drivers/scsi/seagate.c

/* */
This source file includes following definitions.
st0x_setup
tmc8xx_setup
borken_init
borken_wait
seagate_st0x_detect
seagate_st0x_info
seagate_reconnect_intr
seagate_st0x_queue_command
seagate_st0x_command
internal_command
seagate_st0x_abort
seagate_st0x_reset
seagate_st0x_biosparam
   1 /*
   2  *      seagate.c Copyright (C) 1992, 1993 Drew Eckhardt 
   3  *      low level scsi driver for ST01/ST02, Future Domain TMC-885, 
   4  *      TMC-950  by
   5  *
   6  *              Drew Eckhardt 
   7  *
   8  *      <drew@colorado.edu>
   9  *
  10  *      Note : TMC-880 boards don't work because they have two bits in 
  11  *              the status register flipped, I'll fix this "RSN"
  12  *
  13  *      This card does all the I/O via memory mapped I/O, so there is no need
  14  *      to check or snarf a region of the I/O address space.
  15  */
  16 
  17 /*
  18  * Configuration : 
  19  * To use without BIOS -DOVERRIDE=base_address -DCONTROLLER=FD or SEAGATE
  20  * -DIRQ will override the default of 5.
  21  * Note: You can now set these options from the kernel's "command line".
  22  * The syntax is:
  23  *
  24  *     st0x=ADDRESS,IRQ                (for a Seagate controller)
  25  * or:
  26  *     tmc8xx=ADDRESS,IRQ              (for a TMC-8xx or TMC-950 controller)
  27  * eg:
  28  *     tmc8xx=0xC8000,15
  29  *
  30  * will configure the driver for a TMC-8xx style controller using IRQ 15
  31  * with a base address of 0xC8000.
  32  * 
  33  * -DFAST or -DFAST32 will use blind transfers where possible
  34  *
  35  * -DARBITRATE will cause the host adapter to arbitrate for the 
  36  *      bus for better SCSI-II compatibility, rather than just 
  37  *      waiting for BUS FREE and then doing its thing.  Should
  38  *      let us do one command per Lun when I integrate my 
  39  *      reorganization changes into the distribution sources.
  40  *
  41  * -DSLOW_HANDSHAKE will allow compatibility with broken devices that don't 
  42  *      handshake fast enough (ie, some CD ROM's) for the Seagate
  43  *      code.
  44  *
  45  * -DSLOW_RATE=x, x some number will let you specify a default 
  46  *      transfer rate if handshaking isn't working correctly.
  47  */
  48 
  49 
  50 #include <asm/io.h>
  51 #include <asm/system.h>
  52 #include <linux/signal.h>
  53 #include <linux/sched.h>
  54 #include <linux/string.h>
  55 #include "../block/blk.h"
  56 #include "scsi.h"
  57 #include "hosts.h"
  58 #include "seagate.h"
  59 #include "constants.h"
  60 
  61 
  62 #ifndef IRQ
  63 #define IRQ 5
  64 #endif
  65 
  66 #if (defined(FAST32) && !defined(FAST))
  67 #define FAST
  68 #endif
  69 
  70 #if defined(SLOW_RATE) && !defined(SLOW_HANDSHAKE)
  71 #define SLOW_HANDSHAKE
  72 #endif
  73 
  74 #if defined(SLOW_HANDSHAKE) && !defined(SLOW_RATE)
  75 #define SLOW_RATE 50
  76 #endif
  77 
  78 
  79 #if defined(LINKED)
  80 #undef LINKED           /* Linked commands are currently broken ! */
  81 #endif
  82 
  83 static int internal_command(unsigned char target, unsigned char lun,
  84                             const void *cmnd,
  85                          void *buff, int bufflen, int reselect);
  86 
  87 static int incommand;                   /*
  88                                                 set if arbitration has finished and we are 
  89                                                 in some command phase.
  90                                         */
  91 
  92 static void *base_address = NULL;       /*
  93                                                 Where the card ROM starts,
  94                                                 used to calculate memory mapped
  95                                                 register location.
  96                                         */
  97 static volatile int abort_confirm = 0;
  98 
  99 static volatile void *st0x_cr_sr;       /*
 100                                                 control register write,
 101                                                 status register read.
 102                                                 256 bytes in length.
 103 
 104                                                 Read is status of SCSI BUS,
 105                                                 as per STAT masks.
 106 
 107                                         */
 108 
 109 
 110 static volatile void *st0x_dr;         /*
 111                                                 data register, read write
 112                                                 256 bytes in length.
 113                                         */
 114 
 115 
 116 static volatile int st0x_aborted=0;     /* 
 117                                                 set when we are aborted, ie by a time out, etc.
 118                                         */
 119 
 120 static unsigned char controller_type = 0; /* set to SEAGATE for ST0x boards or FD for TMC-8xx boards */
 121 static unsigned char irq = IRQ;
 122                         
 123 #define retcode(result) (((result) << 16) | (message << 8) | status)                    
 124 #define STATUS (*(volatile unsigned char *) st0x_cr_sr)
 125 #define CONTROL STATUS 
 126 #define DATA (*(volatile unsigned char *) st0x_dr)
 127 
 128 void st0x_setup (char *str, int *ints) {
     /*  */
 129     controller_type = SEAGATE;
 130     base_address = (void *) ints[1];
 131     irq = ints[2];
 132 }
 133 
 134 void tmc8xx_setup (char *str, int *ints) {
     /*  */
 135     controller_type = FD;
 136     base_address = (void *) ints[1];
 137     irq = ints[2];
 138 }
 139     
 140 
 141 #ifndef OVERRIDE                
 142 static const char *  seagate_bases[] = {
 143         (char *) 0xc8000, (char *) 0xca000, (char *) 0xcc000,
 144         (char *) 0xce000, (char *) 0xdc000, (char *) 0xde000
 145 };
 146 
 147 typedef struct {
 148         char *signature ;
 149         unsigned offset;
 150         unsigned length;
 151         unsigned char type;
 152 } Signature;
 153         
 154 static const Signature signatures[] = {
 155 #ifdef CONFIG_SCSI_SEAGATE
 156 {"ST01 v1.7  (C) Copyright 1987 Seagate", 15, 37, SEAGATE},
 157 {"SCSI BIOS 2.00  (C) Copyright 1987 Seagate", 15, 40, SEAGATE},
 158 
 159 /*
 160  * The following two lines are NOT mistakes.  One detects ROM revision 
 161  * 3.0.0, the other 3.2.  Since seagate has only one type of SCSI adapter, 
 162  * and this is not going to change, the "SEAGATE" and "SCSI" together
 163  * are probably "good enough"
 164  */
 165 
 166 {"SEAGATE SCSI BIOS ",16, 17, SEAGATE},
 167 {"SEAGATE SCSI BIOS ",17, 17, SEAGATE},
 168 
 169 /*
 170  * However, future domain makes several incompatible SCSI boards, so specific
 171  * signatures must be used.
 172  */
 173 
 174 {"FUTURE DOMAIN CORP. (C) 1986-1989 V5.0C2/14/89", 5, 46, FD},
 175 {"FUTURE DOMAIN CORP. (C) 1986-1989 V6.0A7/28/89", 5, 46, FD},
 176 {"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0105/31/90",5, 47, FD},
 177 {"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0209/18/90",5, 47, FD},
 178 {"FUTURE DOMAIN CORP. (C) 1986-1990 V7.009/18/90", 5, 46, FD},
 179 {"FUTURE DOMAIN CORP. (C) 1992 V8.00.004/02/92",   5, 44, FD},
 180 {"FUTURE DOMAIN TMC-950",                        5, 21, FD},
 181 #endif /* CONFIG_SCSI_SEAGATE */
 182 }
 183 ;
 184 
 185 #define NUM_SIGNATURES (sizeof(signatures) / sizeof(Signature))
 186 #endif /* n OVERRIDE */
 187 
 188 /*
 189  * hostno stores the hostnumber, as told to us by the init routine.
