sun3_NCR5380.c 90.6 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64
/* sun3_NCR5380.c -- adapted from atari_NCR5380.c for the sun3 by 
   Sam Creasey. */ 
/* 
 * NCR 5380 generic driver routines.  These should make it *trivial*
 * 	to implement 5380 SCSI drivers under Linux with a non-trantor
 *	architecture.
 *
 *	Note that these routines also work with NR53c400 family chips.
 *
 * Copyright 1993, Drew Eckhardt
 *	Visionary Computing 
 *	(Unix and Linux consulting and custom programming)
 * 	drew@colorado.edu
 *	+1 (303) 666-5836
 *
 * DISTRIBUTION RELEASE 6. 
 *
 * For more information, please consult 
 *
 * NCR 5380 Family
 * SCSI Protocol Controller
 * Databook
 *
 * NCR Microelectronics
 * 1635 Aeroplaza Drive
 * Colorado Springs, CO 80916
 * 1+ (719) 578-3400
 * 1+ (800) 334-5454
 */

/*
 * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
 * this file, too:
 *
 *  - Some of the debug statements were incorrect (undefined variables and the
 *    like). I fixed that.
 *
 *  - In information_transfer(), I think a #ifdef was wrong. Looking at the
 *    possible DMA transfer size should also happen for REAL_DMA. I added this
 *    in the #if statement.
 *
 *  - When using real DMA, information_transfer() should return in a DATAOUT
 *    phase after starting the DMA. It has nothing more to do.
 *
 *  - The interrupt service routine should run main after end of DMA, too (not
 *    only after RESELECTION interrupts). Additionally, it should _not_ test
 *    for more interrupts after running main, since a DMA process may have
 *    been started and interrupts are turned on now. The new int could happen
 *    inside the execution of NCR5380_intr(), leading to recursive
 *    calls.
 *
 * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
 *    and USLEEP, because these were messing up readability and will never be
 *    needed for Atari SCSI.
 * 
 * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
 *   stuff), and 'main' is executed in a bottom half if awoken by an
 *   interrupt.
 *
 * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
 *   constructs. In my eyes, this made the source rather unreadable, so I
 *   finally replaced that by the *_PRINTK() macros.
 *
 */
65
#include <scsi/scsi_dbg.h>
66
#include <scsi/scsi_transport_spi.h>
Linus Torvalds's avatar
Linus Torvalds committed
67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253

/*
 * Further development / testing that should be done : 
 * 1.  Test linked command handling code after Eric is ready with 
 *     the high level code.
 */

#if (NDEBUG & NDEBUG_LISTS)
#define LIST(x,y) \
  { printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); \
    if ((x)==(y)) udelay(5); }
#define REMOVE(w,x,y,z) \
  { printk("LINE:%d   Removing: %p->%p  %p->%p \n", __LINE__, \
	   (void*)(w), (void*)(x), (void*)(y), (void*)(z)); \
    if ((x)==(y)) udelay(5); }
#else
#define LIST(x,y)
#define REMOVE(w,x,y,z)
#endif

#ifndef notyet
#undef LINKED
#endif

/*
 * Design
 * Issues :
 *
 * The other Linux SCSI drivers were written when Linux was Intel PC-only,
 * and specifically for each board rather than each chip.  This makes their
 * adaptation to platforms like the Mac (Some of which use NCR5380's)
 * more difficult than it has to be.
 *
 * Also, many of the SCSI drivers were written before the command queuing
 * routines were implemented, meaning their implementations of queued 
 * commands were hacked on rather than designed in from the start.
 *
 * When I designed the Linux SCSI drivers I figured that 
 * while having two different SCSI boards in a system might be useful
 * for debugging things, two of the same type wouldn't be used.
 * Well, I was wrong and a number of users have mailed me about running
 * multiple high-performance SCSI boards in a server.
 *
 * Finally, when I get questions from users, I have no idea what 
 * revision of my driver they are running.
 *
 * This driver attempts to address these problems :
 * This is a generic 5380 driver.  To use it on a different platform, 
 * one simply writes appropriate system specific macros (ie, data
 * transfer - some PC's will use the I/O bus, 68K's must use 
 * memory mapped) and drops this file in their 'C' wrapper.
 *
 * As far as command queueing, two queues are maintained for 
 * each 5380 in the system - commands that haven't been issued yet,
 * and commands that are currently executing.  This means that an 
 * unlimited number of commands may be queued, letting 
 * more commands propagate from the higher driver levels giving higher 
 * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported, 
 * allowing multiple commands to propagate all the way to a SCSI-II device 
 * while a command is already executing.
 *
 * To solve the multiple-boards-in-the-same-system problem, 
 * there is a separate instance structure for each instance
 * of a 5380 in the system.  So, multiple NCR5380 drivers will
 * be able to coexist with appropriate changes to the high level
 * SCSI code.  
 *
 * A NCR5380_PUBLIC_REVISION macro is provided, with the release
 * number (updated for each public release) printed by the 
 * NCR5380_print_options command, which should be called from the 
 * wrapper detect function, so that I know what release of the driver
 * users are using.
 *
 * Issues specific to the NCR5380 : 
 *
 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead 
 * piece of hardware that requires you to sit in a loop polling for 
 * the REQ signal as long as you are connected.  Some devices are 
 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect 
 * while doing long seek operations.
 * 
 * The workaround for this is to keep track of devices that have
 * disconnected.  If the device hasn't disconnected, for commands that
 * should disconnect, we do something like 
 *
 * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
 * 
 * Some tweaking of N and M needs to be done.  An algorithm based 
 * on "time to data" would give the best results as long as short time
 * to datas (ie, on the same track) were considered, however these 
 * broken devices are the exception rather than the rule and I'd rather
 * spend my time optimizing for the normal case.
 *
 * Architecture :
 *
 * At the heart of the design is a coroutine, NCR5380_main,
 * which is started when not running by the interrupt handler,
 * timer, and queue command function.  It attempts to establish
 * I_T_L or I_T_L_Q nexuses by removing the commands from the 
 * issue queue and calling NCR5380_select() if a nexus 
 * is not established. 
 *
 * Once a nexus is established, the NCR5380_information_transfer()
 * phase goes through the various phases as instructed by the target.
 * if the target goes into MSG IN and sends a DISCONNECT message,
 * the command structure is placed into the per instance disconnected
 * queue, and NCR5380_main tries to find more work.  If USLEEP
 * was defined, and the target is idle for too long, the system
 * will try to sleep.
 *
 * If a command has disconnected, eventually an interrupt will trigger,
 * calling NCR5380_intr()  which will in turn call NCR5380_reselect
 * to reestablish a nexus.  This will run main if necessary.
 *
 * On command termination, the done function will be called as 
 * appropriate.
 *
 * SCSI pointers are maintained in the SCp field of SCSI command 
 * structures, being initialized after the command is connected
 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
 * Note that in violation of the standard, an implicit SAVE POINTERS operation
 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
 */

/*
 * Using this file :
 * This file a skeleton Linux SCSI driver for the NCR 5380 series
 * of chips.  To use it, you write an architecture specific functions 
 * and macros and include this file in your driver.
 *
 * These macros control options : 
 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
 *	for commands that return with a CHECK CONDITION status. 
 *
 * LINKED - if defined, linked commands are supported.
 *
 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
 *
 * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
 *
 * These macros MUST be defined :
 * 
 * NCR5380_read(register)  - read from the specified register
 *
 * NCR5380_write(register, value) - write to the specific register 
 *
 * Either real DMA *or* pseudo DMA may be implemented
 * REAL functions : 
 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
 * Note that the DMA setup functions should return the number of bytes 
 *	that they were able to program the controller for.
 *
 * Also note that generic i386/PC versions of these macros are 
 *	available as NCR5380_i386_dma_write_setup,
 *	NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
 *
 * NCR5380_dma_write_setup(instance, src, count) - initialize
 * NCR5380_dma_read_setup(instance, dst, count) - initialize
 * NCR5380_dma_residual(instance); - residual count
 *
 * PSEUDO functions :
 * NCR5380_pwrite(instance, src, count)
 * NCR5380_pread(instance, dst, count);
 *
 * If nothing specific to this implementation needs doing (ie, with external
 * hardware), you must also define 
 *  
 * NCR5380_queue_command
 * NCR5380_reset
 * NCR5380_abort
 * NCR5380_proc_info
 *
 * to be the global entry points into the specific driver, ie 
 * #define NCR5380_queue_command t128_queue_command.
 *
 * If this is not done, the routines will be defined as static functions
 * with the NCR5380* names and the user must provide a globally
 * accessible wrapper function.
 *
 * The generic driver is initialized by calling NCR5380_init(instance),
 * after setting the appropriate host specific fields and ID.  If the 
 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
 * possible) function may be used.  Before the specific driver initialization
 * code finishes, NCR5380_print_options should be called.
 */

static struct Scsi_Host *first_instance = NULL;
254
static struct scsi_host_template *the_template = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
255 256 257 258 259 260 261

/* Macros ease life... :-) */
#define	SETUP_HOSTDATA(in)				\
    struct NCR5380_hostdata *hostdata =			\
	(struct NCR5380_hostdata *)(in)->hostdata
#define	HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)

262 263 264
#define	NEXT(cmd)		((struct scsi_cmnd *)(cmd)->host_scribble)
#define	SET_NEXT(cmd, next)	((cmd)->host_scribble = (void *)(next))
#define	NEXTADDR(cmd)		((struct scsi_cmnd **)&((cmd)->host_scribble))
Linus Torvalds's avatar
Linus Torvalds committed
265 266 267 268

#define	HOSTNO		instance->host_no
#define	H_NO(cmd)	(cmd)->device->host->host_no

269
#define SGADDR(buffer) (void *)(((unsigned long)sg_virt(((buffer)))))
Linus Torvalds's avatar
Linus Torvalds committed
270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355

#ifdef SUPPORT_TAGS

/*
 * Functions for handling tagged queuing
 * =====================================
 *
 * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
 *
 * Using consecutive numbers for the tags is no good idea in my eyes. There
 * could be wrong re-usings if the counter (8 bit!) wraps and some early
 * command has been preempted for a long time. My solution: a bitfield for
 * remembering used tags.
 *
 * There's also the problem that each target has a certain queue size, but we
 * cannot know it in advance :-( We just see a QUEUE_FULL status being
 * returned. So, in this case, the driver internal queue size assumption is
 * reduced to the number of active tags if QUEUE_FULL is returned by the
 * target. The command is returned to the mid-level, but with status changed
 * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
 * correctly.
 *
 * We're also not allowed running tagged commands as long as an untagged
 * command is active. And REQUEST SENSE commands after a contingent allegiance
 * condition _must_ be untagged. To keep track whether an untagged command has
 * been issued, the host->busy array is still employed, as it is without
 * support for tagged queuing.
 *
 * One could suspect that there are possible race conditions between
 * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
 * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
 * which already guaranteed to be running at most once. It is also the only
 * place where tags/LUNs are allocated. So no other allocation can slip
 * between that pair, there could only happen a reselection, which can free a
 * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
 * important: the tag bit must be cleared before 'nr_allocated' is decreased.
 */

/* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
#undef TAG_NONE
#define TAG_NONE 0xff

/* For the m68k, the number of bits in 'allocated' must be a multiple of 32! */
#if (MAX_TAGS % 32) != 0
#error "MAX_TAGS must be a multiple of 32!"
#endif

typedef struct {
    char	allocated[MAX_TAGS/8];
    int		nr_allocated;
    int		queue_size;
} TAG_ALLOC;

static TAG_ALLOC TagAlloc[8][8]; /* 8 targets and 8 LUNs */


static void __init init_tags( void )
{
    int target, lun;
    TAG_ALLOC *ta;
    
    if (!setup_use_tagged_queuing)
	return;
    
    for( target = 0; target < 8; ++target ) {
	for( lun = 0; lun < 8; ++lun ) {
	    ta = &TagAlloc[target][lun];
	    memset( &ta->allocated, 0, MAX_TAGS/8 );
	    ta->nr_allocated = 0;
	    /* At the beginning, assume the maximum queue size we could
	     * support (MAX_TAGS). This value will be decreased if the target
	     * returns QUEUE_FULL status.
	     */
	    ta->queue_size = MAX_TAGS;
	}
    }
}


/* Check if we can issue a command to this LUN: First see if the LUN is marked
 * busy by an untagged command. If the command should use tagged queuing, also
 * check that there is a free tag and the target's queue won't overflow. This
 * function should be called with interrupts disabled to avoid race
 * conditions.
 */ 

356
static int is_lun_busy(struct scsi_cmnd *cmd, int should_be_tagged)
Linus Torvalds's avatar
Linus Torvalds committed
357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379
{
    SETUP_HOSTDATA(cmd->device->host);

    if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun))
	return( 1 );
    if (!should_be_tagged ||
	!setup_use_tagged_queuing || !cmd->device->tagged_supported)
	return( 0 );
    if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >=
	TagAlloc[cmd->device->id][cmd->device->lun].queue_size ) {
	TAG_PRINTK( "scsi%d: target %d lun %d: no free tags\n",
		    H_NO(cmd), cmd->device->id, cmd->device->lun );
	return( 1 );
    }
    return( 0 );
}


/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
 * must be called before!), or reserve the LUN in 'busy' if the command is
 * untagged.
 */

380
static void cmd_get_tag(struct scsi_cmnd *cmd, int should_be_tagged)
Linus Torvalds's avatar
Linus Torvalds committed
381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411
{
    SETUP_HOSTDATA(cmd->device->host);

    /* If we or the target don't support tagged queuing, allocate the LUN for
     * an untagged command.
     */
    if (!should_be_tagged ||
	!setup_use_tagged_queuing || !cmd->device->tagged_supported) {
	cmd->tag = TAG_NONE;
	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
	TAG_PRINTK( "scsi%d: target %d lun %d now allocated by untagged "
		    "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun );
    }
    else {
	TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];

	cmd->tag = find_first_zero_bit( &ta->allocated, MAX_TAGS );
	set_bit( cmd->tag, &ta->allocated );
	ta->nr_allocated++;
	TAG_PRINTK( "scsi%d: using tag %d for target %d lun %d "
		    "(now %d tags in use)\n",
		    H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun,
		    ta->nr_allocated );
    }
}


/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
 * unlock the LUN.
 */

412
static void cmd_free_tag(struct scsi_cmnd *cmd)
Linus Torvalds's avatar
Linus Torvalds committed
413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455
{
    SETUP_HOSTDATA(cmd->device->host);

    if (cmd->tag == TAG_NONE) {
	hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
	TAG_PRINTK( "scsi%d: target %d lun %d untagged cmd finished\n",
		    H_NO(cmd), cmd->device->id, cmd->device->lun );
    }
    else if (cmd->tag >= MAX_TAGS) {
	printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
		H_NO(cmd), cmd->tag );
    }
    else {
	TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
	clear_bit( cmd->tag, &ta->allocated );
	ta->nr_allocated--;
	TAG_PRINTK( "scsi%d: freed tag %d for target %d lun %d\n",
		    H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun );
    }
}


static void free_all_tags( void )
{
    int target, lun;
    TAG_ALLOC *ta;

    if (!setup_use_tagged_queuing)
	return;
    
    for( target = 0; target < 8; ++target ) {
	for( lun = 0; lun < 8; ++lun ) {
	    ta = &TagAlloc[target][lun];
	    memset( &ta->allocated, 0, MAX_TAGS/8 );
	    ta->nr_allocated = 0;
	}
    }
}

#endif /* SUPPORT_TAGS */


/*
456
 * Function : void initialize_SCp(struct scsi_cmnd *cmd)
Linus Torvalds's avatar
Linus Torvalds committed
457 458 459 460
 *
 * Purpose : initialize the saved data pointers for cmd to point to the 
 *	start of the buffer.
 *
461
 * Inputs : cmd - struct scsi_cmnd structure to have pointers reset.
Linus Torvalds's avatar
Linus Torvalds committed
462 463
 */

464
static __inline__ void initialize_SCp(struct scsi_cmnd *cmd)
Linus Torvalds's avatar
Linus Torvalds committed
465 466 467 468 469 470
{
    /* 
     * Initialize the Scsi Pointer field so that all of the commands in the 
     * various queues are valid.
     */

471 472 473
    if (scsi_bufflen(cmd)) {
	cmd->SCp.buffer = scsi_sglist(cmd);
	cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
Linus Torvalds's avatar
Linus Torvalds committed
474 475 476 477 478
	cmd->SCp.ptr = (char *) SGADDR(cmd->SCp.buffer);
	cmd->SCp.this_residual = cmd->SCp.buffer->length;
    } else {
	cmd->SCp.buffer = NULL;
	cmd->SCp.buffers_residual = 0;
479 480
	cmd->SCp.ptr = NULL;
	cmd->SCp.this_residual = 0;
Linus Torvalds's avatar
Linus Torvalds committed
481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595
    }
    
}

#include <linux/delay.h>

#if 1
static struct {
    unsigned char mask;
    const char * name;} 
signals[] = {{ SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" }, 
    { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD,  "CD" }, { SR_IO, "IO" }, 
    { SR_SEL, "SEL" }, {0, NULL}}, 
basrs[] = {{BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}},
icrs[] = {{ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
    {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"}, 
    {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"}, 
    {0, NULL}},
mrs[] = {{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"}, 
    {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR, 
    "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
    {MR_MONITOR_BSY, "MODE MONITOR BSY"},
    {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"}, 
    {0, NULL}};

/*
 * Function : void NCR5380_print(struct Scsi_Host *instance)
 *
 * Purpose : print the SCSI bus signals for debugging purposes
 *
 * Input : instance - which NCR5380
 */

static void NCR5380_print(struct Scsi_Host *instance) {
    unsigned char status, data, basr, mr, icr, i;
    unsigned long flags;

    local_irq_save(flags);
    data = NCR5380_read(CURRENT_SCSI_DATA_REG);
    status = NCR5380_read(STATUS_REG);
    mr = NCR5380_read(MODE_REG);
    icr = NCR5380_read(INITIATOR_COMMAND_REG);
    basr = NCR5380_read(BUS_AND_STATUS_REG);
    local_irq_restore(flags);
    printk("STATUS_REG: %02x ", status);
    for (i = 0; signals[i].mask ; ++i) 
	if (status & signals[i].mask)
	    printk(",%s", signals[i].name);
    printk("\nBASR: %02x ", basr);
    for (i = 0; basrs[i].mask ; ++i) 
	if (basr & basrs[i].mask)
	    printk(",%s", basrs[i].name);
    printk("\nICR: %02x ", icr);
    for (i = 0; icrs[i].mask; ++i) 
	if (icr & icrs[i].mask)
	    printk(",%s", icrs[i].name);
    printk("\nMODE: %02x ", mr);
    for (i = 0; mrs[i].mask; ++i) 
	if (mr & mrs[i].mask)
	    printk(",%s", mrs[i].name);
    printk("\n");
}

static struct {
    unsigned char value;
    const char *name;
} phases[] = {
    {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
    {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
    {PHASE_UNKNOWN, "UNKNOWN"}};

/* 
 * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
 *
 * Purpose : print the current SCSI phase for debugging purposes
 *
 * Input : instance - which NCR5380
 */

static void NCR5380_print_phase(struct Scsi_Host *instance)
{
    unsigned char status;
    int i;

    status = NCR5380_read(STATUS_REG);
    if (!(status & SR_REQ)) 
	printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
    else {
	for (i = 0; (phases[i].value != PHASE_UNKNOWN) && 
	    (phases[i].value != (status & PHASE_MASK)); ++i); 
	printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
    }
}

#else /* !NDEBUG */

/* dummies... */
__inline__ void NCR5380_print(struct Scsi_Host *instance) { };
__inline__ void NCR5380_print_phase(struct Scsi_Host *instance) { };

#endif

/*
 * ++roman: New scheme of calling NCR5380_main()
 * 
 * If we're not in an interrupt, we can call our main directly, it cannot be
 * already running. Else, we queue it on a task queue, if not 'main_running'
 * tells us that a lower level is already executing it. This way,
 * 'main_running' needs not be protected in a special way.
 *
 * queue_main() is a utility function for putting our main onto the task
 * queue, if main_running is false. It should be called only from a
 * interrupt or bottom half.
 */

596
#include <linux/gfp.h>
Linus Torvalds's avatar
Linus Torvalds committed
597 598 599 600
#include <linux/workqueue.h>
#include <linux/interrupt.h>

static volatile int main_running = 0;
601
static DECLARE_WORK(NCR5380_tqueue, NCR5380_main);
Linus Torvalds's avatar
Linus Torvalds committed
602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663

static __inline__ void queue_main(void)
{
    if (!main_running) {
	/* If in interrupt and NCR5380_main() not already running,
	   queue it on the 'immediate' task queue, to be processed
	   immediately after the current interrupt processing has
	   finished. */
	schedule_work(&NCR5380_tqueue);
    }
    /* else: nothing to do: the running NCR5380_main() will pick up
       any newly queued command. */
}


static inline void NCR5380_all_init (void)
{
    static int done = 0;
    if (!done) {
	INI_PRINTK("scsi : NCR5380_all_init()\n");
	done = 1;
    }
}

