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/drivers/scsi/arm/acornscsi.c

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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/drivers/acorn/scsi/acornscsi.c
   4 *
   5 *  Acorn SCSI 3 driver
   6 *  By R.M.King.
   7 *
   8 * Abandoned using the Select and Transfer command since there were
   9 * some nasty races between our software and the target devices that
  10 * were not easy to solve, and the device errata had a lot of entries
  11 * for this command, some of them quite nasty...
  12 *
  13 * Changelog:
  14 *  26-Sep-1997	RMK	Re-jigged to use the queue module.
  15 *			Re-coded state machine to be based on driver
  16 *			state not scsi state.  Should be easier to debug.
  17 *			Added acornscsi_release to clean up properly.
  18 *			Updated proc/scsi reporting.
  19 *  05-Oct-1997	RMK	Implemented writing to SCSI devices.
  20 *  06-Oct-1997	RMK	Corrected small (non-serious) bug with the connect/
  21 *			reconnect race condition causing a warning message.
  22 *  12-Oct-1997	RMK	Added catch for re-entering interrupt routine.
  23 *  15-Oct-1997	RMK	Improved handling of commands.
  24 *  27-Jun-1998	RMK	Changed asm/delay.h to linux/delay.h.
  25 *  13-Dec-1998	RMK	Better abort code and command handling.  Extra state
  26 *			transitions added to allow dodgy devices to work.
  27 */
  28#define DEBUG_NO_WRITE	1
  29#define DEBUG_QUEUES	2
  30#define DEBUG_DMA	4
  31#define DEBUG_ABORT	8
  32#define DEBUG_DISCON	16
  33#define DEBUG_CONNECT	32
  34#define DEBUG_PHASES	64
  35#define DEBUG_WRITE	128
  36#define DEBUG_LINK	256
  37#define DEBUG_MESSAGES	512
  38#define DEBUG_RESET	1024
  39#define DEBUG_ALL	(DEBUG_RESET|DEBUG_MESSAGES|DEBUG_LINK|DEBUG_WRITE|\
  40			 DEBUG_PHASES|DEBUG_CONNECT|DEBUG_DISCON|DEBUG_ABORT|\
  41			 DEBUG_DMA|DEBUG_QUEUES)
  42
  43/* DRIVER CONFIGURATION
  44 *
  45 * SCSI-II Tagged queue support.
  46 *
  47 * I don't have any SCSI devices that support it, so it is totally untested
  48 * (except to make sure that it doesn't interfere with any non-tagging
  49 * devices).  It is not fully implemented either - what happens when a
  50 * tagging device reconnects???
  51 *
  52 * You can tell if you have a device that supports tagged queueing my
  53 * cating (eg) /proc/scsi/acornscsi/0 and see if the SCSI revision is reported
  54 * as '2 TAG'.
  55 *
  56 * Also note that CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE is normally set in the config
  57 * scripts, but disabled here.  Once debugged, remove the #undef, otherwise to debug,
  58 * comment out the undef.
  59 */
  60#undef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
  61/*
  62 * SCSI-II Synchronous transfer support.
  63 *
  64 * Tried and tested...
  65 *
  66 * SDTR_SIZE	  - maximum number of un-acknowledged bytes (0 = off, 12 = max)
  67 * SDTR_PERIOD	  - period of REQ signal (min=125, max=1020)
  68 * DEFAULT_PERIOD - default REQ period.
  69 */
  70#define SDTR_SIZE	12
  71#define SDTR_PERIOD	125
  72#define DEFAULT_PERIOD	500
  73
  74/*
  75 * Debugging information
  76 *
  77 * DEBUG	  - bit mask from list above
  78 * DEBUG_TARGET   - is defined to the target number if you want to debug
  79 *		    a specific target. [only recon/write/dma].
  80 */
  81#define DEBUG (DEBUG_RESET|DEBUG_WRITE|DEBUG_NO_WRITE)
  82/* only allow writing to SCSI device 0 */
  83#define NO_WRITE 0xFE
  84/*#define DEBUG_TARGET 2*/
  85/*
  86 * Select timeout time (in 10ms units)
  87 *
  88 * This is the timeout used between the start of selection and the WD33C93
  89 * chip deciding that the device isn't responding.
  90 */
  91#define TIMEOUT_TIME 10
  92/*
  93 * Define this if you want to have verbose explanation of SCSI
  94 * status/messages.
  95 */
  96#undef CONFIG_ACORNSCSI_CONSTANTS
  97/*
  98 * Define this if you want to use the on board DMAC [don't remove this option]
  99 * If not set, then use PIO mode (not currently supported).
 100 */
 101#define USE_DMAC
 102
 103/*
 104 * ====================================================================================
 105 */
 106
 107#ifdef DEBUG_TARGET
 108#define DBG(cmd,xxx...) \
 109  if (cmd->device->id == DEBUG_TARGET) { \
 110    xxx; \
 111  }
 112#else
 113#define DBG(cmd,xxx...) xxx
 114#endif
 115
 116#include <linux/module.h>
 117#include <linux/kernel.h>
 118#include <linux/string.h>
 119#include <linux/signal.h>
 120#include <linux/errno.h>
 121#include <linux/proc_fs.h>
 122#include <linux/ioport.h>
 123#include <linux/blkdev.h>
 124#include <linux/delay.h>
 125#include <linux/interrupt.h>
 126#include <linux/init.h>
 127#include <linux/bitops.h>
 128#include <linux/stringify.h>
 129#include <linux/io.h>
 130
 131#include <asm/ecard.h>
 132
 133#include "../scsi.h"
 134#include <scsi/scsi_dbg.h>
 135#include <scsi/scsi_host.h>
 136#include <scsi/scsi_transport_spi.h>
 137#include "acornscsi.h"
 138#include "msgqueue.h"
 139#include "scsi.h"
 140
 141#include <scsi/scsicam.h>
 142
 143#define VER_MAJOR 2
 144#define VER_MINOR 0
 145#define VER_PATCH 6
 146
 147#ifndef ABORT_TAG
 148#define ABORT_TAG 0xd
 149#else
 150#error "Yippee!  ABORT TAG is now defined!  Remove this error!"
 151#endif
 152
 153#ifdef USE_DMAC
 154/*
 155 * DMAC setup parameters
 156 */ 
 157#define INIT_DEVCON0	(DEVCON0_RQL|DEVCON0_EXW|DEVCON0_CMP)
 158#define INIT_DEVCON1	(DEVCON1_BHLD)
 159#define DMAC_READ	(MODECON_READ)
 160#define DMAC_WRITE	(MODECON_WRITE)
 161#define INIT_SBICDMA	(CTRL_DMABURST)
 162
 163#define scsi_xferred	have_data_in
 164
 165/*
 166 * Size of on-board DMA buffer
 167 */
 168#define DMAC_BUFFER_SIZE	65536
 169#endif
 170
 171#define STATUS_BUFFER_TO_PRINT	24
 172
 173unsigned int sdtr_period = SDTR_PERIOD;
 174unsigned int sdtr_size   = SDTR_SIZE;
 175
 176static void acornscsi_done(AS_Host *host, struct scsi_cmnd **SCpntp,
 177			   unsigned int result);
 178static int acornscsi_reconnect_finish(AS_Host *host);
 179static void acornscsi_dma_cleanup(AS_Host *host);
 180static void acornscsi_abortcmd(AS_Host *host, unsigned char tag);
 181
 182/* ====================================================================================
 183 * Miscellaneous
 184 */
 185
 186/* Offsets from MEMC base */
 187#define SBIC_REGIDX	0x2000
 188#define SBIC_REGVAL	0x2004
 189#define DMAC_OFFSET	0x3000
 190
 191/* Offsets from FAST IOC base */
 192#define INT_REG		0x2000
 193#define PAGE_REG	0x3000
 194
 195static inline void sbic_arm_write(AS_Host *host, unsigned int reg, unsigned int value)
 196{
 197    writeb(reg, host->base + SBIC_REGIDX);
 198    writeb(value, host->base + SBIC_REGVAL);
 199}
 200
 201static inline int sbic_arm_read(AS_Host *host, unsigned int reg)
 202{
 203    if(reg == SBIC_ASR)
 204	   return readl(host->base + SBIC_REGIDX) & 255;
 205    writeb(reg, host->base + SBIC_REGIDX);
 206    return readl(host->base + SBIC_REGVAL) & 255;
 207}
 208
 209#define sbic_arm_writenext(host, val)	writeb((val), (host)->base + SBIC_REGVAL)
 210#define sbic_arm_readnext(host) 	readb((host)->base + SBIC_REGVAL)
 211
 212#ifdef USE_DMAC
 213#define dmac_read(host,reg) \
 214	readb((host)->base + DMAC_OFFSET + ((reg) << 2))
 215
