                }
1210        }
1211
1212        DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1213                   HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
1214                   NCR5380_read(STATUS_REG));
1215
1216        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1217        NCR5380_write(MODE_REG, MR_BASE);
1218        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1219
1220        transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
1221        hostdata->dma_len = 0;
1222
1223        data = (unsigned char **)&hostdata->connected->SCp.ptr;
1224        count = &hostdata->connected->SCp.this_residual;
1225        *data += transfered;
1226        *count -= transfered;
1227
1228        if (atari_read_overruns) {
1229                if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1230                        cnt = toPIO = atari_read_overruns;
1231                        if (overrun) {
1232                                DMA_PRINTK("Got an input overrun, using saved byte\n");
1233                                *(*data)++ = saved_data;
1234                                (*count)--;
1235                                cnt--;
1236                                toPIO--;
1237                        }
1238                        DMA_PRINTK("Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1239                        NCR5380_transfer_pio(instance, &p, &cnt, data);
1240                        *count -= toPIO - cnt;
1241                }
1242        }
1243}
1244#endif /* REAL_DMA */
1245
1246
1247/*
1248 * Function : void NCR5380_intr (int irq)
1249 *
1250 * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1251 *      from the disconnected queue, and restarting NCR5380_main()
1252 *      as required.
1253 *
1254 * Inputs : int irq, irq that caused this interrupt.
1255 *
1256 */
1257
1258static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1259{
1260        struct Scsi_Host *instance = first_instance;
1261        int done = 1, handled = 0;
1262        unsigned char basr;
1263
1264        INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);
1265
1266        /* Look for pending interrupts */
1267        basr = NCR5380_read(BUS_AND_STATUS_REG);
1268        INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
1269        /* dispatch to appropriate routine if found and done=0 */
1270        if (basr & BASR_IRQ) {
1271                NCR_PRINT(NDEBUG_INTR);
1272                if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
1273                        done = 0;
1274                        ENABLE_IRQ();
1275                        INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
1276                        NCR5380_reselect(instance);
1277                        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1278                } else if (basr & BASR_PARITY_ERROR) {
1279                        INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
1280                        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1281                } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1282                        INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
1283                        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1284                } else {
1285                        /*
1286                         * The rest of the interrupt conditions can occur only during a
1287                         * DMA transfer
1288                         */
1289
1290#if defined(REAL_DMA)
1291                        /*
1292                         * We should only get PHASE MISMATCH and EOP interrupts if we have
1293                         * DMA enabled, so do a sanity check based on the current setting
1294                         * of the MODE register.
1295                         */
1296
1297                        if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
1298                            ((basr & BASR_END_DMA_TRANSFER) ||
1299                             !(basr & BASR_PHASE_MATCH))) {
1300
1301                                INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1302                                NCR5380_dma_complete( instance );
1303                                done = 0;
1304                                ENABLE_IRQ();
1305                        } else
1306#endif /* REAL_DMA */
1307                        {
1308/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1309                                if (basr & BASR_PHASE_MATCH)
1310                                        printk(KERN_NOTICE "scsi%d: unknown interrupt, "
1311                                               "BASR 0x%x, MR 0x%x, SR 0x%x\n",
1312                                               HOSTNO, basr, NCR5380_read(MODE_REG),
1313                                               NCR5380_read(STATUS_REG));
1314                                (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1315                        }
1316                } /* if !(SELECTION || PARITY) */
1317                handled = 1;
1318        } /* BASR & IRQ */ else {
1319                printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
1320                       "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
1321                       NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1322                (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1323        }
1324
1325        if (!done) {
1326                INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
1327                /* Put a call to NCR5380_main() on the queue... */
1328                queue_main();
1329        }
1330        return IRQ_RETVAL(handled);
1331}
1332
1333#ifdef NCR5380_STATS
1334static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd *cmd)
1335{
1336# ifdef NCR5380_STAT_LIMIT
1337        if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
1338# endif
1339                switch (cmd->cmnd[0]) {
1340                case WRITE:
1341                case WRITE_6:
1342                case WRITE_10:
1343                        hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
1344                        /*hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);*/
1345                        hostdata->pendingw--;
1346                        break;
1347                case READ:
1348                case READ_6:
1349                case READ_10:
1350                        hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
1351                        /*hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);*/
1352                        hostdata->pendingr--;
1353                        break;
1354                }
1355}
1356#endif
1357
1358/*
1359 * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1360 *      int tag);
1361 *
1362 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1363 *      including ARBITRATION, SELECTION, and initial message out for
1364 *      IDENTIFY and queue messages.
1365 *
1366 * Inputs : instance - instantiation of the 5380 driver on which this
1367 *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1368 *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1369 *      the command that is presently connected.
1370 *
1371 * Returns : -1 if selection could not execute for some reason,
1372 *      0 if selection succeeded or failed because the target
1373 *      did not respond.
1374 *
1375 * Side effects :
1376 *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1377 *              with registers as they should have been on entry - ie
1378 *              SELECT_ENABLE will be set appropriately, the NCR5380
1379 *              will cease to drive any SCSI bus signals.
1380 *
1381 *      If successful : I_T_L or I_T_L_Q nexus will be established,
1382 *              instance->connected will be set to cmd.
1383 *              SELECT interrupt will be disabled.
1384 *
1385 *      If failed (no target) : cmd->scsi_done() will be called, and the
1386 *              cmd->result host byte set to DID_BAD_TARGET.
1387 */
1388
1389static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
1390{
1391        SETUP_HOSTDATA(instance);
1392        unsigned char tmp[3], phase;
1393        unsigned char *data;
1394        int len;
1395        unsigned long timeout;
1396        unsigned long flags;
1397
1398        hostdata->restart_select = 0;
1399        NCR_PRINT(NDEBUG_ARBITRATION);
1400        ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
1401                   instance->this_id);
1402
1403        /*
1404         * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1405         * data bus during SELECTION.
1406         */
1407
1408        local_irq_save(flags);
1409        if (hostdata->connected) {
1410                local_irq_restore(flags);
1411                return -1;
1412        }
1413        NCR5380_write(TARGET_COMMAND_REG, 0);
1414
1415        /*
1416         * Start arbitration.
1417         */
1418
1419        NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1420        NCR5380_write(MODE_REG, MR_ARBITRATE);
1421
1422        local_irq_restore(flags);
1423
1424        /* Wait for arbitration logic to complete */
1425#if defined(NCR_TIMEOUT)
1426        {
1427                unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
1428
1429                while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1430                       time_before(jiffies, timeout) && !hostdata->connected)
1431                        ;
1432                if (time_after_eq(jiffies, timeout)) {
1433                        printk("scsi : arbitration timeout at %d\n", __LINE__);
1434                        NCR5380_write(MODE_REG, MR_BASE);
1435                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1436                        return -1;
1437                }
1438        }
1439#else /* NCR_TIMEOUT */
1440        while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1441               !hostdata->connected)
1442                ;
1443#endif
1444
1445        ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);
1446
1447        if (hostdata->connected) {
1448                NCR5380_write(MODE_REG, MR_BASE);
1449                return -1;
1450        }
1451        /*
1452         * The arbitration delay is 2.2us, but this is a minimum and there is
1453         * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1454         * the integral nature of udelay().