 
/*
 * Function : void NCR58380_print_options (struct Scsi_Host *instance)
 *
 * Purpose : called by probe code indicating the NCR5380 driver
 *	     options that were selected.
 *
 * Inputs : instance, pointer to this instance.  Unused.
 */

static void __init NCR5380_print_options (struct Scsi_Host *instance)
{
    printk(" generic options"
#ifdef AUTOSENSE 
    " AUTOSENSE"
#endif
#ifdef REAL_DMA
    " REAL DMA"
#endif
#ifdef PARITY
    " PARITY"
#endif
#ifdef SUPPORT_TAGS
    " SCSI-2 TAGGED QUEUING"
#endif
    );
    printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
}

/*
 * Function : void NCR5380_print_status (struct Scsi_Host *instance)
 *
 * Purpose : print commands in the various queues, called from
 *	NCR5380_abort and NCR5380_debug to aid debugging.
 *
 * Inputs : instance, pointer to this instance.  
 */

664
static void lprint_Scsi_Cmnd(Scsi_Cmnd *cmd)
Linus Torvalds's avatar
Linus Torvalds committed
665
{
666 667 668 669 670 671 672 673 674 675
	int i, s;
	unsigned char *command;
	printk("scsi%d: destination target %d, lun %d\n",
		H_NO(cmd), cmd->device->id, cmd->device->lun);
	printk(KERN_CONT "        command = ");
	command = cmd->cmnd;
	printk(KERN_CONT "%2d (0x%02x)", command[0], command[0]);
	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
		printk(KERN_CONT " %02x", command[i]);
	printk("\n");
Linus Torvalds's avatar
Linus Torvalds committed
676 677
}

678
static void NCR5380_print_status(struct Scsi_Host *instance)
Linus Torvalds's avatar
Linus Torvalds committed
679
{
680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707
	struct NCR5380_hostdata *hostdata;
	Scsi_Cmnd *ptr;
	unsigned long flags;

	NCR_PRINT(NDEBUG_ANY);
	NCR_PRINT_PHASE(NDEBUG_ANY);

	hostdata = (struct NCR5380_hostdata *)instance->hostdata;

	printk("\nNCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
	local_irq_save(flags);
	printk("NCR5380: coroutine is%s running.\n",
		main_running ? "" : "n't");
	if (!hostdata->connected)
		printk("scsi%d: no currently connected command\n", HOSTNO);
	else
		lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected);
	printk("scsi%d: issue_queue\n", HOSTNO);
	for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
		lprint_Scsi_Cmnd(ptr);

	printk("scsi%d: disconnected_queue\n", HOSTNO);
	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
	     ptr = NEXT(ptr))
		lprint_Scsi_Cmnd(ptr);

	local_irq_restore(flags);
	printk("\n");
Linus Torvalds's avatar
Linus Torvalds committed
708 709
}

710
static void show_Scsi_Cmnd(Scsi_Cmnd *cmd, struct seq_file *m)
Linus Torvalds's avatar
Linus Torvalds committed
711
{
712 713 714 715 716 717 718 719 720 721
	int i, s;
	unsigned char *command;
	seq_printf(m, "scsi%d: destination target %d, lun %d\n",
		H_NO(cmd), cmd->device->id, cmd->device->lun);
	seq_printf(m, "        command = ");
	command = cmd->cmnd;
	seq_printf(m, "%2d (0x%02x)", command[0], command[0]);
	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
		seq_printf(m, " %02x", command[i]);
	seq_printf(m, "\n");
Linus Torvalds's avatar
Linus Torvalds committed
722 723
}

724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751
static int NCR5380_show_info(struct seq_file *m, struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata;
	Scsi_Cmnd *ptr;
	unsigned long flags;

	hostdata = (struct NCR5380_hostdata *)instance->hostdata;

	seq_printf(m, "NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
	local_irq_save(flags);
	seq_printf(m, "NCR5380: coroutine is%s running.\n",
		main_running ? "" : "n't");
	if (!hostdata->connected)
		seq_printf(m, "scsi%d: no currently connected command\n", HOSTNO);
	else
		show_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, m);
	seq_printf(m, "scsi%d: issue_queue\n", HOSTNO);
	for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
		show_Scsi_Cmnd(ptr, m);

	seq_printf(m, "scsi%d: disconnected_queue\n", HOSTNO);
	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
	     ptr = NEXT(ptr))
		show_Scsi_Cmnd(ptr, m);

	local_irq_restore(flags);
	return 0;
}
Linus Torvalds's avatar
Linus Torvalds committed
752 753 754 755 756 757 758 759 760 761 762 763 764

/* 
 * Function : void NCR5380_init (struct Scsi_Host *instance)
 *
 * Purpose : initializes *instance and corresponding 5380 chip.
 *
 * Inputs : instance - instantiation of the 5380 driver.  
 *
 * Notes : I assume that the host, hostno, and id bits have been
 * 	set correctly.  I don't care about the irq and other fields. 
 * 
 */

765
static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
Linus Torvalds's avatar
Linus Torvalds committed
766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812
{
    int i;
    SETUP_HOSTDATA(instance);

    NCR5380_all_init();

    hostdata->aborted = 0;
    hostdata->id_mask = 1 << instance->this_id;
    hostdata->id_higher_mask = 0;
    for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
	if (i > hostdata->id_mask)
	    hostdata->id_higher_mask |= i;
    for (i = 0; i < 8; ++i)
	hostdata->busy[i] = 0;
#ifdef SUPPORT_TAGS
    init_tags();
#endif
#if defined (REAL_DMA)
    hostdata->dma_len = 0;
#endif
    hostdata->targets_present = 0;
    hostdata->connected = NULL;
    hostdata->issue_queue = NULL;
    hostdata->disconnected_queue = NULL;
    hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;

    if (!the_template) {
	the_template = instance->hostt;
	first_instance = instance;
    }
	

#ifndef AUTOSENSE
    if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
	 printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
	        "        without AUTOSENSE option, contingent allegiance conditions may\n"
	        "        be incorrectly cleared.\n", HOSTNO);
#endif /* def AUTOSENSE */

    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
    NCR5380_write(MODE_REG, MR_BASE);
    NCR5380_write(TARGET_COMMAND_REG, 0);
    NCR5380_write(SELECT_ENABLE_REG, 0);

    return 0;
}

813 814 815 816 817
static void NCR5380_exit(struct Scsi_Host *instance)
{
	/* Empty, as we didn't schedule any delayed work */
}

Linus Torvalds's avatar
Linus Torvalds committed
818
/* 
819 820
 * Function : int NCR5380_queue_command (struct scsi_cmnd *cmd,
 *	void (*done)(struct scsi_cmnd *))
Linus Torvalds's avatar
Linus Torvalds committed
821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836
 *
 * Purpose :  enqueues a SCSI command
 *
 * Inputs : cmd - SCSI command, done - function called on completion, with
 *	a pointer to the command descriptor.
 * 
 * Returns : 0
 *
 * Side effects : 
 *      cmd is added to the per instance issue_queue, with minor 
 *	twiddling done to the host specific fields of cmd.  If the 
 *	main coroutine is not running, it is restarted.
 *
 */

/* Only make static if a wrapper function is used */
Jeff Garzik's avatar
Jeff Garzik committed
837
static int NCR5380_queue_command_lck(struct scsi_cmnd *cmd,
838
				 void (*done)(struct scsi_cmnd *))
Linus Torvalds's avatar
Linus Torvalds committed
839 840
{
    SETUP_HOSTDATA(cmd->device->host);
841
    struct scsi_cmnd *tmp;
Linus Torvalds's avatar
Linus Torvalds committed
842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864
    unsigned long flags;

#if (NDEBUG & NDEBUG_NO_WRITE)
    switch (cmd->cmnd[0]) {
    case WRITE_6:
    case WRITE_10:
	printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
	       H_NO(cmd));
	cmd->result = (DID_ERROR << 16);
	done(cmd);
	return 0;
    }
#endif /* (NDEBUG & NDEBUG_NO_WRITE) */


#ifdef NCR5380_STATS
# if 0
    if (!hostdata->connected && !hostdata->issue_queue &&
	!hostdata->disconnected_queue) {
	hostdata->timebase = jiffies;
    }
# endif
# ifdef NCR5380_STAT_LIMIT
865
    if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
Linus Torvalds's avatar
Linus Torvalds committed
866 867 868 869 870 871 872
# endif
	switch (cmd->cmnd[0])
	{
	    case WRITE:
	    case WRITE_6:
	    case WRITE_10:
		hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
873
		hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
Linus Torvalds's avatar
Linus Torvalds committed
874 875 876 877 878 879
		hostdata->pendingw++;
		break;
	    case READ:
	    case READ_6:
	    case READ_10:
		hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
880
		hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
Linus Torvalds's avatar
Linus Torvalds committed
881 882 883 884 885 886 887 888 889 890
		hostdata->pendingr++;
		break;
	}
#endif

    /* 
     * We use the host_scribble field as a pointer to the next command  
     * in a queue 
     */

891
    SET_NEXT(cmd, NULL);
Linus Torvalds's avatar
Linus Torvalds committed
892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918
    cmd->scsi_done = done;

    cmd->result = 0;


    /* 
     * Insert the cmd into the issue queue. Note that REQUEST SENSE 
     * commands are added to the head of the queue since any command will
     * clear the contingent allegiance condition that exists and the 
     * sense data is only guaranteed to be valid while the condition exists.
     */

    local_irq_save(flags);
    /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
     * Otherwise a running NCR5380_main may steal the lock.
     * Lock before actually inserting due to fairness reasons explained in
     * atari_scsi.c. If we insert first, then it's impossible for this driver
     * to release the lock.
     * Stop timer for this command while waiting for the lock, or timeouts
     * may happen (and they really do), and it's no good if the command doesn't
     * appear in any of the queues.
     * ++roman: Just disabling the NCR interrupt isn't sufficient here,
     * because also a timer int can trigger an abort or reset, which would
     * alter queues and touch the lock.
     */
    if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
	LIST(cmd, hostdata->issue_queue);
919
	SET_NEXT(cmd, hostdata->issue_queue);
Linus Torvalds's avatar
Linus Torvalds committed
920 921
	hostdata->issue_queue = cmd;
    } else {
922
	for (tmp = (struct scsi_cmnd *)hostdata->issue_queue;
Linus Torvalds's avatar
Linus Torvalds committed
923 924 925
	     NEXT(tmp); tmp = NEXT(tmp))
	    ;
	LIST(cmd, tmp);
926
	SET_NEXT(tmp, cmd);
Linus Torvalds's avatar
Linus Torvalds committed
927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947
    }

    local_irq_restore(flags);

    QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
	      (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");