 216#define dmac_write(host,reg,value) \
 217	({ writeb((value), (host)->base + DMAC_OFFSET + ((reg) << 2)); })
 218
 219#define dmac_clearintr(host) 	writeb(0, (host)->fast + INT_REG)
 220
 221static inline unsigned int dmac_address(AS_Host *host)
 222{
 223    return dmac_read(host, DMAC_TXADRHI) << 16 |
 224	   dmac_read(host, DMAC_TXADRMD) << 8 |
 225	   dmac_read(host, DMAC_TXADRLO);
 226}
 227
 228static
 229void acornscsi_dumpdma(AS_Host *host, char *where)
 230{
 231	unsigned int mode, addr, len;
 232
 233	mode = dmac_read(host, DMAC_MODECON);
 234	addr = dmac_address(host);
 235	len  = dmac_read(host, DMAC_TXCNTHI) << 8 |
 236	       dmac_read(host, DMAC_TXCNTLO);
 237
 238	printk("scsi%d: %s: DMAC %02x @%06x+%04x msk %02x, ",
 239		host->host->host_no, where,
 240		mode, addr, (len + 1) & 0xffff,
 241		dmac_read(host, DMAC_MASKREG));
 242
 243	printk("DMA @%06x, ", host->dma.start_addr);
 244	printk("BH @%p +%04x, ", host->scsi.SCp.ptr,
 245		host->scsi.SCp.this_residual);
 246	printk("DT @+%04x ST @+%04x", host->dma.transferred,
 247		host->scsi.SCp.scsi_xferred);
 248	printk("\n");
 249}
 250#endif
 251
 252static
 253unsigned long acornscsi_sbic_xfcount(AS_Host *host)
 254{
 255    unsigned long length;
 256
 257    length = sbic_arm_read(host, SBIC_TRANSCNTH) << 16;
 258    length |= sbic_arm_readnext(host) << 8;
 259    length |= sbic_arm_readnext(host);
 260
 261    return length;
 262}
 263
 264static int
 265acornscsi_sbic_wait(AS_Host *host, int stat_mask, int stat, int timeout, char *msg)
 266{
 267	int asr;
 268
 269	do {
 270		asr = sbic_arm_read(host, SBIC_ASR);
 271
 272		if ((asr & stat_mask) == stat)
 273			return 0;
 274
 275		udelay(1);
 276	} while (--timeout);
 277
 278	printk("scsi%d: timeout while %s\n", host->host->host_no, msg);
 279
 280	return -1;
 281}
 282
 283static
 284int acornscsi_sbic_issuecmd(AS_Host *host, int command)
 285{
 286    if (acornscsi_sbic_wait(host, ASR_CIP, 0, 1000, "issuing command"))
 287	return -1;
 288
 289    sbic_arm_write(host, SBIC_CMND, command);
 290
 291    return 0;
 292}
 293
 294static void
 295acornscsi_csdelay(unsigned int cs)
 296{
 297    unsigned long target_jiffies, flags;
 298
 299    target_jiffies = jiffies + 1 + cs * HZ / 100;
 300
 301    local_save_flags(flags);
 302    local_irq_enable();
 303
 304    while (time_before(jiffies, target_jiffies)) barrier();
 305
 306    local_irq_restore(flags);
 307}
 308
 309static
 310void acornscsi_resetcard(AS_Host *host)
 311{
 312    unsigned int i, timeout;
 313
 314    /* assert reset line */
 315    host->card.page_reg = 0x80;
 316    writeb(host->card.page_reg, host->fast + PAGE_REG);
 317
 318    /* wait 3 cs.  SCSI standard says 25ms. */
 319    acornscsi_csdelay(3);
 320
 321    host->card.page_reg = 0;
 322    writeb(host->card.page_reg, host->fast + PAGE_REG);
 323
 324    /*
 325     * Should get a reset from the card
 326     */
 327    timeout = 1000;
 328    do {
 329	if (readb(host->fast + INT_REG) & 8)
 330	    break;
 331	udelay(1);
 332    } while (--timeout);
 333
 334    if (timeout == 0)
 335	printk("scsi%d: timeout while resetting card\n",
 336		host->host->host_no);
 337
 338    sbic_arm_read(host, SBIC_ASR);
 339    sbic_arm_read(host, SBIC_SSR);
 340
 341    /* setup sbic - WD33C93A */
 342    sbic_arm_write(host, SBIC_OWNID, OWNID_EAF | host->host->this_id);
 343    sbic_arm_write(host, SBIC_CMND, CMND_RESET);
 344
 345    /*
 346     * Command should cause a reset interrupt
 347     */
 348    timeout = 1000;
 349    do {
 350	if (readb(host->fast + INT_REG) & 8)
 351	    break;
 352	udelay(1);
 353    } while (--timeout);
 354
 355    if (timeout == 0)
 356	printk("scsi%d: timeout while resetting card\n",
 357		host->host->host_no);
 358
 359    sbic_arm_read(host, SBIC_ASR);
 360    if (sbic_arm_read(host, SBIC_SSR) != 0x01)
 361	printk(KERN_CRIT "scsi%d: WD33C93A didn't give enhanced reset interrupt\n",
 362		host->host->host_no);
 363
 364    sbic_arm_write(host, SBIC_CTRL, INIT_SBICDMA | CTRL_IDI);
 365    sbic_arm_write(host, SBIC_TIMEOUT, TIMEOUT_TIME);
 366    sbic_arm_write(host, SBIC_SYNCHTRANSFER, SYNCHTRANSFER_2DBA);
 367    sbic_arm_write(host, SBIC_SOURCEID, SOURCEID_ER | SOURCEID_DSP);
 368
 369    host->card.page_reg = 0x40;
 370    writeb(host->card.page_reg, host->fast + PAGE_REG);
 371
 372    /* setup dmac - uPC71071 */
 373    dmac_write(host, DMAC_INIT, 0);
 374#ifdef USE_DMAC
 375    dmac_write(host, DMAC_INIT, INIT_8BIT);
 376    dmac_write(host, DMAC_CHANNEL, CHANNEL_0);
 377    dmac_write(host, DMAC_DEVCON0, INIT_DEVCON0);
 378    dmac_write(host, DMAC_DEVCON1, INIT_DEVCON1);
 379#endif
 380
 381    host->SCpnt = NULL;
 382    host->scsi.phase = PHASE_IDLE;
 383    host->scsi.disconnectable = 0;
 384
 385    memset(host->busyluns, 0, sizeof(host->busyluns));
 386
 387    for (i = 0; i < 8; i++) {
 388	host->device[i].sync_state = SYNC_NEGOCIATE;
 389	host->device[i].disconnect_ok = 1;
 390    }
 391
 392    /* wait 25 cs.  SCSI standard says 250ms. */
 393    acornscsi_csdelay(25);
 394}
 395
 396/*=============================================================================================
 397 * Utility routines (eg. debug)
 398 */
 399#ifdef CONFIG_ACORNSCSI_CONSTANTS
 400static char *acornscsi_interrupttype[] = {
 401  "rst",  "suc",  "p/a",  "3",
 402  "term", "5",	  "6",	  "7",
 403  "serv", "9",	  "a",	  "b",
 404  "c",	  "d",	  "e",	  "f"
 405};
 406
 407static signed char acornscsi_map[] = {
 408  0,  1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 409 -1,  2, -1, -1,  -1, -1,  3, -1,   4,	5,  6,	7,   8,  9, 10, 11,
 410 12, 13, 14, -1,  -1, -1, -1, -1,   4,	5,  6,	7,   8,  9, 10, 11,
 411 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 412 15, 16, 17, 18,  19, -1, -1, 20,   4,	5,  6,	7,   8,  9, 10, 11,
 413 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 414 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 415 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 416 21, 22, -1, -1,  -1, 23, -1, -1,   4,	5,  6,	7,   8,  9, 10, 11,
 417 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 418 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 419 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 420 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 421 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 422 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
 423 -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1
 424};      
 425
 426static char *acornscsi_interruptcode[] = {
 427    /* 0 */
 428    "reset - normal mode",	/* 00 */
 429    "reset - advanced mode",	/* 01 */
 430
 431    /* 2 */
 432    "sel",			/* 11 */
 433    "sel+xfer", 		/* 16 */
 434    "data-out", 		/* 18 */
 435    "data-in",			/* 19 */
 436    "cmd",			/* 1A */
 437    "stat",			/* 1B */
 438    "??-out",			/* 1C */
 439    "??-in",			/* 1D */
 440    "msg-out",			/* 1E */
 441    "msg-in",			/* 1F */
 442
 443    /* 12 */
 444    "/ACK asserted",		/* 20 */
 445    "save-data-ptr",		/* 21 */
 446    "{re}sel",			/* 22 */
 447
 448    /* 15 */
 449    "inv cmd",			/* 40 */
 450    "unexpected disconnect",	/* 41 */
 451    "sel timeout",		/* 42 */
 452    "P err",			/* 43 */