1455         *
1456         */
1457
1458        udelay(3);
1459
1460        /* Check for lost arbitration */
1461        if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1462            (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1463            (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1464            hostdata->connected) {
1465                NCR5380_write(MODE_REG, MR_BASE);
1466                ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1467                           HOSTNO);
1468                return -1;
1469        }
1470
1471        /* after/during arbitration, BSY should be asserted.
1472           IBM DPES-31080 Version S31Q works now */
1473        /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
1474        NCR5380_write(INITIATOR_COMMAND_REG,
1475                      ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1476
1477        if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1478            hostdata->connected) {
1479                NCR5380_write(MODE_REG, MR_BASE);
1480                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1481                ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1482                           HOSTNO);
1483                return -1;
1484        }
1485
1486        /*
1487         * Again, bus clear + bus settle time is 1.2us, however, this is
1488         * a minimum so we'll udelay ceil(1.2)
1489         */
1490
1491#ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
1492        /* ++roman: But some targets (see above :-) seem to need a bit more... */
1493        udelay(15);
1494#else
1495        udelay(2);
1496#endif
1497
1498        if (hostdata->connected) {
1499                NCR5380_write(MODE_REG, MR_BASE);
1500                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1501                return -1;
1502        }
1503
1504        ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);
1505
1506        /*
1507         * Now that we have won arbitration, start Selection process, asserting
1508         * the host and target ID's on the SCSI bus.
1509         */
1510
1511        NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
1512
1513        /*
1514         * Raise ATN while SEL is true before BSY goes false from arbitration,
1515         * since this is the only way to guarantee that we'll get a MESSAGE OUT
1516         * phase immediately after selection.
1517         */
1518
1519        NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
1520                      ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1521        NCR5380_write(MODE_REG, MR_BASE);
1522
1523        /*
1524         * Reselect interrupts must be turned off prior to the dropping of BSY,
1525         * otherwise we will trigger an interrupt.
1526         */
1527
1528        if (hostdata->connected) {
1529                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1530                return -1;
1531        }
1532
1533        NCR5380_write(SELECT_ENABLE_REG, 0);
1534
1535        /*
1536         * The initiator shall then wait at least two deskew delays and release
1537         * the BSY signal.
1538         */
1539        udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1540
1541        /* Reset BSY */
1542        NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
1543                      ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1544
1545        /*
1546         * Something weird happens when we cease to drive BSY - looks
1547         * like the board/chip is letting us do another read before the
1548         * appropriate propagation delay has expired, and we're confusing
1549         * a BSY signal from ourselves as the target's response to SELECTION.
1550         *
1551         * A small delay (the 'C++' frontend breaks the pipeline with an
1552         * unnecessary jump, making it work on my 386-33/Trantor T128, the
1553         * tighter 'C' code breaks and requires this) solves the problem -
1554         * the 1 us delay is arbitrary, and only used because this delay will
1555         * be the same on other platforms and since it works here, it should
1556         * work there.
1557         *
1558         * wingel suggests that this could be due to failing to wait
1559         * one deskew delay.
1560         */
1561
1562        udelay(1);
1563
1564        SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
1565
1566        /*
1567         * The SCSI specification calls for a 250 ms timeout for the actual
1568         * selection.
1569         */
1570
1571        timeout = jiffies + 25;
1572
1573        /*
1574         * XXX very interesting - we're seeing a bounce where the BSY we
1575         * asserted is being reflected / still asserted (propagation delay?)
1576         * and it's detecting as true.  Sigh.
1577         */
1578
1579#if 0
1580        /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
1581         * IO while SEL is true. But again, there are some disks out the in the
1582         * world that do that nevertheless. (Somebody claimed that this announces
1583         * reselection capability of the target.) So we better skip that test and
1584         * only wait for BSY... (Famous german words: Der Kl├╝gere gibt nach :-)
1585         */
1586
1587        while (time_before(jiffies, timeout) &&
1588               !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
1589                ;
1590
1591        if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1592                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1593                NCR5380_reselect(instance);
1594                printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
1595                       HOSTNO);
1596                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1597                return -1;
1598        }
1599#else
1600        while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
1601                ;
1602#endif
1603
1604        /*
1605         * No less than two deskew delays after the initiator detects the
1606         * BSY signal is true, it shall release the SEL signal and may
1607         * change the DATA BUS.                                     -wingel
1608         */
1609
1610        udelay(1);
1611
1612        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1613
1614        if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1615                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1616                if (hostdata->targets_present & (1 << cmd->device->id)) {
1617                        printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
1618                        if (hostdata->restart_select)
1619                                printk(KERN_NOTICE "\trestart select\n");
1620                        NCR_PRINT(NDEBUG_ANY);
1621                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1622                        return -1;
1623                }
1624                cmd->result = DID_BAD_TARGET << 16;
1625#ifdef NCR5380_STATS
1626                collect_stats(hostdata, cmd);
1627#endif
1628#ifdef SUPPORT_TAGS
1629                cmd_free_tag(cmd);
1630#endif
1631                cmd->scsi_done(cmd);
1632                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1633                SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
1634                NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1635                return 0;
1636        }
1637
1638        hostdata->targets_present |= (1 << cmd->device->id);
1639
1640        /*
1641         * Since we followed the SCSI spec, and raised ATN while SEL
1642         * was true but before BSY was false during selection, the information
1643         * transfer phase should be a MESSAGE OUT phase so that we can send the
1644         * IDENTIFY message.
1645         *
1646         * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1647         * message (2 bytes) with a tag ID that we increment with every command
1648         * until it wraps back to 0.
1649         *
1650         * XXX - it turns out that there are some broken SCSI-II devices,
1651         *           which claim to support tagged queuing but fail when more than
1652         *           some number of commands are issued at once.
1653         */
1654
1655        /* Wait for start of REQ/ACK handshake */
1656        while (!(NCR5380_read(STATUS_REG) & SR_REQ))
1657                ;
1658
1659        SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1660                   HOSTNO, cmd->device->id);
1661        tmp[0] = IDENTIFY(1, cmd->device->lun);
1662
1663#ifdef SUPPORT_TAGS
1664        if (cmd->tag != TAG_NONE) {
1665                tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1666                tmp[2] = cmd->tag;
1667                len = 3;
1668        } else
1669                len = 1;
1670#else
1671        len = 1;
1672        cmd->tag = 0;
1673#endif /* SUPPORT_TAGS */
1674
1675        /* Send message(s) */
1676        data = tmp;
1677        phase = PHASE_MSGOUT;
1678        NCR5380_transfer_pio(instance, &phase, &len, &data);
1679        SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
1680        /* XXX need to handle errors here */
1681        hostdata->connected = cmd;
1682#ifndef SUPPORT_TAGS
1683        hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1684#endif
1685
1686        initialize_SCp(cmd);
1687
1688        return 0;
1689}
1690
1691/*
1692 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1693 *      unsigned char *phase, int *count, unsigned char **data)
1694 *
1695 * Purpose : transfers data in given phase using polled I/O
1696 *
1697 * Inputs : instance - instance of driver, *phase - pointer to
1698 *      what phase is expected, *count - pointer to number of
1699 *      bytes to transfer, **data - pointer to data pointer.
1700 *
1701 * Returns : -1 when different phase is entered without transferring
1702 *      maximum number of bytes, 0 if all bytes are transferred or exit
1703 *      is in same phase.
1704 *
1705 *      Also, *phase, *count, *data are modified in place.
1706 *
1707 * XXX Note : handling for bus free may be useful.
