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/drivers/scsi/wd33c93.c

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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (c) 1996 John Shifflett, GeoLog Consulting
   4 *    john@geolog.com
   5 *    jshiffle@netcom.com
   6 */
   7
   8/*
   9 * Drew Eckhardt's excellent 'Generic NCR5380' sources from Linux-PC
  10 * provided much of the inspiration and some of the code for this
  11 * driver. Everything I know about Amiga DMA was gleaned from careful
  12 * reading of Hamish Mcdonald's original wd33c93 driver; in fact, I
  13 * borrowed shamelessly from all over that source. Thanks Hamish!
  14 *
  15 * _This_ driver is (I feel) an improvement over the old one in
  16 * several respects:
  17 *
  18 *    -  Target Disconnection/Reconnection  is now supported. Any
  19 *          system with more than one device active on the SCSI bus
  20 *          will benefit from this. The driver defaults to what I
  21 *          call 'adaptive disconnect' - meaning that each command
  22 *          is evaluated individually as to whether or not it should
  23 *          be run with the option to disconnect/reselect (if the
  24 *          device chooses), or as a "SCSI-bus-hog".
  25 *
  26 *    -  Synchronous data transfers are now supported. Because of
  27 *          a few devices that choke after telling the driver that
  28 *          they can do sync transfers, we don't automatically use
  29 *          this faster protocol - it can be enabled via the command-
  30 *          line on a device-by-device basis.
  31 *
  32 *    -  Runtime operating parameters can now be specified through
  33 *       the 'amiboot' or the 'insmod' command line. For amiboot do:
  34 *          "amiboot [usual stuff] wd33c93=blah,blah,blah"
  35 *       The defaults should be good for most people. See the comment
  36 *       for 'setup_strings' below for more details.
  37 *
  38 *    -  The old driver relied exclusively on what the Western Digital
  39 *          docs call "Combination Level 2 Commands", which are a great
  40 *          idea in that the CPU is relieved of a lot of interrupt
  41 *          overhead. However, by accepting a certain (user-settable)
  42 *          amount of additional interrupts, this driver achieves
  43 *          better control over the SCSI bus, and data transfers are
  44 *          almost as fast while being much easier to define, track,
  45 *          and debug.
  46 *
  47 *
  48 * TODO:
  49 *       more speed. linked commands.
  50 *
  51 *
  52 * People with bug reports, wish-lists, complaints, comments,
  53 * or improvements are asked to pah-leeez email me (John Shifflett)
  54 * at john@geolog.com or jshiffle@netcom.com! I'm anxious to get
  55 * this thing into as good a shape as possible, and I'm positive
  56 * there are lots of lurking bugs and "Stupid Places".
  57 *
  58 * Updates:
  59 *
  60 * Added support for pre -A chips, which don't have advanced features
  61 * and will generate CSR_RESEL rather than CSR_RESEL_AM.
  62 *	Richard Hirst <richard@sleepie.demon.co.uk>  August 2000
  63 *
  64 * Added support for Burst Mode DMA and Fast SCSI. Enabled the use of
  65 * default_sx_per for asynchronous data transfers. Added adjustment
  66 * of transfer periods in sx_table to the actual input-clock.
  67 *  peter fuerst <post@pfrst.de>  February 2007
  68 */
  69
  70#include <linux/module.h>
  71
  72#include <linux/string.h>
  73#include <linux/delay.h>
  74#include <linux/init.h>
  75#include <linux/interrupt.h>
  76#include <linux/blkdev.h>
  77
  78#include <scsi/scsi.h>
  79#include <scsi/scsi_cmnd.h>
  80#include <scsi/scsi_device.h>
  81#include <scsi/scsi_host.h>
  82
  83#include <asm/irq.h>
  84
  85#include "wd33c93.h"
  86
  87#define optimum_sx_per(hostdata) (hostdata)->sx_table[1].period_ns
  88
  89
  90#define WD33C93_VERSION    "1.26++"
  91#define WD33C93_DATE       "10/Feb/2007"
  92
  93MODULE_AUTHOR("John Shifflett");
  94MODULE_DESCRIPTION("Generic WD33C93 SCSI driver");
  95MODULE_LICENSE("GPL");
  96
  97/*
  98 * 'setup_strings' is a single string used to pass operating parameters and
  99 * settings from the kernel/module command-line to the driver. 'setup_args[]'
 100 * is an array of strings that define the compile-time default values for
 101 * these settings. If Linux boots with an amiboot or insmod command-line,
 102 * those settings are combined with 'setup_args[]'. Note that amiboot
 103 * command-lines are prefixed with "wd33c93=" while insmod uses a
 104 * "setup_strings=" prefix. The driver recognizes the following keywords
 105 * (lower case required) and arguments:
 106 *
 107 * -  nosync:bitmask -bitmask is a byte where the 1st 7 bits correspond with
 108 *                    the 7 possible SCSI devices. Set a bit to negotiate for
 109 *                    asynchronous transfers on that device. To maintain
 110 *                    backwards compatibility, a command-line such as
 111 *                    "wd33c93=255" will be automatically translated to
 112 *                    "wd33c93=nosync:0xff".
 113 * -  nodma:x        -x = 1 to disable DMA, x = 0 to enable it. Argument is
 114 *                    optional - if not present, same as "nodma:1".
 115 * -  period:ns      -ns is the minimum # of nanoseconds in a SCSI data transfer
 116 *                    period. Default is 500; acceptable values are 250 - 1000.
 117 * -  disconnect:x   -x = 0 to never allow disconnects, 2 to always allow them.
 118 *                    x = 1 does 'adaptive' disconnects, which is the default
 119 *                    and generally the best choice.
 120 * -  debug:x        -If 'DEBUGGING_ON' is defined, x is a bit mask that causes
 121 *                    various types of debug output to printed - see the DB_xxx
 122 *                    defines in wd33c93.h
 123 * -  clock:x        -x = clock input in MHz for WD33c93 chip. Normal values
 124 *                    would be from 8 through 20. Default is 8.
 125 * -  burst:x        -x = 1 to use Burst Mode (or Demand-Mode) DMA, x = 0 to use
 126 *                    Single Byte DMA, which is the default. Argument is
 127 *                    optional - if not present, same as "burst:1".
 128 * -  fast:x         -x = 1 to enable Fast SCSI, which is only effective with
 129 *                    input-clock divisor 4 (WD33C93_FS_16_20), x = 0 to disable
 130 *                    it, which is the default.  Argument is optional - if not
 131 *                    present, same as "fast:1".
 132 * -  next           -No argument. Used to separate blocks of keywords when
 133 *                    there's more than one host adapter in the system.
 134 *
 135 * Syntax Notes:
 136 * -  Numeric arguments can be decimal or the '0x' form of hex notation. There
 137 *    _must_ be a colon between a keyword and its numeric argument, with no
 138 *    spaces.
 139 * -  Keywords are separated by commas, no spaces, in the standard kernel
 140 *    command-line manner.
 141 * -  A keyword in the 'nth' comma-separated command-line member will overwrite
 142 *    the 'nth' element of setup_args[]. A blank command-line member (in
 143 *    other words, a comma with no preceding keyword) will _not_ overwrite
 144 *    the corresponding setup_args[] element.
 145 * -  If a keyword is used more than once, the first one applies to the first
 146 *    SCSI host found, the second to the second card, etc, unless the 'next'
 147 *    keyword is used to change the order.