 453    "P err+ATN",		/* 44 */
 454    "bad status byte",		/* 47 */
 455
 456    /* 21 */
 457    "resel, no id",		/* 80 */
 458    "resel",			/* 81 */
 459    "discon",			/* 85 */
 460};
 461
 462static
 463void print_scsi_status(unsigned int ssr)
 464{
 465    if (acornscsi_map[ssr] != -1)
 466	printk("%s:%s",
 467		acornscsi_interrupttype[(ssr >> 4)],
 468		acornscsi_interruptcode[acornscsi_map[ssr]]);
 469    else
 470	printk("%X:%X", ssr >> 4, ssr & 0x0f);    
 471}    
 472#endif
 473
 474static
 475void print_sbic_status(int asr, int ssr, int cmdphase)
 476{
 477#ifdef CONFIG_ACORNSCSI_CONSTANTS
 478    printk("sbic: %c%c%c%c%c%c ",
 479	    asr & ASR_INT ? 'I' : 'i',
 480	    asr & ASR_LCI ? 'L' : 'l',
 481	    asr & ASR_BSY ? 'B' : 'b',
 482	    asr & ASR_CIP ? 'C' : 'c',
 483	    asr & ASR_PE  ? 'P' : 'p',
 484	    asr & ASR_DBR ? 'D' : 'd');
 485    printk("scsi: ");
 486    print_scsi_status(ssr);
 487    printk(" ph %02X\n", cmdphase);
 488#else
 489    printk("sbic: %02X scsi: %X:%X ph: %02X\n",
 490	    asr, (ssr & 0xf0)>>4, ssr & 0x0f, cmdphase);
 491#endif
 492}
 493
 494static void
 495acornscsi_dumplogline(AS_Host *host, int target, int line)
 496{
 497	unsigned long prev;
 498	signed int ptr;
 499
 500	ptr = host->status_ptr[target] - STATUS_BUFFER_TO_PRINT;
 501	if (ptr < 0)
 502		ptr += STATUS_BUFFER_SIZE;
 503
 504	printk("%c: %3s:", target == 8 ? 'H' : '0' + target,
 505		line == 0 ? "ph" : line == 1 ? "ssr" : "int");
 506
 507	prev = host->status[target][ptr].when;
 508
 509	for (; ptr != host->status_ptr[target]; ptr = (ptr + 1) & (STATUS_BUFFER_SIZE - 1)) {
 510		unsigned long time_diff;
 511
 512		if (!host->status[target][ptr].when)
 513			continue;
 514
 515		switch (line) {
 516		case 0:
 517			printk("%c%02X", host->status[target][ptr].irq ? '-' : ' ',
 518					 host->status[target][ptr].ph);
 519			break;
 520
 521		case 1:
 522			printk(" %02X", host->status[target][ptr].ssr);
 523			break;
 524
 525		case 2:
 526			time_diff = host->status[target][ptr].when - prev;
 527			prev = host->status[target][ptr].when;
 528			if (time_diff == 0)
 529				printk("==^");
 530			else if (time_diff >= 100)
 531				printk("   ");
 532			else
 533				printk(" %02ld", time_diff);
 534			break;
 535		}
 536	}
 537
 538	printk("\n");
 539}
 540
 541static
 542void acornscsi_dumplog(AS_Host *host, int target)
 543{
 544    do {
 545	acornscsi_dumplogline(host, target, 0);
 546	acornscsi_dumplogline(host, target, 1);
 547	acornscsi_dumplogline(host, target, 2);
 548
 549	if (target == 8)
 550	    break;
 551
 552	target = 8;
 553    } while (1);
 554}
 555
 556static
 557char acornscsi_target(AS_Host *host)
 558{
 559	if (host->SCpnt)
 560		return '0' + host->SCpnt->device->id;
 561	return 'H';
 562}
 563
 564/*
 565 * Prototype: cmdtype_t acornscsi_cmdtype(int command)
 566 * Purpose  : differentiate READ from WRITE from other commands
 567 * Params   : command - command to interpret
 568 * Returns  : CMD_READ	- command reads data,
 569 *	      CMD_WRITE - command writes data,
 570 *	      CMD_MISC	- everything else
 571 */
 572static inline
 573cmdtype_t acornscsi_cmdtype(int command)
 574{
 575    switch (command) {
 576    case WRITE_6:  case WRITE_10:  case WRITE_12:
 577	return CMD_WRITE;
 578    case READ_6:   case READ_10:   case READ_12:
 579	return CMD_READ;
 580    default:
 581	return CMD_MISC;
 582    }
 583}
 584
 585/*
 586 * Prototype: int acornscsi_datadirection(int command)
 587 * Purpose  : differentiate between commands that have a DATA IN phase
 588 *	      and a DATA OUT phase
 589 * Params   : command - command to interpret
 590 * Returns  : DATADIR_OUT - data out phase expected
 591 *	      DATADIR_IN  - data in phase expected
 592 */
 593static
 594datadir_t acornscsi_datadirection(int command)
 595{
 596    switch (command) {
 597    case CHANGE_DEFINITION:	case COMPARE:		case COPY:
 598    case COPY_VERIFY:		case LOG_SELECT:	case MODE_SELECT:
 599    case MODE_SELECT_10:	case SEND_DIAGNOSTIC:	case WRITE_BUFFER:
 600    case FORMAT_UNIT:		case REASSIGN_BLOCKS:	case RESERVE:
 601    case SEARCH_EQUAL:		case SEARCH_HIGH:	case SEARCH_LOW:
 602    case WRITE_6:		case WRITE_10:		case WRITE_VERIFY:
 603    case UPDATE_BLOCK:		case WRITE_LONG:	case WRITE_SAME:
 604    case SEARCH_HIGH_12:	case SEARCH_EQUAL_12:	case SEARCH_LOW_12:
 605    case WRITE_12:		case WRITE_VERIFY_12:	case SET_WINDOW:
 606    case MEDIUM_SCAN:		case SEND_VOLUME_TAG:	case 0xea:
 607	return DATADIR_OUT;
 608    default:
 609	return DATADIR_IN;
 610    }
 611}
 612
 613/*
 614 * Purpose  : provide values for synchronous transfers with 33C93.
 615 * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
 616 *	Modified by Russell King for 8MHz WD33C93A
 617 */
 618static struct sync_xfer_tbl {
 619    unsigned int period_ns;
 620    unsigned char reg_value;
 621} sync_xfer_table[] = {
 622    {	1, 0x20 },    { 249, 0x20 },	{ 374, 0x30 },
 623    { 499, 0x40 },    { 624, 0x50 },	{ 749, 0x60 },
 624    { 874, 0x70 },    { 999, 0x00 },	{   0,	  0 }
 625};
 626
 627/*
 628 * Prototype: int acornscsi_getperiod(unsigned char syncxfer)
 629 * Purpose  : period for the synchronous transfer setting
 630 * Params   : syncxfer SYNCXFER register value
 631 * Returns  : period in ns.
 632 */
 633static
 634int acornscsi_getperiod(unsigned char syncxfer)
 635{
 636    int i;
 637
 638    syncxfer &= 0xf0;
 639    if (syncxfer == 0x10)
 640	syncxfer = 0;
 641
 642    for (i = 1; sync_xfer_table[i].period_ns; i++)
 643	if (syncxfer == sync_xfer_table[i].reg_value)
 644	    return sync_xfer_table[i].period_ns;
 645    return 0;
 646}
 647
 648/*
 649 * Prototype: int round_period(unsigned int period)
 650 * Purpose  : return index into above table for a required REQ period
 651 * Params   : period - time (ns) for REQ
 652 * Returns  : table index
 653 * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
 654 */
 655static inline
 656int round_period(unsigned int period)
 657{
 658    int i;
 659
 660    for (i = 1; sync_xfer_table[i].period_ns; i++) {
 661	if ((period <= sync_xfer_table[i].period_ns) &&
 662	    (period > sync_xfer_table[i - 1].period_ns))
 663	    return i;
 664    }
 665    return 7;
 666}
 667
 668/*
 669 * Prototype: unsigned char calc_sync_xfer(unsigned int period, unsigned int offset)
 670 * Purpose  : calculate value for 33c93s SYNC register
 671 * Params   : period - time (ns) for REQ
 672 *	      offset - offset in bytes between REQ/ACK
 673 * Returns  : value for SYNC register
 674 * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
 675 */
 676static
 677unsigned char __maybe_unused calc_sync_xfer(unsigned int period,
 678					    unsigned int offset)
 679{
 680    return sync_xfer_table[round_period(period)].reg_value |
 681		((offset < SDTR_SIZE) ? offset : SDTR_SIZE);
 682}
 683
 684/* ====================================================================================
 685 * Command functions
 686 */
 687/*
 688 * Function: acornscsi_kick(AS_Host *host)
 689 * Purpose : kick next command to interface
 690 * Params  : host - host to send command to
 691 * Returns : INTR_IDLE if idle, otherwise INTR_PROCESSING
 692 * Notes   : interrupts are always disabled!