1708 */
1709
1710/*
1711 * Note : this code is not as quick as it could be, however it
1712 * IS 100% reliable, and for the actual data transfer where speed
1713 * counts, we will always do a pseudo DMA or DMA transfer.
1714 */
1715
1716static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1717                                unsigned char *phase, int *count,
1718                                unsigned char **data)
1719{
1720        register unsigned char p = *phase, tmp;
1721        register int c = *count;
1722        register unsigned char *d = *data;
1723
1724        /*
1725         * The NCR5380 chip will only drive the SCSI bus when the
1726         * phase specified in the appropriate bits of the TARGET COMMAND
1727         * REGISTER match the STATUS REGISTER
1728         */
1729
1730        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1731
1732        do {
1733                /*
1734                 * Wait for assertion of REQ, after which the phase bits will be
1735                 * valid
1736                 */
1737                while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1738                        ;
1739
1740                HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);
1741
1742                /* Check for phase mismatch */
1743                if ((tmp & PHASE_MASK) != p) {
1744                        PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
1745                        NCR_PRINT_PHASE(NDEBUG_PIO);
1746                        break;
1747                }
1748
1749                /* Do actual transfer from SCSI bus to / from memory */
1750                if (!(p & SR_IO))
1751                        NCR5380_write(OUTPUT_DATA_REG, *d);
1752                else
1753                        *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1754
1755                ++d;
1756
1757                /*
1758                 * The SCSI standard suggests that in MSGOUT phase, the initiator
1759                 * should drop ATN on the last byte of the message phase
1760                 * after REQ has been asserted for the handshake but before
1761                 * the initiator raises ACK.
1762                 */
1763
1764                if (!(p & SR_IO)) {
1765                        if (!((p & SR_MSG) && c > 1)) {
1766                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1767                                NCR_PRINT(NDEBUG_PIO);
1768                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1769                                              ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1770                        } else {
1771                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1772                                              ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1773                                NCR_PRINT(NDEBUG_PIO);
1774                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1775                                              ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1776                        }
1777                } else {
1778                        NCR_PRINT(NDEBUG_PIO);
1779                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1780                }
1781
1782                while (NCR5380_read(STATUS_REG) & SR_REQ)
1783                        ;
1784
1785                HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);
1786
1787                /*
1788                 * We have several special cases to consider during REQ/ACK handshaking :
1789                 * 1.  We were in MSGOUT phase, and we are on the last byte of the
1790                 *      message.  ATN must be dropped as ACK is dropped.
1791                 *
1792                 * 2.  We are in a MSGIN phase, and we are on the last byte of the
1793                 *      message.  We must exit with ACK asserted, so that the calling
1794                 *      code may raise ATN before dropping ACK to reject the message.
1795                 *
1796                 * 3.  ACK and ATN are clear and the target may proceed as normal.
1797                 */
1798                if (!(p == PHASE_MSGIN && c == 1)) {
1799                        if (p == PHASE_MSGOUT && c > 1)
1800                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1801                        else
1802                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1803                }
1804        } while (--c);
1805
1806        PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);
1807
1808        *count = c;
1809        *data = d;
1810        tmp = NCR5380_read(STATUS_REG);
1811        /* The phase read from the bus is valid if either REQ is (already)
1812         * asserted or if ACK hasn't been released yet. The latter is the case if
1813         * we're in MSGIN and all wanted bytes have been received.
1814         */
1815        if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
1816                *phase = tmp & PHASE_MASK;
1817        else
1818                *phase = PHASE_UNKNOWN;
1819
1820        if (!c || (*phase == p))
1821                return 0;
1822        else
1823                return -1;
1824}
1825
1826/*
1827 * Function : do_abort (Scsi_Host *host)
1828 *
1829 * Purpose : abort the currently established nexus.  Should only be
1830 *      called from a routine which can drop into a
1831 *
1832 * Returns : 0 on success, -1 on failure.
1833 */
1834
1835static int do_abort(struct Scsi_Host *host)
1836{
1837        unsigned char tmp, *msgptr, phase;
1838        int len;
1839
1840        /* Request message out phase */
1841        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1842
1843        /*
1844         * Wait for the target to indicate a valid phase by asserting
1845         * REQ.  Once this happens, we'll have either a MSGOUT phase
1846         * and can immediately send the ABORT message, or we'll have some
1847         * other phase and will have to source/sink data.
1848         *
1849         * We really don't care what value was on the bus or what value
1850         * the target sees, so we just handshake.
1851         */
1852
1853        while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1854                ;
1855
1856        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1857
1858        if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1859                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1860                              ICR_ASSERT_ACK);
1861                while (NCR5380_read(STATUS_REG) & SR_REQ)
1862                        ;
1863                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1864        }
1865
1866        tmp = ABORT;
1867        msgptr = &tmp;
1868        len = 1;
1869        phase = PHASE_MSGOUT;
1870        NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1871
1872        /*
1873         * If we got here, and the command completed successfully,
1874         * we're about to go into bus free state.
1875         */
1876
1877        return len ? -1 : 0;
1878}
1879
1880#if defined(REAL_DMA)
1881/*
1882 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1883 *      unsigned char *phase, int *count, unsigned char **data)
1884 *
1885 * Purpose : transfers data in given phase using either real
1886 *      or pseudo DMA.
1887 *
1888 * Inputs : instance - instance of driver, *phase - pointer to
1889 *      what phase is expected, *count - pointer to number of
1890 *      bytes to transfer, **data - pointer to data pointer.
1891 *
1892 * Returns : -1 when different phase is entered without transferring
1893 *      maximum number of bytes, 0 if all bytes or transferred or exit
1894 *      is in same phase.
1895 *
1896 *      Also, *phase, *count, *data are modified in place.
1897 *
1898 */
1899
1900
1901static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1902                                unsigned char *phase, int *count,
1903                                unsigned char **data)
1904{
1905        SETUP_HOSTDATA(instance);
1906        register int c = *count;
1907        register unsigned char p = *phase;
1908        register unsigned char *d = *data;
1909        unsigned char tmp;
1910        unsigned long flags;
1911
1912        if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1913                *phase = tmp;
1914                return -1;
1915        }
1916
1917        if (atari_read_overruns && (p & SR_IO))
1918                c -= atari_read_overruns;
1919
1920        DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1921                   HOSTNO, (p & SR_IO) ? "reading" : "writing",
1922                   c, (p & SR_IO) ? "to" : "from", d);
1923
1924        NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1925
1926#ifdef REAL_DMA
1927        NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1928#endif /* def REAL_DMA  */
1929
1930        if (IS_A_TT()) {
1931                /* On the Medusa, it is a must to initialize the DMA before
1932                 * starting the NCR. This is also the cleaner way for the TT.
1933                 */
1934                local_irq_save(flags);
1935                hostdata->dma_len = (p & SR_IO) ?
1936                        NCR5380_dma_read_setup(instance, d, c) :
1937                        NCR5380_dma_write_setup(instance, d, c);
1938                local_irq_restore(flags);
1939        }
1940
1941        if (p & SR_IO)
1942                NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1943        else {
1944                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1945                NCR5380_write(START_DMA_SEND_REG, 0);
1946        }
1947
1948        if (!IS_A_TT()) {
1949                /* On the Falcon, the DMA setup must be done after the last */
1950                /* NCR access, else the DMA setup gets trashed!