 148 *
 149 * Some amiboot examples (for insmod, use 'setup_strings' instead of 'wd33c93'):
 150 * -  wd33c93=nosync:255
 151 * -  wd33c93=nodma
 152 * -  wd33c93=nodma:1
 153 * -  wd33c93=disconnect:2,nosync:0x08,period:250
 154 * -  wd33c93=debug:0x1c
 155 */
 156
 157/* Normally, no defaults are specified */
 158static char *setup_args[] = { "", "", "", "", "", "", "", "", "", "" };
 159
 160static char *setup_strings;
 161module_param(setup_strings, charp, 0);
 162
 163static void wd33c93_execute(struct Scsi_Host *instance);
 164
 165#ifdef CONFIG_WD33C93_PIO
 166static inline uchar
 167read_wd33c93(const wd33c93_regs regs, uchar reg_num)
 168{
 169	uchar data;
 170
 171	outb(reg_num, regs.SASR);
 172	data = inb(regs.SCMD);
 173	return data;
 174}
 175
 176static inline unsigned long
 177read_wd33c93_count(const wd33c93_regs regs)
 178{
 179	unsigned long value;
 180
 181	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
 182	value = inb(regs.SCMD) << 16;
 183	value |= inb(regs.SCMD) << 8;
 184	value |= inb(regs.SCMD);
 185	return value;
 186}
 187
 188static inline uchar
 189read_aux_stat(const wd33c93_regs regs)
 190{
 191	return inb(regs.SASR);
 192}
 193
 194static inline void
 195write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
 196{
 197      outb(reg_num, regs.SASR);
 198      outb(value, regs.SCMD);
 199}
 200
 201static inline void
 202write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
 203{
 204	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
 205	outb((value >> 16) & 0xff, regs.SCMD);
 206	outb((value >> 8) & 0xff, regs.SCMD);
 207	outb( value & 0xff, regs.SCMD);
 208}
 209
 210#define write_wd33c93_cmd(regs, cmd) \
 211	write_wd33c93((regs), WD_COMMAND, (cmd))
 212
 213static inline void
 214write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
 215{
 216	int i;
 217
 218	outb(WD_CDB_1, regs.SASR);
 219	for (i=0; i<len; i++)
 220		outb(cmnd[i], regs.SCMD);
 221}
 222
 223#else /* CONFIG_WD33C93_PIO */
 224static inline uchar
 225read_wd33c93(const wd33c93_regs regs, uchar reg_num)
 226{
 227	*regs.SASR = reg_num;
 228	mb();
 229	return (*regs.SCMD);
 230}
 231
 232static unsigned long
 233read_wd33c93_count(const wd33c93_regs regs)
 234{
 235	unsigned long value;
 236
 237	*regs.SASR = WD_TRANSFER_COUNT_MSB;
 238	mb();
 239	value = *regs.SCMD << 16;
 240	value |= *regs.SCMD << 8;
 241	value |= *regs.SCMD;
 242	mb();
 243	return value;
 244}
 245
 246static inline uchar
 247read_aux_stat(const wd33c93_regs regs)
 248{
 249	return *regs.SASR;
 250}
 251
 252static inline void
 253write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
 254{
 255	*regs.SASR = reg_num;
 256	mb();
 257	*regs.SCMD = value;
 258	mb();
 259}
 260
 261static void
 262write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
 263{
 264	*regs.SASR = WD_TRANSFER_COUNT_MSB;
 265	mb();
 266	*regs.SCMD = value >> 16;
 267	*regs.SCMD = value >> 8;
 268	*regs.SCMD = value;
 269	mb();
 270}
 271
 272static inline void
 273write_wd33c93_cmd(const wd33c93_regs regs, uchar cmd)
 274{
 275	*regs.SASR = WD_COMMAND;
 276	mb();
 277	*regs.SCMD = cmd;
 278	mb();
 279}
 280
 281static inline void
 282write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
 283{
 284	int i;
 285
 286	*regs.SASR = WD_CDB_1;
 287	for (i = 0; i < len; i++)
 288		*regs.SCMD = cmnd[i];
 289}
 290#endif /* CONFIG_WD33C93_PIO */
 291
 292static inline uchar
 293read_1_byte(const wd33c93_regs regs)
 294{
 295	uchar asr;
 296	uchar x = 0;
 297
 298	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
 299	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO | 0x80);
 300	do {
 301		asr = read_aux_stat(regs);
 302		if (asr & ASR_DBR)
 303			x = read_wd33c93(regs, WD_DATA);
 304	} while (!(asr & ASR_INT));
 305	return x;
 306}
 307
 308static int
 309round_period(unsigned int period, const struct sx_period *sx_table)
 310{
 311	int x;
 312
 313	for (x = 1; sx_table[x].period_ns; x++) {
 314		if ((period <= sx_table[x - 0].period_ns) &&
 315		    (period > sx_table[x - 1].period_ns)) {
 316			return x;
 317		}
 318	}
 319	return 7;
 320}
 321
 322/*
 323 * Calculate Synchronous Transfer Register value from SDTR code.
 324 */
 325static uchar
 326calc_sync_xfer(unsigned int period, unsigned int offset, unsigned int fast,
 327               const struct sx_period *sx_table)
 328{
 329	/* When doing Fast SCSI synchronous data transfers, the corresponding
 330	 * value in 'sx_table' is two times the actually used transfer period.
 331	 */
 332	uchar result;
 333
 334	if (offset && fast) {
 335		fast = STR_FSS;
 336		period *= 2;
 337	} else {
 338		fast = 0;
 339	}
 340	period *= 4;		/* convert SDTR code to ns */
 341	result = sx_table[round_period(period,sx_table)].reg_value;
 342	result |= (offset < OPTIMUM_SX_OFF) ? offset : OPTIMUM_SX_OFF;
 343	result |= fast;
 344	return result;
 345}
 346
 347/*
 348 * Calculate SDTR code bytes [3],[4] from period and offset.
 349 */
 350static inline void
 351calc_sync_msg(unsigned int period, unsigned int offset, unsigned int fast,
 352                uchar  msg[2])
 353{
 354	/* 'period' is a "normal"-mode value, like the ones in 'sx_table'. The
 355	 * actually used transfer period for Fast SCSI synchronous data
 356	 * transfers is half that value.
 357	 */
 358	period /= 4;
 359	if (offset && fast)
 360		period /= 2;
 361	msg[0] = period;
 362	msg[1] = offset;
 363}
 364
 365static int
 366wd33c93_queuecommand_lck(struct scsi_cmnd *cmd,
 367		void (*done)(struct scsi_cmnd *))
 368{
 369	struct WD33C93_hostdata *hostdata;
 370	struct scsi_cmnd *tmp;
 371
 372	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
 373
 374	DB(DB_QUEUE_COMMAND,
 375	   printk("Q-%d-%02x( ", cmd->device->id, cmd->cmnd[0]))
 376
 377/* Set up a few fields in the scsi_cmnd structure for our own use:
 378 *  - host_scribble is the pointer to the next cmd in the input queue
 379 *  - scsi_done points to the routine we call when a cmd is finished
 380 *  - result is what you'd expect
 381 */
 382	cmd->host_scribble = NULL;
 383	cmd->scsi_done = done;
 384	cmd->result = 0;
 385
 386/* We use the Scsi_Pointer structure that's included with each command
 387 * as a scratchpad (as it's intended to be used!). The handy thing about
 388 * the SCp.xxx fields is that they're always associated with a given
 389 * cmd, and are preserved across disconnect-reselect. This means we
 390 * can pretty much ignore SAVE_POINTERS and RESTORE_POINTERS messages
 391 * if we keep all the critical pointers and counters in SCp:
 392 *  - SCp.ptr is the pointer into the RAM buffer
 393 *  - SCp.this_residual is the size of that buffer
 394 *  - SCp.buffer points to the current scatter-gather buffer
 395 *  - SCp.buffers_residual tells us how many S.G. buffers there are
 396 *  - SCp.have_data_in is not used
 397 *  - SCp.sent_command is not used
 398 *  - SCp.phase records this command's SRCID_ER bit setting
 399 */
 400
 401	if (scsi_bufflen(cmd)) {
 402		cmd->SCp.buffer = scsi_sglist(cmd);
 403		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 404		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 405		cmd->SCp.this_residual = cmd->SCp.buffer->length;
 406	} else {
 407		cmd->SCp.buffer = NULL;
 408		cmd->SCp.buffers_residual = 0;
 409		cmd->SCp.ptr = NULL;
 410		cmd->SCp.this_residual = 0;
 411	}
 412
 413/* WD docs state that at the conclusion of a "LEVEL2" command, the
 414 * status byte can be retrieved from the LUN register. Apparently,
 415 * this is the case only for *uninterrupted* LEVEL2 commands! If
 416 * there are any unexpected phases entered, even if they are 100%
 417 * legal (different devices may choose to do things differently),
 418 * the LEVEL2 command sequence is exited. This often occurs prior
 419 * to receiving the status byte, in which case the driver does a
 420 * status phase interrupt and gets the status byte on its own.