    /* If queue_command() is called from an interrupt (real one or bottom
     * half), we let queue_main() do the job of taking care about main. If it
     * is already running, this is a no-op, else main will be queued.
     *
     * If we're not in an interrupt, we can call NCR5380_main()
     * unconditionally, because it cannot be already running.
     */
    if (in_interrupt() || ((flags >> 8) & 7) >= 6)
	queue_main();
    else
	NCR5380_main(NULL);
    return 0;
}

Jeff Garzik's avatar
Jeff Garzik committed
948 949
static DEF_SCSI_QCMD(NCR5380_queue_command)

Linus Torvalds's avatar
Linus Torvalds committed
950 951 952 953 954 955 956 957 958 959 960 961
/*
 * Function : NCR5380_main (void) 
 *
 * Purpose : NCR5380_main is a coroutine that runs as long as more work can 
 *	be done on the NCR5380 host adapters in a system.  Both 
 *	NCR5380_queue_command() and NCR5380_intr() will try to start it 
 *	in case it is not running.
 * 
 * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should 
 *  reenable them.  This prevents reentrancy and kernel stack overflow.
 */ 	
    
962
static void NCR5380_main (struct work_struct *bl)
Linus Torvalds's avatar
Linus Torvalds committed
963
{
964
    struct scsi_cmnd *tmp, *prev;
Linus Torvalds's avatar
Linus Torvalds committed
965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006
    struct Scsi_Host *instance = first_instance;
    struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
    int done;
    unsigned long flags;
    
    /*
     * We run (with interrupts disabled) until we're sure that none of 
     * the host adapters have anything that can be done, at which point 
     * we set main_running to 0 and exit.
     *
     * Interrupts are enabled before doing various other internal 
     * instructions, after we've decided that we need to run through
     * the loop again.
     *
     * this should prevent any race conditions.
     * 
     * ++roman: Just disabling the NCR interrupt isn't sufficient here,
     * because also a timer int can trigger an abort or reset, which can
     * alter queues and touch the Falcon lock.
     */

    /* Tell int handlers main() is now already executing.  Note that
       no races are possible here. If an int comes in before
       'main_running' is set here, and queues/executes main via the
       task queue, it doesn't do any harm, just this instance of main
       won't find any work left to do. */
    if (main_running)
    	return;
    main_running = 1;

    local_save_flags(flags);
    do {
	local_irq_disable(); /* Freeze request queues */
	done = 1;
	
	if (!hostdata->connected) {
	    MAIN_PRINTK( "scsi%d: not connected\n", HOSTNO );
	    /*
	     * Search through the issue_queue for a command destined
	     * for a target that's not busy.
	     */
#if (NDEBUG & NDEBUG_LISTS)
1007
	    for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1008 1009 1010 1011
		 tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
		;
	    if ((tmp == prev) && tmp) printk(" LOOP\n");/* else printk("\n");*/
#endif
1012
	    for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
Linus Torvalds's avatar
Linus Torvalds committed
1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
		 prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp) ) {

#if (NDEBUG & NDEBUG_LISTS)
		if (prev != tmp)
		    printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
			   tmp, tmp->target, hostdata->busy[tmp->target],
			   tmp->lun);
#endif
		/*  When we find one, remove it from the issue queue. */
		/* ++guenther: possible race with Falcon locking */
		if (
#ifdef SUPPORT_TAGS
		    !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
#else
		    !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
#endif
		    ) {
		    /* ++guenther: just to be sure, this must be atomic */
		    local_irq_disable();
		    if (prev) {
		        REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1034
			SET_NEXT(prev, NEXT(tmp));
Linus Torvalds's avatar
Linus Torvalds committed
1035 1036 1037 1038
		    } else {
		        REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
			hostdata->issue_queue = NEXT(tmp);
		    }
1039
		    SET_NEXT(tmp, NULL);
Linus Torvalds's avatar
Linus Torvalds committed
1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072
		    
		    /* reenable interrupts after finding one */
		    local_irq_restore(flags);
		    
		    /* 
		     * Attempt to establish an I_T_L nexus here. 
		     * On success, instance->hostdata->connected is set.
		     * On failure, we must add the command back to the
		     *   issue queue so we can keep trying.	
		     */
		    MAIN_PRINTK("scsi%d: main(): command for target %d "
				"lun %d removed from issue_queue\n",
				HOSTNO, tmp->target, tmp->lun);
		    /* 
		     * REQUEST SENSE commands are issued without tagged
		     * queueing, even on SCSI-II devices because the 
		     * contingent allegiance condition exists for the 
		     * entire unit.
		     */
		    /* ++roman: ...and the standard also requires that
		     * REQUEST SENSE command are untagged.
		     */
		    
#ifdef SUPPORT_TAGS
		    cmd_get_tag( tmp, tmp->cmnd[0] != REQUEST_SENSE );
#endif
		    if (!NCR5380_select(instance, tmp, 
			    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : 
			    TAG_NEXT)) {
			break;
		    } else {
			local_irq_disable();
			LIST(tmp, hostdata->issue_queue);
1073
			SET_NEXT(tmp, hostdata->issue_queue);
Linus Torvalds's avatar
Linus Torvalds committed
1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
			hostdata->issue_queue = tmp;
#ifdef SUPPORT_TAGS
			cmd_free_tag( tmp );
#endif
			local_irq_restore(flags);
			MAIN_PRINTK("scsi%d: main(): select() failed, "
				    "returned to issue_queue\n", HOSTNO);
			if (hostdata->connected)
			    break;
		    }
		} /* if target/lun/target queue is not busy */
	    } /* for issue_queue */
	} /* if (!hostdata->connected) */
	if (hostdata->connected 
#ifdef REAL_DMA
	    && !hostdata->dma_len
#endif
	    ) {
	    local_irq_restore(flags);
	    MAIN_PRINTK("scsi%d: main: performing information transfer\n",
			HOSTNO);
	    NCR5380_information_transfer(instance);
	    MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
	    done = 0;
	}
    } while (!done);

    /* Better allow ints _after_ 'main_running' has been cleared, else
       an interrupt could believe we'll pick up the work it left for
       us, but we won't see it anymore here... */
    main_running = 0;
    local_irq_restore(flags);
}


#ifdef REAL_DMA
/*
 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
 *
 * Purpose : Called by interrupt handler when DMA finishes or a phase
 *	mismatch occurs (which would finish the DMA transfer).  
 *
 * Inputs : instance - this instance of the NCR5380.
 *
 */

static void NCR5380_dma_complete( struct Scsi_Host *instance )
{
    SETUP_HOSTDATA(instance);
    int           transfered;
    unsigned char **data;
    volatile int  *count;

    if (!hostdata->connected) {
	printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
	       "no connected cmd\n", HOSTNO);
	return;
    }

    DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
	       HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
	       NCR5380_read(STATUS_REG));

    if((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
	    printk("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n", HOSTNO);
	    printk("please e-mail sammy@sammy.net with a description of how this\n");
	    printk("error was produced.\n");
	    BUG();
    }

    /* make sure we're not stuck in a data phase */
    if((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH |
					    BASR_ACK)) ==
       (BASR_PHASE_MATCH | BASR_ACK)) {
	    printk("scsi%d: BASR %02x\n", HOSTNO, NCR5380_read(BUS_AND_STATUS_REG));
	    printk("scsi%d: bus stuck in data phase -- probably a single byte "
		   "overrun!\n", HOSTNO);
	    printk("not prepared for this error!\n");
	    printk("please e-mail sammy@sammy.net with a description of how this\n");
	    printk("error was produced.\n");
	    BUG();
    }



    (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
    NCR5380_write(MODE_REG, MR_BASE);
    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

    transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
    hostdata->dma_len = 0;

    data = (unsigned char **) &(hostdata->connected->SCp.ptr);
    count = &(hostdata->connected->SCp.this_residual);
    *data += transfered;
    *count -= transfered;

}
#endif /* REAL_DMA */


/*
 * Function : void NCR5380_intr (int irq)
 * 
 * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 *	from the disconnected queue, and restarting NCR5380_main() 
 *	as required.
 *
 * Inputs : int irq, irq that caused this interrupt.
 *
 */

1186
static irqreturn_t NCR5380_intr (int irq, void *dev_id)
Linus Torvalds's avatar
Linus Torvalds committed
1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
{
    struct Scsi_Host *instance = first_instance;
    int done = 1, handled = 0;
    unsigned char basr;

    INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);

    /* Look for pending interrupts */
    basr = NCR5380_read(BUS_AND_STATUS_REG);
    INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
    /* dispatch to appropriate routine if found and done=0 */
    if (basr & BASR_IRQ) {
	NCR_PRINT(NDEBUG_INTR);
	if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
	    done = 0;
1202
//	    ENABLE_IRQ();
Linus Torvalds's avatar
Linus Torvalds committed
1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234
	    INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
	    NCR5380_reselect(instance);
	    (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	}
	else if (basr & BASR_PARITY_ERROR) {
	    INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
	    (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	}
	else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
	    INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
	    (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	}
	else {
	    /*  
	     * The rest of the interrupt conditions can occur only during a
	     * DMA transfer
	     */

#if defined(REAL_DMA)
	    /*
	     * We should only get PHASE MISMATCH and EOP interrupts if we have
	     * DMA enabled, so do a sanity check based on the current setting
	     * of the MODE register.
	     */

	    if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
		((basr & BASR_END_DMA_TRANSFER) || 
		 !(basr & BASR_PHASE_MATCH))) {
		    
		INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
		NCR5380_dma_complete( instance );
		done = 0;
1235
//		ENABLE_IRQ();
Linus Torvalds's avatar
Linus Torvalds committed
1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272
	    } else
#endif /* REAL_DMA */
	    {
/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
		if (basr & BASR_PHASE_MATCH)
		   INT_PRINTK("scsi%d: unknown interrupt, "
			   "BASR 0x%x, MR 0x%x, SR 0x%x\n",
			   HOSTNO, basr, NCR5380_read(MODE_REG),
			   NCR5380_read(STATUS_REG));
		(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_DMA_ENABLE;
#endif
	    }
	} /* if !(SELECTION || PARITY) */
	handled = 1;
    } /* BASR & IRQ */
    else {

	printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
	       "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
	       NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
	(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_DMA_ENABLE;
#endif
    }
    
    if (!done) {
	INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
	/* Put a call to NCR5380_main() on the queue... */
	queue_main();
    }
    return IRQ_RETVAL(handled);
}