 190  */
 191 
 192 static int hostno = -1;
 193 static void seagate_reconnect_intr(int);
 194 
 195 #ifdef FAST
 196 static int fast = 1;
 197 #endif 
 198 
 199 #ifdef SLOW_HANDSHAKE
 200 /* 
 201  * Support for broken devices : 
 202  * The Seagate board has a handshaking problem.  Namely, a lack 
 203  * thereof for slow devices.  You can blast 600K/second through 
 204  * it if you are polling for each byte, more if you do a blind 
 205  * transfer.  In the first case, with a fast device, REQ will 
 206  * transition high-low or high-low-high before your loop restarts 
 207  * and you'll have no problems.  In the second case, the board 
 208  * will insert wait states for up to 13.2 usecs for REQ to 
 209  * transition low->high, and everything will work.
 210  *
 211  * However, there's nothing in the state machine that says 
 212  * you *HAVE* to see a high-low-high set of transitions before
 213  * sending the next byte, and slow things like the Trantor CD ROMS
 214  * will break because of this.
 215  * 
 216  * So, we need to slow things down, which isn't as simple as it 
 217  * seems.  We can't slow things down period, because then people
 218  * who don't recompile their kernels will shoot me for ruining 
 219  * their performance.  We need to do it on a case per case basis.
 220  *
 221  * The best for performance will be to, only for borken devices 
 222  * (this is stored on a per-target basis in the scsi_devices array)
 223  * 
 224  * Wait for a low->high transition before continuing with that 
 225  * transfer.  If we timeout, continue anyways.  We don't need 
 226  * a long timeout, because REQ should only be asserted until the 
 227  * corresponding ACK is received and processed.
 228  *
 229  * Note that we can't use the system timer for this, because of 
 230  * resolution, and we *really* can't use the timer chip since 
 231  * gettimeofday() and the beeper routines use that.  So,
 232  * the best thing for us to do will be to calibrate a timing
 233  * loop in the initialization code using the timer chip before
 234  * gettimeofday() can screw with it.
 235  */
 236 
 237 static int borken_calibration = 0;
 238 static void borken_init (void) {
     /*  */
 239   register int count = 0, start = jiffies + 1, stop = start + 25;
 240 
 241   while (jiffies < start);
 242   for (;jiffies < stop; ++count);
 243 
 244 /* 
 245  * Ok, we now have a count for .25 seconds.  Convert to a 
 246  * count per second and divide by transfer rate in K.
 247  */
 248 
 249   borken_calibration =  (count * 4) / (SLOW_RATE*1024);
 250 
 251   if (borken_calibration < 1)
 252         borken_calibration = 1;
 253 #if (DEBUG & DEBUG_BORKEN)
 254   printk("scsi%d : borken calibrated to %dK/sec, %d cycles per transfer\n", 
 255         hostno, BORKEN_RATE, borken_calibration);
 256 #endif
 257 }
 258 
 259 static inline void borken_wait(void) {
     /*  */
 260   register int count;
 261   for (count = borken_calibration; count && (STATUS & STAT_REQ); 
 262         --count);
 263 #if (DEBUG & DEBUG_BORKEN) 
 264   if (count)
 265         printk("scsi%d : borken timeout\n", hostno);
 266 #endif 
 267 }
 268 
 269 #endif /* def SLOW_HANDSHAKE */
 270 
 271 int seagate_st0x_detect (Scsi_Host_Template * tpnt)
     /*  */
 272         {
 273      struct Scsi_Host *instance;
 274 #ifndef OVERRIDE
 275         int i,j;
 276 #endif 
 277 
 278 /*
 279  *      First, we try for the manual override.
 280  */
 281 #ifdef DEBUG 
 282         printk("Autodetecting seagate ST0x\n");
 283 #endif
 284         
 285         if (hostno != -1)
 286                 {
 287                 printk ("ERROR : seagate_st0x_detect() called twice.\n");
 288                 return 0;
 289                 }
 290 
 291       /* If the user specified the controller type from the command line,
 292          controller_type will be non-zero, so don't try and detect one */
 293 
 294         if (!controller_type) {
 295 #ifdef OVERRIDE
 296         base_address = (void *) OVERRIDE;
 297 
 298 /* CONTROLLER is used to override controller (SEAGATE or FD). PM: 07/01/93 */
 299 #ifdef CONTROLLER
 300         controller_type = CONTROLLER;
 301 #else
 302 #error Please use -DCONTROLLER=SEAGATE or -DCONTROLLER=FD to override controller type
 303 #endif /* CONTROLLER */
 304 #ifdef DEBUG
 305         printk("Base address overridden to %x, controller type is %s\n",
 306                 base_address,controller_type == SEAGATE ? "SEAGATE" : "FD");
 307 #endif 
 308 #else /* OVERRIDE */    
 309 /*
 310  *      To detect this card, we simply look for the signature
 311  *      from the BIOS version notice in all the possible locations
 312  *      of the ROM's.  This has a nice side effect of not trashing
 313  *      any register locations that might be used by something else.
 314  *
 315  * XXX - note that we probably should be probing the address
 316  * space for the on-board RAM instead.
 317  */
 318 
 319         for (i = 0; i < (sizeof (seagate_bases) / sizeof (char  * )); ++i)
 320                 for (j = 0; !base_address && j < NUM_SIGNATURES; ++j)
 321                 if (!memcmp ((void *) (seagate_bases[i] +
 322                     signatures[j].offset), (void *) signatures[j].signature,
 323                     signatures[j].length)) {
 324                         base_address = (void *) seagate_bases[i];
 325                         controller_type = signatures[j].type;
 326                 }
 327 #endif /* OVERRIDE */
 328         } /* (! controller_type) */
 329  
 330         tpnt->this_id = (controller_type == SEAGATE) ? 7 : 6;
 331 
 332         if (base_address)
 333                 {
 334                 st0x_cr_sr =(void *) (((unsigned char *) base_address) + (controller_type == SEAGATE ? 0x1a00 : 0x1c00)); 
 335                 st0x_dr = (void *) (((unsigned char *) base_address ) + (controller_type == SEAGATE ? 0x1c00 : 0x1e00));
 336 #ifdef DEBUG
 337                 printk("ST0x detected. Base address = %x, cr = %x, dr = %x\n", base_address, st0x_cr_sr, st0x_dr);
 338 #endif
 339 /*
 340  *      At all times, we will use IRQ 5.  Should also check for IRQ3 if we 
 341  *      loose our first interrupt.
 342  */
 343                 instance = scsi_register(tpnt, 0);
 344                 hostno = instance->host_no;
 345                 if (request_irq((int) irq, seagate_reconnect_intr, SA_INTERRUPT, "seagate")) {
 346                         printk("scsi%d : unable to allocate IRQ%d\n",
 347                                 hostno, (int) irq);
 348                         return 0;
 349                 }
 350 #ifdef SLOW_HANDSHAKE
 351                 borken_init();
 352 #endif
 353                 
 354                 return 1;
 355                 }
 356         else
 357                 {
 358 #ifdef DEBUG
 359                 printk("ST0x not detected.\n");
 360 #endif
 361                 return 0;
 362                 }
 363         }
 364          
 365 const char *seagate_st0x_info(void) {
     /*  */
 366       static char buffer[256];
 367         sprintf(buffer, "scsi%d : %s at irq %d address %p options :"
 368 #ifdef ARBITRATE
 369 " ARBITRATE"
 370 #endif
 371 #ifdef SLOW_HANDSHAKE
 372 " SLOW_HANDSHAKE"
 373 #endif
 374 #ifdef FAST
 375 #ifdef FAST32
 376 " FAST32"
 377 #else
 378 " FAST"
 379 #endif
 380 #endif
 381  
 382 #ifdef LINKED
 383 " LINKED"
 384 #endif
 385               "\n", hostno, (controller_type == SEAGATE) ? "seagate" : 
 386               "FD TMC-8xx", irq, base_address);
 387         return buffer;
 388 }
 389 
 390 /*
 391  * These are our saved pointers for the outstanding command that is 
 392  * waiting for a reconnect
 393  */
 394 
 395 static unsigned char current_target, current_lun;
 396 static unsigned char *current_cmnd, *current_data;
 397 static int current_nobuffs;
 398 static struct scatterlist *current_buffer;
 399 static int current_bufflen;
 400 
 401 #ifdef LINKED
 402 
 403 /* 
 404  * linked_connected indicates weather or not we are currently connected to 
 405  * linked_target, linked_lun and in an INFORMATION TRANSFER phase,
 406  * using linked commands.