 421 * While such a command can then be "resumed" (ie restarted to
 422 * finish up as a LEVEL2 command), the LUN register will NOT be
 423 * a valid status byte at the command's conclusion, and we must
 424 * use the byte obtained during the earlier interrupt. Here, we
 425 * preset SCp.Status to an illegal value (0xff) so that when
 426 * this command finally completes, we can tell where the actual
 427 * status byte is stored.
 428 */
 429
 430	cmd->SCp.Status = ILLEGAL_STATUS_BYTE;
 431
 432	/*
 433	 * Add the cmd to the end of 'input_Q'. Note that REQUEST SENSE
 434	 * commands are added to the head of the queue so that the desired
 435	 * sense data is not lost before REQUEST_SENSE executes.
 436	 */
 437
 438	spin_lock_irq(&hostdata->lock);
 439
 440	if (!(hostdata->input_Q) || (cmd->cmnd[0] == REQUEST_SENSE)) {
 441		cmd->host_scribble = (uchar *) hostdata->input_Q;
 442		hostdata->input_Q = cmd;
 443	} else {		/* find the end of the queue */
 444		for (tmp = (struct scsi_cmnd *) hostdata->input_Q;
 445		     tmp->host_scribble;
 446		     tmp = (struct scsi_cmnd *) tmp->host_scribble) ;
 447		tmp->host_scribble = (uchar *) cmd;
 448	}
 449
 450/* We know that there's at least one command in 'input_Q' now.
 451 * Go see if any of them are runnable!
 452 */
 453
 454	wd33c93_execute(cmd->device->host);
 455
 456	DB(DB_QUEUE_COMMAND, printk(")Q "))
 457
 458	spin_unlock_irq(&hostdata->lock);
 459	return 0;
 460}
 461
 462DEF_SCSI_QCMD(wd33c93_queuecommand)
 463
 464/*
 465 * This routine attempts to start a scsi command. If the host_card is
 466 * already connected, we give up immediately. Otherwise, look through
 467 * the input_Q, using the first command we find that's intended
 468 * for a currently non-busy target/lun.
 469 *
 470 * wd33c93_execute() is always called with interrupts disabled or from
 471 * the wd33c93_intr itself, which means that a wd33c93 interrupt
 472 * cannot occur while we are in here.
 473 */
 474static void
 475wd33c93_execute(struct Scsi_Host *instance)
 476{
 477	struct WD33C93_hostdata *hostdata =
 478	    (struct WD33C93_hostdata *) instance->hostdata;
 479	const wd33c93_regs regs = hostdata->regs;
 480	struct scsi_cmnd *cmd, *prev;
 481
 482	DB(DB_EXECUTE, printk("EX("))
 483	if (hostdata->selecting || hostdata->connected) {
 484		DB(DB_EXECUTE, printk(")EX-0 "))
 485		return;
 486	}
 487
 488	/*
 489	 * Search through the input_Q for a command destined
 490	 * for an idle target/lun.
 491	 */
 492
 493	cmd = (struct scsi_cmnd *) hostdata->input_Q;
 494	prev = NULL;
 495	while (cmd) {
 496		if (!(hostdata->busy[cmd->device->id] &
 497		      (1 << (cmd->device->lun & 0xff))))
 498			break;
 499		prev = cmd;
 500		cmd = (struct scsi_cmnd *) cmd->host_scribble;
 501	}
 502
 503	/* quit if queue empty or all possible targets are busy */
 504
 505	if (!cmd) {
 506		DB(DB_EXECUTE, printk(")EX-1 "))
 507		return;
 508	}
 509
 510	/*  remove command from queue */
 511
 512	if (prev)
 513		prev->host_scribble = cmd->host_scribble;
 514	else
 515		hostdata->input_Q = (struct scsi_cmnd *) cmd->host_scribble;
 516
 517#ifdef PROC_STATISTICS
 518	hostdata->cmd_cnt[cmd->device->id]++;
 519#endif
 520
 521	/*
 522	 * Start the selection process
 523	 */
 524
 525	if (cmd->sc_data_direction == DMA_TO_DEVICE)
 526		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
 527	else
 528		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id | DSTID_DPD);
 529
 530/* Now we need to figure out whether or not this command is a good
 531 * candidate for disconnect/reselect. We guess to the best of our
 532 * ability, based on a set of hierarchical rules. When several
 533 * devices are operating simultaneously, disconnects are usually
 534 * an advantage. In a single device system, or if only 1 device
 535 * is being accessed, transfers usually go faster if disconnects
 536 * are not allowed:
 537 *
 538 * + Commands should NEVER disconnect if hostdata->disconnect =
 539 *   DIS_NEVER (this holds for tape drives also), and ALWAYS
 540 *   disconnect if hostdata->disconnect = DIS_ALWAYS.
 541 * + Tape drive commands should always be allowed to disconnect.
 542 * + Disconnect should be allowed if disconnected_Q isn't empty.
 543 * + Commands should NOT disconnect if input_Q is empty.
 544 * + Disconnect should be allowed if there are commands in input_Q
 545 *   for a different target/lun. In this case, the other commands
 546 *   should be made disconnect-able, if not already.
 547 *
 548 * I know, I know - this code would flunk me out of any
 549 * "C Programming 101" class ever offered. But it's easy
 550 * to change around and experiment with for now.
 551 */
 552
 553	cmd->SCp.phase = 0;	/* assume no disconnect */
 554	if (hostdata->disconnect == DIS_NEVER)
 555		goto no;
 556	if (hostdata->disconnect == DIS_ALWAYS)
 557		goto yes;
 558	if (cmd->device->type == 1)	/* tape drive? */
 559		goto yes;
 560	if (hostdata->disconnected_Q)	/* other commands disconnected? */
 561		goto yes;
 562	if (!(hostdata->input_Q))	/* input_Q empty? */
 563		goto no;
 564	for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
 565	     prev = (struct scsi_cmnd *) prev->host_scribble) {
 566		if ((prev->device->id != cmd->device->id) ||
 567		    (prev->device->lun != cmd->device->lun)) {
 568			for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
 569			     prev = (struct scsi_cmnd *) prev->host_scribble)
 570				prev->SCp.phase = 1;
 571			goto yes;
 572		}
 573	}
 574
 575	goto no;
 576
 577 yes:
 578	cmd->SCp.phase = 1;
 579
 580#ifdef PROC_STATISTICS
 581	hostdata->disc_allowed_cnt[cmd->device->id]++;
 582#endif
 583
 584 no:
 585
 586	write_wd33c93(regs, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0));
 587
 588	write_wd33c93(regs, WD_TARGET_LUN, (u8)cmd->device->lun);
 589	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
 590		      hostdata->sync_xfer[cmd->device->id]);
 591	hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
 592
 593	if ((hostdata->level2 == L2_NONE) ||
 594	    (hostdata->sync_stat[cmd->device->id] == SS_UNSET)) {
 595
 596		/*
 597		 * Do a 'Select-With-ATN' command. This will end with
 598		 * one of the following interrupts:
 599		 *    CSR_RESEL_AM:  failure - can try again later.
 600		 *    CSR_TIMEOUT:   failure - give up.
 601		 *    CSR_SELECT:    success - proceed.
 602		 */
 603
 604		hostdata->selecting = cmd;
 605
 606/* Every target has its own synchronous transfer setting, kept in the
 607 * sync_xfer array, and a corresponding status byte in sync_stat[].