 693 */
 694static
 695intr_ret_t acornscsi_kick(AS_Host *host)
 696{
 697    int from_queue = 0;
 698    struct scsi_cmnd *SCpnt;
 699
 700    /* first check to see if a command is waiting to be executed */
 701    SCpnt = host->origSCpnt;
 702    host->origSCpnt = NULL;
 703
 704    /* retrieve next command */
 705    if (!SCpnt) {
 706	SCpnt = queue_remove_exclude(&host->queues.issue, host->busyluns);
 707	if (!SCpnt)
 708	    return INTR_IDLE;
 709
 710	from_queue = 1;
 711    }
 712
 713    if (host->scsi.disconnectable && host->SCpnt) {
 714	queue_add_cmd_tail(&host->queues.disconnected, host->SCpnt);
 715	host->scsi.disconnectable = 0;
 716#if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
 717	DBG(host->SCpnt, printk("scsi%d.%c: moved command to disconnected queue\n",
 718		host->host->host_no, acornscsi_target(host)));
 719#endif
 720	host->SCpnt = NULL;
 721    }
 722
 723    /*
 724     * If we have an interrupt pending, then we may have been reselected.
 725     * In this case, we don't want to write to the registers
 726     */
 727    if (!(sbic_arm_read(host, SBIC_ASR) & (ASR_INT|ASR_BSY|ASR_CIP))) {
 728	sbic_arm_write(host, SBIC_DESTID, SCpnt->device->id);
 729	sbic_arm_write(host, SBIC_CMND, CMND_SELWITHATN);
 730    }
 731
 732    /*
 733     * claim host busy - all of these must happen atomically wrt
 734     * our interrupt routine.  Failure means command loss.
 735     */
 736    host->scsi.phase = PHASE_CONNECTING;
 737    host->SCpnt = SCpnt;
 738    host->scsi.SCp = SCpnt->SCp;
 739    host->dma.xfer_setup = 0;
 740    host->dma.xfer_required = 0;
 741    host->dma.xfer_done = 0;
 742
 743#if (DEBUG & (DEBUG_ABORT|DEBUG_CONNECT))
 744    DBG(SCpnt,printk("scsi%d.%c: starting cmd %02X\n",
 745	    host->host->host_no, '0' + SCpnt->device->id,
 746	    SCpnt->cmnd[0]));
 747#endif
 748
 749    if (from_queue) {
 750#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
 751	/*
 752	 * tagged queueing - allocate a new tag to this command
 753	 */
 754	if (SCpnt->device->simple_tags) {
 755	    SCpnt->device->current_tag += 1;
 756	    if (SCpnt->device->current_tag == 0)
 757		SCpnt->device->current_tag = 1;
 758	    SCpnt->tag = SCpnt->device->current_tag;
 759	} else
 760#endif
 761	    set_bit(SCpnt->device->id * 8 +
 762		    (u8)(SCpnt->device->lun & 0x07), host->busyluns);
 763
 764	host->stats.removes += 1;
 765
 766	switch (acornscsi_cmdtype(SCpnt->cmnd[0])) {
 767	case CMD_WRITE:
 768	    host->stats.writes += 1;
 769	    break;
 770	case CMD_READ:
 771	    host->stats.reads += 1;
 772	    break;
 773	case CMD_MISC:
 774	    host->stats.miscs += 1;
 775	    break;
 776	}
 777    }
 778
 779    return INTR_PROCESSING;
 780}    
 781
 782/*
 783 * Function: void acornscsi_done(AS_Host *host, struct scsi_cmnd **SCpntp, unsigned int result)
 784 * Purpose : complete processing for command
 785 * Params  : host   - interface that completed
 786 *	     result - driver byte of result
 787 */
 788static void acornscsi_done(AS_Host *host, struct scsi_cmnd **SCpntp,
 789			   unsigned int result)
 790{
 791	struct scsi_cmnd *SCpnt = *SCpntp;
 792
 793    /* clean up */
 794    sbic_arm_write(host, SBIC_SOURCEID, SOURCEID_ER | SOURCEID_DSP);
 795
 796    host->stats.fins += 1;
 797
 798    if (SCpnt) {
 799	*SCpntp = NULL;
 800
 801	acornscsi_dma_cleanup(host);
 802
 803	SCpnt->result = result << 16 | host->scsi.SCp.Message << 8 | host->scsi.SCp.Status;
 804
 805	/*
 806	 * In theory, this should not happen.  In practice, it seems to.
 807	 * Only trigger an error if the device attempts to report all happy
 808	 * but with untransferred buffers...  If we don't do something, then
 809	 * data loss will occur.  Should we check SCpnt->underflow here?
 810	 * It doesn't appear to be set to something meaningful by the higher
 811	 * levels all the time.
 812	 */
 813	if (result == DID_OK) {
 814		int xfer_warn = 0;
 815
 816		if (SCpnt->underflow == 0) {
 817			if (host->scsi.SCp.ptr &&
 818			    acornscsi_cmdtype(SCpnt->cmnd[0]) != CMD_MISC)
 819				xfer_warn = 1;
 820		} else {
 821			if (host->scsi.SCp.scsi_xferred < SCpnt->underflow ||
 822			    host->scsi.SCp.scsi_xferred != host->dma.transferred)
 823				xfer_warn = 1;
 824		}
 825
 826		/* ANSI standard says: (SCSI-2 Rev 10c Sect 5.6.6)
 827		 *  Targets which break data transfers into multiple
 828		 *  connections shall end each successful connection
 829		 *  (except possibly the last) with a SAVE DATA
 830		 *  POINTER - DISCONNECT message sequence.
 831		 *
 832		 * This makes it difficult to ensure that a transfer has
 833		 * completed.  If we reach the end of a transfer during
 834		 * the command, then we can only have finished the transfer.
 835		 * therefore, if we seem to have some data remaining, this
 836		 * is not a problem.
 837		 */
 838		if (host->dma.xfer_done)
 839			xfer_warn = 0;
 840
 841		if (xfer_warn) {
 842		    switch (status_byte(SCpnt->result)) {
 843		    case CHECK_CONDITION:
 844		    case COMMAND_TERMINATED:
 845		    case BUSY:
 846		    case QUEUE_FULL:
 847		    case RESERVATION_CONFLICT:
 848			break;
 849
 850		    default:
 851			scmd_printk(KERN_ERR, SCpnt,
 852				    "incomplete data transfer detected: "
 853				    "result=%08X", SCpnt->result);
 854			scsi_print_command(SCpnt);
 855			acornscsi_dumpdma(host, "done");
 856			acornscsi_dumplog(host, SCpnt->device->id);
 857			set_host_byte(SCpnt, DID_ERROR);
 858		    }
 859		}
 860	}
 861
 862	if (!SCpnt->scsi_done)
 863	    panic("scsi%d.H: null scsi_done function in acornscsi_done", host->host->host_no);
 864
 865	clear_bit(SCpnt->device->id * 8 +
 866		  (u8)(SCpnt->device->lun & 0x7), host->busyluns);
 867
 868	SCpnt->scsi_done(SCpnt);
 869    } else
 870	printk("scsi%d: null command in acornscsi_done", host->host->host_no);
 871
 872    host->scsi.phase = PHASE_IDLE;
 873}
 874
 875/* ====================================================================================
 876 * DMA routines
 877 */
 878/*
 879 * Purpose  : update SCSI Data Pointer
 880 * Notes    : this will only be one SG entry or less
 881 */
 882static
 883void acornscsi_data_updateptr(AS_Host *host, struct scsi_pointer *SCp, unsigned int length)
 884{
 885    SCp->ptr += length;
 886    SCp->this_residual -= length;
 887
 888    if (SCp->this_residual == 0 && next_SCp(SCp) == 0)
 889	host->dma.xfer_done = 1;
 890}
 891
 892/*
 893 * Prototype: void acornscsi_data_read(AS_Host *host, char *ptr,
 894 *				unsigned int start_addr, unsigned int length)
 895 * Purpose  : read data from DMA RAM
 896 * Params   : host - host to transfer from
 897 *	      ptr  - DRAM address
 898 *	      start_addr - host mem address
 899 *	      length - number of bytes to transfer
 900 * Notes    : this will only be one SG entry or less
 901 */
 902static
 903void acornscsi_data_read(AS_Host *host, char *ptr,
 904				 unsigned int start_addr, unsigned int length)
 905{