 407  */
 408 
 409 static int linked_connected = 0;
 410 static unsigned char linked_target, linked_lun;
 411 #endif
 412 
 413 
 414 static void (*done_fn)(Scsi_Cmnd *) = NULL;
 415 static Scsi_Cmnd * SCint = NULL;
 416 
 417 /*
 418  * These control whether or not disconnect / reconnect will be attempted,
 419  * or are being attempted.
 420  */
 421 
 422 #define NO_RECONNECT    0
 423 #define RECONNECT_NOW   1
 424 #define CAN_RECONNECT   2
 425 
 426 #ifdef LINKED
 427 
 428 /*
 429  * LINKED_RIGHT indicates that we are currently connected to the correct target
 430  * for this command, LINKED_WRONG indicates that we are connected to the wrong 
 431  * target.  Note that these imply CAN_RECONNECT.
 432  */
 433 
 434 #define LINKED_RIGHT    3
 435 #define LINKED_WRONG    4
 436 #endif
 437 
 438 /*
 439  * This determines if we are expecting to reconnect or not.
 440  */
 441 
 442 static int should_reconnect = 0;
 443 
 444 /*
 445  * The seagate_reconnect_intr routine is called when a target reselects the 
 446  * host adapter.  This occurs on the interrupt triggered by the target 
 447  * asserting SEL.
 448  */
 449 
 450 static void seagate_reconnect_intr (int unused)
     /*  */
 451         {
 452         int temp;
 453         Scsi_Cmnd * SCtmp;
 454 
 455 /* enable all other interrupts. */      
 456         sti();
 457 #if (DEBUG & PHASE_RESELECT)
 458         printk("scsi%d : seagate_reconnect_intr() called\n", hostno);
 459 #endif
 460 
 461         if (!should_reconnect)
 462             printk("scsi%d: unexpected interrupt.\n", hostno);
 463         else {
 464                  should_reconnect = 0;
 465 
 466 #if (DEBUG & PHASE_RESELECT)
 467                 printk("scsi%d : internal_command("
 468                        "%d, %08x, %08x, %d, RECONNECT_NOW\n", hostno, 
 469                         current_target, current_data, current_bufflen);
 470 #endif
 471         
 472                 temp =  internal_command (current_target, current_lun,
 473                         current_cmnd, current_data, current_bufflen,
 474                         RECONNECT_NOW);
 475 
 476                 if (msg_byte(temp) != DISCONNECT) {
 477                         if (done_fn) {
 478 #if (DEBUG & PHASE_RESELECT)
 479                                 printk("scsi%d : done_fn(%d,%08x)", hostno, 
 480                                 hostno, temp);
 481 #endif
 482                                 if(!SCint) panic("SCint == NULL in seagate");
 483                                 SCtmp = SCint;
 484                                 SCint = NULL;
 485                                 SCtmp->result = temp;
 486                                 done_fn (SCtmp);
 487                         } else
 488                                 printk("done_fn() not defined.\n");
 489                         }
 490                 }
 491         } 
 492 
 493 /* 
 494  * The seagate_st0x_queue_command() function provides a queued interface
 495  * to the seagate SCSI driver.  Basically, it just passes control onto the
 496  * seagate_command() function, after fixing it so that the done_fn()
 497  * is set to the one passed to the function.  We have to be very careful,
 498  * because there are some commands on some devices that do not disconnect,
 499  * and if we simply call the done_fn when the command is done then another
 500  * command is started and queue_command is called again...  We end up
 501  * overflowing the kernel stack, and this tends not to be such a good idea.
 502  */
 503 
 504 static int recursion_depth = 0;
 505 
 506 int seagate_st0x_queue_command (Scsi_Cmnd * SCpnt,  void (*done)(Scsi_Cmnd *))
     /*  */
 507         {
 508         int result, reconnect;
 509         Scsi_Cmnd * SCtmp;
 510 
 511         done_fn = done;
 512         current_target = SCpnt->target;
 513         current_lun = SCpnt->lun;
 514         (const void *) current_cmnd = SCpnt->cmnd;
 515         current_data = (unsigned char *) SCpnt->request_buffer;
 516         current_bufflen = SCpnt->request_bufflen;
 517         SCint = SCpnt;
 518         if(recursion_depth) {
 519           return 0;
 520         };
 521         recursion_depth++;
 522         do{
 523 #ifdef LINKED
 524 /*
 525  * Set linked command bit in control field of SCSI command.
 526  */
 527 
 528           current_cmnd[COMMAND_SIZE(current_cmnd[0])] |= 0x01;
 529           if (linked_connected) {
 530 #if (DEBUG & DEBUG_LINKED) 
 531             printk("scsi%d : using linked commands, current I_T_L nexus is ",
 532               hostno);
 533 #endif
 534             if ((linked_target == current_target) && 
 535               (linked_lun == current_lun)) {
 536 #if (DEBUG & DEBUG_LINKED) 
 537             printk("correct\n");
 538 #endif
 539               reconnect = LINKED_RIGHT;
 540             } else {
 541 #if (DEBUG & DEBUG_LINKED) 
 542             printk("incorrect\n");
 543 #endif
 544               reconnect = LINKED_WRONG;
 545             }
 546           } else 
 547 #endif /* LINKED */
 548             reconnect = CAN_RECONNECT;
 549 
 550 
 551 
 552 
 553 
 554           result = internal_command (SCint->target, SCint->lun, SCint->cmnd, SCint->request_buffer,
 555                                      SCint->request_bufflen, 
 556                                      reconnect);
 557           if (msg_byte(result) == DISCONNECT)  break;
 558           SCtmp = SCint;
 559           SCint = NULL;
 560           SCtmp->result = result;
 561           done_fn (SCtmp);
 562         } while(SCint);
 563         recursion_depth--;
 564         return 0;
 565       }
 566 
 567 int seagate_st0x_command (Scsi_Cmnd * SCpnt) {
     /*  */
 568         return internal_command (SCpnt->target, SCpnt->lun, SCpnt->cmnd, SCpnt->request_buffer,
 569                                  SCpnt->request_bufflen, 
 570                                  (int) NO_RECONNECT);
 571 }
 572         
 573 static int internal_command(unsigned char target, unsigned char lun, const void *cmnd,
     /*  */
 574                          void *buff, int bufflen, int reselect) {
 575         int len = 0;
 576         unsigned char *data = NULL;     
 577         struct scatterlist *buffer = NULL;
 578         int nobuffs = 0;
 579         int clock;                      
 580         int temp;
 581 #ifdef SLOW_HANDSHAKE
 582         int borken;     /* Does the current target require Very Slow I/O ? */
 583 #endif
 584 
 585 
 586 #if (DEBUG & PHASE_DATAIN) || (DEBUG & PHASE_DATOUT) 
 587         int transfered = 0;
 588 #endif
 589 
 590 #if (((DEBUG & PHASE_ETC) == PHASE_ETC) || (DEBUG & PRINT_COMMAND) || \
 591         (DEBUG & PHASE_EXIT))   
 592         int i;
 593 #endif
 594 
 595 #if ((DEBUG & PHASE_ETC) == PHASE_ETC)
 596         int phase=0, newphase;
 597 #endif
 598 
 599         int done = 0;
 600         unsigned char status = 0;       
 601         unsigned char message = 0;
 602         register unsigned char status_read;
 603 
 604         unsigned transfersize = 0, underflow = 0;
 605 
 606         incommand = 0;
 607         st0x_aborted = 0;
 608 
 609 #ifdef SLOW_HANDSHAKE
 610         borken = (int) SCint->device->borken;
 611 #endif
 612 
 613 #if (DEBUG & PRINT_COMMAND)
 614         printk ("scsi%d : target = %d, command = ", hostno, target);
 615         print_command((unsigned char *) cmnd);
 616         printk("\n");
 617 #endif
 618 
 619 #if (DEBUG & PHASE_RESELECT)
 620         switch (reselect) {
 621         case RECONNECT_NOW :
 622                 printk("scsi%d : reconnecting\n", hostno);
 623                 break;
 624 #ifdef LINKED
 625         case LINKED_RIGHT : 
 626                 printk("scsi%d : connected, can reconnect\n", hostno);
 627                 break;
 628         case LINKED_WRONG :
 629                 printk("scsi%d : connected to wrong target, can reconnect\n",
 630                         hostno);
 631                 break;          
 632 #endif
 633         case CAN_RECONNECT :
 634                 printk("scsi%d : allowed to reconnect\n", hostno);
 635                 break;
 636         default :
 637                 printk("scsi%d : not allowed to reconnect\n", hostno);
 638         }
 639 #endif
 640         
 641 
 642         if (target == (controller_type == SEAGATE ? 7 : 6))
 643                 return DID_BAD_TARGET;
 644 
 645 /*
 646  *      We work it differently depending on if this is is "the first time,"
 647  *      or a reconnect.  If this is a reselect phase, then SEL will 
 648  *      be asserted, and we must skip selection / arbitration phases.