#ifdef NCR5380_STATS
1273 1274
static void collect_stats(struct NCR5380_hostdata *hostdata,
			  struct scsi_cmnd *cmd)
Linus Torvalds's avatar
Linus Torvalds committed
1275 1276
{
# ifdef NCR5380_STAT_LIMIT
1277
    if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
Linus Torvalds's avatar
Linus Torvalds committed
1278 1279 1280 1281 1282 1283 1284
# endif
	switch (cmd->cmnd[0])
	{
	    case WRITE:
	    case WRITE_6:
	    case WRITE_10:
		hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
1285
		/*hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);*/
Linus Torvalds's avatar
Linus Torvalds committed
1286 1287 1288 1289 1290 1291
		hostdata->pendingw--;
		break;
	    case READ:
	    case READ_6:
	    case READ_10:
		hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
1292
		/*hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);*/
Linus Torvalds's avatar
Linus Torvalds committed
1293 1294 1295 1296 1297 1298 1299
		hostdata->pendingr--;
		break;
	}
}
#endif

/* 
1300 1301
 * Function : int NCR5380_select(struct Scsi_Host *instance,
 * 				 struct scsi_cmnd *cmd,	int tag);
Linus Torvalds's avatar
Linus Torvalds committed
1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329
 *
 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
 *	including ARBITRATION, SELECTION, and initial message out for 
 *	IDENTIFY and queue messages. 
 *
 * Inputs : instance - instantiation of the 5380 driver on which this 
 * 	target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for 
 *	new tag, TAG_NONE for untagged queueing, otherwise set to the tag for 
 *	the command that is presently connected.
 * 
 * Returns : -1 if selection could not execute for some reason,
 *	0 if selection succeeded or failed because the target 
 * 	did not respond.
 *
 * Side effects : 
 * 	If bus busy, arbitration failed, etc, NCR5380_select() will exit 
 *		with registers as they should have been on entry - ie
 *		SELECT_ENABLE will be set appropriately, the NCR5380
 *		will cease to drive any SCSI bus signals.
 *
 *	If successful : I_T_L or I_T_L_Q nexus will be established, 
 *		instance->connected will be set to cmd.  
 * 		SELECT interrupt will be disabled.
 *
 *	If failed (no target) : cmd->scsi_done() will be called, and the 
 *		cmd->result host byte set to DID_BAD_TARGET.
 */

1330 1331
static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd,
			  int tag)
Linus Torvalds's avatar
Linus Torvalds committed
1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367
{
    SETUP_HOSTDATA(instance);
    unsigned char tmp[3], phase;
    unsigned char *data;
    int len;
    unsigned long timeout;
    unsigned long flags;

    hostdata->restart_select = 0;
    NCR_PRINT(NDEBUG_ARBITRATION);
    ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
	       instance->this_id);

    /* 
     * Set the phase bits to 0, otherwise the NCR5380 won't drive the 
     * data bus during SELECTION.
     */

    local_irq_save(flags);
    if (hostdata->connected) {
	local_irq_restore(flags);
	return -1;
    }
    NCR5380_write(TARGET_COMMAND_REG, 0);


    /* 
     * Start arbitration.
     */
    
    NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
    NCR5380_write(MODE_REG, MR_ARBITRATE);

    local_irq_restore(flags);

    /* Wait for arbitration logic to complete */
1368
#ifdef NCR_TIMEOUT
Linus Torvalds's avatar
Linus Torvalds committed
1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526
    {
      unsigned long timeout = jiffies + 2*NCR_TIMEOUT;

      while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
	   && time_before(jiffies, timeout) && !hostdata->connected)
	;
      if (time_after_eq(jiffies, timeout))
      {
	printk("scsi : arbitration timeout at %d\n", __LINE__);
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	return -1;
      }
    }
#else /* NCR_TIMEOUT */
    while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
	 && !hostdata->connected);
#endif

    ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);

    if (hostdata->connected) {
	NCR5380_write(MODE_REG, MR_BASE); 
	return -1;
    }
    /* 
     * The arbitration delay is 2.2us, but this is a minimum and there is 
     * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
     * the integral nature of udelay().
     *
     */

    udelay(3);

    /* Check for lost arbitration */
    if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
	(NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
	(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
	hostdata->connected) {
	NCR5380_write(MODE_REG, MR_BASE); 
	ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
		   HOSTNO);
	return -1;
    }

     /* after/during arbitration, BSY should be asserted.
	IBM DPES-31080 Version S31Q works now */
     /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL |
					 ICR_ASSERT_BSY ) ;
    
    if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
	hostdata->connected) {
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
		   HOSTNO);
	return -1;
    }

    /* 
     * Again, bus clear + bus settle time is 1.2us, however, this is 
     * a minimum so we'll udelay ceil(1.2)
     */

#ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
    /* ++roman: But some targets (see above :-) seem to need a bit more... */
    udelay(15);
#else
    udelay(2);
#endif
    
    if (hostdata->connected) {
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	return -1;
    }

    ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);

    /* 
     * Now that we have won arbitration, start Selection process, asserting 
     * the host and target ID's on the SCSI bus.
     */

    NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));

    /* 
     * Raise ATN while SEL is true before BSY goes false from arbitration,
     * since this is the only way to guarantee that we'll get a MESSAGE OUT
     * phase immediately after selection.
     */

    NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | 
	ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
    NCR5380_write(MODE_REG, MR_BASE);

    /* 
     * Reselect interrupts must be turned off prior to the dropping of BSY,
     * otherwise we will trigger an interrupt.
     */

    if (hostdata->connected) {
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	return -1;
    }

    NCR5380_write(SELECT_ENABLE_REG, 0);

    /*
     * The initiator shall then wait at least two deskew delays and release 
     * the BSY signal.
     */
    udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */

    /* Reset BSY */
    NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | 
	ICR_ASSERT_ATN | ICR_ASSERT_SEL));

    /* 
     * Something weird happens when we cease to drive BSY - looks
     * like the board/chip is letting us do another read before the 
     * appropriate propagation delay has expired, and we're confusing
     * a BSY signal from ourselves as the target's response to SELECTION.
     *
     * A small delay (the 'C++' frontend breaks the pipeline with an
     * unnecessary jump, making it work on my 386-33/Trantor T128, the
     * tighter 'C' code breaks and requires this) solves the problem - 
     * the 1 us delay is arbitrary, and only used because this delay will 
     * be the same on other platforms and since it works here, it should 
     * work there.
     *
     * wingel suggests that this could be due to failing to wait
     * one deskew delay.
     */

    udelay(1);

    SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);

    /* 
     * The SCSI specification calls for a 250 ms timeout for the actual 
     * selection.
     */

    timeout = jiffies + 25; 

    /* 
     * XXX very interesting - we're seeing a bounce where the BSY we 
     * asserted is being reflected / still asserted (propagation delay?)
     * and it's detecting as true.  Sigh.
     */

#if 0
    /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
     * IO while SEL is true. But again, there are some disks out the in the
     * world that do that nevertheless. (Somebody claimed that this announces
     * reselection capability of the target.) So we better skip that test and
1527
     * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
Linus Torvalds's avatar
Linus Torvalds committed
1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645
     */

    while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & 
	(SR_BSY | SR_IO)));

    if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == 
	    (SR_SEL | SR_IO)) {
	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	    NCR5380_reselect(instance);
	    printk (KERN_ERR "scsi%d: reselection after won arbitration?\n",
		    HOSTNO);
	    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	    return -1;
    }
#else
    while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY));
#endif

    /* 
     * No less than two deskew delays after the initiator detects the 
     * BSY signal is true, it shall release the SEL signal and may 
     * change the DATA BUS.                                     -wingel
     */

    udelay(1);

    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);

    if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	if (hostdata->targets_present & (1 << cmd->device->id)) {
	    printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
	    if (hostdata->restart_select)
		printk(KERN_NOTICE "\trestart select\n");
	    NCR_PRINT(NDEBUG_ANY);
	    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	    return -1;
	}
	cmd->result = DID_BAD_TARGET << 16;
#ifdef NCR5380_STATS
	collect_stats(hostdata, cmd);
#endif
#ifdef SUPPORT_TAGS
	cmd_free_tag( cmd );
#endif
	cmd->scsi_done(cmd);
	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	return 0;
    } 

    hostdata->targets_present |= (1 << cmd->device->id);

    /*
     * Since we followed the SCSI spec, and raised ATN while SEL 
     * was true but before BSY was false during selection, the information
     * transfer phase should be a MESSAGE OUT phase so that we can send the
     * IDENTIFY message.
     * 
     * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
     * message (2 bytes) with a tag ID that we increment with every command
     * until it wraps back to 0.
     *
     * XXX - it turns out that there are some broken SCSI-II devices,
     *	     which claim to support tagged queuing but fail when more than
     *	     some number of commands are issued at once.
     */

    /* Wait for start of REQ/ACK handshake */
    while (!(NCR5380_read(STATUS_REG) & SR_REQ));

    SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
	       HOSTNO, cmd->device->id);
    tmp[0] = IDENTIFY(1, cmd->device->lun);

#ifdef SUPPORT_TAGS
    if (cmd->tag != TAG_NONE) {
	tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
	tmp[2] = cmd->tag;
	len = 3;
    } else 
	len = 1;
#else
    len = 1;
    cmd->tag=0;
#endif /* SUPPORT_TAGS */

    /* Send message(s) */
    data = tmp;
    phase = PHASE_MSGOUT;
    NCR5380_transfer_pio(instance, &phase, &len, &data);
    SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
    /* XXX need to handle errors here */
    hostdata->connected = cmd;
#ifndef SUPPORT_TAGS
    hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
#endif    
#ifdef SUN3_SCSI_VME
    dregs->csr |= CSR_INTR;
#endif
    initialize_SCp(cmd);


    return 0;
}

/* 
 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance, 
 *      unsigned char *phase, int *count, unsigned char **data)
 *
 * Purpose : transfers data in given phase using polled I/O
 *
 * Inputs : instance - instance of driver, *phase - pointer to 
 *	what phase is expected, *count - pointer to number of 
 *	bytes to transfer, **data - pointer to data pointer.
 * 
 * Returns : -1 when different phase is entered without transferring
1646
 *	maximum number of bytes, 0 if all bytes are transferred or exit
Linus Torvalds's avatar
Linus Torvalds committed
1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794
 *	is in same phase.
 *
 * 	Also, *phase, *count, *data are modified in place.
 *
 * XXX Note : handling for bus free may be useful.
 */

/*
 * Note : this code is not as quick as it could be, however it 
 * IS 100% reliable, and for the actual data transfer where speed
 * counts, we will always do a pseudo DMA or DMA transfer.
 */

static int NCR5380_transfer_pio( struct Scsi_Host *instance, 
				 unsigned char *phase, int *count,
				 unsigned char **data)
{
    register unsigned char p = *phase, tmp;
    register int c = *count;
    register unsigned char *d = *data;