 608 * Each target's sync_stat[] entry is initialized to SX_UNSET, and its
 609 * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET
 610 * means that the parameters are undetermined as yet, and that we
 611 * need to send an SDTR message to this device after selection is
 612 * complete: We set SS_FIRST to tell the interrupt routine to do so.
 613 * If we've been asked not to try synchronous transfers on this
 614 * target (and _all_ luns within it), we'll still send the SDTR message
 615 * later, but at that time we'll negotiate for async by specifying a
 616 * sync fifo depth of 0.
 617 */
 618		if (hostdata->sync_stat[cmd->device->id] == SS_UNSET)
 619			hostdata->sync_stat[cmd->device->id] = SS_FIRST;
 620		hostdata->state = S_SELECTING;
 621		write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
 622		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN);
 623	} else {
 624
 625		/*
 626		 * Do a 'Select-With-ATN-Xfer' command. This will end with
 627		 * one of the following interrupts:
 628		 *    CSR_RESEL_AM:  failure - can try again later.
 629		 *    CSR_TIMEOUT:   failure - give up.
 630		 *    anything else: success - proceed.
 631		 */
 632
 633		hostdata->connected = cmd;
 634		write_wd33c93(regs, WD_COMMAND_PHASE, 0);
 635
 636		/* copy command_descriptor_block into WD chip
 637		 * (take advantage of auto-incrementing)
 638		 */
 639
 640		write_wd33c93_cdb(regs, cmd->cmd_len, cmd->cmnd);
 641
 642		/* The wd33c93 only knows about Group 0, 1, and 5 commands when
 643		 * it's doing a 'select-and-transfer'. To be safe, we write the
 644		 * size of the CDB into the OWN_ID register for every case. This
 645		 * way there won't be problems with vendor-unique, audio, etc.
 646		 */
 647
 648		write_wd33c93(regs, WD_OWN_ID, cmd->cmd_len);
 649
 650		/* When doing a non-disconnect command with DMA, we can save
 651		 * ourselves a DATA phase interrupt later by setting everything
 652		 * up ahead of time.
 653		 */
 654
 655		if ((cmd->SCp.phase == 0) && (hostdata->no_dma == 0)) {
 656			if (hostdata->dma_setup(cmd,
 657			    (cmd->sc_data_direction == DMA_TO_DEVICE) ?
 658			     DATA_OUT_DIR : DATA_IN_DIR))
 659				write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
 660			else {
 661				write_wd33c93_count(regs,
 662						    cmd->SCp.this_residual);
 663				write_wd33c93(regs, WD_CONTROL,
 664					      CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
 665				hostdata->dma = D_DMA_RUNNING;
 666			}
 667		} else
 668			write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
 669
 670		hostdata->state = S_RUNNING_LEVEL2;
 671		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
 672	}
 673
 674	/*
 675	 * Since the SCSI bus can handle only 1 connection at a time,
 676	 * we get out of here now. If the selection fails, or when
 677	 * the command disconnects, we'll come back to this routine
 678	 * to search the input_Q again...
 679	 */
 680
 681	DB(DB_EXECUTE,
 682	   printk("%s)EX-2 ", (cmd->SCp.phase) ? "d:" : ""))
 683}
 684
 685static void
 686transfer_pio(const wd33c93_regs regs, uchar * buf, int cnt,
 687	     int data_in_dir, struct WD33C93_hostdata *hostdata)
 688{
 689	uchar asr;
 690
 691	DB(DB_TRANSFER,
 692	   printk("(%p,%d,%s:", buf, cnt, data_in_dir ? "in" : "out"))
 693
 694	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
 695	write_wd33c93_count(regs, cnt);
 696	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
 697	if (data_in_dir) {
 698		do {
 699			asr = read_aux_stat(regs);
 700			if (asr & ASR_DBR)
 701				*buf++ = read_wd33c93(regs, WD_DATA);
 702		} while (!(asr & ASR_INT));
 703	} else {
 704		do {
 705			asr = read_aux_stat(regs);
 706			if (asr & ASR_DBR)
 707				write_wd33c93(regs, WD_DATA, *buf++);
 708		} while (!(asr & ASR_INT));
 709	}
 710
 711	/* Note: we are returning with the interrupt UN-cleared.
 712	 * Since (presumably) an entire I/O operation has
 713	 * completed, the bus phase is probably different, and
 714	 * the interrupt routine will discover this when it
 715	 * responds to the uncleared int.
 716	 */
 717
 718}
 719
 720static void
 721transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
 722		int data_in_dir)
 723{
 724	struct WD33C93_hostdata *hostdata;
 725	unsigned long length;
 726
 727	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
 728
 729/* Normally, you'd expect 'this_residual' to be non-zero here.
 730 * In a series of scatter-gather transfers, however, this
 731 * routine will usually be called with 'this_residual' equal
 732 * to 0 and 'buffers_residual' non-zero. This means that a
 733 * previous transfer completed, clearing 'this_residual', and
 734 * now we need to setup the next scatter-gather buffer as the
 735 * source or destination for THIS transfer.
 736 */
 737	if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
 738		cmd->SCp.buffer = sg_next(cmd->SCp.buffer);
 739		--cmd->SCp.buffers_residual;
 740		cmd->SCp.this_residual = cmd->SCp.buffer->length;
 741		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 742	}
 743	if (!cmd->SCp.this_residual) /* avoid bogus setups */
 744		return;
 745
 746	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
 747		      hostdata->sync_xfer[cmd->device->id]);
 748
 749/* 'hostdata->no_dma' is TRUE if we don't even want to try DMA.
 750 * Update 'this_residual' and 'ptr' after 'transfer_pio()' returns.
 751 */
 752
 753	if (hostdata->no_dma || hostdata->dma_setup(cmd, data_in_dir)) {
 754#ifdef PROC_STATISTICS
 755		hostdata->pio_cnt++;
 756#endif
 757		transfer_pio(regs, (uchar *) cmd->SCp.ptr,
 758			     cmd->SCp.this_residual, data_in_dir, hostdata);
 759		length = cmd->SCp.this_residual;
 760		cmd->SCp.this_residual = read_wd33c93_count(regs);
 761		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
 762	}
 763
 764/* We are able to do DMA (in fact, the Amiga hardware is
 765 * already going!), so start up the wd33c93 in DMA mode.
 766 * We set 'hostdata->dma' = D_DMA_RUNNING so that when the
 767 * transfer completes and causes an interrupt, we're
 768 * reminded to tell the Amiga to shut down its end. We'll
 769 * postpone the updating of 'this_residual' and 'ptr'
 770 * until then.
 771 */
 772
 773	else {
 774#ifdef PROC_STATISTICS
 775		hostdata->dma_cnt++;
 776#endif
 777		write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
 778		write_wd33c93_count(regs, cmd->SCp.this_residual);
 779
 780		if ((hostdata->level2 >= L2_DATA) ||
 781		    (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
 782			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
 783			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
 784			hostdata->state = S_RUNNING_LEVEL2;
 785		} else
 786			write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
 787
 788		hostdata->dma = D_DMA_RUNNING;
 789	}
 790}
 791
 792void
 793wd33c93_intr(struct Scsi_Host *instance)
 794{
 795	struct WD33C93_hostdata *hostdata =
 796	    (struct WD33C93_hostdata *) instance->hostdata;
 797	const wd33c93_regs regs = hostdata->regs;
 798	struct scsi_cmnd *patch, *cmd;
 799	uchar asr, sr, phs, id, lun, *ucp, msg;
 800	unsigned long length, flags;
 801
 802	asr = read_aux_stat(regs);
 803	if (!(asr & ASR_INT) || (asr & ASR_BSY))
 804		return;
 805
 806	spin_lock_irqsave(&hostdata->lock, flags);
 807
 808#ifdef PROC_STATISTICS
 809	hostdata->int_cnt++;
 810#endif
 811
 812	cmd = (struct scsi_cmnd *) hostdata->connected;	/* assume we're connected */
 813	sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear the interrupt */
 814	phs = read_wd33c93(regs, WD_COMMAND_PHASE);
 815
 816	DB(DB_INTR, printk("{%02x:%02x-", asr, sr))
 817
 818/* After starting a DMA transfer, the next interrupt
 819 * is guaranteed to be in response to completion of
 820 * the transfer. Since the Amiga DMA hardware runs in
 821 * in an open-ended fashion, it needs to be told when
 822 * to stop; do that here if D_DMA_RUNNING is true.