 649  */
 650 
 651         switch (reselect) {
 652         case RECONNECT_NOW:
 653 #if (DEBUG & PHASE_RESELECT)
 654                 printk("scsi%d : phase RESELECT \n", hostno);
 655 #endif
 656 
 657 /*
 658  *      At this point, we should find the logical or of our ID and the original
 659  *      target's ID on the BUS, with BSY, SEL, and I/O signals asserted.
 660  *
 661  *      After ARBITRATION phase is completed, only SEL, BSY, and the 
 662  *      target ID are asserted.  A valid initiator ID is not on the bus
 663  *      until IO is asserted, so we must wait for that.
 664  */
 665                 clock = jiffies + 10;
 666                 for (;;) {
 667                         temp = STATUS;
 668                         if ((temp & STAT_IO) && !(temp & STAT_BSY))
 669                                 break;
 670 
 671                         if (jiffies > clock) {
 672 #if (DEBUG & PHASE_RESELECT)
 673                                 printk("scsi%d : RESELECT timed out while waiting for IO .\n",
 674                                         hostno);
 675 #endif
 676                                 return (DID_BAD_INTR << 16);
 677                         }
 678                 }
 679 
 680 /* 
 681  *      After I/O is asserted by the target, we can read our ID and its
 682  *      ID off of the BUS.
 683  */
 684  
 685                 if (!((temp = DATA) & (controller_type == SEAGATE ? 0x80 : 0x40)))
 686                         {
 687 #if (DEBUG & PHASE_RESELECT)
 688                         printk("scsi%d : detected reconnect request to different target.\n" 
 689                                "\tData bus = %d\n", hostno, temp);
 690 #endif
 691                         return (DID_BAD_INTR << 16);
 692                         }
 693 
 694                 if (!(temp & (1 << current_target)))
 695                         {
 696                         printk("scsi%d : Unexpected reselect interrupt.  Data bus = %d\n",
 697                                 hostno, temp);
 698                         return (DID_BAD_INTR << 16);
 699                         }
 700 
 701                 buffer=current_buffer;  
 702                 cmnd=current_cmnd;      /* WDE add */
 703                 data=current_data;      /* WDE add */
 704                 len=current_bufflen;    /* WDE add */
 705                 nobuffs=current_nobuffs;
 706 
 707 /*
 708  *      We have determined that we have been selected.  At this point, 
 709  *      we must respond to the reselection by asserting BSY ourselves
 710  */
 711 
 712 #if 1
 713                 CONTROL = (BASE_CMD | CMD_DRVR_ENABLE | CMD_BSY);
 714 #else
 715                 CONTROL = (BASE_CMD | CMD_BSY);
 716 #endif
 717 
 718 /*
 719  *      The target will drop SEL, and raise BSY, at which time we must drop
 720  *      BSY.
 721  */
 722 
 723                 for (clock = jiffies + 10; (jiffies < clock) &&  (STATUS & STAT_SEL););
 724 
 725                 if (jiffies >= clock)
 726                         { 
 727                         CONTROL = (BASE_CMD | CMD_INTR);
 728 #if (DEBUG & PHASE_RESELECT)
 729                         printk("scsi%d : RESELECT timed out while waiting for SEL.\n",
 730                                 hostno);
 731 #endif
 732                         return (DID_BAD_INTR << 16);                             
 733                         }
 734 
 735                 CONTROL = BASE_CMD;
 736 
 737 /*
 738  *      At this point, we have connected with the target and can get 
 739  *      on with our lives.
 740  */      
 741                 break;
 742         case CAN_RECONNECT:
 743 
 744 #ifdef LINKED
 745 /*
 746  * This is a bletcherous hack, just as bad as the Unix #! interpreter stuff.
 747  * If it turns out we are using the wrong I_T_L nexus, the easiest way to deal
 748  * with it is to go into our INFORMATION TRANSFER PHASE code, send a ABORT 
 749  * message on MESSAGE OUT phase, and then loop back to here.
 750  */
 751   
 752 connect_loop :
 753 
 754 #endif
 755 
 756 #if (DEBUG & PHASE_BUS_FREE)
 757                 printk ("scsi%d : phase = BUS FREE \n", hostno);
 758 #endif
 759 
 760 /*
 761  *      BUS FREE PHASE
 762  *
 763  *      On entry, we make sure that the BUS is in a BUS FREE
 764  *      phase, by insuring that both BSY and SEL are low for
 765  *      at least one bus settle delay.  Several reads help
 766  *      eliminate wire glitch.
 767  */
 768 
 769                 clock = jiffies + ST0X_BUS_FREE_DELAY;  
 770 
 771 #if !defined (ARBITRATE) 
 772                 while (((STATUS |  STATUS | STATUS) & 
 773                          (STAT_BSY | STAT_SEL)) && 
 774                          (!st0x_aborted) && (jiffies < clock));
 775 
 776                 if (jiffies > clock)
 777                         return retcode(DID_BUS_BUSY);
 778                 else if (st0x_aborted)
 779                         return retcode(st0x_aborted);
 780 #endif
 781 
 782 #if (DEBUG & PHASE_SELECTION)
 783                 printk("scsi%d : phase = SELECTION\n", hostno);
 784 #endif
 785 
 786                 clock = jiffies + ST0X_SELECTION_DELAY;
 787 
 788 /*
 789  * Arbitration/selection procedure : 
 790  * 1.  Disable drivers
 791  * 2.  Write HOST adapter address bit
 792  * 3.  Set start arbitration.
 793  * 4.  We get either ARBITRATION COMPLETE or SELECT at this
 794  *     point.
 795  * 5.  OR our ID and targets on bus.