    /* 
     * The NCR5380 chip will only drive the SCSI bus when the 
     * phase specified in the appropriate bits of the TARGET COMMAND
     * REGISTER match the STATUS REGISTER
     */

    NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));

    do {
	/* 
	 * Wait for assertion of REQ, after which the phase bits will be 
	 * valid 
	 */
	while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ));

	HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);

	/* Check for phase mismatch */	
	if ((tmp & PHASE_MASK) != p) {
	    PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
	    NCR_PRINT_PHASE(NDEBUG_PIO);
	    break;
	}

	/* Do actual transfer from SCSI bus to / from memory */
	if (!(p & SR_IO)) 
	    NCR5380_write(OUTPUT_DATA_REG, *d);
	else 
	    *d = NCR5380_read(CURRENT_SCSI_DATA_REG);

	++d;

	/* 
	 * The SCSI standard suggests that in MSGOUT phase, the initiator
	 * should drop ATN on the last byte of the message phase
	 * after REQ has been asserted for the handshake but before
	 * the initiator raises ACK.
	 */

	if (!(p & SR_IO)) {
	    if (!((p & SR_MSG) && c > 1)) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
		    ICR_ASSERT_DATA);
		NCR_PRINT(NDEBUG_PIO);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
			ICR_ASSERT_DATA | ICR_ASSERT_ACK);
	    } else {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
		    ICR_ASSERT_DATA | ICR_ASSERT_ATN);
		NCR_PRINT(NDEBUG_PIO);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
		    ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
	    }
	} else {
	    NCR_PRINT(NDEBUG_PIO);
	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
	}

	while (NCR5380_read(STATUS_REG) & SR_REQ);

	HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);

/*
 * We have several special cases to consider during REQ/ACK handshaking : 
 * 1.  We were in MSGOUT phase, and we are on the last byte of the 
 *	message.  ATN must be dropped as ACK is dropped.
 *
 * 2.  We are in a MSGIN phase, and we are on the last byte of the  
 *	message.  We must exit with ACK asserted, so that the calling
 *	code may raise ATN before dropping ACK to reject the message.
 *
 * 3.  ACK and ATN are clear and the target may proceed as normal.
 */
	if (!(p == PHASE_MSGIN && c == 1)) {  
	    if (p == PHASE_MSGOUT && c > 1)
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
	    else
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	} 
    } while (--c);

    PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);

    *count = c;
    *data = d;
    tmp = NCR5380_read(STATUS_REG);
    /* The phase read from the bus is valid if either REQ is (already)
     * asserted or if ACK hasn't been released yet. The latter is the case if
     * we're in MSGIN and all wanted bytes have been received. */
    if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
	*phase = tmp & PHASE_MASK;
    else 
	*phase = PHASE_UNKNOWN;

    if (!c || (*phase == p))
	return 0;
    else 
	return -1;
}

/*
 * Function : do_abort (Scsi_Host *host)
 * 
 * Purpose : abort the currently established nexus.  Should only be 
 * 	called from a routine which can drop into a 
 * 
 * Returns : 0 on success, -1 on failure.
 */

static int do_abort (struct Scsi_Host *host) 
{
    unsigned char tmp, *msgptr, phase;
    int len;

    /* Request message out phase */
    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);

    /* 
     * Wait for the target to indicate a valid phase by asserting 
     * REQ.  Once this happens, we'll have either a MSGOUT phase 
     * and can immediately send the ABORT message, or we'll have some 
     * other phase and will have to source/sink data.
     * 
     * We really don't care what value was on the bus or what value
     * the target sees, so we just handshake.
     */
    
1795
    while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ));
Linus Torvalds's avatar
Linus Torvalds committed
1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832

    NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

    if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | 
		      ICR_ASSERT_ACK);
	while (NCR5380_read(STATUS_REG) & SR_REQ);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
    }
   
    tmp = ABORT;
    msgptr = &tmp;
    len = 1;
    phase = PHASE_MSGOUT;
    NCR5380_transfer_pio (host, &phase, &len, &msgptr);

    /*
     * If we got here, and the command completed successfully,
     * we're about to go into bus free state.
     */

    return len ? -1 : 0;
}

#if defined(REAL_DMA)
/* 
 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance, 
 *      unsigned char *phase, int *count, unsigned char **data)
 *
 * Purpose : transfers data in given phase using either real
 *	or pseudo DMA.
 *
 * Inputs : instance - instance of driver, *phase - pointer to 
 *	what phase is expected, *count - pointer to number of 
 *	bytes to transfer, **data - pointer to data pointer.
 * 
 * Returns : -1 when different phase is entered without transferring
1833
 *	maximum number of bytes, 0 if all bytes or transferred or exit
Linus Torvalds's avatar
Linus Torvalds committed
1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920
 *	is in same phase.
 *
 * 	Also, *phase, *count, *data are modified in place.
 *
 */


static int NCR5380_transfer_dma( struct Scsi_Host *instance, 
				 unsigned char *phase, int *count,
				 unsigned char **data)
{
    SETUP_HOSTDATA(instance);
    register int c = *count;
    register unsigned char p = *phase;
    unsigned long flags;

    /* sanity check */
    if(!sun3_dma_setup_done) {
	 printk("scsi%d: transfer_dma without setup!\n", HOSTNO);
	 BUG();
    }
    hostdata->dma_len = c;

    DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
	       HOSTNO, (p & SR_IO) ? "reading" : "writing",
	       c, (p & SR_IO) ? "to" : "from", *data);

    /* netbsd turns off ints here, why not be safe and do it too */
    local_irq_save(flags);
    
    /* send start chain */
    sun3scsi_dma_start(c, *data);
    
    if (p & SR_IO) {
	    NCR5380_write(TARGET_COMMAND_REG, 1);
	    NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	    NCR5380_write(INITIATOR_COMMAND_REG, 0);
	    NCR5380_write(MODE_REG, (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
	    NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
    } else {
	    NCR5380_write(TARGET_COMMAND_REG, 0);
	    NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
	    NCR5380_write(MODE_REG, (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
	    NCR5380_write(START_DMA_SEND_REG, 0);
    }

#ifdef SUN3_SCSI_VME
    dregs->csr |= CSR_DMA_ENABLE;
#endif

    local_irq_restore(flags);

    sun3_dma_active = 1;
    return 0;
}
#endif /* defined(REAL_DMA) */

/*
 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
 *
 * Purpose : run through the various SCSI phases and do as the target 
 * 	directs us to.  Operates on the currently connected command, 
 *	instance->connected.
 *
 * Inputs : instance, instance for which we are doing commands
 *
 * Side effects : SCSI things happen, the disconnected queue will be 
 *	modified if a command disconnects, *instance->connected will
 *	change.
 *
 * XXX Note : we need to watch for bus free or a reset condition here 
 * 	to recover from an unexpected bus free condition.
 */
 
static void NCR5380_information_transfer (struct Scsi_Host *instance)
{
    SETUP_HOSTDATA(instance);
    unsigned long flags;
    unsigned char msgout = NOP;
    int sink = 0;
    int len;
#if defined(REAL_DMA)
    int transfersize;
#endif
    unsigned char *data;
    unsigned char phase, tmp, extended_msg[10], old_phase=0xff;
1921
    struct scsi_cmnd *cmd = (struct scsi_cmnd *) hostdata->connected;
Linus Torvalds's avatar
Linus Torvalds committed
1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952

#ifdef SUN3_SCSI_VME
    dregs->csr |= CSR_INTR;
#endif

    while (1) {
	tmp = NCR5380_read(STATUS_REG);
	/* We only have a valid SCSI phase when REQ is asserted */
	if (tmp & SR_REQ) {
	    phase = (tmp & PHASE_MASK); 
 	    if (phase != old_phase) {
		old_phase = phase;
		NCR_PRINT_PHASE(NDEBUG_INFORMATION);
	    }

	    if(phase == PHASE_CMDOUT) {
		    void *d;
		    unsigned long count;

		if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
			count = cmd->SCp.buffer->length;
			d = SGADDR(cmd->SCp.buffer);
		} else {
			count = cmd->SCp.this_residual;
			d = cmd->SCp.ptr;
		}
#ifdef REAL_DMA
		/* this command setup for dma yet? */
		if((count > SUN3_DMA_MINSIZE) && (sun3_dma_setup_done
						  != cmd))
		{
1953
			if (cmd->request->cmd_type == REQ_TYPE_FS) {
Linus Torvalds's avatar
Linus Torvalds committed
1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985
				sun3scsi_dma_setup(d, count,
						   rq_data_dir(cmd->request));
				sun3_dma_setup_done = cmd;
			}
		}
#endif
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_INTR;
#endif
	    }

	    
	    if (sink && (phase != PHASE_MSGOUT)) {
		NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | 
		    ICR_ASSERT_ACK);
		while (NCR5380_read(STATUS_REG) & SR_REQ);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
		    ICR_ASSERT_ATN);
		sink = 0;
		continue;
	    }

	    switch (phase) {
	    case PHASE_DATAOUT:
#if (NDEBUG & NDEBUG_NO_DATAOUT)
		printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
		       "aborted\n", HOSTNO);
		sink = 1;
		do_abort(instance);
		cmd->result = DID_ERROR  << 16;
1986
		cmd->scsi_done(cmd);
Linus Torvalds's avatar
Linus Torvalds committed
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040
		return;
#endif
	    case PHASE_DATAIN:
		/* 
		 * If there is no room left in the current buffer in the
		 * scatter-gather list, move onto the next one.
		 */
		if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
		    ++cmd->SCp.buffer;
		    --cmd->SCp.buffers_residual;
		    cmd->SCp.this_residual = cmd->SCp.buffer->length;
		    cmd->SCp.ptr = SGADDR(cmd->SCp.buffer);
		    INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
			       HOSTNO, cmd->SCp.this_residual,
			       cmd->SCp.buffers_residual);
		}

		/*
		 * The preferred transfer method is going to be 
		 * PSEUDO-DMA for systems that are strictly PIO,
		 * since we can let the hardware do the handshaking.
		 *
		 * For this to work, we need to know the transfersize
		 * ahead of time, since the pseudo-DMA code will sit
		 * in an unconditional loop.
		 */

/* ++roman: I suggest, this should be
 *   #if def(REAL_DMA)
 * instead of leaving REAL_DMA out.
 */