1951                 */
1952                local_irq_save(flags);
1953                hostdata->dma_len = (p & SR_IO) ?
1954                        NCR5380_dma_read_setup(instance, d, c) :
1955                        NCR5380_dma_write_setup(instance, d, c);
1956                local_irq_restore(flags);
1957        }
1958        return 0;
1959}
1960#endif /* defined(REAL_DMA) */
1961
1962/*
1963 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1964 *
1965 * Purpose : run through the various SCSI phases and do as the target
1966 *      directs us to.  Operates on the currently connected command,
1967 *      instance->connected.
1968 *
1969 * Inputs : instance, instance for which we are doing commands
1970 *
1971 * Side effects : SCSI things happen, the disconnected queue will be
1972 *      modified if a command disconnects, *instance->connected will
1973 *      change.
1974 *
1975 * XXX Note : we need to watch for bus free or a reset condition here
1976 *      to recover from an unexpected bus free condition.
1977 */
1978
1979static void NCR5380_information_transfer(struct Scsi_Host *instance)
1980{
1981        SETUP_HOSTDATA(instance);
1982        unsigned long flags;
1983        unsigned char msgout = NOP;
1984        int sink = 0;
1985        int len;
1986#if defined(REAL_DMA)
1987        int transfersize;
1988#endif
1989        unsigned char *data;
1990        unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1991        Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
1992
1993        while (1) {
1994                tmp = NCR5380_read(STATUS_REG);
1995                /* We only have a valid SCSI phase when REQ is asserted */
1996                if (tmp & SR_REQ) {
1997                        phase = (tmp & PHASE_MASK);
1998                        if (phase != old_phase) {
1999                                old_phase = phase;
2000                                NCR_PRINT_PHASE(NDEBUG_INFORMATION);
2001                        }
2002
2003                        if (sink && (phase != PHASE_MSGOUT)) {
2004                                NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2005
2006                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
2007                                              ICR_ASSERT_ACK);
2008                                while (NCR5380_read(STATUS_REG) & SR_REQ)
2009                                        ;
2010                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2011                                              ICR_ASSERT_ATN);
2012                                sink = 0;
2013                                continue;
2014                        }
2015
2016                        switch (phase) {
2017                        case PHASE_DATAOUT:
2018#if (NDEBUG & NDEBUG_NO_DATAOUT)
2019                                printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
2020                                       "aborted\n", HOSTNO);
2021                                sink = 1;
2022                                do_abort(instance);
2023                                cmd->result = DID_ERROR << 16;
2024                                cmd->scsi_done(cmd);
2025                                return;
2026#endif
2027                        case PHASE_DATAIN:
2028                                /*
2029                                 * If there is no room left in the current buffer in the
2030                                 * scatter-gather list, move onto the next one.
2031                                 */
2032
2033                                if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2034                                        ++cmd->SCp.buffer;
2035                                        --cmd->SCp.buffers_residual;
2036                                        cmd->SCp.this_residual = cmd->SCp.buffer->length;
2037                                        cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2038                                        /* ++roman: Try to merge some scatter-buffers if
2039                                         * they are at contiguous physical addresses.
2040                                         */
2041                                        merge_contiguous_buffers(cmd);
2042                                        INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
2043                                                   HOSTNO, cmd->SCp.this_residual,
2044                                                   cmd->SCp.buffers_residual);
2045                                }
2046
2047                                /*
2048                                 * The preferred transfer method is going to be
2049                                 * PSEUDO-DMA for systems that are strictly PIO,
2050                                 * since we can let the hardware do the handshaking.
2051                                 *
2052                                 * For this to work, we need to know the transfersize
2053                                 * ahead of time, since the pseudo-DMA code will sit
2054                                 * in an unconditional loop.
2055                                 */
2056
2057                                /* ++roman: I suggest, this should be
2058                                 *   #if def(REAL_DMA)
2059                                 * instead of leaving REAL_DMA out.
2060                                 */
2061
2062#if defined(REAL_DMA)
2063                                if (!cmd->device->borken &&
2064                                    (transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
2065                                        len = transfersize;
2066                                        cmd->SCp.phase = phase;
2067                                        if (NCR5380_transfer_dma(instance, &phase,
2068                                            &len, (unsigned char **)&cmd->SCp.ptr)) {
2069                                                /*
2070                                                 * If the watchdog timer fires, all future
2071                                                 * accesses to this device will use the
2072                                                 * polled-IO. */
2073                                                printk(KERN_NOTICE "scsi%d: switching target %d "
2074                                                           "lun %d to slow handshake\n", HOSTNO,
2075                                                           cmd->device->id, cmd->device->lun);
2076                                                cmd->device->borken = 1;
2077                                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2078                                                        ICR_ASSERT_ATN);
2079                                                sink = 1;
2080                                                do_abort(instance);
2081                                                cmd->result = DID_ERROR << 16;
2082                                                cmd->scsi_done(cmd);
2083                                                /* XXX - need to source or sink data here, as appropriate */
2084                                        } else {
2085#ifdef REAL_DMA
2086                                                /* ++roman: When using real DMA,
2087                                                 * information_transfer() should return after
2088                                                 * starting DMA since it has nothing more to
2089                                                 * do.
2090                                                 */
2091                                                return;
2092#else
2093                                                cmd->SCp.this_residual -= transfersize - len;
2094#endif
2095                                        }
2096                                } else
2097#endif /* defined(REAL_DMA) */
2098                                        NCR5380_transfer_pio(instance, &phase,
2099                                                             (int *)&cmd->SCp.this_residual,
2100                                                             (unsigned char **)&cmd->SCp.ptr);
2101                                break;
2102                        case PHASE_MSGIN:
2103                                len = 1;
2104                                data = &tmp;
2105                                NCR5380_write(SELECT_ENABLE_REG, 0);    /* disable reselects */
2106                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2107                                cmd->SCp.Message = tmp;
2108
2109                                switch (tmp) {
2110                                /*
2111                                 * Linking lets us reduce the time required to get the
2112                                 * next command out to the device, hopefully this will
2113                                 * mean we don't waste another revolution due to the delays
2114                                 * required by ARBITRATION and another SELECTION.
2115                                 *
2116                                 * In the current implementation proposal, low level drivers
2117                                 * merely have to start the next command, pointed to by
2118                                 * next_link, done() is called as with unlinked commands.
2119                                 */
2120#ifdef LINKED
2121                                case LINKED_CMD_COMPLETE:
2122                                case LINKED_FLG_CMD_COMPLETE:
2123                                        /* Accept message by clearing ACK */
2124                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2125
2126                                        LNK_PRINTK("scsi%d: target %d lun %d linked command "
2127                                                   "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
2128
2129                                        /* Enable reselect interrupts */
2130                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2131                                        /*
2132                                         * Sanity check : A linked command should only terminate
2133                                         * with one of these messages if there are more linked
2134                                         * commands available.