 796  * 6.  Enable SCSI drivers and asserted SEL and ATTN
 797  */
 798                 
 799 #if defined(ARBITRATE)  
 800         cli();
 801         CONTROL = 0;
 802         DATA = (controller_type == SEAGATE) ? 0x80 : 0x40;
 803         CONTROL = CMD_START_ARB; 
 804         sti();
 805         while (!((status_read = STATUS) & (STAT_ARB_CMPL | STAT_SEL)) &&
 806                 (jiffies < clock) && !st0x_aborted);
 807 
 808         if (!(status_read & STAT_ARB_CMPL)) {
 809 #if (DEBUG & PHASE_SELECTION)
 810                 if (status_read & STAT_SEL) 
 811                         printk("scsi%d : arbitration lost\n", hostno);
 812                 else
 813                         printk("scsi%d : arbitration timeout.\n", hostno);
 814 #endif
 815                 CONTROL = BASE_CMD;
 816                 return retcode(DID_NO_CONNECT);
 817         };
 818 
 819 #if (DEBUG & PHASE_SELECTION)
 820         printk("scsi%d : arbitration complete\n", hostno);
 821 #endif
 822 #endif
 823 
 824 
 825 /*
 826  *      When the SCSI device decides that we're gawking at it, it will 
 827  *      respond by asserting BUSY on the bus.
 828  *
 829  *      Note : the Seagate ST-01/02 product manual says that we should 
 830  *      twiddle the DATA register before the control register.  However,
 831  *      this does not work reliably so we do it the other way around.
 832  *
 833  *      Probably could be a problem with arbitration too, we really should
 834  *      try this with a SCSI protocol or logic analyzer to see what is 
 835  *      going on.
 836  */
 837         cli();
 838         DATA = (unsigned char) ((1 << target) | (controller_type == SEAGATE ? 0x80 : 0x40));
 839         CONTROL = BASE_CMD | CMD_DRVR_ENABLE | CMD_SEL | 
 840                 (reselect ? CMD_ATTN : 0);
 841         sti();
 842                 while (!((status_read = STATUS) & STAT_BSY) && 
 843                         (jiffies < clock) && !st0x_aborted)
 844 
 845 #if 0 && (DEBUG & PHASE_SELECTION)
 846                 {
 847                 temp = clock - jiffies;
 848 
 849                 if (!(jiffies % 5))
 850                         printk("seagate_st0x_timeout : %d            \r",temp);
 851         
 852                 }
 853                 printk("Done.                                             \n");
 854                 printk("scsi%d : status = %02x, seagate_st0x_timeout = %d, aborted = %02x \n", 
 855                         hostno, status_read, temp, st0x_aborted);
 856 #else
 857                 ;
 858 #endif
 859         
 860 
 861                 if ((jiffies >= clock)  && !(status_read & STAT_BSY))
 862                         {
 863 #if (DEBUG & PHASE_SELECTION)
 864                         printk ("scsi%d : NO CONNECT with target %d, status = %x \n", 
 865                                 hostno, target, STATUS);
 866 #endif
 867                         return retcode(DID_NO_CONNECT);
 868                         }
 869 
 870 /*
 871  *      If we have been aborted, and we have a command in progress, IE the 
 872  *      target still has BSY asserted, then we will reset the bus, and 
 873  *      notify the midlevel driver to expect sense.
 874  */
 875 
 876                 if (st0x_aborted) {
 877                         CONTROL = BASE_CMD;
 878                         if (STATUS & STAT_BSY) {
 879                                 printk("scsi%d : BST asserted after we've been aborted.\n",
 880                                         hostno);
 881                                 seagate_st0x_reset(NULL);
 882                                 return retcode(DID_RESET);
 883                         }
 884                         return retcode(st0x_aborted);
 885                 }       
 886 
 887 /* Establish current pointers.  Take into account scatter / gather */
 888 
 889         if ((nobuffs = SCint->use_sg)) {
 890 #if (DEBUG & DEBUG_SG)
 891         {
 892         int i;
 893         printk("scsi%d : scatter gather requested, using %d buffers.\n",
 894                 hostno, nobuffs);
 895         for (i = 0; i < nobuffs; ++i)
 896                 printk("scsi%d : buffer %d address = %08x length = %d\n",
 897                         hostno, i, buffer[i].address, buffer[i].length);
 898         }
 899 #endif
 900                 
 901                 buffer = (struct scatterlist *) SCint->buffer;
 902                 len = buffer->length;
 903                 data = (unsigned char *) buffer->address;
 904         } else {
 905 #if (DEBUG & DEBUG_SG)
 906         printk("scsi%d : scatter gather not requested.\n", hostno);
 907 #endif
 908                 buffer = NULL;
 909                 len = SCint->request_bufflen;
 910                 data = (unsigned char *) SCint->request_buffer;
 911         }
 912 
 913 #if (DEBUG & (PHASE_DATAIN | PHASE_DATAOUT))
 914         printk("scsi%d : len = %d\n", hostno, len);
 915 #endif
 916 
 917                 break;
 918 #ifdef LINKED
 919         case LINKED_RIGHT:
 920                 break;
 921         case LINKED_WRONG:
 922                 break;
 923 #endif
 924         }
 925 
 926 /*
 927  *      There are several conditions under which we wish to send a message : 
 928  *      1.  When we are allowing disconnect / reconnect, and need to establish
 929  *          the I_T_L nexus via an IDENTIFY with the DiscPriv bit set.
 930  *
 931  *      2.  When we are doing linked commands, are have the wrong I_T_L nexus
 932  *          established and want to send an ABORT message.
 933  */
 934 
 935         
 936         CONTROL = BASE_CMD | CMD_DRVR_ENABLE | 
 937                 (((reselect == CAN_RECONNECT)
 938 #ifdef LINKED 
 939                 || (reselect == LINKED_WRONG)
 940 #endif 
 941                 )  ? CMD_ATTN : 0) ;
 942         
 943 /*
 944  *      INFORMATION TRANSFER PHASE
 945  *
 946  *      The nasty looking read / write inline assembler loops we use for 
 947  *      DATAIN and DATAOUT phases are approximately 4-5 times as fast as 
 948  *      the 'C' versions - since we're moving 1024 bytes of data, this
 949  *      really adds up.
 950  */
 951 
 952 #if ((DEBUG & PHASE_ETC) == PHASE_ETC)
 953         printk("scsi%d : phase = INFORMATION TRANSFER\n", hostno);
 954 #endif  
 955 
 956         incommand = 1;
 957         transfersize = SCint->transfersize;
 958         underflow = SCint->underflow;
 959 
 960 
 961 /*
 962  *      Now, we poll the device for status information,
 963  *      and handle any requests it makes.  Note that since we are unsure of 
 964  *      how much data will be flowing across the system, etc and cannot 
 965  *      make reasonable timeouts, that we will instead have the midlevel
 966  *      driver handle any timeouts that occur in this phase.
 967  */
 968 
 969         while (((status_read = STATUS) & STAT_BSY) && !st0x_aborted && !done) 
 970                 {
 971 #ifdef PARITY
 972                 if (status_read & STAT_PARITY)
 973                         {
 974                         printk("scsi%d : got parity error\n", hostno);
 975                         st0x_aborted = DID_PARITY;
 976                         }       
 977 #endif
 978 
 979                 if (status_read & STAT_REQ)
 980                         {
 981 #if ((DEBUG & PHASE_ETC) == PHASE_ETC)
 982                         if ((newphase = (status_read & REQ_MASK)) != phase)
 983                                 {
 984                                 phase = newphase;
 985                                 switch (phase)
 986                                 {
 987                                 case REQ_DATAOUT: 
 988                                         printk("scsi%d : phase = DATA OUT\n",
 989                                                 hostno); 
 990                                         break;
 991                                 case REQ_DATAIN : 
 992                                         printk("scsi%d : phase = DATA IN\n",
 993                                                 hostno); 
 994                                         break;
 995                                 case REQ_CMDOUT : 
 996                                         printk("scsi%d : phase = COMMAND OUT\n",
 997                                                 hostno); 
 998                                         break;
 999                                 case REQ_STATIN :
1000                                          printk("scsi%d : phase = STATUS IN\n",
1001                                                 hostno); 
1002                                         break;
1003                                 case REQ_MSGOUT :
1004                                         printk("scsi%d : phase = MESSAGE OUT\n",
1005                                                 hostno); 
1006                                         break;
1007                                 case REQ_MSGIN :
1008                                         printk("scsi%d : phase = MESSAGE IN\n",
1009                                                 hostno);
1010                                         break;
1011                                 default : 
1012                                         printk("scsi%d : phase = UNKNOWN\n",
1013                                                 hostno); 
1014                                         st0x_aborted = DID_ERROR; 
1015                                 }       
1016                                 }
1017 #endif
1018                 switch (status_read & REQ_MASK)
1019                 {                       
1020                 case REQ_DATAOUT : 
1021 /*
1022  * If we are in fast mode, then we simply splat the data out
1023  * in word-sized chunks as fast as we can.