 906    extern void __acornscsi_in(void __iomem *, char *buf, int len);
 907    unsigned int page, offset, len = length;
 908
 909    page = (start_addr >> 12);
 910    offset = start_addr & ((1 << 12) - 1);
 911
 912    writeb((page & 0x3f) | host->card.page_reg, host->fast + PAGE_REG);
 913
 914    while (len > 0) {
 915	unsigned int this_len;
 916
 917	if (len + offset > (1 << 12))
 918	    this_len = (1 << 12) - offset;
 919	else
 920	    this_len = len;
 921
 922	__acornscsi_in(host->base + (offset << 1), ptr, this_len);
 923
 924	offset += this_len;
 925	ptr += this_len;
 926	len -= this_len;
 927
 928	if (offset == (1 << 12)) {
 929	    offset = 0;
 930	    page ++;
 931	    writeb((page & 0x3f) | host->card.page_reg, host->fast + PAGE_REG);
 932	}
 933    }
 934    writeb(host->card.page_reg, host->fast + PAGE_REG);
 935}
 936
 937/*
 938 * Prototype: void acornscsi_data_write(AS_Host *host, char *ptr,
 939 *				unsigned int start_addr, unsigned int length)
 940 * Purpose  : write data to DMA RAM
 941 * Params   : host - host to transfer from
 942 *	      ptr  - DRAM address
 943 *	      start_addr - host mem address
 944 *	      length - number of bytes to transfer
 945 * Notes    : this will only be one SG entry or less
 946 */
 947static
 948void acornscsi_data_write(AS_Host *host, char *ptr,
 949				 unsigned int start_addr, unsigned int length)
 950{
 951    extern void __acornscsi_out(void __iomem *, char *buf, int len);
 952    unsigned int page, offset, len = length;
 953
 954    page = (start_addr >> 12);
 955    offset = start_addr & ((1 << 12) - 1);
 956
 957    writeb((page & 0x3f) | host->card.page_reg, host->fast + PAGE_REG);
 958
 959    while (len > 0) {
 960	unsigned int this_len;
 961
 962	if (len + offset > (1 << 12))
 963	    this_len = (1 << 12) - offset;
 964	else
 965	    this_len = len;
 966
 967	__acornscsi_out(host->base + (offset << 1), ptr, this_len);
 968
 969	offset += this_len;
 970	ptr += this_len;
 971	len -= this_len;
 972
 973	if (offset == (1 << 12)) {
 974	    offset = 0;
 975	    page ++;
 976	    writeb((page & 0x3f) | host->card.page_reg, host->fast + PAGE_REG);
 977	}
 978    }
 979    writeb(host->card.page_reg, host->fast + PAGE_REG);
 980}
 981
 982/* =========================================================================================
 983 * On-board DMA routines
 984 */
 985#ifdef USE_DMAC
 986/*
 987 * Prototype: void acornscsi_dmastop(AS_Host *host)
 988 * Purpose  : stop all DMA
 989 * Params   : host - host on which to stop DMA
 990 * Notes    : This is called when leaving DATA IN/OUT phase,
 991 *	      or when interface is RESET
 992 */
 993static inline
 994void acornscsi_dma_stop(AS_Host *host)
 995{
 996    dmac_write(host, DMAC_MASKREG, MASK_ON);
 997    dmac_clearintr(host);
 998
 999#if (DEBUG & DEBUG_DMA)
1000    DBG(host->SCpnt, acornscsi_dumpdma(host, "stop"));
1001#endif
1002}
1003
1004/*
1005 * Function: void acornscsi_dma_setup(AS_Host *host, dmadir_t direction)
1006 * Purpose : setup DMA controller for data transfer
1007 * Params  : host - host to setup
1008 *	     direction - data transfer direction
1009 * Notes   : This is called when entering DATA I/O phase, not
1010 *	     while we're in a DATA I/O phase
1011 */
1012static
1013void acornscsi_dma_setup(AS_Host *host, dmadir_t direction)
1014{
1015    unsigned int address, length, mode;
1016
1017    host->dma.direction = direction;
1018
1019    dmac_write(host, DMAC_MASKREG, MASK_ON);
1020
1021    if (direction == DMA_OUT) {
1022#if (DEBUG & DEBUG_NO_WRITE)
1023	if (NO_WRITE & (1 << host->SCpnt->device->id)) {
1024	    printk(KERN_CRIT "scsi%d.%c: I can't handle DMA_OUT!\n",
1025		    host->host->host_no, acornscsi_target(host));
1026	    return;
1027	}
1028#endif
1029	mode = DMAC_WRITE;
1030    } else
1031	mode = DMAC_READ;
1032
1033    /*
1034     * Allocate some buffer space, limited to half the buffer size
1035     */
1036    length = min_t(unsigned int, host->scsi.SCp.this_residual, DMAC_BUFFER_SIZE / 2);
1037    if (length) {
1038	host->dma.start_addr = address = host->dma.free_addr;
1039	host->dma.free_addr = (host->dma.free_addr + length) &
1040				(DMAC_BUFFER_SIZE - 1);
1041
1042	/*
1043	 * Transfer data to DMA memory
1044	 */
1045	if (direction == DMA_OUT)
1046	    acornscsi_data_write(host, host->scsi.SCp.ptr, host->dma.start_addr,
1047				length);
1048
1049	length -= 1;
1050	dmac_write(host, DMAC_TXCNTLO, length);
1051	dmac_write(host, DMAC_TXCNTHI, length >> 8);
1052	dmac_write(host, DMAC_TXADRLO, address);
1053	dmac_write(host, DMAC_TXADRMD, address >> 8);
1054	dmac_write(host, DMAC_TXADRHI, 0);
1055	dmac_write(host, DMAC_MODECON, mode);
1056	dmac_write(host, DMAC_MASKREG, MASK_OFF);
1057
1058#if (DEBUG & DEBUG_DMA)
1059	DBG(host->SCpnt, acornscsi_dumpdma(host, "strt"));
1060#endif
1061	host->dma.xfer_setup = 1;
1062    }
1063}
1064
1065/*
1066 * Function: void acornscsi_dma_cleanup(AS_Host *host)
1067 * Purpose : ensure that all DMA transfers are up-to-date & host->scsi.SCp is correct
1068 * Params  : host - host to finish
1069 * Notes   : This is called when a command is:
1070 *		terminating, RESTORE_POINTERS, SAVE_POINTERS, DISCONNECT
1071 *	   : This must not return until all transfers are completed.
1072 */
1073static
1074void acornscsi_dma_cleanup(AS_Host *host)
1075{
1076    dmac_write(host, DMAC_MASKREG, MASK_ON);
1077    dmac_clearintr(host);
1078
1079    /*
1080     * Check for a pending transfer
1081     */
1082    if (host->dma.xfer_required) {
1083	host->dma.xfer_required = 0;
1084	if (host->dma.direction == DMA_IN)
1085	    acornscsi_data_read(host, host->dma.xfer_ptr,
1086				 host->dma.xfer_start, host->dma.xfer_length);
1087    }
1088
1089    /*
1090     * Has a transfer been setup?
1091     */
1092    if (host->dma.xfer_setup) {
1093	unsigned int transferred;
1094
1095	host->dma.xfer_setup = 0;
1096
1097#if (DEBUG & DEBUG_DMA)
1098	DBG(host->SCpnt, acornscsi_dumpdma(host, "cupi"));
1099#endif
1100
1101	/*
1102	 * Calculate number of bytes transferred from DMA.
1103	 */
1104	transferred = dmac_address(host) - host->dma.start_addr;
1105	host->dma.transferred += transferred;
1106
1107	if (host->dma.direction == DMA_IN)
1108	    acornscsi_data_read(host, host->scsi.SCp.ptr,
1109				 host->dma.start_addr, transferred);
1110
1111	/*
1112	 * Update SCSI pointers
1113	 */
1114	acornscsi_data_updateptr(host, &host->scsi.SCp, transferred);
1115#if (DEBUG & DEBUG_DMA)
1116	DBG(host->SCpnt, acornscsi_dumpdma(host, "cupo"));
1117#endif
1118    }
1119}
1120
1121/*
1122 * Function: void acornscsi_dmacintr(AS_Host *host)
1123 * Purpose : handle interrupts from DMAC device
1124 * Params  : host - host to process
1125 * Notes   : If reading, we schedule the read to main memory &
1126 *	     allow the transfer to continue.
1127 *	   : If writing, we fill the onboard DMA memory from main
1128 *	     memory.
1129 *	   : Called whenever DMAC finished it's current transfer.