2135                                         */
2136
2137                                        if (!cmd->next_link) {
2138                                                 printk(KERN_NOTICE "scsi%d: target %d lun %d "
2139                                                        "linked command complete, no next_link\n",
2140                                                        HOSTNO, cmd->device->id, cmd->device->lun);
2141                                                sink = 1;
2142                                                do_abort(instance);
2143                                                return;
2144                                        }
2145
2146                                        initialize_SCp(cmd->next_link);
2147                                        /* The next command is still part of this process; copy it
2148                                         * and don't free it! */
2149                                        cmd->next_link->tag = cmd->tag;
2150                                        cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2151                                        LNK_PRINTK("scsi%d: target %d lun %d linked request "
2152                                                   "done, calling scsi_done().\n",
2153                                                   HOSTNO, cmd->device->id, cmd->device->lun);
2154#ifdef NCR5380_STATS
2155                                        collect_stats(hostdata, cmd);
2156#endif
2157                                        cmd->scsi_done(cmd);
2158                                        cmd = hostdata->connected;
2159                                        break;
2160#endif /* def LINKED */
2161                                case ABORT:
2162                                case COMMAND_COMPLETE:
2163                                        /* Accept message by clearing ACK */
2164                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2165                                        /* ++guenther: possible race with Falcon locking */
2166                                        falcon_dont_release++;
2167                                        hostdata->connected = NULL;
2168                                        QU_PRINTK("scsi%d: command for target %d, lun %d "
2169                                                  "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2170#ifdef SUPPORT_TAGS
2171                                        cmd_free_tag(cmd);
2172                                        if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2173                                                /* Turn a QUEUE FULL status into BUSY, I think the
2174                                                 * mid level cannot handle QUEUE FULL :-( (The
2175                                                 * command is retried after BUSY). Also update our
2176                                                 * queue size to the number of currently issued
2177                                                 * commands now.
2178                                                 */
2179                                                /* ++Andreas: the mid level code knows about
2180                                                   QUEUE_FULL now. */
2181                                                TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
2182                                                TAG_PRINTK("scsi%d: target %d lun %d returned "
2183                                                           "QUEUE_FULL after %d commands\n",
2184                                                           HOSTNO, cmd->device->id, cmd->device->lun,
2185                                                           ta->nr_allocated);
2186                                                if (ta->queue_size > ta->nr_allocated)
2187                                                        ta->nr_allocated = ta->queue_size;
2188                                        }
2189#else
2190                                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2191#endif
2192                                        /* Enable reselect interrupts */
2193                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2194
2195                                        /*
2196                                         * I'm not sure what the correct thing to do here is :
2197                                         *
2198                                         * If the command that just executed is NOT a request
2199                                         * sense, the obvious thing to do is to set the result
2200                                         * code to the values of the stored parameters.
2201                                         *
2202                                         * If it was a REQUEST SENSE command, we need some way to
2203                                         * differentiate between the failure code of the original
2204                                         * and the failure code of the REQUEST sense - the obvious
2205                                         * case is success, where we fall through and leave the
2206                                         * result code unchanged.
2207                                         *
2208                                         * The non-obvious place is where the REQUEST SENSE failed
2209                                         */
2210
2211                                        if (cmd->cmnd[0] != REQUEST_SENSE)
2212                                                cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2213                                        else if (status_byte(cmd->SCp.Status) != GOOD)
2214                                                cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2215
2216#ifdef AUTOSENSE
2217                                        if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2218                                                hostdata->ses.cmd_len) {
2219                                                scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2220                                                hostdata->ses.cmd_len = 0 ;
2221                                        }
2222
2223                                        if ((cmd->cmnd[0] != REQUEST_SENSE) &&
2224                                            (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2225                                                scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2226
2227                                                ASEN_PRINTK("scsi%d: performing request sense\n", HOSTNO);
2228
2229                                                local_irq_save(flags);
2230                                                LIST(cmd,hostdata->issue_queue);
2231                                                SET_NEXT(cmd, hostdata->issue_queue);
2232                                                hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2233                                                local_irq_restore(flags);
2234                                                QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
2235                                                          "issue queue\n", H_NO(cmd));
2236                                        } else
2237#endif /* def AUTOSENSE */
2238                                        {
2239#ifdef NCR5380_STATS
2240                                                collect_stats(hostdata, cmd);
2241#endif
2242                                                cmd->scsi_done(cmd);
2243                                        }
2244
2245                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2246                                        /*
2247                                         * Restore phase bits to 0 so an interrupted selection,
2248                                         * arbitration can resume.
2249                                         */
2250                                        NCR5380_write(TARGET_COMMAND_REG, 0);
2251
2252                                        while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2253                                                barrier();
2254
2255                                        falcon_dont_release--;
2256                                        /* ++roman: For Falcon SCSI, release the lock on the
2257                                         * ST-DMA here if no other commands are waiting on the
2258                                         * disconnected queue.
2259                                         */
2260                                        falcon_release_lock_if_possible(hostdata);
2261                                        return;
2262                                case MESSAGE_REJECT:
2263                                        /* Accept message by clearing ACK */
2264                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2265                                        /* Enable reselect interrupts */
2266                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2267                                        switch (hostdata->last_message) {
2268                                        case HEAD_OF_QUEUE_TAG:
2269                                        case ORDERED_QUEUE_TAG:
2270                                        case SIMPLE_QUEUE_TAG:
2271                                                /* The target obviously doesn't support tagged
2272                                                 * queuing, even though it announced this ability in
2273                                                 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2274                                                 * clear 'tagged_supported' and lock the LUN, since
2275                                                 * the command is treated as untagged further on.
2276                                                 */
2277                                                cmd->device->tagged_supported = 0;
2278                                                hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2279                                                cmd->tag = TAG_NONE;
2280                                                TAG_PRINTK("scsi%d: target %d lun %d rejected "
2281                                                           "QUEUE_TAG message; tagged queuing "
2282                                                           "disabled\n",
2283                                                           HOSTNO, cmd->device->id, cmd->device->lun);
2284                                                break;
2285                                        }
2286                                        break;
2287                                case DISCONNECT:
2288                                        /* Accept message by clearing ACK */
2289                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2290                                        local_irq_save(flags);
2291                                        cmd->device->disconnect = 1;
2292                                        LIST(cmd,hostdata->disconnected_queue);
2293                                        SET_NEXT(cmd, hostdata->disconnected_queue);
2294                                        hostdata->connected = NULL;
2295                                        hostdata->disconnected_queue = cmd;
2296                                        local_irq_restore(flags);
2297                                        QU_PRINTK("scsi%d: command for target %d lun %d was "
2298                                                  "moved from connected to the "
2299                                                  "disconnected_queue\n", HOSTNO,
2300                                                  cmd->device->id, cmd->device->lun);
2301                                        /*
2302                                         * Restore phase bits to 0 so an interrupted selection,
2303                                         * arbitration can resume.
2304                                         */
2305                                        NCR5380_write(TARGET_COMMAND_REG, 0);
2306
2307                                        /* Enable reselect interrupts */
2308                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2309                                        /* Wait for bus free to avoid nasty timeouts */
2310                                        while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2311                                                barrier();
2312                                        return;
2313                                        /*
2314                                         * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2315                                         * operation, in violation of the SCSI spec so we can safely
2316                                         * ignore SAVE/RESTORE pointers calls.
2317                                         *
2318                                         * Unfortunately, some disks violate the SCSI spec and
2319                                         * don't issue the required SAVE_POINTERS message before
2320                                         * disconnecting, and we have to break spec to remain
2321                                         * compatible.