1024  */
1025 
1026 #ifdef FAST 
1027 if (!len) {
1028 #if 0 
1029         printk("scsi%d: underflow to target %d lun %d \n", 
1030                 hostno, target, lun);
1031         st0x_aborted = DID_ERROR;
1032         fast = 0;
1033 #endif
1034         break;
1035 }
1036 
1037 if (fast && transfersize && !(len % transfersize) && (len >= transfersize)
1038 #ifdef FAST32
1039         && !(transfersize % 4)
1040 #endif
1041         ) {
1042 #if (DEBUG & DEBUG_FAST) 
1043         printk("scsi%d : FAST transfer, underflow = %d, transfersize = %d\n"
1044                "         len = %d, data = %08x\n", hostno, SCint->underflow, 
1045                SCint->transfersize, len, data);
1046 #endif
1047 
1048         __asm__("
1049         cld;
1050 "
1051 #ifdef FAST32
1052 "       shr $2, %%ecx;
1053 1:      lodsl;
1054         movl %%eax, (%%edi);
1055 "
1056 #else
1057 "1:     lodsb;
1058         movb %%al, (%%edi);
1059 "
1060 #endif
1061 "       loop 1b;" : :
1062         /* input */
1063         "D" (st0x_dr), "S" (data), "c" (SCint->transfersize) :
1064         /* clobbered */
1065         "eax", "ecx", "esi" );
1066 
1067         len -= transfersize;
1068         data += transfersize;
1069 
1070 #if (DEBUG & DEBUG_FAST)
1071         printk("scsi%d : FAST transfer complete len = %d data = %08x\n", 
1072                 hostno, len, data);
1073 #endif
1074 
1075 
1076 } else 
1077 #endif
1078 
1079 {
1080 /*
1081  *      We loop as long as we are in a data out phase, there is data to send, 
1082  *      and BSY is still active.
1083  */
1084                 __asm__ (
1085 
1086 /*
1087         Local variables : 
1088         len = ecx
1089         data = esi
1090         st0x_cr_sr = ebx
1091         st0x_dr =  edi
1092 
1093         Test for any data here at all.
1094 */
1095         "\torl %%ecx, %%ecx
1096         jz 2f
1097 
1098         cld
1099 
1100         movl _st0x_cr_sr, %%ebx
1101         movl _st0x_dr, %%edi
1102         
1103 1:      movb (%%ebx), %%al\n"
1104 /*
1105         Test for BSY
1106 */
1107 
1108         "\ttest $1, %%al
1109         jz 2f\n"
1110 
1111 /*
1112         Test for data out phase - STATUS & REQ_MASK should be REQ_DATAOUT, which is 0.
1113 */
1114         "\ttest $0xe, %%al
1115         jnz 2f  \n"
1116 /*
1117         Test for REQ
1118 */      
1119         "\ttest $0x10, %%al
1120         jz 1b
1121         lodsb
1122         movb %%al, (%%edi) 
1123         loop 1b
1124 
1125 2: 
1126                                                                         ":
1127 /* output */
1128 "=S" (data), "=c" (len) :
1129 /* input */
1130 "0" (data), "1" (len) :
1131 /* clobbered */
1132 "eax", "ebx", "edi"); 
1133 }
1134 
1135                         if (!len && nobuffs) {
1136                                 --nobuffs;
1137                                 ++buffer;
1138                                 len = buffer->length;
1139                                 data = (unsigned char *) buffer->address;
1140 #if (DEBUG & DEBUG_SG)
1141         printk("scsi%d : next scatter-gather buffer len = %d address = %08x\n",
1142                 hostno, len, data);
1143 #endif
1144                         }
1145                         break;
1146 
1147                 case REQ_DATAIN : 
1148 #ifdef SLOW_HANDSHAKE
1149         if (borken) {
1150 #if (DEBUG & (PHASE_DATAIN))
1151                 transfered += len;
1152 #endif
1153                 for (; len && (STATUS & (REQ_MASK | STAT_REQ)) == (REQ_DATAIN |
1154                         STAT_REQ); --len) {
1155                                 *data++ = DATA;
1156                                 borken_wait();
1157 }
1158 #if (DEBUG & (PHASE_DATAIN))
1159                 transfered -= len;
1160 #endif
1161         } else
1162 #endif
1163 #ifdef FAST
1164 if (fast && transfersize && !(len % transfersize) && (len >= transfersize)
1165 #ifdef FAST32
1166         && !(transfersize % 4)
1167 #endif
1168         ) {
1169 #if (DEBUG & DEBUG_FAST) 
1170         printk("scsi%d : FAST transfer, underflow = %d, transfersize = %d\n"
1171                "         len = %d, data = %08x\n", hostno, SCint->underflow, 
1172                SCint->transfersize, len, data);
1173 #endif
1174         __asm__("
1175         cld;
1176 "
1177 #ifdef FAST32
1178 "       shr $2, %%ecx;
1179 1:      movl (%%esi), %%eax;
1180         stosl;
1181 "
1182 #else
1183 "1:     movb (%%esi), %%al;
1184         stosb;
1185 "
1186 #endif
1187 
1188 "       loop 1b;" : :
1189         /* input */
1190         "S" (st0x_dr), "D" (data), "c" (SCint->transfersize) :
1191         /* clobbered */
1192         "eax", "ecx", "edi");
1193 
1194         len -= transfersize;
1195         data += transfersize;
1196 
1197 #if (DEBUG & PHASE_DATAIN)
1198         printk("scsi%d: transfered += %d\n", hostno, transfersize);
1199         transfered += transfersize;
1200 #endif
1201 
1202 #if (DEBUG & DEBUG_FAST)
1203         printk("scsi%d : FAST transfer complete len = %d data = %08x\n", 
1204                 hostno, len, data);
1205 #endif
1206 
1207 } else
1208 #endif
1209 {
1210 
1211 #if (DEBUG & PHASE_DATAIN)
1212         printk("scsi%d: transfered += %d\n", hostno, len);
1213         transfered += len;      /* Assume we'll transfer it all, then
1214                                    subtract what we *didn't* transfer */
1215 #endif
1216         
1217 /*
1218  *      We loop as long as we are in a data in phase, there is room to read, 
1219  *      and BSY is still active
1220  */
1221  
1222                         __asm__ (
1223 /*
1224         Local variables : 
1225         ecx = len
1226         edi = data
1227         esi = st0x_cr_sr
1228         ebx = st0x_dr
1229 
1230         Test for room to read
1231 */
1232         "\torl %%ecx, %%ecx
1233         jz 2f
1234 
1235         cld
1236         movl _st0x_cr_sr, %%esi
1237         movl _st0x_dr, %%ebx
1238 
1239 1:      movb (%%esi), %%al\n"
1240 /*
1241         Test for BSY
1242 */
1243 
1244         "\ttest $1, %%al 
1245         jz 2f\n"