1130 */
1131static
1132void acornscsi_dma_intr(AS_Host *host)
1133{
1134    unsigned int address, length, transferred;
1135
1136#if (DEBUG & DEBUG_DMA)
1137    DBG(host->SCpnt, acornscsi_dumpdma(host, "inti"));
1138#endif
1139
1140    dmac_write(host, DMAC_MASKREG, MASK_ON);
1141    dmac_clearintr(host);
1142
1143    /*
1144     * Calculate amount transferred via DMA
1145     */
1146    transferred = dmac_address(host) - host->dma.start_addr;
1147    host->dma.transferred += transferred;
1148
1149    /*
1150     * Schedule DMA transfer off board
1151     */
1152    if (host->dma.direction == DMA_IN) {
1153	host->dma.xfer_start = host->dma.start_addr;
1154	host->dma.xfer_length = transferred;
1155	host->dma.xfer_ptr = host->scsi.SCp.ptr;
1156	host->dma.xfer_required = 1;
1157    }
1158
1159    acornscsi_data_updateptr(host, &host->scsi.SCp, transferred);
1160
1161    /*
1162     * Allocate some buffer space, limited to half the on-board RAM size
1163     */
1164    length = min_t(unsigned int, host->scsi.SCp.this_residual, DMAC_BUFFER_SIZE / 2);
1165    if (length) {
1166	host->dma.start_addr = address = host->dma.free_addr;
1167	host->dma.free_addr = (host->dma.free_addr + length) &
1168				(DMAC_BUFFER_SIZE - 1);
1169
1170	/*
1171	 * Transfer data to DMA memory
1172	 */
1173	if (host->dma.direction == DMA_OUT)
1174	    acornscsi_data_write(host, host->scsi.SCp.ptr, host->dma.start_addr,
1175				length);
1176
1177	length -= 1;
1178	dmac_write(host, DMAC_TXCNTLO, length);
1179	dmac_write(host, DMAC_TXCNTHI, length >> 8);
1180	dmac_write(host, DMAC_TXADRLO, address);
1181	dmac_write(host, DMAC_TXADRMD, address >> 8);
1182	dmac_write(host, DMAC_TXADRHI, 0);
1183	dmac_write(host, DMAC_MASKREG, MASK_OFF);
1184
1185#if (DEBUG & DEBUG_DMA)
1186	DBG(host->SCpnt, acornscsi_dumpdma(host, "into"));
1187#endif
1188    } else {
1189	host->dma.xfer_setup = 0;
1190#if 0
1191	/*
1192	 * If the interface still wants more, then this is an error.
1193	 * We give it another byte, but we also attempt to raise an
1194	 * attention condition.  We continue giving one byte until
1195	 * the device recognises the attention.
1196	 */
1197	if (dmac_read(host, DMAC_STATUS) & STATUS_RQ0) {
1198	    acornscsi_abortcmd(host, host->SCpnt->tag);
1199
1200	    dmac_write(host, DMAC_TXCNTLO, 0);
1201	    dmac_write(host, DMAC_TXCNTHI, 0);
1202	    dmac_write(host, DMAC_TXADRLO, 0);
1203	    dmac_write(host, DMAC_TXADRMD, 0);
1204	    dmac_write(host, DMAC_TXADRHI, 0);
1205	    dmac_write(host, DMAC_MASKREG, MASK_OFF);
1206	}
1207#endif
1208    }
1209}
1210
1211/*
1212 * Function: void acornscsi_dma_xfer(AS_Host *host)
1213 * Purpose : transfer data between AcornSCSI and memory
1214 * Params  : host - host to process
1215 */
1216static
1217void acornscsi_dma_xfer(AS_Host *host)
1218{
1219    host->dma.xfer_required = 0;
1220
1221    if (host->dma.direction == DMA_IN)
1222	acornscsi_data_read(host, host->dma.xfer_ptr,
1223				host->dma.xfer_start, host->dma.xfer_length);
1224}
1225
1226/*
1227 * Function: void acornscsi_dma_adjust(AS_Host *host)
1228 * Purpose : adjust DMA pointers & count for bytes transferred to
1229 *	     SBIC but not SCSI bus.
1230 * Params  : host - host to adjust DMA count for
1231 */
1232static
1233void acornscsi_dma_adjust(AS_Host *host)
1234{
1235    if (host->dma.xfer_setup) {
1236	signed long transferred;
1237#if (DEBUG & (DEBUG_DMA|DEBUG_WRITE))
1238	DBG(host->SCpnt, acornscsi_dumpdma(host, "adji"));
1239#endif
1240	/*
1241	 * Calculate correct DMA address - DMA is ahead of SCSI bus while
1242	 * writing.
1243	 *  host->scsi.SCp.scsi_xferred is the number of bytes
1244	 *  actually transferred to/from the SCSI bus.
1245	 *  host->dma.transferred is the number of bytes transferred
1246	 *  over DMA since host->dma.start_addr was last set.
1247	 *
1248	 * real_dma_addr = host->dma.start_addr + host->scsi.SCp.scsi_xferred
1249	 *		   - host->dma.transferred
1250	 */
1251	transferred = host->scsi.SCp.scsi_xferred - host->dma.transferred;
1252	if (transferred < 0)
1253	    printk("scsi%d.%c: Ack! DMA write correction %ld < 0!\n",
1254		    host->host->host_no, acornscsi_target(host), transferred);
1255	else if (transferred == 0)
1256	    host->dma.xfer_setup = 0;
1257	else {
1258	    transferred += host->dma.start_addr;
1259	    dmac_write(host, DMAC_TXADRLO, transferred);
1260	    dmac_write(host, DMAC_TXADRMD, transferred >> 8);
1261	    dmac_write(host, DMAC_TXADRHI, transferred >> 16);
1262#if (DEBUG & (DEBUG_DMA|DEBUG_WRITE))
1263	    DBG(host->SCpnt, acornscsi_dumpdma(host, "adjo"));
1264#endif
1265	}
1266    }
1267}
1268#endif
1269
1270/* =========================================================================================
1271 * Data I/O
1272 */
1273static int
1274acornscsi_write_pio(AS_Host *host, char *bytes, int *ptr, int len, unsigned int max_timeout)
1275{
1276	unsigned int asr, timeout = max_timeout;
1277	int my_ptr = *ptr;
1278
1279	while (my_ptr < len) {
1280		asr = sbic_arm_read(host, SBIC_ASR);
1281
1282		if (asr & ASR_DBR) {
1283			timeout = max_timeout;
1284
1285			sbic_arm_write(host, SBIC_DATA, bytes[my_ptr++]);
1286		} else if (asr & ASR_INT)
1287			break;
1288		else if (--timeout == 0)
1289			break;
1290		udelay(1);
1291	}
1292
1293	*ptr = my_ptr;
1294
1295	return (timeout == 0) ? -1 : 0;
1296}
1297
1298/*
1299 * Function: void acornscsi_sendcommand(AS_Host *host)
1300 * Purpose : send a command to a target
1301 * Params  : host - host which is connected to target
1302 */
1303static void
1304acornscsi_sendcommand(AS_Host *host)
1305{
1306	struct scsi_cmnd *SCpnt = host->SCpnt;
1307
1308    sbic_arm_write(host, SBIC_TRANSCNTH, 0);
1309    sbic_arm_writenext(host, 0);
1310    sbic_arm_writenext(host, SCpnt->cmd_len - host->scsi.SCp.sent_command);
1311
1312    acornscsi_sbic_issuecmd(host, CMND_XFERINFO);
1313
1314    if (acornscsi_write_pio(host, SCpnt->cmnd,
1315	(int *)&host->scsi.SCp.sent_command, SCpnt->cmd_len, 1000000))
1316	printk("scsi%d: timeout while sending command\n", host->host->host_no);
1317
1318    host->scsi.phase = PHASE_COMMAND;
1319}
1320
1321static
1322void acornscsi_sendmessage(AS_Host *host)
1323{
1324    unsigned int message_length = msgqueue_msglength(&host->scsi.msgs);
1325    unsigned int msgnr;
1326    struct message *msg;
1327
1328#if (DEBUG & DEBUG_MESSAGES)
1329    printk("scsi%d.%c: sending message ",
1330	    host->host->host_no, acornscsi_target(host));
1331#endif
1332
1333    switch (message_length) {
1334    case 0:
1335	acornscsi_sbic_issuecmd(host, CMND_XFERINFO | CMND_SBT);
1336
1337	acornscsi_sbic_wait(host, ASR_DBR, ASR_DBR, 1000, "sending message 1");
1338
1339	sbic_arm_write(host, SBIC_DATA, NOP);
1340
1341	host->scsi.last_message = NOP;
1342#if (DEBUG & DEBUG_MESSAGES)
1343	printk("NOP");
1344#endif
1345	break;
1346
1347    case 1:
1348	acornscsi_sbic_issuecmd(host, CMND_XFERINFO | CMND_SBT);
1349	msg = msgqueue_getmsg(&host->scsi.msgs, 0);
1350
1351	acornscsi_sbic_wait(host, ASR_DBR, ASR_DBR, 1000, "sending message 2");
1352
1353	sbic_arm_write(host, SBIC_DATA, msg->msg[0]);
1354
1355	host->scsi.last_message = msg->msg[0];
1356#if (DEBUG & DEBUG_MESSAGES)
1357	spi_print_msg(msg->msg);
1358#endif
1359	break;
1360
1361    default:
1362	/*
1363	 * ANSI standard says: (SCSI-2 Rev 10c Sect 5.6.14)
1364	 * 'When a target sends this (MESSAGE_REJECT) message, it
1365	 *  shall change to MESSAGE IN phase and send this message
1366	 *  prior to requesting additional message bytes from the
1367	 *  initiator.  This provides an interlock so that the
1368	 *  initiator can determine which message byte is rejected.