2322                                         */
2323                                case SAVE_POINTERS:
2324                                case RESTORE_POINTERS:
2325                                        /* Accept message by clearing ACK */
2326                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2327                                        /* Enable reselect interrupts */
2328                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2329                                        break;
2330                                case EXTENDED_MESSAGE:
2331                                        /*
2332                                         * Extended messages are sent in the following format :
2333                                         * Byte
2334                                         * 0            EXTENDED_MESSAGE == 1
2335                                         * 1            length (includes one byte for code, doesn't
2336                                         *              include first two bytes)
2337                                         * 2            code
2338                                         * 3..length+1  arguments
2339                                         *
2340                                         * Start the extended message buffer with the EXTENDED_MESSAGE
2341                                         * byte, since spi_print_msg() wants the whole thing.
2342                                         */
2343                                        extended_msg[0] = EXTENDED_MESSAGE;
2344                                        /* Accept first byte by clearing ACK */
2345                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2346
2347                                        EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);
2348
2349                                        len = 2;
2350                                        data = extended_msg + 1;
2351                                        phase = PHASE_MSGIN;
2352                                        NCR5380_transfer_pio(instance, &phase, &len, &data);
2353                                        EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2354                                                   (int)extended_msg[1], (int)extended_msg[2]);
2355
2356                                        if (!len && extended_msg[1] <=
2357                                            (sizeof(extended_msg) - 1)) {
2358                                                /* Accept third byte by clearing ACK */
2359                                                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2360                                                len = extended_msg[1] - 1;
2361                                                data = extended_msg + 3;
2362                                                phase = PHASE_MSGIN;
2363
2364                                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2365                                                EXT_PRINTK("scsi%d: message received, residual %d\n",
2366                                                           HOSTNO, len);
2367
2368                                                switch (extended_msg[2]) {
2369                                                case EXTENDED_SDTR:
2370                                                case EXTENDED_WDTR:
2371                                                case EXTENDED_MODIFY_DATA_POINTER:
2372                                                case EXTENDED_EXTENDED_IDENTIFY:
2373                                                        tmp = 0;
2374                                                }
2375                                        } else if (len) {
2376                                                printk(KERN_NOTICE "scsi%d: error receiving "
2377                                                       "extended message\n", HOSTNO);
2378                                                tmp = 0;
2379                                        } else {
2380                                                printk(KERN_NOTICE "scsi%d: extended message "
2381                                                           "code %02x length %d is too long\n",
2382                                                           HOSTNO, extended_msg[2], extended_msg[1]);
2383                                                tmp = 0;
2384                                        }
2385                                        /* Fall through to reject message */
2386
2387                                        /*
2388                                         * If we get something weird that we aren't expecting,
2389                                         * reject it.
2390                                         */
2391                                default:
2392                                        if (!tmp) {
2393                                                printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
2394                                                spi_print_msg(extended_msg);
2395                                                printk("\n");
2396                                        } else if (tmp != EXTENDED_MESSAGE)
2397                                                printk(KERN_DEBUG "scsi%d: rejecting unknown "
2398                                                       "message %02x from target %d, lun %d\n",
2399                                                       HOSTNO, tmp, cmd->device->id, cmd->device->lun);
2400                                        else
2401                                                printk(KERN_DEBUG "scsi%d: rejecting unknown "
2402                                                       "extended message "
2403                                                       "code %02x, length %d from target %d, lun %d\n",
2404                                                       HOSTNO, extended_msg[1], extended_msg[0],
2405                                                       cmd->device->id, cmd->device->lun);
2406
2407
2408                                        msgout = MESSAGE_REJECT;
2409                                        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2410                                        break;
2411                                } /* switch (tmp) */
2412                                break;
2413                        case PHASE_MSGOUT:
2414                                len = 1;
2415                                data = &msgout;
2416                                hostdata->last_message = msgout;
2417                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2418                                if (msgout == ABORT) {
2419#ifdef SUPPORT_TAGS
2420                                        cmd_free_tag(cmd);
2421#else
2422                                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2423#endif
2424                                        hostdata->connected = NULL;
2425                                        cmd->result = DID_ERROR << 16;
2426#ifdef NCR5380_STATS
2427                                        collect_stats(hostdata, cmd);
2428#endif
2429                                        cmd->scsi_done(cmd);
2430                                        NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2431                                        falcon_release_lock_if_possible(hostdata);
2432                                        return;
2433                                }
2434                                msgout = NOP;
2435                                break;
2436                        case PHASE_CMDOUT:
2437                                len = cmd->cmd_len;
2438                                data = cmd->cmnd;
2439                                /*
2440                                 * XXX for performance reasons, on machines with a
2441                                 * PSEUDO-DMA architecture we should probably
2442                                 * use the dma transfer function.
2443                                 */
2444                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2445                                break;
2446                        case PHASE_STATIN:
2447                                len = 1;
2448                                data = &tmp;
2449                                NCR5380_transfer_pio(instance, &phase, &len, &data);
2450                                cmd->SCp.Status = tmp;
2451                                break;
2452                        default:
2453                                printk("scsi%d: unknown phase\n", HOSTNO);
2454                                NCR_PRINT(NDEBUG_ANY);
2455                        } /* switch(phase) */
2456                } /* if (tmp * SR_REQ) */
2457        } /* while (1) */
2458}
2459
2460/*
2461 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2462 *
2463 * Purpose : does reselection, initializing the instance->connected
2464 *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2465 *      nexus has been reestablished,
2466 *
2467 * Inputs : instance - this instance of the NCR5380.
2468 *
2469 */
2470
2471
2472static void NCR5380_reselect(struct Scsi_Host *instance)
2473{
2474        SETUP_HOSTDATA(instance);
2475        unsigned char target_mask;
2476        unsigned char lun, phase;
2477        int len;
2478#ifdef SUPPORT_TAGS
2479        unsigned char tag;
2480#endif
2481        unsigned char msg[3];
2482        unsigned char *data;
2483        Scsi_Cmnd *tmp = NULL, *prev;
2484/*      unsigned long flags; */
2485
2486        /*
2487         * Disable arbitration, etc. since the host adapter obviously
2488         * lost, and tell an interrupted NCR5380_select() to restart.
2489         */
2490
2491        NCR5380_write(MODE_REG, MR_BASE);
2492        hostdata->restart_select = 1;
2493
2494        target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2495
2496        RSL_PRINTK("scsi%d: reselect\n", HOSTNO);
2497
2498        /*
2499         * At this point, we have detected that our SCSI ID is on the bus,
2500         * SEL is true and BSY was false for at least one bus settle delay
2501         * (400 ns).
2502         *
2503         * We must assert BSY ourselves, until the target drops the SEL
2504         * signal.
2505         */
2506
2507        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2508
2509        while (NCR5380_read(STATUS_REG) & SR_SEL)
2510                ;
2511        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2512
2513        /*
2514         * Wait for target to go into MSGIN.
2515         */
2516
2517        while (!(NCR5380_read(STATUS_REG) & SR_REQ))
2518                ;
2519
2520        len = 1;
2521        data = msg;
2522        phase = PHASE_MSGIN;
2523        NCR5380_transfer_pio(instance, &phase, &len, &data);
2524
2525        if (!(msg[0] & 0x80)) {
2526                printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2527                spi_print_msg(msg);
2528                do_abort(instance);
2529                return;
2530        }
2531        lun = (msg[0] & 0x07);
2532
2533#ifdef SUPPORT_TAGS
2534        /* If the phase is still MSGIN, the target wants to send some more
2535         * messages. In case it supports tagged queuing, this is probably a
2536         * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2537         */
2538        tag = TAG_NONE;
2539        if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2540                /* Accept previous IDENTIFY message by clearing ACK */
2541                NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2542                len = 2;
2543                data = msg + 1;
2544                if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2545                    msg[1] == SIMPLE_QUEUE_TAG)
2546                        tag = msg[2];
2547                TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
2548                           "reselection\n", HOSTNO, target_mask, lun, tag);
2549        }
2550#endif
2551
2552        /*
2553         * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2554         * just reestablished, and remove it from the disconnected queue.