1246 
1247 /*
1248         Test for data in phase - STATUS & REQ_MASK should be REQ_DATAIN, = STAT_IO, which is 4.
1249 */
1250         "\tmovb $0xe, %%ah      
1251         andb %%al, %%ah
1252         cmpb $0x04, %%ah
1253         jne 2f\n"
1254                 
1255 /*
1256         Test for REQ
1257 */      
1258         "\ttest $0x10, %%al
1259         jz 1b
1260 
1261         movb (%%ebx), %%al      
1262         stosb   
1263         loop 1b\n"
1264 
1265 "2:\n"
1266                                                                         :
1267 /* output */
1268 "=D" (data), "=c" (len) :
1269 /* input */
1270 "0" (data), "1" (len) :
1271 /* clobbered */
1272 "eax","ebx", "esi"); 
1273 
1274 #if (DEBUG & PHASE_DATAIN)
1275         printk("scsi%d: transfered -= %d\n", hostno, len);
1276         transfered -= len;              /* Since we assumed all of Len got 
1277                                          * transfered, correct our mistake */
1278 #endif
1279 }
1280         
1281                         if (!len && nobuffs) {
1282                                 --nobuffs;
1283                                 ++buffer;
1284                                 len = buffer->length;
1285                                 data = (unsigned char *) buffer->address;
1286 #if (DEBUG & DEBUG_SG)
1287         printk("scsi%d : next scatter-gather buffer len = %d address = %08x\n",
1288                 hostno, len, data);
1289 #endif
1290                         }
1291 
1292                         break;
1293 
1294                 case REQ_CMDOUT : 
1295                         while (((status_read = STATUS) & STAT_BSY) && 
1296                                ((status_read & REQ_MASK) == REQ_CMDOUT))
1297                                 if (status_read & STAT_REQ) {
1298                                         DATA = *(unsigned char *) cmnd;
1299                                         cmnd = 1+(unsigned char *) cmnd;
1300 #ifdef SLOW_HANDSHAKE
1301                                         if (borken) 
1302                                                 borken_wait();
1303 #endif
1304                                 }
1305                         break;
1306         
1307                 case REQ_STATIN : 
1308                         status = DATA;
1309                         break;
1310                                 
1311                 case REQ_MSGOUT : 
1312 /*
1313  *      We can only have sent a MSG OUT if we requested to do this 
1314  *      by raising ATTN.  So, we must drop ATTN.
1315  */
1316 
1317                         CONTROL = BASE_CMD | CMD_DRVR_ENABLE;
1318 /*
1319  *      If we are reconnecting, then we must send an IDENTIFY message in 
1320  *       response  to MSGOUT.
1321  */
1322                         switch (reselect) {
1323                         case CAN_RECONNECT:
1324                                 DATA = IDENTIFY(1, lun);
1325 
1326 #if (DEBUG & (PHASE_RESELECT | PHASE_MSGOUT)) 
1327                                 printk("scsi%d : sent IDENTIFY message.\n", hostno);
1328 #endif
1329                                 break;
1330 #ifdef LINKED
1331                         case LINKED_WRONG:
1332                                 DATA = ABORT;
1333                                 linked_connected = 0;
1334                                 reselect = CAN_RECONNECT;
1335                                 goto connect_loop;
1336 #if (DEBUG & (PHASE_MSGOUT | DEBUG_LINKED))
1337                                 printk("scsi%d : sent ABORT message to cancel incorrect I_T_L nexus.\n", hostno);
1338 #endif
1339 #endif /* LINKED */
1340 #if (DEBUG & DEBUG_LINKED) 
1341             printk("correct\n");
1342 #endif
1343                         default:
1344                                 DATA = NOP;
1345                                 printk("scsi%d : target %d requested MSGOUT, sent NOP message.\n", hostno, target);
1346                         }
1347                         break;
1348                                         
1349                 case REQ_MSGIN : 
1350                         switch (message = DATA) {
1351                         case DISCONNECT :
1352                                 should_reconnect = 1;
1353                                 current_data = data;    /* WDE add */
1354                                 current_buffer = buffer;
1355                                 current_bufflen = len;  /* WDE add */
1356                                 current_nobuffs = nobuffs;
1357 #ifdef LINKED
1358                                 linked_connected = 0;
1359 #endif
1360                                 done=1;
1361 #if (DEBUG & (PHASE_RESELECT | PHASE_MSGIN))
1362                                 printk("scsi%d : disconnected.\n", hostno);
1363 #endif
1364                                 break;
1365 
1366 #ifdef LINKED
1367                         case LINKED_CMD_COMPLETE:
1368                         case LINKED_FLG_CMD_COMPLETE:
1369 #endif
1370                         case COMMAND_COMPLETE :
1371 /*
1372  * Note : we should check for underflow here.   
1373  */
1374 #if (DEBUG & PHASE_MSGIN)       
1375                                 printk("scsi%d : command complete.\n", hostno);
1376 #endif
1377                                 done = 1;
1378                                 break;
1379                         case ABORT :
1380 #if (DEBUG & PHASE_MSGIN)
1381                                 printk("scsi%d : abort message.\n", hostno);
1382 #endif
1383                                 done=1;
1384                                 break;
1385                         case SAVE_POINTERS :
1386                                 current_buffer = buffer;
1387                                 current_bufflen = len;  /* WDE add */
1388                                 current_data = data;    /* WDE mod */
1389                                 current_nobuffs = nobuffs;
1390 #if (DEBUG & PHASE_MSGIN)
1391                                 printk("scsi%d : pointers saved.\n", hostno);
1392 #endif 
1393                                 break;
1394                         case RESTORE_POINTERS:
1395                                 buffer=current_buffer;
1396                                 cmnd=current_cmnd;
1397                                 data=current_data;      /* WDE mod */
1398                                 len=current_bufflen;
1399                                 nobuffs=current_nobuffs;
1400 #if (DEBUG & PHASE_MSGIN)
1401                                 printk("scsi%d : pointers restored.\n", hostno);
1402 #endif
1403                                 break;
1404                         default:
1405 
1406 /*
1407  *      IDENTIFY distinguishes itself from the other messages by setting the
1408  *      high byte.
1409  *      
1410  *      Note : we need to handle at least one outstanding command per LUN,
1411  *      and need to hash the SCSI command for that I_T_L nexus based on the 
1412  *      known ID (at this point) and LUN.
1413  */
1414 
1415                                 if (message & 0x80) {
1416 #if (DEBUG & PHASE_MSGIN)
1417                                         printk("scsi%d : IDENTIFY message received from id %d, lun %d.\n",
1418                                                 hostno, target, message & 7);
1419 #endif
1420                                 } else {
1421 
1422 /*
1423  *      We should go into a MESSAGE OUT phase, and send  a MESSAGE_REJECT 
1424  *      if we run into a message that we don't like.  The seagate driver 
1425  *      needs some serious restructuring first though.
1426  */
1427 
1428 #if (DEBUG & PHASE_MSGIN)
1429                                         printk("scsi%d : unknown message %d from target %d.\n",
1430                                                 hostno,  message,   target);
1431 #endif  
1432                                 }
1433                         }
1434                         break;
1435 
1436                 default : 
1437                         printk("scsi%d : unknown phase.\n", hostno); 
1438                         st0x_aborted = DID_ERROR; 
1439                 }       
1440 
1441 #ifdef SLOW_HANDSHAKE
1442 /*
1443  * I really don't care to deal with borken devices in each single 
1444  * byte transfer case (ie, message in, message out, status), so
1445  * I'll do the wait here if necessary.
1446  */
1447                 if (borken)
1448                         borken_wait();
1449 #endif
1450  
1451                 } /* if ends */
1452                 } /* while ends */
1453 
1454 #if (DEBUG & (PHASE_DATAIN | PHASE_DATAOUT | PHASE_EXIT))
1455         printk("scsi%d : Transfered %d bytes\n", hostno, transfered);
1456 #endif
1457 
1458 #if (DEBUG & PHASE_EXIT)
1459 #if 0           /* Doesn't work for scatter / gather */
1460         printk("Buffer : \n");
1461         for (i = 0; i < 20; ++i) 
1462                 printk ("%02x  ", ((unsigned char *) data)[i]); /* WDE mod */
1463         printk("\n");
1464 #endif
1465         printk("scsi%d : status = ", hostno);
1466         print_status(status);
1467         printk("message = %02x\n", message);
1468 #endif
1469 
1470 
1471 /* We shouldn't reach this until *after* BSY has been deasserted */
1472 #ifdef notyet
1473         if (st0x_aborted) {
1474                 if (STATUS & STAT_BSY) {        
1475                         seagate_st0x_reset(NULL);
1476                         st0x_aborted = DID_RESET;
1477                 } 
1478                 abort_confirm = 1;
1479         } 
1480 #endif
1481 
1482 #ifdef LINKED
1483 else {
1484 /*
1485  * Fix the message byte so that unsuspecting high level drivers don't 
1486  * puke when they see a LINKED COMMAND message in place of the COMMAND 
1487  * COMPLETE they may be expecting.  Shouldn't be necessary, but it's 
1488  * better to be on the safe side. 