1369	 */
1370	sbic_arm_write(host, SBIC_TRANSCNTH, 0);
1371	sbic_arm_writenext(host, 0);
1372	sbic_arm_writenext(host, message_length);
1373	acornscsi_sbic_issuecmd(host, CMND_XFERINFO);
1374
1375	msgnr = 0;
1376	while ((msg = msgqueue_getmsg(&host->scsi.msgs, msgnr++)) != NULL) {
1377	    unsigned int i;
1378#if (DEBUG & DEBUG_MESSAGES)
1379	    spi_print_msg(msg);
1380#endif
1381	    i = 0;
1382	    if (acornscsi_write_pio(host, msg->msg, &i, msg->length, 1000000))
1383		printk("scsi%d: timeout while sending message\n", host->host->host_no);
1384
1385	    host->scsi.last_message = msg->msg[0];
1386	    if (msg->msg[0] == EXTENDED_MESSAGE)
1387		host->scsi.last_message |= msg->msg[2] << 8;
1388
1389	    if (i != msg->length)
1390		break;
1391	}
1392	break;
1393    }
1394#if (DEBUG & DEBUG_MESSAGES)
1395    printk("\n");
1396#endif
1397}
1398
1399/*
1400 * Function: void acornscsi_readstatusbyte(AS_Host *host)
1401 * Purpose : Read status byte from connected target
1402 * Params  : host - host connected to target
1403 */
1404static
1405void acornscsi_readstatusbyte(AS_Host *host)
1406{
1407    acornscsi_sbic_issuecmd(host, CMND_XFERINFO|CMND_SBT);
1408    acornscsi_sbic_wait(host, ASR_DBR, ASR_DBR, 1000, "reading status byte");
1409    host->scsi.SCp.Status = sbic_arm_read(host, SBIC_DATA);
1410}
1411
1412/*
1413 * Function: unsigned char acornscsi_readmessagebyte(AS_Host *host)
1414 * Purpose : Read one message byte from connected target
1415 * Params  : host - host connected to target
1416 */
1417static
1418unsigned char acornscsi_readmessagebyte(AS_Host *host)
1419{
1420    unsigned char message;
1421
1422    acornscsi_sbic_issuecmd(host, CMND_XFERINFO | CMND_SBT);
1423
1424    acornscsi_sbic_wait(host, ASR_DBR, ASR_DBR, 1000, "for message byte");
1425
1426    message = sbic_arm_read(host, SBIC_DATA);
1427
1428    /* wait for MSGIN-XFER-PAUSED */
1429    acornscsi_sbic_wait(host, ASR_INT, ASR_INT, 1000, "for interrupt after message byte");
1430
1431    sbic_arm_read(host, SBIC_SSR);
1432
1433    return message;
1434}
1435
1436/*
1437 * Function: void acornscsi_message(AS_Host *host)
1438 * Purpose : Read complete message from connected target & action message
1439 * Params  : host - host connected to target
1440 */
1441static
1442void acornscsi_message(AS_Host *host)
1443{
1444    unsigned char message[16];
1445    unsigned int msgidx = 0, msglen = 1;
1446
1447    do {
1448	message[msgidx] = acornscsi_readmessagebyte(host);
1449
1450	switch (msgidx) {
1451	case 0:
1452	    if (message[0] == EXTENDED_MESSAGE ||
1453		(message[0] >= 0x20 && message[0] <= 0x2f))
1454		msglen = 2;
1455	    break;
1456
1457	case 1:
1458	    if (message[0] == EXTENDED_MESSAGE)
1459		msglen += message[msgidx];
1460	    break;
1461	}
1462	msgidx += 1;
1463	if (msgidx < msglen) {
1464	    acornscsi_sbic_issuecmd(host, CMND_NEGATEACK);
1465
1466	    /* wait for next msg-in */
1467	    acornscsi_sbic_wait(host, ASR_INT, ASR_INT, 1000, "for interrupt after negate ack");
1468	    sbic_arm_read(host, SBIC_SSR);
1469	}
1470    } while (msgidx < msglen);
1471
1472#if (DEBUG & DEBUG_MESSAGES)
1473    printk("scsi%d.%c: message in: ",
1474	    host->host->host_no, acornscsi_target(host));
1475    spi_print_msg(message);
1476    printk("\n");
1477#endif
1478
1479    if (host->scsi.phase == PHASE_RECONNECTED) {
1480	/*
1481	 * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 5.6.17)
1482	 * 'Whenever a target reconnects to an initiator to continue
1483	 *  a tagged I/O process, the SIMPLE QUEUE TAG message shall
1484	 *  be sent immediately following the IDENTIFY message...'
1485	 */
1486	if (message[0] == SIMPLE_QUEUE_TAG)
1487	    host->scsi.reconnected.tag = message[1];
1488	if (acornscsi_reconnect_finish(host))
1489	    host->scsi.phase = PHASE_MSGIN;
1490    }
1491
1492    switch (message[0]) {
1493    case ABORT:
1494    case ABORT_TAG:
1495    case COMMAND_COMPLETE:
1496	if (host->scsi.phase != PHASE_STATUSIN) {
1497	    printk(KERN_ERR "scsi%d.%c: command complete following non-status in phase?\n",
1498		    host->host->host_no, acornscsi_target(host));
1499	    acornscsi_dumplog(host, host->SCpnt->device->id);
1500	}
1501	host->scsi.phase = PHASE_DONE;
1502	host->scsi.SCp.Message = message[0];
1503	break;
1504
1505    case SAVE_POINTERS:
1506	/*
1507	 * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 5.6.20)
1508	 * 'The SAVE DATA POINTER message is sent from a target to
1509	 *  direct the initiator to copy the active data pointer to
1510	 *  the saved data pointer for the current I/O process.
1511	 */
1512	acornscsi_dma_cleanup(host);
1513	host->SCpnt->SCp = host->scsi.SCp;
1514	host->SCpnt->SCp.sent_command = 0;
1515	host->scsi.phase = PHASE_MSGIN;
1516	break;
1517
1518    case RESTORE_POINTERS:
1519	/*
1520	 * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 5.6.19)
1521	 * 'The RESTORE POINTERS message is sent from a target to
1522	 *  direct the initiator to copy the most recently saved
1523	 *  command, data, and status pointers for the I/O process
1524	 *  to the corresponding active pointers.  The command and
1525	 *  status pointers shall be restored to the beginning of
1526	 *  the present command and status areas.'
1527	 */
1528	acornscsi_dma_cleanup(host);
1529	host->scsi.SCp = host->SCpnt->SCp;
1530	host->scsi.phase = PHASE_MSGIN;
1531	break;
1532
1533    case DISCONNECT:
1534	/*
1535	 * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 6.4.2)
1536	 * 'On those occasions when an error or exception condition occurs
1537	 *  and the target elects to repeat the information transfer, the
1538	 *  target may repeat the transfer either issuing a RESTORE POINTERS
1539	 *  message or by disconnecting without issuing a SAVE POINTERS
1540	 *  message.  When reconnection is completed, the most recent
1541	 *  saved pointer values are restored.'
1542	 */
1543	acornscsi_dma_cleanup(host);
1544	host->scsi.phase = PHASE_DISCONNECT;
1545	break;
1546
1547    case MESSAGE_REJECT:
1548#if 0 /* this isn't needed any more */
1549	/*
1550	 * If we were negociating sync transfer, we don't yet know if
1551	 * this REJECT is for the sync transfer or for the tagged queue/wide
1552	 * transfer.  Re-initiate sync transfer negotiation now, and if
1553	 * we got a REJECT in response to SDTR, then it'll be set to DONE.
1554	 */
1555	if (host->device[host->SCpnt->device->id].sync_state == SYNC_SENT_REQUEST)
1556	    host->device[host->SCpnt->device->id].sync_state = SYNC_NEGOCIATE;
1557#endif
1558
1559	/*
1560	 * If we have any messages waiting to go out, then assert ATN now
1561	 */
1562	if (msgqueue_msglength(&host->scsi.msgs))
1563	    acornscsi_sbic_issuecmd(host, CMND_ASSERTATN);
1564
1565	switch (host->scsi.last_message) {
1566#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
1567	case HEAD_OF_QUEUE_TAG:
1568	case ORDERED_QUEUE_TAG:
1569	case SIMPLE_QUEUE_TAG:
1570	    /*
1571	     * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 5.6.17)
1572	     *  If a target does not implement tagged queuing and a queue tag
1573	     *  message is received, it shall respond with a MESSAGE REJECT
1574	     *  message and accept the I/O process as if it were untagged.