 823 * Also, we have to update 'this_residual' and 'ptr'
 824 * based on the contents of the TRANSFER_COUNT register,
 825 * in case the device decided to do an intermediate
 826 * disconnect (a device may do this if it has to do a
 827 * seek, or just to be nice and let other devices have
 828 * some bus time during long transfers). After doing
 829 * whatever is needed, we go on and service the WD3393
 830 * interrupt normally.
 831 */
 832	    if (hostdata->dma == D_DMA_RUNNING) {
 833		DB(DB_TRANSFER,
 834		   printk("[%p/%d:", cmd->SCp.ptr, cmd->SCp.this_residual))
 835		    hostdata->dma_stop(cmd->device->host, cmd, 1);
 836		hostdata->dma = D_DMA_OFF;
 837		length = cmd->SCp.this_residual;
 838		cmd->SCp.this_residual = read_wd33c93_count(regs);
 839		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
 840		DB(DB_TRANSFER,
 841		   printk("%p/%d]", cmd->SCp.ptr, cmd->SCp.this_residual))
 842	}
 843
 844/* Respond to the specific WD3393 interrupt - there are quite a few! */
 845	switch (sr) {
 846	case CSR_TIMEOUT:
 847		DB(DB_INTR, printk("TIMEOUT"))
 848
 849		    if (hostdata->state == S_RUNNING_LEVEL2)
 850			hostdata->connected = NULL;
 851		else {
 852			cmd = (struct scsi_cmnd *) hostdata->selecting;	/* get a valid cmd */
 853			hostdata->selecting = NULL;
 854		}
 855
 856		cmd->result = DID_NO_CONNECT << 16;
 857		hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
 858		hostdata->state = S_UNCONNECTED;
 859		cmd->scsi_done(cmd);
 860
 861		/* From esp.c:
 862		 * There is a window of time within the scsi_done() path
 863		 * of execution where interrupts are turned back on full
 864		 * blast and left that way.  During that time we could
 865		 * reconnect to a disconnected command, then we'd bomb
 866		 * out below.  We could also end up executing two commands
 867		 * at _once_.  ...just so you know why the restore_flags()
 868		 * is here...
 869		 */
 870
 871		spin_unlock_irqrestore(&hostdata->lock, flags);
 872
 873/* We are not connected to a target - check to see if there
 874 * are commands waiting to be executed.
 875 */
 876
 877		wd33c93_execute(instance);
 878		break;
 879
 880/* Note: this interrupt should not occur in a LEVEL2 command */
 881
 882	case CSR_SELECT:
 883		DB(DB_INTR, printk("SELECT"))
 884		    hostdata->connected = cmd =
 885		    (struct scsi_cmnd *) hostdata->selecting;
 886		hostdata->selecting = NULL;
 887
 888		/* construct an IDENTIFY message with correct disconnect bit */
 889
 890		hostdata->outgoing_msg[0] = IDENTIFY(0, cmd->device->lun);
 891		if (cmd->SCp.phase)
 892			hostdata->outgoing_msg[0] |= 0x40;
 893
 894		if (hostdata->sync_stat[cmd->device->id] == SS_FIRST) {
 895
 896			hostdata->sync_stat[cmd->device->id] = SS_WAITING;
 897
 898/* Tack on a 2nd message to ask about synchronous transfers. If we've
 899 * been asked to do only asynchronous transfers on this device, we
 900 * request a fifo depth of 0, which is equivalent to async - should
 901 * solve the problems some people have had with GVP's Guru ROM.
 902 */
 903
 904			hostdata->outgoing_msg[1] = EXTENDED_MESSAGE;
 905			hostdata->outgoing_msg[2] = 3;
 906			hostdata->outgoing_msg[3] = EXTENDED_SDTR;
 907			if (hostdata->no_sync & (1 << cmd->device->id)) {
 908				calc_sync_msg(hostdata->default_sx_per, 0,
 909						0, hostdata->outgoing_msg + 4);
 910			} else {
 911				calc_sync_msg(optimum_sx_per(hostdata),
 912						OPTIMUM_SX_OFF,
 913						hostdata->fast,
 914						hostdata->outgoing_msg + 4);
 915			}
 916			hostdata->outgoing_len = 6;
 917#ifdef SYNC_DEBUG
 918			ucp = hostdata->outgoing_msg + 1;
 919			printk(" sending SDTR %02x03%02x%02x%02x ",
 920				ucp[0], ucp[2], ucp[3], ucp[4]);
 921#endif
 922		} else
 923			hostdata->outgoing_len = 1;
 924
 925		hostdata->state = S_CONNECTED;
 926		spin_unlock_irqrestore(&hostdata->lock, flags);
 927		break;
 928
 929	case CSR_XFER_DONE | PHS_DATA_IN:
 930	case CSR_UNEXP | PHS_DATA_IN:
 931	case CSR_SRV_REQ | PHS_DATA_IN:
 932		DB(DB_INTR,
 933		   printk("IN-%d.%d", cmd->SCp.this_residual,
 934			  cmd->SCp.buffers_residual))
 935		    transfer_bytes(regs, cmd, DATA_IN_DIR);
 936		if (hostdata->state != S_RUNNING_LEVEL2)
 937			hostdata->state = S_CONNECTED;
 938		spin_unlock_irqrestore(&hostdata->lock, flags);
 939		break;
 940
 941	case CSR_XFER_DONE | PHS_DATA_OUT:
 942	case CSR_UNEXP | PHS_DATA_OUT:
 943	case CSR_SRV_REQ | PHS_DATA_OUT:
 944		DB(DB_INTR,
 945		   printk("OUT-%d.%d", cmd->SCp.this_residual,
 946			  cmd->SCp.buffers_residual))
 947		    transfer_bytes(regs, cmd, DATA_OUT_DIR);
 948		if (hostdata->state != S_RUNNING_LEVEL2)
 949			hostdata->state = S_CONNECTED;
 950		spin_unlock_irqrestore(&hostdata->lock, flags);
 951		break;
 952
 953/* Note: this interrupt should not occur in a LEVEL2 command */
 954
 955	case CSR_XFER_DONE | PHS_COMMAND:
 956	case CSR_UNEXP | PHS_COMMAND:
 957	case CSR_SRV_REQ | PHS_COMMAND:
 958		DB(DB_INTR, printk("CMND-%02x", cmd->cmnd[0]))
 959		    transfer_pio(regs, cmd->cmnd, cmd->cmd_len, DATA_OUT_DIR,
 960				 hostdata);
 961		hostdata->state = S_CONNECTED;
 962		spin_unlock_irqrestore(&hostdata->lock, flags);
 963		break;
 964
 965	case CSR_XFER_DONE | PHS_STATUS:
 966	case CSR_UNEXP | PHS_STATUS:
 967	case CSR_SRV_REQ | PHS_STATUS:
 968		DB(DB_INTR, printk("STATUS="))
 969		cmd->SCp.Status = read_1_byte(regs);
 970		DB(DB_INTR, printk("%02x", cmd->SCp.Status))
 971		    if (hostdata->level2 >= L2_BASIC) {
 972			sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
 973			udelay(7);
 974			hostdata->state = S_RUNNING_LEVEL2;
 975			write_wd33c93(regs, WD_COMMAND_PHASE, 0x50);
 976			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
 977		} else {
 978			hostdata->state = S_CONNECTED;
 979		}
 980		spin_unlock_irqrestore(&hostdata->lock, flags);
 981		break;
 982
 983	case CSR_XFER_DONE | PHS_MESS_IN:
 984	case CSR_UNEXP | PHS_MESS_IN:
 985	case CSR_SRV_REQ | PHS_MESS_IN:
 986		DB(DB_INTR, printk("MSG_IN="))
 987
 988		msg = read_1_byte(regs);
 989		sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
 990		udelay(7);
 991
 992		hostdata->incoming_msg[hostdata->incoming_ptr] = msg;
 993		if (hostdata->incoming_msg[0] == EXTENDED_MESSAGE)
 994			msg = EXTENDED_MESSAGE;
 995		else
 996			hostdata->incoming_ptr = 0;
 997
 998		cmd->SCp.Message = msg;
 999		switch (msg) {
1000
1001		case COMMAND_COMPLETE:
1002			DB(DB_INTR, printk("CCMP"))
1003			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1004			hostdata->state = S_PRE_CMP_DISC;