#if defined(REAL_DMA)
//		if (!cmd->device->borken &&
		if((transfersize =
		    NCR5380_dma_xfer_len(instance,cmd,phase)) > SUN3_DMA_MINSIZE) {
		    len = transfersize;
		    cmd->SCp.phase = phase;

		    if (NCR5380_transfer_dma(instance, &phase,
			&len, (unsigned char **) &cmd->SCp.ptr)) {
			/*
			 * If the watchdog timer fires, all future
			 * accesses to this device will use the
			 * polled-IO. */ 
			printk(KERN_NOTICE "scsi%d: switching target %d "
			       "lun %d to slow handshake\n", HOSTNO,
			       cmd->device->id, cmd->device->lun);
			cmd->device->borken = 1;
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
			    ICR_ASSERT_ATN);
			sink = 1;
			do_abort(instance);
			cmd->result = DID_ERROR  << 16;
2041
			cmd->scsi_done(cmd);
Linus Torvalds's avatar
Linus Torvalds committed
2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179
			/* XXX - need to source or sink data here, as appropriate */
		    } else {
#ifdef REAL_DMA
			/* ++roman: When using real DMA,
			 * information_transfer() should return after
			 * starting DMA since it has nothing more to
			 * do.
			 */
				    return;
#else			
			cmd->SCp.this_residual -= transfersize - len;
#endif
		    }
		} else 
#endif /* defined(REAL_DMA) */
		  NCR5380_transfer_pio(instance, &phase, 
		    (int *) &cmd->SCp.this_residual, (unsigned char **)
		    &cmd->SCp.ptr);
#ifdef REAL_DMA
		/* if we had intended to dma that command clear it */
		if(sun3_dma_setup_done == cmd)
			sun3_dma_setup_done = NULL;
#endif

		break;
	    case PHASE_MSGIN:
		len = 1;
		data = &tmp;
		NCR5380_write(SELECT_ENABLE_REG, 0); 	/* disable reselects */
		NCR5380_transfer_pio(instance, &phase, &len, &data);
		cmd->SCp.Message = tmp;
		
		switch (tmp) {
		/*
		 * Linking lets us reduce the time required to get the 
		 * next command out to the device, hopefully this will
		 * mean we don't waste another revolution due to the delays
		 * required by ARBITRATION and another SELECTION.
		 *
		 * In the current implementation proposal, low level drivers
		 * merely have to start the next command, pointed to by 
		 * next_link, done() is called as with unlinked commands.
		 */
#ifdef LINKED
		case LINKED_CMD_COMPLETE:
		case LINKED_FLG_CMD_COMPLETE:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    
		    LNK_PRINTK("scsi%d: target %d lun %d linked command "
			       "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);

		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    /*
		     * Sanity check : A linked command should only terminate
		     * with one of these messages if there are more linked
		     * commands available.
		     */

		    if (!cmd->next_link) {
			 printk(KERN_NOTICE "scsi%d: target %d lun %d "
				"linked command complete, no next_link\n",
				HOSTNO, cmd->device->id, cmd->device->lun);
			    sink = 1;
			    do_abort (instance);
			    return;
		    }

		    initialize_SCp(cmd->next_link);
		    /* The next command is still part of this process; copy it
		     * and don't free it! */
		    cmd->next_link->tag = cmd->tag;
		    cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); 
		    LNK_PRINTK("scsi%d: target %d lun %d linked request "
			       "done, calling scsi_done().\n",
			       HOSTNO, cmd->device->id, cmd->device->lun);
#ifdef NCR5380_STATS
		    collect_stats(hostdata, cmd);
#endif
		    cmd->scsi_done(cmd);
		    cmd = hostdata->connected;
		    break;
#endif /* def LINKED */
		case ABORT:
		case COMMAND_COMPLETE: 
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    hostdata->connected = NULL;
		    QU_PRINTK("scsi%d: command for target %d, lun %d "
			      "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
#ifdef SUPPORT_TAGS
		    cmd_free_tag( cmd );
		    if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
			/* Turn a QUEUE FULL status into BUSY, I think the
			 * mid level cannot handle QUEUE FULL :-( (The
			 * command is retried after BUSY). Also update our
			 * queue size to the number of currently issued
			 * commands now.
			 */
			/* ++Andreas: the mid level code knows about
			   QUEUE_FULL now. */
			TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
			TAG_PRINTK("scsi%d: target %d lun %d returned "
				   "QUEUE_FULL after %d commands\n",
				   HOSTNO, cmd->device->id, cmd->device->lun,
				   ta->nr_allocated);
			if (ta->queue_size > ta->nr_allocated)
			    ta->nr_allocated = ta->queue_size;
		    }
#else
		    hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);

		    /* 
		     * I'm not sure what the correct thing to do here is : 
		     * 
		     * If the command that just executed is NOT a request 
		     * sense, the obvious thing to do is to set the result
		     * code to the values of the stored parameters.
		     * 
		     * If it was a REQUEST SENSE command, we need some way to
		     * differentiate between the failure code of the original
		     * and the failure code of the REQUEST sense - the obvious
		     * case is success, where we fall through and leave the
		     * result code unchanged.
		     * 
		     * The non-obvious place is where the REQUEST SENSE failed
		     */

		    if (cmd->cmnd[0] != REQUEST_SENSE) 
			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); 
		    else if (status_byte(cmd->SCp.Status) != GOOD)
			cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
		    
#ifdef AUTOSENSE
2180 2181 2182 2183 2184 2185
		    if ((cmd->cmnd[0] == REQUEST_SENSE) &&
			                        hostdata->ses.cmd_len) {
			scsi_eh_restore_cmnd(cmd, &hostdata->ses);
			hostdata->ses.cmd_len = 0 ;
		    }

Linus Torvalds's avatar
Linus Torvalds committed
2186 2187
		    if ((cmd->cmnd[0] != REQUEST_SENSE) && 
			(status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2188
			scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
Linus Torvalds's avatar
Linus Torvalds committed
2189 2190 2191 2192 2193 2194 2195 2196 2197
			ASEN_PRINTK("scsi%d: performing request sense\n",
				    HOSTNO);
			/* this is initialized from initialize_SCp 
			cmd->SCp.buffer = NULL;
			cmd->SCp.buffers_residual = 0;
			*/

			local_irq_save(flags);
			LIST(cmd,hostdata->issue_queue);
2198
			SET_NEXT(cmd, hostdata->issue_queue);
2199
		        hostdata->issue_queue = (struct scsi_cmnd *) cmd;
Linus Torvalds's avatar
Linus Torvalds committed
2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253
		        local_irq_restore(flags);
			QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
				  "issue queue\n", H_NO(cmd));
		   } else
#endif /* def AUTOSENSE */
		   {
#ifdef NCR5380_STATS
		       collect_stats(hostdata, cmd);
#endif
		       cmd->scsi_done(cmd);
		    }

		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    /* 
		     * Restore phase bits to 0 so an interrupted selection, 
		     * arbitration can resume.
		     */
		    NCR5380_write(TARGET_COMMAND_REG, 0);
		    
		    while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
			barrier();

		    return;
		case MESSAGE_REJECT:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    switch (hostdata->last_message) {
		    case HEAD_OF_QUEUE_TAG:
		    case ORDERED_QUEUE_TAG:
		    case SIMPLE_QUEUE_TAG:
			/* The target obviously doesn't support tagged
			 * queuing, even though it announced this ability in
			 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
			 * clear 'tagged_supported' and lock the LUN, since
			 * the command is treated as untagged further on.
			 */
			cmd->device->tagged_supported = 0;
			hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
			cmd->tag = TAG_NONE;
			TAG_PRINTK("scsi%d: target %d lun %d rejected "
				   "QUEUE_TAG message; tagged queuing "
				   "disabled\n",
				   HOSTNO, cmd->device->id, cmd->device->lun);
			break;
		    }
		    break;
		case DISCONNECT:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    local_irq_save(flags);
		    cmd->device->disconnect = 1;
		    LIST(cmd,hostdata->disconnected_queue);
2254
		    SET_NEXT(cmd, hostdata->disconnected_queue);
Linus Torvalds's avatar
Linus Torvalds committed
2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304
		    hostdata->connected = NULL;
		    hostdata->disconnected_queue = cmd;
		    local_irq_restore(flags);
		    QU_PRINTK("scsi%d: command for target %d lun %d was "
			      "moved from connected to the "
			      "disconnected_queue\n", HOSTNO, 
			      cmd->device->id, cmd->device->lun);
		    /* 
		     * Restore phase bits to 0 so an interrupted selection, 
		     * arbitration can resume.
		     */
		    NCR5380_write(TARGET_COMMAND_REG, 0);

		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    /* Wait for bus free to avoid nasty timeouts */
		    while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
		    	barrier();
#ifdef SUN3_SCSI_VME
		    dregs->csr |= CSR_DMA_ENABLE;
#endif
		    return;
		/* 
		 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
		 * operation, in violation of the SCSI spec so we can safely 
		 * ignore SAVE/RESTORE pointers calls.
		 *
		 * Unfortunately, some disks violate the SCSI spec and 
		 * don't issue the required SAVE_POINTERS message before
		 * disconnecting, and we have to break spec to remain 
		 * compatible.
		 */
		case SAVE_POINTERS:
		case RESTORE_POINTERS:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    break;
		case EXTENDED_MESSAGE:
/* 
 * Extended messages are sent in the following format :
 * Byte 	
 * 0		EXTENDED_MESSAGE == 1
 * 1		length (includes one byte for code, doesn't 
 *		include first two bytes)
 * 2 		code
 * 3..length+1	arguments
 *
 * Start the extended message buffer with the EXTENDED_MESSAGE
2305
 * byte, since spi_print_msg() wants the whole thing.  
Linus Torvalds's avatar
Linus Torvalds committed
2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357
 */
		    extended_msg[0] = EXTENDED_MESSAGE;
		    /* Accept first byte by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

		    EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);

		    len = 2;
		    data = extended_msg + 1;
		    phase = PHASE_MSGIN;
		    NCR5380_transfer_pio(instance, &phase, &len, &data);
		    EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
			       (int)extended_msg[1], (int)extended_msg[2]);

		    if (!len && extended_msg[1] <= 
			(sizeof (extended_msg) - 1)) {
			/* Accept third byte by clearing ACK */
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
			len = extended_msg[1] - 1;
			data = extended_msg + 3;
			phase = PHASE_MSGIN;

			NCR5380_transfer_pio(instance, &phase, &len, &data);
			EXT_PRINTK("scsi%d: message received, residual %d\n",
				   HOSTNO, len);

			switch (extended_msg[2]) {
			case EXTENDED_SDTR:
			case EXTENDED_WDTR:
			case EXTENDED_MODIFY_DATA_POINTER:
			case EXTENDED_EXTENDED_IDENTIFY:
			    tmp = 0;
			}
		    } else if (len) {
			printk(KERN_NOTICE "scsi%d: error receiving "
			       "extended message\n", HOSTNO);
			tmp = 0;
		    } else {
			printk(KERN_NOTICE "scsi%d: extended message "
			       "code %02x length %d is too long\n",
			       HOSTNO, extended_msg[2], extended_msg[1]);
			tmp = 0;
		    }
		/* Fall through to reject message */