1575	     */
1576	    printk(KERN_NOTICE "scsi%d.%c: disabling tagged queueing\n",
1577		    host->host->host_no, acornscsi_target(host));
1578	    host->SCpnt->device->simple_tags = 0;
1579	    set_bit(host->SCpnt->device->id * 8 +
1580		    (u8)(host->SCpnt->device->lun & 0x7), host->busyluns);
1581	    break;
1582#endif
1583	case EXTENDED_MESSAGE | (EXTENDED_SDTR << 8):
1584	    /*
1585	     * Target can't handle synchronous transfers
1586	     */
1587	    printk(KERN_NOTICE "scsi%d.%c: Using asynchronous transfer\n",
1588		    host->host->host_no, acornscsi_target(host));
1589	    host->device[host->SCpnt->device->id].sync_xfer = SYNCHTRANSFER_2DBA;
1590	    host->device[host->SCpnt->device->id].sync_state = SYNC_ASYNCHRONOUS;
1591	    sbic_arm_write(host, SBIC_SYNCHTRANSFER, host->device[host->SCpnt->device->id].sync_xfer);
1592	    break;
1593
1594	default:
1595	    break;
1596	}
1597	break;
1598
1599    case QUEUE_FULL:
1600	/* TODO: target queue is full */
1601	break;
1602
1603    case SIMPLE_QUEUE_TAG:
1604	/* tag queue reconnect... message[1] = queue tag.  Print something to indicate something happened! */
1605	printk("scsi%d.%c: reconnect queue tag %02X\n",
1606		host->host->host_no, acornscsi_target(host),
1607		message[1]);
1608	break;
1609
1610    case EXTENDED_MESSAGE:
1611	switch (message[2]) {
1612#ifdef CONFIG_SCSI_ACORNSCSI_SYNC
1613	case EXTENDED_SDTR:
1614	    if (host->device[host->SCpnt->device->id].sync_state == SYNC_SENT_REQUEST) {
1615		/*
1616		 * We requested synchronous transfers.  This isn't quite right...
1617		 * We can only say if this succeeded if we proceed on to execute the
1618		 * command from this message.  If we get a MESSAGE PARITY ERROR,
1619		 * and the target retries fail, then we fallback to asynchronous mode
1620		 */
1621		host->device[host->SCpnt->device->id].sync_state = SYNC_COMPLETED;
1622		printk(KERN_NOTICE "scsi%d.%c: Using synchronous transfer, offset %d, %d ns\n",
1623			host->host->host_no, acornscsi_target(host),
1624			message[4], message[3] * 4);
1625		host->device[host->SCpnt->device->id].sync_xfer =
1626			calc_sync_xfer(message[3] * 4, message[4]);
1627	    } else {
1628		unsigned char period, length;
1629		/*
1630		 * Target requested synchronous transfers.  The agreement is only
1631		 * to be in operation AFTER the target leaves message out phase.
1632		 */
1633		acornscsi_sbic_issuecmd(host, CMND_ASSERTATN);
1634		period = max_t(unsigned int, message[3], sdtr_period / 4);
1635		length = min_t(unsigned int, message[4], sdtr_size);
1636		msgqueue_addmsg(&host->scsi.msgs, 5, EXTENDED_MESSAGE, 3,
1637				 EXTENDED_SDTR, period, length);
1638		host->device[host->SCpnt->device->id].sync_xfer =
1639			calc_sync_xfer(period * 4, length);
1640	    }
1641	    sbic_arm_write(host, SBIC_SYNCHTRANSFER, host->device[host->SCpnt->device->id].sync_xfer);
1642	    break;
1643#else
1644	    /* We do not accept synchronous transfers.  Respond with a
1645	     * MESSAGE_REJECT.
1646	     */
1647#endif
1648
1649	case EXTENDED_WDTR:
1650	    /* The WD33C93A is only 8-bit.  We respond with a MESSAGE_REJECT
1651	     * to a wide data transfer request.
1652	     */
1653	default:
1654	    acornscsi_sbic_issuecmd(host, CMND_ASSERTATN);
1655	    msgqueue_flush(&host->scsi.msgs);
1656	    msgqueue_addmsg(&host->scsi.msgs, 1, MESSAGE_REJECT);
1657	    break;
1658	}
1659	break;
1660
1661    default: /* reject message */
1662	printk(KERN_ERR "scsi%d.%c: unrecognised message %02X, rejecting\n",
1663		host->host->host_no, acornscsi_target(host),
1664		message[0]);
1665	acornscsi_sbic_issuecmd(host, CMND_ASSERTATN);
1666	msgqueue_flush(&host->scsi.msgs);
1667	msgqueue_addmsg(&host->scsi.msgs, 1, MESSAGE_REJECT);
1668	host->scsi.phase = PHASE_MSGIN;
1669	break;
1670    }
1671    acornscsi_sbic_issuecmd(host, CMND_NEGATEACK);
1672}
1673
1674/*
1675 * Function: int acornscsi_buildmessages(AS_Host *host)
1676 * Purpose : build the connection messages for a host
1677 * Params  : host - host to add messages to
1678 */
1679static
1680void acornscsi_buildmessages(AS_Host *host)
1681{
1682#if 0
1683    /* does the device need resetting? */
1684    if (cmd_reset) {
1685	msgqueue_addmsg(&host->scsi.msgs, 1, BUS_DEVICE_RESET);
1686	return;
1687    }
1688#endif
1689
1690    msgqueue_addmsg(&host->scsi.msgs, 1,
1691		     IDENTIFY(host->device[host->SCpnt->device->id].disconnect_ok,
1692			     host->SCpnt->device->lun));
1693
1694#if 0
1695    /* does the device need the current command aborted */
1696    if (cmd_aborted) {
1697	acornscsi_abortcmd(host->SCpnt->tag);
1698	return;
1699    }
1700#endif
1701
1702#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
1703    if (host->SCpnt->tag) {
1704	unsigned int tag_type;
1705
1706	if (host->SCpnt->cmnd[0] == REQUEST_SENSE ||
1707	    host->SCpnt->cmnd[0] == TEST_UNIT_READY ||
1708	    host->SCpnt->cmnd[0] == INQUIRY)
1709	    tag_type = HEAD_OF_QUEUE_TAG;
1710	else
1711	    tag_type = SIMPLE_QUEUE_TAG;
1712	msgqueue_addmsg(&host->scsi.msgs, 2, tag_type, host->SCpnt->tag);
1713    }
1714#endif
1715
1716#ifdef CONFIG_SCSI_ACORNSCSI_SYNC
1717    if (host->device[host->SCpnt->device->id].sync_state == SYNC_NEGOCIATE) {
1718	host->device[host->SCpnt->device->id].sync_state = SYNC_SENT_REQUEST;
1719	msgqueue_addmsg(&host->scsi.msgs, 5,
1720			 EXTENDED_MESSAGE, 3, EXTENDED_SDTR,
1721			 sdtr_period / 4, sdtr_size);
1722    }
1723#endif
1724}
1725
1726/*
1727 * Function: int acornscsi_starttransfer(AS_Host *host)
1728 * Purpose : transfer data to/from connected target
1729 * Params  : host - host to which target is connected
1730 * Returns : 0 if failure
1731 */
1732static
1733int acornscsi_starttransfer(AS_Host *host)
1734{
1735    int residual;
1736
1737    if (!host->scsi.SCp.ptr /*&& host->scsi.SCp.this_residual*/) {
1738	printk(KERN_ERR "scsi%d.%c: null buffer passed to acornscsi_starttransfer\n",
1739		host->host->host_no, acornscsi_target(host));
1740	return 0;
1741    }
1742
1743    residual = scsi_bufflen(host->SCpnt) - host->scsi.SCp.scsi_xferred;
1744
1745    sbic_arm_write(host, SBIC_SYNCHTRANSFER, host->device[host->SCpnt->device->id].sync_xfer);
1746    sbic_arm_writenext(host, residual >> 16);
1747    sbic_arm_writenext(host, residual >> 8);
1748    sbic_arm_writenext(host, residual);
1749    acornscsi_sbic_issuecmd(host, CMND_XFERINFO);
1750    return 1;
1751}
1752
1753/* =========================================================================================
1754 * Connection & Disconnection
1755 */
1756/*
1757 * Function : acornscsi_reconnect(AS_Host *host)
1758 * Purpose  : reconnect a previously disconnected command
1759 * Params   : host - host specific data
1760 * Remarks  : SCSI spec says:
1761 *		'The set of active pointers is restored from the set
1762 *		 of saved pointers upon reconnection of the I/O proces…

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