1005			break;
1006
1007		case SAVE_POINTERS:
1008			DB(DB_INTR, printk("SDP"))
1009			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1010			hostdata->state = S_CONNECTED;
1011			break;
1012
1013		case RESTORE_POINTERS:
1014			DB(DB_INTR, printk("RDP"))
1015			    if (hostdata->level2 >= L2_BASIC) {
1016				write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
1017				write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1018				hostdata->state = S_RUNNING_LEVEL2;
1019			} else {
1020				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1021				hostdata->state = S_CONNECTED;
1022			}
1023			break;
1024
1025		case DISCONNECT:
1026			DB(DB_INTR, printk("DIS"))
1027			    cmd->device->disconnect = 1;
1028			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1029			hostdata->state = S_PRE_TMP_DISC;
1030			break;
1031
1032		case MESSAGE_REJECT:
1033			DB(DB_INTR, printk("REJ"))
1034#ifdef SYNC_DEBUG
1035			    printk("-REJ-");
1036#endif
1037			if (hostdata->sync_stat[cmd->device->id] == SS_WAITING) {
1038				hostdata->sync_stat[cmd->device->id] = SS_SET;
1039				/* we want default_sx_per, not DEFAULT_SX_PER */
1040				hostdata->sync_xfer[cmd->device->id] =
1041					calc_sync_xfer(hostdata->default_sx_per
1042						/ 4, 0, 0, hostdata->sx_table);
1043			}
1044			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1045			hostdata->state = S_CONNECTED;
1046			break;
1047
1048		case EXTENDED_MESSAGE:
1049			DB(DB_INTR, printk("EXT"))
1050
1051			    ucp = hostdata->incoming_msg;
1052
1053#ifdef SYNC_DEBUG
1054			printk("%02x", ucp[hostdata->incoming_ptr]);
1055#endif
1056			/* Is this the last byte of the extended message? */
1057
1058			if ((hostdata->incoming_ptr >= 2) &&
1059			    (hostdata->incoming_ptr == (ucp[1] + 1))) {
1060
1061				switch (ucp[2]) {	/* what's the EXTENDED code? */
1062				case EXTENDED_SDTR:
1063					/* default to default async period */
1064					id = calc_sync_xfer(hostdata->
1065							default_sx_per / 4, 0,
1066							0, hostdata->sx_table);
1067					if (hostdata->sync_stat[cmd->device->id] !=
1068					    SS_WAITING) {
1069
1070/* A device has sent an unsolicited SDTR message; rather than go
1071 * through the effort of decoding it and then figuring out what
1072 * our reply should be, we're just gonna say that we have a
1073 * synchronous fifo depth of 0. This will result in asynchronous
1074 * transfers - not ideal but so much easier.
1075 * Actually, this is OK because it assures us that if we don't
1076 * specifically ask for sync transfers, we won't do any.
1077 */
1078
1079						write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1080						hostdata->outgoing_msg[0] =
1081						    EXTENDED_MESSAGE;
1082						hostdata->outgoing_msg[1] = 3;
1083						hostdata->outgoing_msg[2] =
1084						    EXTENDED_SDTR;
1085						calc_sync_msg(hostdata->
1086							default_sx_per, 0,
1087							0, hostdata->outgoing_msg + 3);
1088						hostdata->outgoing_len = 5;
1089					} else {
1090						if (ucp[4]) /* well, sync transfer */
1091							id = calc_sync_xfer(ucp[3], ucp[4],
1092									hostdata->fast,
1093									hostdata->sx_table);
1094						else if (ucp[3]) /* very unlikely... */
1095							id = calc_sync_xfer(ucp[3], ucp[4],
1096									0, hostdata->sx_table);
1097					}
1098					hostdata->sync_xfer[cmd->device->id] = id;
1099#ifdef SYNC_DEBUG
1100					printk(" sync_xfer=%02x\n",
1101					       hostdata->sync_xfer[cmd->device->id]);
1102#endif
1103					hostdata->sync_stat[cmd->device->id] =
1104					    SS_SET;
1105					write_wd33c93_cmd(regs,
1106							  WD_CMD_NEGATE_ACK);
1107					hostdata->state = S_CONNECTED;
1108					break;
1109				case EXTENDED_WDTR:
1110					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1111					printk("sending WDTR ");
1112					hostdata->outgoing_msg[0] =
1113					    EXTENDED_MESSAGE;
1114					hostdata->outgoing_msg[1] = 2;
1115					hostdata->outgoing_msg[2] =
1116					    EXTENDED_WDTR;
1117					hostdata->outgoing_msg[3] = 0;	/* 8 bit transfer width */
1118					hostdata->outgoing_len = 4;
1119					write_wd33c93_cmd(regs,
1120							  WD_CMD_NEGATE_ACK);
1121					hostdata->state = S_CONNECTED;
1122					break;
1123				default:
1124					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1125					printk
1126					    ("Rejecting Unknown Extended Message(%02x). ",
1127					     ucp[2]);
1128					hostdata->outgoing_msg[0] =
1129					    MESSAGE_REJECT;
1130					hostdata->outgoing_len = 1;
1131					write_wd33c93_cmd(regs,
1132							  WD_CMD_NEGATE_ACK);
1133					hostdata->state = S_CONNECTED;
1134					break;
1135				}
1136				hostdata->incoming_ptr = 0;
1137			}
1138
1139			/* We need to read more MESS_IN bytes for the extended message */
1140
1141			else {
1142				hostdata->incoming_ptr++;
1143				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1144				hostdata->state = S_CONNECTED;
1145			}
1146			break;
1147
1148		default:
1149			printk("Rejecting Unknown Message(%02x) ", msg);
1150			write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
1151			hostdata->outgoing_msg[0] = MESSAGE_REJECT;
1152			hostdata->outgoing_len = 1;
1153			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1154			hostdata->state = S_CONNECTED;
1155		}
1156		spin_unlock_irqrestore(&hostdata->lock, flags);
1157		break;
1158
1159/* Note: this interrupt will occur only after a LEVEL2 command */
1160
1161	case CSR_SEL_XFER_DONE:
1162
1163/* Make sure that reselection is enabled at this point - it may
1164 * have been turned off for the command that just completed.
1165 */
1166
1167		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1168		if (phs == 0x60) {
1169			DB(DB_INTR, printk("SX-DONE"))
1170			    cmd->SCp.Message = COMMAND_COMPLETE;
1171			lun = read_wd33c93(regs, WD_TARGET_LUN);
1172			DB(DB_INTR, printk(":%d.%d", cmd->SCp.Status, lun))
1173			    hostdata->connected = NULL;
1174			hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1175			hostdata->state = S_UNCONNECTED;
1176			if (cmd->SCp.Status == ILLEGAL_STATUS_BYTE)
1177				cmd->SCp.Status = lun;
1178			if (cmd->cmnd[0] == REQUEST_SENSE
1179			    && cmd->SCp.Status != GOOD)
1180				cmd->result =
1181				    (cmd->
1182				     result & 0x00ffff) | (DID_ERROR << 16);
1183			else
1184				cmd->result =
1185				    cmd->SCp.Status | (cmd->SCp.Message << 8);
1186			cmd->scsi_done(cmd);
1187
1188/* We are no longer  connected to a target - check to see if
1189 * there are commands waiting to be executed.