		/* 
  		 * If we get something weird that we aren't expecting, 
 		 * reject it.
		 */
		default:
		    if (!tmp) {
			printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
2358
			spi_print_msg(extended_msg);
Linus Torvalds's avatar
Linus Torvalds committed
2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428
			printk("\n");
		    } else if (tmp != EXTENDED_MESSAGE)
			printk(KERN_DEBUG "scsi%d: rejecting unknown "
			       "message %02x from target %d, lun %d\n",
			       HOSTNO, tmp, cmd->device->id, cmd->device->lun);
		    else
			printk(KERN_DEBUG "scsi%d: rejecting unknown "
			       "extended message "
			       "code %02x, length %d from target %d, lun %d\n",
			       HOSTNO, extended_msg[1], extended_msg[0],
			       cmd->device->id, cmd->device->lun);
   

		    msgout = MESSAGE_REJECT;
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
			ICR_ASSERT_ATN);
		    break;
		} /* switch (tmp) */
		break;
	    case PHASE_MSGOUT:
		len = 1;
		data = &msgout;
		hostdata->last_message = msgout;
		NCR5380_transfer_pio(instance, &phase, &len, &data);
		if (msgout == ABORT) {
#ifdef SUPPORT_TAGS
		    cmd_free_tag( cmd );
#else
		    hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
		    hostdata->connected = NULL;
		    cmd->result = DID_ERROR << 16;
#ifdef NCR5380_STATS
		    collect_stats(hostdata, cmd);
#endif
		    cmd->scsi_done(cmd);
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    return;
		}
		msgout = NOP;
		break;
	    case PHASE_CMDOUT:
		len = cmd->cmd_len;
		data = cmd->cmnd;
		/* 
		 * XXX for performance reasons, on machines with a 
		 * PSEUDO-DMA architecture we should probably 
		 * use the dma transfer function.  
		 */
		NCR5380_transfer_pio(instance, &phase, &len, 
		    &data);
		break;
	    case PHASE_STATIN:
		len = 1;
		data = &tmp;
		NCR5380_transfer_pio(instance, &phase, &len, &data);
		cmd->SCp.Status = tmp;
		break;
	    default:
		printk("scsi%d: unknown phase\n", HOSTNO);
		NCR_PRINT(NDEBUG_ANY);
	    } /* switch(phase) */
	} /* if (tmp * SR_REQ) */ 
    } /* while (1) */
}

/*
 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
 *
 * Purpose : does reselection, initializing the instance->connected 
2429
 *	field to point to the struct scsi_cmnd for which the I_T_L or I_T_L_Q
Linus Torvalds's avatar
Linus Torvalds committed
2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447
 *	nexus has been reestablished,
 *	
 * Inputs : instance - this instance of the NCR5380.
 *
 */

/* it might eventually prove necessary to do a dma setup on
   reselection, but it doesn't seem to be needed now -- sam */

static void NCR5380_reselect (struct Scsi_Host *instance)
{
    SETUP_HOSTDATA(instance);
    unsigned char target_mask;
    unsigned char lun;
#ifdef SUPPORT_TAGS
    unsigned char tag;
#endif
    unsigned char msg[3];
2448
    struct scsi_cmnd *tmp = NULL, *prev;
Linus Torvalds's avatar
Linus Torvalds committed
2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492
/*    unsigned long flags; */

    /*
     * Disable arbitration, etc. since the host adapter obviously
     * lost, and tell an interrupted NCR5380_select() to restart.
     */

    NCR5380_write(MODE_REG, MR_BASE);
    hostdata->restart_select = 1;

    target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);

    RSL_PRINTK("scsi%d: reselect\n", HOSTNO);

    /* 
     * At this point, we have detected that our SCSI ID is on the bus,
     * SEL is true and BSY was false for at least one bus settle delay
     * (400 ns).
     *
     * We must assert BSY ourselves, until the target drops the SEL
     * signal.
     */

    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
    
    while (NCR5380_read(STATUS_REG) & SR_SEL);
    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

    /*
     * Wait for target to go into MSGIN.
     */

    while (!(NCR5380_read(STATUS_REG) & SR_REQ));

#if 1
    // acknowledge toggle to MSGIN
    NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));

    // peek at the byte without really hitting the bus
    msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
#endif

    if (!(msg[0] & 0x80)) {
	printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2493
	spi_print_msg(msg);
Linus Torvalds's avatar
Linus Torvalds committed
2494 2495 2496 2497 2498 2499 2500 2501 2502 2503
	do_abort(instance);
	return;
    }
    lun = (msg[0] & 0x07);

    /* 
     * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we 
     * just reestablished, and remove it from the disconnected queue.
     */

2504
    for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
2505 2506 2507 2508 2509 2510 2511 2512
	 tmp; prev = tmp, tmp = NEXT(tmp) ) {
	if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
#ifdef SUPPORT_TAGS
	    && (tag == tmp->tag) 
#endif
	    ) {
	    if (prev) {
		REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2513
		SET_NEXT(prev, NEXT(tmp));
Linus Torvalds's avatar
Linus Torvalds committed
2514 2515 2516 2517
	    } else {
		REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
		hostdata->disconnected_queue = NEXT(tmp);
	    }
2518
	    SET_NEXT(tmp, NULL);
Linus Torvalds's avatar
Linus Torvalds committed
2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594
	    break;
	}
    }
    
    if (!tmp) {
	printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
#ifdef SUPPORT_TAGS
		"tag %d "
#endif
		"not in disconnected_queue.\n",
		HOSTNO, target_mask, lun
#ifdef SUPPORT_TAGS
		, tag
#endif
		);
	/* 
	 * Since we have an established nexus that we can't do anything
	 * with, we must abort it.  
	 */
	do_abort(instance);
	return;
    }
#if 1
    /* engage dma setup for the command we just saw */
    {
	    void *d;
	    unsigned long count;

	    if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
		    count = tmp->SCp.buffer->length;
		    d = SGADDR(tmp->SCp.buffer);
	    } else {
		    count = tmp->SCp.this_residual;
		    d = tmp->SCp.ptr;
	    }
#ifdef REAL_DMA
	    /* setup this command for dma if not already */
	    if((count > SUN3_DMA_MINSIZE) && (sun3_dma_setup_done != tmp))
	    {
		    sun3scsi_dma_setup(d, count, rq_data_dir(tmp->request));
		    sun3_dma_setup_done = tmp;
	    }
#endif
    }
#endif

    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
    /* Accept message by clearing ACK */
    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

#ifdef SUPPORT_TAGS
    /* If the phase is still MSGIN, the target wants to send some more
     * messages. In case it supports tagged queuing, this is probably a
     * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
     */
    tag = TAG_NONE;
    if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
	/* Accept previous IDENTIFY message by clearing ACK */
	NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE );
	len = 2;
	data = msg+1;
	if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
	    msg[1] == SIMPLE_QUEUE_TAG)
	    tag = msg[2];
	TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
		   "reselection\n", HOSTNO, target_mask, lun, tag);
    }
#endif
    
    hostdata->connected = tmp;
    RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
	       HOSTNO, tmp->target, tmp->lun, tmp->tag);
}


/*
2595
 * Function : int NCR5380_abort(struct scsi_cmnd *cmd)
Linus Torvalds's avatar
Linus Torvalds committed
2596 2597 2598
 *
 * Purpose : abort a command
 *
2599
 * Inputs : cmd - the struct scsi_cmnd to abort, code - code to set the
Linus Torvalds's avatar
Linus Torvalds committed
2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610
 * 	host byte of the result field to, if zero DID_ABORTED is 
 *	used.
 *
 * Returns : 0 - success, -1 on failure.
 *
 * XXX - there is no way to abort the command that is currently 
 * 	 connected, you have to wait for it to complete.  If this is 
 *	 a problem, we could implement longjmp() / setjmp(), setjmp()
 * 	 called where the loop started in NCR5380_main().
 */

2611
static int NCR5380_abort(struct scsi_cmnd *cmd)
Linus Torvalds's avatar
Linus Torvalds committed
2612 2613 2614
{
    struct Scsi_Host *instance = cmd->device->host;
    SETUP_HOSTDATA(instance);
2615
    struct scsi_cmnd *tmp, **prev;
Linus Torvalds's avatar
Linus Torvalds committed
2616 2617 2618
    unsigned long flags;

    printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
2619
    scsi_print_command(cmd);
Linus Torvalds's avatar
Linus Torvalds committed
2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679

    NCR5380_print_status (instance);

    local_irq_save(flags);
    
    ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
		NCR5380_read(BUS_AND_STATUS_REG),
		NCR5380_read(STATUS_REG));

#if 1
/* 
 * Case 1 : If the command is the currently executing command, 
 * we'll set the aborted flag and return control so that 
 * information transfer routine can exit cleanly.
 */

    if (hostdata->connected == cmd) {

	ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
/*
 * We should perform BSY checking, and make sure we haven't slipped
 * into BUS FREE.
 */

/*	NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
/* 
 * Since we can't change phases until we've completed the current 
 * handshake, we have to source or sink a byte of data if the current
 * phase is not MSGOUT.
 */

/* 
 * Return control to the executing NCR drive so we can clear the
 * aborted flag and get back into our main loop.
 */ 

	if (do_abort(instance) == 0) {
	  hostdata->aborted = 1;
	  hostdata->connected = NULL;
	  cmd->result = DID_ABORT << 16;
#ifdef SUPPORT_TAGS
	  cmd_free_tag( cmd );
#else
	  hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
	  local_irq_restore(flags);
	  cmd->scsi_done(cmd);
	  return SCSI_ABORT_SUCCESS;
	} else {
/*	  local_irq_restore(flags); */
	  printk("scsi%d: abort of connected command failed!\n", HOSTNO);
	  return SCSI_ABORT_ERROR;
	} 
   }
#endif

/* 
 * Case 2 : If the command hasn't been issued yet, we simply remove it 
 * 	    from the issue queue.
 */
2680 2681 2682
    for (prev = (struct scsi_cmnd **) &(hostdata->issue_queue),
	tmp = (struct scsi_cmnd *) hostdata->issue_queue;
	tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp))
Linus Torvalds's avatar
Linus Torvalds committed
2683 2684 2685
	if (cmd == tmp) {
	    REMOVE(5, *prev, tmp, NEXT(tmp));
	    (*prev) = NEXT(tmp);
2686
	    SET_NEXT(tmp, NULL);
Linus Torvalds's avatar
Linus Torvalds committed
2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738
	    tmp->result = DID_ABORT << 16;
	    local_irq_restore(flags);
	    ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n