2555         */
2556
2557        for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL;
2558             tmp; prev = tmp, tmp = NEXT(tmp)) {
2559                if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2560#ifdef SUPPORT_TAGS
2561                    && (tag == tmp->tag)
2562#endif
2563                    ) {
2564                        /* ++guenther: prevent race with falcon_release_lock */
2565                        falcon_dont_release++;
2566                        if (prev) {
2567                                REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2568                                SET_NEXT(prev, NEXT(tmp));
2569                        } else {
2570                                REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
2571                                hostdata->disconnected_queue = NEXT(tmp);
2572                        }
2573                        SET_NEXT(tmp, NULL);
2574                        break;
2575                }
2576        }
2577
2578        if (!tmp) {
2579                printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
2580#ifdef SUPPORT_TAGS
2581                       "tag %d "
2582#endif
2583                       "not in disconnected_queue.\n",
2584                       HOSTNO, target_mask, lun
2585#ifdef SUPPORT_TAGS
2586                       , tag
2587#endif
2588                        );
2589                /*
2590                 * Since we have an established nexus that we can't do anything
2591                 * with, we must abort it.
2592                 */
2593                do_abort(instance);
2594                return;
2595        }
2596
2597        /* Accept message by clearing ACK */
2598        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2599
2600        hostdata->connected = tmp;
2601        RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
2602                   HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
2603        falcon_dont_release--;
2604}
2605
2606
2607/*
2608 * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2609 *
2610 * Purpose : abort a command
2611 *
2612 * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2613 *      host byte of the result field to, if zero DID_ABORTED is
2614 *      used.
2615 *
2616 * Returns : 0 - success, -1 on failure.
2617 *
2618 * XXX - there is no way to abort the command that is currently
2619 *       connected, you have to wait for it to complete.  If this is
2620 *       a problem, we could implement longjmp() / setjmp(), setjmp()
2621 *       called where the loop started in NCR5380_main().
2622 */
2623
2624static
2625int NCR5380_abort(Scsi_Cmnd *cmd)
2626{
2627        struct Scsi_Host *instance = cmd->device->host;
2628        SETUP_HOSTDATA(instance);
2629        Scsi_Cmnd *tmp, **prev;
2630        unsigned long flags;
2631
2632        printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
2633        scsi_print_command(cmd);
2634
2635        NCR5380_print_status(instance);
2636
2637        local_irq_save(flags);
2638
2639        if (!IS_A_TT() && !falcon_got_lock)
2640                printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
2641                       HOSTNO);
2642
2643        ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2644                    NCR5380_read(BUS_AND_STATUS_REG),
2645                    NCR5380_read(STATUS_REG));
2646
2647#if 1
2648        /*
2649         * Case 1 : If the command is the currently executing command,
2650         * we'll set the aborted flag and return control so that
2651         * information transfer routine can exit cleanly.
2652         */
2653
2654        if (hostdata->connected == cmd) {
2655
2656                ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
2657                /*
2658                 * We should perform BSY checking, and make sure we haven't slipped
2659                 * into BUS FREE.
2660                 */
2661
2662                /*      NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2663                /*
2664                 * Since we can't change phases until we've completed the current
2665                 * handshake, we have to source or sink a byte of data if the current
2666                 * phase is not MSGOUT.
2667                 */
2668
2669                /*
2670                 * Return control to the executing NCR drive so we can clear the
2671                 * aborted flag and get back into our main loop.
2672                 */
2673
2674                if (do_abort(instance) == 0) {
2675                        hostdata->aborted = 1;
2676                        hostdata->connected = NULL;
2677                        cmd->result = DID_ABORT << 16;
2678#ifdef SUPPORT_TAGS
2679                        cmd_free_tag(cmd);
2680#else
2681                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2682#endif
2683                        local_irq_restore(flags);
2684                        cmd->scsi_done(cmd);
2685                        falcon_release_lock_if_possible(hostdata);
2686                        return SCSI_ABORT_SUCCESS;
2687                } else {
2688/*                      local_irq_restore(flags); */
2689                        printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2690                        return SCSI_ABORT_ERROR;
2691                }
2692        }
2693#endif
2694
2695        /*
2696         * Case 2 : If the command hasn't been issued yet, we simply remove it
2697         *          from the issue queue.
2698         */
2699        for (prev = (Scsi_Cmnd **)&(hostdata->issue_queue),
2700             tmp = (Scsi_Cmnd *)hostdata->issue_queue;
2701             tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2702                if (cmd == tmp) {
2703                        REMOVE(5, *prev, tmp, NEXT(tmp));
2704                        (*prev) = NEXT(tmp);
2705                        SET_NEXT(tmp, NULL);
2706                        tmp->result = DID_ABORT << 16;
2707                        local_irq_restore(flags);
2708                        ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
2709                                    HOSTNO);
2710                        /* Tagged queuing note: no tag to free here, hasn't been assigned
2711                         * yet... */
2712                        tmp->scsi_done(tmp);
2713                        falcon_release_lock_if_possible(hostdata);
2714                        return SCSI_ABORT_SUCCESS;
2715                }
2716        }
2717
2718        /*
2719         * Case 3 : If any commands are connected, we're going to fail the abort
2720         *          and let the high level SCSI driver retry at a later time or
2721         *          issue a reset.
2722         *
2723         *          Timeouts, and therefore aborted commands, will be highly unlikely
2724         *          and handling them cleanly in this situation would make the common
2725         *          case of noresets less efficient, and would pollute our code.  So,
2726         *          we fail.
2727         */
2728
2729        if (hostdata->connected) {
2730                local_irq_restore(flags);
2731                ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
2732                return SCSI_ABORT_SNOOZE;
2733        }
2734
2735        /*
2736         * Case 4: If the command is currently disconnected from the bus, and
2737         *      there are no connected commands, we reconnect the I_T_L or
2738         *      I_T_L_Q nexus associated with it, go into message out, and send
2739         *      an abort message.
2740         *
2741         * This case is especially ugly. In order to reestablish the nexus, we
2742         * need to call NCR5380_select().  The easiest way to implement this
2743         * function was to abort if the bus was busy, and let the interrupt
2744         * handler triggered on the SEL for reselect take care of lost arbitrations
2745         * where necessary, meaning interrupts need to be enabled.
2746         *
2747         * When interrupts are enabled, the queues may change - so we
2748         * can't remove it from the disconnected queue before selecting it
2749         * because that could cause a failure in hashing the nexus if that
2750         * device reselected.
2751         *
2752         * Since the queues may change, we can't use the pointers from when we
2753         * first locate it.
2754         *
2755         * So, we must first locate the command, and if NCR5380_select()
2756         * succeeds, then issue the abort, relocate the command and remove
2757         * it from the disconnected queue.