1489  *
1490  * A non LINKED* message byte will indicate that the command completed, 
1491  * and we are now disconnected.
1492  */
1493 
1494                 switch (message) {
1495                 case LINKED_CMD_COMPLETE :
1496                 case LINKED_FLG_CMD_COMPLETE : 
1497                         message = COMMAND_COMPLETE;
1498                         linked_target = current_target;
1499                         linked_lun = current_lun;
1500                         linked_connected = 1;
1501 #if (DEBUG & DEBUG_LINKED)
1502                         printk("scsi%d : keeping I_T_L nexus established for linked command.\n", 
1503                                 hostno);
1504 #endif
1505 /*
1506  * We also will need to adjust status to accommodate intermediate conditions.
1507  */
1508                         if ((status == INTERMEDIATE_GOOD) ||
1509                                 (status == INTERMEDIATE_C_GOOD))
1510                                 status = GOOD;
1511                         
1512                         break;
1513 /*
1514  * We should also handle what are "normal" termination messages 
1515  * here (ABORT, BUS_DEVICE_RESET?, and COMMAND_COMPLETE individually, 
1516  * and flake if things aren't right.
1517  */
1518 
1519                 default :
1520 #if (DEBUG & DEBUG_LINKED)
1521                         printk("scsi%d : closing I_T_L nexus.\n", hostno);
1522 #endif
1523                         linked_connected = 0;
1524                 }
1525         }
1526 #endif /* LINKED */
1527 
1528 
1529 
1530 
1531         if (should_reconnect) {
1532 #if (DEBUG & PHASE_RESELECT)
1533                 printk("scsi%d : exiting seagate_st0x_queue_command() with reconnect enabled.\n",
1534                         hostno);
1535 #endif
1536                 CONTROL = BASE_CMD | CMD_INTR ;
1537         } else 
1538                 CONTROL = BASE_CMD;
1539 
1540         return retcode (st0x_aborted);
1541         }
1542 
1543 int seagate_st0x_abort (Scsi_Cmnd * SCpnt)
     /*  */
1544         {
1545           st0x_aborted = DID_ABORT;
1546           
1547           return SCSI_ABORT_PENDING;
1548         }
1549 
1550 /*
1551         the seagate_st0x_reset function resets the SCSI bus
1552 */
1553         
1554 int seagate_st0x_reset (Scsi_Cmnd * SCpnt)
     /*  */
1555         {
1556         unsigned clock;
1557         /*
1558                 No timeouts - this command is going to fail because 
1559                 it was reset.
1560         */
1561 
1562 #ifdef DEBUG
1563         printk("In seagate_st0x_reset()\n");
1564 #endif
1565 
1566 
1567         /* assert  RESET signal on SCSI bus.  */
1568                 
1569         CONTROL = BASE_CMD  | CMD_RST;
1570         clock=jiffies+2;
1571 
1572         
1573         /* Wait.  */
1574         
1575         while (jiffies < clock);
1576 
1577         CONTROL = BASE_CMD;
1578         
1579         st0x_aborted = DID_RESET;
1580 
1581 #ifdef DEBUG
1582         printk("SCSI bus reset.\n");
1583 #endif
1584         return SCSI_RESET_WAKEUP;
1585         }
1586 
1587 #include <asm/segment.h>
1588 #include "sd.h"
1589 #include "scsi_ioctl.h"
1590 
1591 int seagate_st0x_biosparam(Disk * disk, int dev, int* ip) {
     /*  */
1592   unsigned char buf[256 + sizeof(int) * 2], cmd[6], *data, *page;
1593   int *sizes, result, formatted_sectors, total_sectors;
1594   int cylinders, heads, sectors;
1595 
1596 /*
1597  * Only SCSI-I CCS drives and later implement the necessary mode sense 
1598  * pages.  
1599  */
1600 
1601   if (disk->device->scsi_level < 2) 
1602         return -1;
1603 
1604   sizes = (int *) buf;
1605   data = (unsigned char *) (sizes + 2);
1606 
1607   cmd[0] = MODE_SENSE;
1608   cmd[1] = (disk->device->lun << 5) & 0xe5;
1609   cmd[2] = 0x04; /* Read page 4, rigid disk geometry page current values */
1610   cmd[3] = 0;
1611   cmd[4] = 255;
1612   cmd[5] = 0;
1613 
1614 /*
1615  * We are transferring 0 bytes in the out direction, and expect to get back
1616  * 24 bytes for each mode page.
1617  */
1618 
1619   sizes[0] = 0;
1620   sizes[1] = 256;
1621 
1622   memcpy (data, cmd, 6);
1623 
1624   if (!(result = kernel_scsi_ioctl (disk->device, SCSI_IOCTL_SEND_COMMAND, (void *) buf))) {
1625 /*
1626  * The mode page lies beyond the MODE SENSE header, with length 4, and 
1627  * the BLOCK DESCRIPTOR, with length header[3].
1628  */
1629 
1630     page = data + 4 + data[3];
1631     heads = (int) page[5];
1632     cylinders = (page[2] << 16) | (page[3] << 8) | page[4];
1633 
1634     cmd[2] = 0x03; /* Read page 3, format page current values */
1635     memcpy (data, cmd, 6);
1636 
1637     if (!(result = kernel_scsi_ioctl (disk->device, SCSI_IOCTL_SEND_COMMAND, (void *) buf))) {
1638       page = data + 4 + data[3];
1639       sectors = (page[10] << 8) | page[11];     
1640 
1641         
1642 /*
1643  * Get the total number of formatted sectors from the block descriptor, 
1644  * so we can tell how many are being used for alternates.  
1645  */
1646 
1647       formatted_sectors = (data[4 + 1] << 16) | (data[4 + 2] << 8) |
1648         data[4 + 3] ;
1649 
1650       total_sectors = (heads * cylinders * sectors);
1651 
1652 /*
1653  * Adjust the real geometry by subtracting 
1654  * (spare sectors / (heads * tracks)) cylinders from the number of cylinders.
1655  *
1656  * It appears that the CE cylinder CAN be a partial cylinder.
1657  */
1658 
1659      
1660 printk("scsi%d : heads = %d cylinders = %d sectors = %d total = %d formatted = %d\n",
1661     hostno, heads, cylinders, sectors, total_sectors, formatted_sectors);
1662 
1663       if (!heads || !sectors || !cylinders)
1664         result = -1;
1665       else
1666         cylinders -= ((total_sectors - formatted_sectors) / (heads * sectors));
1667 
1668 /*
1669  * Now, we need to do a sanity check on the geometry to see if it is 
1670  * BIOS compatible.  The maximum BIOS geometry is 1024 cylinders * 
1671  * 256 heads * 64 sectors. 
1672  */
1673 
1674       if ((cylinders > 1024) || (sectors > 64)) 
1675         result = -1;
1676       else {
1677         ip[0] = heads;
1678         ip[1] = sectors;
1679         ip[2] = cylinders;
1680       }
1681 
1682 /* 
1683  * There should be an alternate mapping for things the seagate doesn't
1684  * understand, but I couldn't say what it is with reasonable certainty.
1685  */
1686 
1687       }
1688     }
1689     
1690   return result;
1691 }
/* */
root/drivers/scsi/seagate.c

DEFINITIONS