1190 */
1191			spin_unlock_irqrestore(&hostdata->lock, flags);
1192			wd33c93_execute(instance);
1193		} else {
1194			printk
1195			    ("%02x:%02x:%02x: Unknown SEL_XFER_DONE phase!!---",
1196			     asr, sr, phs);
1197			spin_unlock_irqrestore(&hostdata->lock, flags);
1198		}
1199		break;
1200
1201/* Note: this interrupt will occur only after a LEVEL2 command */
1202
1203	case CSR_SDP:
1204		DB(DB_INTR, printk("SDP"))
1205		    hostdata->state = S_RUNNING_LEVEL2;
1206		write_wd33c93(regs, WD_COMMAND_PHASE, 0x41);
1207		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1208		spin_unlock_irqrestore(&hostdata->lock, flags);
1209		break;
1210
1211	case CSR_XFER_DONE | PHS_MESS_OUT:
1212	case CSR_UNEXP | PHS_MESS_OUT:
1213	case CSR_SRV_REQ | PHS_MESS_OUT:
1214		DB(DB_INTR, printk("MSG_OUT="))
1215
1216/* To get here, we've probably requested MESSAGE_OUT and have
1217 * already put the correct bytes in outgoing_msg[] and filled
1218 * in outgoing_len. We simply send them out to the SCSI bus.
1219 * Sometimes we get MESSAGE_OUT phase when we're not expecting
1220 * it - like when our SDTR message is rejected by a target. Some
1221 * targets send the REJECT before receiving all of the extended
1222 * message, and then seem to go back to MESSAGE_OUT for a byte
1223 * or two. Not sure why, or if I'm doing something wrong to
1224 * cause this to happen. Regardless, it seems that sending
1225 * NOP messages in these situations results in no harm and
1226 * makes everyone happy.
1227 */
1228		    if (hostdata->outgoing_len == 0) {
1229			hostdata->outgoing_len = 1;
1230			hostdata->outgoing_msg[0] = NOP;
1231		}
1232		transfer_pio(regs, hostdata->outgoing_msg,
1233			     hostdata->outgoing_len, DATA_OUT_DIR, hostdata);
1234		DB(DB_INTR, printk("%02x", hostdata->outgoing_msg[0]))
1235		    hostdata->outgoing_len = 0;
1236		hostdata->state = S_CONNECTED;
1237		spin_unlock_irqrestore(&hostdata->lock, flags);
1238		break;
1239
1240	case CSR_UNEXP_DISC:
1241
1242/* I think I've seen this after a request-sense that was in response
1243 * to an error condition, but not sure. We certainly need to do
1244 * something when we get this interrupt - the question is 'what?'.
1245 * Let's think positively, and assume some command has finished
1246 * in a legal manner (like a command that provokes a request-sense),
1247 * so we treat it as a normal command-complete-disconnect.
1248 */
1249
1250/* Make sure that reselection is enabled at this point - it may
1251 * have been turned off for the command that just completed.
1252 */
1253
1254		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1255		if (cmd == NULL) {
1256			printk(" - Already disconnected! ");
1257			hostdata->state = S_UNCONNECTED;
1258			spin_unlock_irqrestore(&hostdata->lock, flags);
1259			return;
1260		}
1261		DB(DB_INTR, printk("UNEXP_DISC"))
1262		    hostdata->connected = NULL;
1263		hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1264		hostdata->state = S_UNCONNECTED;
1265		if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
1266			cmd->result =
1267			    (cmd->result & 0x00ffff) | (DID_ERROR << 16);
1268		else
1269			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
1270		cmd->scsi_done(cmd);
1271
1272/* We are no longer connected to a target - check to see if
1273 * there are commands waiting to be executed.
1274 */
1275		/* look above for comments on scsi_done() */
1276		spin_unlock_irqrestore(&hostdata->lock, flags);
1277		wd33c93_execute(instance);
1278		break;
1279
1280	case CSR_DISC:
1281
1282/* Make sure that reselection is enabled at this point - it may
1283 * have been turned off for the command that just completed.
1284 */
1285
1286		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
1287		DB(DB_INTR, printk("DISC"))
1288		    if (cmd == NULL) {
1289			printk(" - Already disconnected! ");
1290			hostdata->state = S_UNCONNECTED;
1291		}
1292		switch (hostdata->state) {
1293		case S_PRE_CMP_DISC:
1294			hostdata->connected = NULL;
1295			hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1296			hostdata->state = S_UNCONNECTED;
1297			DB(DB_INTR, printk(":%d", cmd->SCp.Status))
1298			    if (cmd->cmnd[0] == REQUEST_SENSE
1299				&& cmd->SCp.Status != GOOD)
1300				cmd->result =
1301				    (cmd->
1302				     result & 0x00ffff) | (DID_ERROR << 16);
1303			else
1304				cmd->result =
1305				    cmd->SCp.Status | (cmd->SCp.Message << 8);
1306			cmd->scsi_done(cmd);
1307			break;
1308		case S_PRE_TMP_DISC:
1309		case S_RUNNING_LEVEL2:
1310			cmd->host_scribble = (uchar *) hostdata->disconnected_Q;
1311			hostdata->disconnected_Q = cmd;
1312			hostdata->connected = NULL;
1313			hostdata->state = S_UNCONNECTED;
1314
1315#ifdef PROC_STATISTICS
1316			hostdata->disc_done_cnt[cmd->device->id]++;
1317#endif
1318
1319			break;
1320		default:
1321			printk("*** Unexpected DISCONNECT interrupt! ***");
1322			hostdata->state = S_UNCONNECTED;
1323		}
1324
1325/* We are no longer connected to a target - check to see if
1326 * there are commands waiting to be executed.
1327 */
1328		spin_unlock_irqrestore(&hostdata->lock, flags);
1329		wd33c93_execute(instance);
1330		break;
1331
1332	case CSR_RESEL_AM:
1333	case CSR_RESEL:
1334		DB(DB_INTR, printk("RESEL%s", sr == CSR_RESEL_AM ? "_AM" : ""))
1335
1336		    /* Old chips (pre -A ???) don't have advanced features and will
1337		     * generate CSR_RESEL.  In that case we have to extract the LUN the
1338		     * hard way (see below).
1339		     * First we have to make sure this reselection didn't
1340		     * happen during Arbitration/Selection of some other device.
1341		     * If yes, put losing command back on top of input_Q.
1342		     */
1343		    if (hostdata->level2 <= L2_NONE) {
1344
1345			if (hostdata->selecting) {
1346				cmd = (struct scsi_cmnd *) hostdata->selecting;
1347				hostdata->selecting = NULL;
1348				hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xff));
1349				cmd->host_scribble =
1350				    (uchar *) hostdata->input_Q;
1351				hostdata->input_Q = cmd;
1352			}
1353		}
1354
1355		else {
1356
1357			if (cmd) {
1358				if (phs == 0x00) {
1359					hostdata->busy[cmd->device->id] &=
1360						~(1 << (cmd->device->lun & 0xff));
1361					cmd->host_scribble =
1362					    (uchar *) hostdata->input_Q;
1363					hostdata->input_Q = cmd;
1364				} else {
1365					printk
1366					    ("---%02x:%02x:%02x-TROUBLE: Intrusive ReSelect!---",
1367					     asr, sr, phs);
1368					while (1)
1369						printk("\r");
1370				}
1371			}
1372
1373		}
1374
1375		/* OK - find out which device reselected us. */
1376
1377		id = read_wd33c93(regs, WD_SOURCE_ID);
1378		id &= SRCID_MASK;
1379
1380		/* and extract the lun from the ID message. (Note that we don't
1381		 * bother to check for a valid message here - I guess this is
1382		 * not the right way to go, but...)