2758         */
2759
2760        for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
2761             tmp = NEXT(tmp)) {
2762                if (cmd == tmp) {
2763                        local_irq_restore(flags);
2764                        ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
2765
2766                        if (NCR5380_select(instance, cmd, (int)cmd->tag))
2767                                return SCSI_ABORT_BUSY;
2768
2769                        ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);
2770
2771                        do_abort(instance);
2772
2773                        local_irq_save(flags);
2774                        for (prev = (Scsi_Cmnd **)&(hostdata->disconnected_queue),
2775                             tmp = (Scsi_Cmnd *)hostdata->disconnected_queue;
2776                             tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2777                                if (cmd == tmp) {
2778                                        REMOVE(5, *prev, tmp, NEXT(tmp));
2779                                        *prev = NEXT(tmp);
2780                                        SET_NEXT(tmp, NULL);
2781                                        tmp->result = DID_ABORT << 16;
2782                                        /* We must unlock the tag/LUN immediately here, since the
2783                                         * target goes to BUS FREE and doesn't send us another
2784                                         * message (COMMAND_COMPLETE or the like)
2785                                         */
2786#ifdef SUPPORT_TAGS
2787                                        cmd_free_tag(tmp);
2788#else
2789                                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2790#endif
2791                                        local_irq_restore(flags);
2792                                        tmp->scsi_done(tmp);
2793                                        falcon_release_lock_if_possible(hostdata);
2794                                        return SCSI_ABORT_SUCCESS;
2795                                }
2796                        }
2797                }
2798        }
2799
2800        /*
2801         * Case 5 : If we reached this point, the command was not found in any of
2802         *          the queues.
2803         *
2804         * We probably reached this point because of an unlikely race condition
2805         * between the command completing successfully and the abortion code,
2806         * so we won't panic, but we will notify the user in case something really
2807         * broke.
2808         */
2809
2810        local_irq_restore(flags);
2811        printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
2812
2813        /* Maybe it is sufficient just to release the ST-DMA lock... (if
2814         * possible at all) At least, we should check if the lock could be
2815         * released after the abort, in case it is kept due to some bug.
2816         */
2817        falcon_release_lock_if_possible(hostdata);
2818
2819        return SCSI_ABORT_NOT_RUNNING;
2820}
2821
2822
2823/*
2824 * Function : int NCR5380_reset (Scsi_Cmnd *cmd)
2825 *
2826 * Purpose : reset the SCSI bus.
2827 *
2828 * Returns : SCSI_RESET_WAKEUP
2829 *
2830 */
2831
2832static int NCR5380_bus_reset(Scsi_Cmnd *cmd)
2833{
2834        SETUP_HOSTDATA(cmd->device->host);
2835        int i;
2836        unsigned long flags;
2837#if 1
2838        Scsi_Cmnd *connected, *disconnected_queue;
2839#endif
2840
2841        if (!IS_A_TT() && !falcon_got_lock)
2842                printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
2843                       H_NO(cmd));
2844
2845        NCR5380_print_status(cmd->device->host);
2846
2847        /* get in phase */
2848        NCR5380_write(TARGET_COMMAND_REG,
2849                      PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
2850        /* assert RST */
2851        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
2852        udelay(40);
2853        /* reset NCR registers */
2854        NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2855        NCR5380_write(MODE_REG, MR_BASE);
2856        NCR5380_write(TARGET_COMMAND_REG, 0);
2857        NCR5380_write(SELECT_ENABLE_REG, 0);
2858        /* ++roman: reset interrupt condition! otherwise no interrupts don't get
2859         * through anymore ... */
2860        (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2861
2862#if 1   /* XXX Should now be done by midlevel code, but it's broken XXX */
2863        /* XXX see below                                            XXX */
2864
2865        /* MSch: old-style reset: actually abort all command processing here */
2866
2867        /* After the reset, there are no more connected or disconnected commands
2868         * and no busy units; to avoid problems with re-inserting the commands
2869         * into the issue_queue (via scsi_done()), the aborted commands are
2870         * remembered in local variables first.
2871         */
2872        local_irq_save(flags);
2873        connected = (Scsi_Cmnd *)hostdata->connected;
2874        hostdata->connected = NULL;
2875        disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
2876        hostdata->disconnected_queue = NULL;
2877#ifdef SUPPORT_TAGS
2878        free_all_tags();
2879#endif
2880        for (i = 0; i < 8; ++i)
2881                hostdata->busy[i] = 0;
2882#ifdef REAL_DMA
2883        hostdata->dma_len = 0;
2884#endif
2885        local_irq_restore(flags);
2886
2887        /* In order to tell the mid-level code which commands were aborted,
2888         * set the command status to DID_RESET and call scsi_done() !!!
2889         * This ultimately aborts processing of these commands in the mid-level.
2890         */
2891
2892        if ((cmd = connected)) {
2893                ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2894                cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2895                cmd->scsi_done(cmd);
2896        }
2897
2898        for (i = 0; (cmd = disconnected_queue); ++i) {
2899                disconnected_queue = NEXT(cmd);
2900                SET_NEXT(cmd, NULL);
2901                cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2902                cmd->scsi_done(cmd);
2903        }
2904        if (i > 0)
2905                ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);
2906
2907        /* The Falcon lock should be released after a reset...
2908         */
2909        /* ++guenther: moved to atari_scsi_reset(), to prevent a race between
2910         * unlocking and enabling dma interrupt.
2911         */
2912/*      falcon_release_lock_if_possible( hostdata );*/
2913
2914        /* since all commands have been explicitly terminated, we need to tell
2915         * the midlevel code that the reset was SUCCESSFUL, and there is no
2916         * need to 'wake up' the commands by a request_sense
2917         */
2918        return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
2919#else /* 1 */
2920
2921        /* MSch: new-style reset handling: let the mid-level do what it can */
2922
2923        /* ++guenther: MID-LEVEL IS STILL BROKEN.
2924         * Mid-level is supposed to requeue all commands that were active on the
2925         * various low-level queues. In fact it does this, but that's not enough
2926         * because all these commands are subject to timeout. And if a timeout
2927         * happens for any removed command, *_abort() is called but all queues
2928         * are now empty. Abort then gives up the falcon lock, which is fatal,
2929         * since the mid-level will queue more commands and must have the lock
2930         * (it's all happening inside timer interrupt handler!!).
2931         * Even worse, abort will return NOT_RUNNING for all those commands not
2932         * on any queue, so they won't be retried ...
2933         *
2934         * Conclusion: either scsi.c disables timeout for all resetted commands
2935         * immediately, or we lose!  As of linux-2.0.20 it doesn't.
2936         */
2937
2938        /* After the reset, there are no more connected or disconnected commands
2939         * and no busy units; so clear the low-level status here to avoid
2940         * conflicts when the mid-level code tries to wake up the affected
2941         * commands!
2942         */
2943
2944        if (hostdata->issue_queue)
2945                ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
2946        if (hostdata->connected)
2947                ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2948        if (hostdata->disconnected_queue)
2949                ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
2950
2951        local_irq_save(flags);
2952        hostdata->issue_queue = NULL;
2953        hostdata->connected = NULL;
2954        hostdata->disconnected_queue = NULL;
2955#ifdef SUPPORT_TAGS
2956        free_all_tags();
2957#endif
2958        for (i = 0; i < 8; ++i)
2959                hostdata->busy[i] = 0;
2960#ifdef REAL_DMA
2961        hostdata->dma_len = 0;
2962#endif
2963        local_irq_restore(flags);
2964
2965        /* we did no complete reset of all commands, so a wakeup is required */
2966        return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
2967#endif /* 1 */
2968}
2969
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.