1383		 */
1384
1385		if (sr == CSR_RESEL_AM) {
1386			lun = read_wd33c93(regs, WD_DATA);
1387			if (hostdata->level2 < L2_RESELECT)
1388				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
1389			lun &= 7;
1390		} else {
1391			/* Old chip; wait for msgin phase to pick up the LUN. */
1392			for (lun = 255; lun; lun--) {
1393				if ((asr = read_aux_stat(regs)) & ASR_INT)
1394					break;
1395				udelay(10);
1396			}
1397			if (!(asr & ASR_INT)) {
1398				printk
1399				    ("wd33c93: Reselected without IDENTIFY\n");
1400				lun = 0;
1401			} else {
1402				/* Verify this is a change to MSG_IN and read the message */
1403				sr = read_wd33c93(regs, WD_SCSI_STATUS);
1404				udelay(7);
1405				if (sr == (CSR_ABORT | PHS_MESS_IN) ||
1406				    sr == (CSR_UNEXP | PHS_MESS_IN) ||
1407				    sr == (CSR_SRV_REQ | PHS_MESS_IN)) {
1408					/* Got MSG_IN, grab target LUN */
1409					lun = read_1_byte(regs);
1410					/* Now we expect a 'paused with ACK asserted' int.. */
1411					asr = read_aux_stat(regs);
1412					if (!(asr & ASR_INT)) {
1413						udelay(10);
1414						asr = read_aux_stat(regs);
1415						if (!(asr & ASR_INT))
1416							printk
1417							    ("wd33c93: No int after LUN on RESEL (%02x)\n",
1418							     asr);
1419					}
1420					sr = read_wd33c93(regs, WD_SCSI_STATUS);
1421					udelay(7);
1422					if (sr != CSR_MSGIN)
1423						printk
1424						    ("wd33c93: Not paused with ACK on RESEL (%02x)\n",
1425						     sr);
1426					lun &= 7;
1427					write_wd33c93_cmd(regs,
1428							  WD_CMD_NEGATE_ACK);
1429				} else {
1430					printk
1431					    ("wd33c93: Not MSG_IN on reselect (%02x)\n",
1432					     sr);
1433					lun = 0;
1434				}
1435			}
1436		}
1437
1438		/* Now we look for the command that's reconnecting. */
1439
1440		cmd = (struct scsi_cmnd *) hostdata->disconnected_Q;
1441		patch = NULL;
1442		while (cmd) {
1443			if (id == cmd->device->id && lun == (u8)cmd->device->lun)
1444				break;
1445			patch = cmd;
1446			cmd = (struct scsi_cmnd *) cmd->host_scribble;
1447		}
1448
1449		/* Hmm. Couldn't find a valid command.... What to do? */
1450
1451		if (!cmd) {
1452			printk
1453			    ("---TROUBLE: target %d.%d not in disconnect queue---",
1454			     id, (u8)lun);
1455			spin_unlock_irqrestore(&hostdata->lock, flags);
1456			return;
1457		}
1458
1459		/* Ok, found the command - now start it up again. */
1460
1461		if (patch)
1462			patch->host_scribble = cmd->host_scribble;
1463		else
1464			hostdata->disconnected_Q =
1465			    (struct scsi_cmnd *) cmd->host_scribble;
1466		hostdata->connected = cmd;
1467
1468		/* We don't need to worry about 'initialize_SCp()' or 'hostdata->busy[]'
1469		 * because these things are preserved over a disconnect.
1470		 * But we DO need to fix the DPD bit so it's correct for this command.
1471		 */
1472
1473		if (cmd->sc_data_direction == DMA_TO_DEVICE)
1474			write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
1475		else
1476			write_wd33c93(regs, WD_DESTINATION_ID,
1477				      cmd->device->id | DSTID_DPD);
1478		if (hostdata->level2 >= L2_RESELECT) {
1479			write_wd33c93_count(regs, 0);	/* we want a DATA_PHASE interrupt */
1480			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
1481			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
1482			hostdata->state = S_RUNNING_LEVEL2;
1483		} else
1484			hostdata->state = S_CONNECTED;
1485
1486		    spin_unlock_irqrestore(&hostdata->lock, flags);
1487		break;
1488
1489	default:
1490		printk("--UNKNOWN INTERRUPT:%02x:%02x:%02x--", asr, sr, phs);
1491		spin_unlock_irqrestore(&hostdata->lock, flags);
1492	}
1493
1494	DB(DB_INTR, printk("} "))
1495
1496}
1497
1498static void
1499reset_wd33c93(struct Scsi_Host *instance)
1500{
1501	struct WD33C93_hostdata *hostdata =
1502	    (struct WD33C93_hostdata *) instance->hostdata;
1503	const wd33c93_regs regs = hostdata->regs;
1504	uchar sr;
1505
1506#ifdef CONFIG_SGI_IP22
1507	{
1508		int busycount = 0;
1509		extern void sgiwd93_reset(unsigned long);
1510		/* wait 'til the chip gets some time for us */
1511		while ((read_aux_stat(regs) & ASR_BSY) && busycount++ < 100)
1512			udelay (10);
1513	/*
1514 	 * there are scsi devices out there, which manage to lock up
1515	 * the wd33c93 in a busy condition. In this state it won't
1516	 * accept the reset command. The only way to solve this is to
1517 	 * give the chip a hardware reset (if possible). The code below
1518	 * does this for the SGI Indy, where this is possible
1519	 */
1520	/* still busy ? */
1521	if (read_aux_stat(regs) & ASR_BSY)
1522		sgiwd93_reset(instance->base); /* yeah, give it the hard one */
1523	}
1524#endif
1525
1526	write_wd33c93(regs, WD_OWN_ID, OWNID_EAF | OWNID_RAF |
1527		      instance->this_id | hostdata->clock_freq);
1528	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1529	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
1530		      calc_sync_xfer(hostdata->default_sx_per / 4,
1531				     DEFAULT_SX_OFF, 0, hostdata->sx_table));
1532	write_wd33c93(regs, WD_COMMAND, WD_CMD_RESET);
1533
1534
1535#ifdef CONFIG_MVME147_SCSI
1536	udelay(25);		/* The old wd33c93 on MVME147 needs this, at least */
1537#endif
1538
1539	while (!(read_aux_stat(regs) & ASR_INT))
1540		;
1541	sr = read_wd33c93(regs, WD_SCSI_STATUS);
1542
1543	hostdata->microcode = read_wd33c93(regs, WD_CDB_1);
1544	if (sr == 0x00)
1545		hostdata->chip = C_WD33C93;
1546	else if (sr == 0x01) {
1547		write_wd33c93(regs, WD_QUEUE_TAG, 0xa5);	/* any random number */
1548		sr = read_wd33c93(regs, WD_QUEUE_TAG);
1549		if (sr == 0xa5) {
1550			hostdata->chip = C_WD33C93B;
1551			write_wd33c93(regs, WD_QUEUE_TAG, 0);
1552		} else
1553			hostdata->chip = C_WD33C93A;
1554	} else
1555		hostdata->chip = C_UNKNOWN_CHIP;
1556
1557	if (hostdata->chip != C_WD33C93B)	/* Fast SCSI unavailable */
1558		hostdata->fast = 0;
1559
1560	write_wd33c93(regs, WD_TIMEOUT_PERIOD, TIMEOUT_PERIOD_VALUE);
1561	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
1562}
1563
1564int
1565wd33c93_host_reset(struct scsi_cmnd * SCpnt)
1566{
1567	struct Scsi_Host *instance;
1568	struct WD33C93_hostdata *hostdata;
1569	int i;
1570
1571	instance = SCpnt->device->host;
1572	spin_lock_irq(instance->host_lock);
1573	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
1574
1575	printk("scsi%d: reset. ", instance->host_no);
1576	disable_irq(instance->irq);
1577
1578	hostdata->dma_stop(instance, NULL, 0);
1579	for (i = 0; i < 8; i++) {
1580		hostdata->busy[i] = 0;
1581		hostdata->sync_xfer[i] =
1582			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
1583					0, hostdata->sx_table);
1584		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
1585	}
1586	hostdata->input_Q = NULL;
1587	hostdata->selecting = NULL;
1588	hostdata->connected = NULL;
1589	hostdata->disconnected_Q = NULL;
1590	hostdata->state = S_UNCONNECTED

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